Dissertation on
“ROLE OF CT IN DIAGNOSING APPENDICITIS IN ULTRASOUND NEGATIVE PATIENTS”
Submitted in partial fulfilment of the regulations required for the award of
M.D. DEGREE IN
RADIODIAGNOSIS BRANCH VII
REG. NO : 201718152
THE TAMILNADU DR. M.G.R. MEDICAL UNIVERSITY CHENNAI – 600032
COIMBATORE MEDICAL COLLEGE COIMBATORE
MAY 2020
DECLARATION
I DR. D.JAYARAJA, declare that I carried out this work on
“ROLE OF CT IN DIAGNOSING APPENDICITIS IN ULTRASOUND NEGATIVE PATIENTS”at the department of Radiodiagnosis, COIMBATORE MEDICAL COLLEGE HOSPITAL. I also declare that this bonafide work or a part of this work was not submitted by me or any other for any award, degree, or diploma to any other university, board either in India or abroad.
This is submitted to The Tamilnadu Dr. M.G.R. Medical University, Chennai in partial fulfillment of the rules and regulation for the M. D. Degree examination in Radiodiagnosis.
DR .D.JAYARAJA
Place:
Date
:
CERTIFICATE BY THE INSTITUTION
This is to certify that DR.D.JAYARAJA, Post - Graduate Student (May 2017 to May 2020) in the Department of Radiodiagnosis,
COIMBATORE MEDICAL COLLEGE HOSPITAL,COIMBATORE, has done this dissertation on “ROLE OF CT IN DIAGNOSING APPENDICITIS IN ULTRASOUND NEGATIVE PATIENTS
”
under my guidance and supervision in partial fulfillment of the regulations laid down by the Tamilnadu Dr. M. G. R. Medical University, Chennai, for M.D.(Radiodiagnosis) Degree Examination to be held in May 2020.
Date: Guide and Professor, Department of Radiodiagnosis,
Coimbatore medical college &Hospital,
Date: DR.N.Murali M.D.R.D, Professor and HOD
Department of Radiodiagnosis,
Coimbatore medical college &Hospital,
Date: Dean,
Coimbatore medical college &Hospital,
CERTIFICATE BY THE GUIDE
This is to certify that DR.D JAYARAJA, Post - Graduate Student (May 2017 To May 2020) in the Department of Radiodiagnosis,
Coimbatore medical college &Hospital, has done this dissertation on
“ROLE OF CT IN DIAGNOSING APPENDICITIS IN ULTRASOUND NEGATIVE PATIENTS”under my guidance and supervision in partial fulfillment of the regulations laid down by the Tamilnadu Dr.
M.G.R. Medical University, Chennai, for M.D. (Radiodiagnosis), Degree Examination to be held in May 2020 .
DR.N.Murali M.D.R.D, Professor and HOD,
Department of Radiodiagnosis,
Coimbatore medical college &Hospital,
ACKNOWLEDGEMENT
I heartfully thank the ALMIGHTY, for showering his endless grace and blessings on me and making me able to complete this venture successfully . I am extremely grateful to my parents, wife and son for being a constant source of encouragement and moral support.
I express my profound gratitude to my esteemed Professor and HOD Dr.N.
Murali,M.D(RD),Department of Radiodiagnosis,CMCH for motivating and extending in valuable guidance to perform and complete this dissertation.
I would like to thank Dr.N.Sundari, M.D(RD) for her helping me narrow down the dissertation topic.
I would like to thank Dr.Subashree, M.D(RD), DNB for her guidance.
I would like to specially thank Dr.M. Praveen Kumar, M.D(RD) and Dr. Infant Pushpa Venisha, MD(RD),Dr Kalaivani,MD(R.D) for their useful academical inputs.
I would also like to thank my colleagues Dr. Sathya, Dr. Arun, Dr. Karthick, Dr.Priyamvadha Rajshree and also other post graduates for their assistance and support.
I would like to specially thank all other Assistant Professors of the Department of Radio Diagnosis ,Coimbatore Medical College and Hospital for their voluntary and useful guidance.
I also express my gratitude Dr.B.Asokan,M.S.,Mch.,The Dean, Coimbatore Medical College Hospital for providing facilities to carry out and complete the study successfully.
I sincerely thank the members of Institutional Ethical committee, CMCH for approving my dissertation topic.
I thank Dr Amudhan Aravind M.D (Pharm) who helped me with the statistics portion of the thesis.
I sincerely thank all the patients who participated in this study for their cooperation.
ABSTRACT
AIM AND OBJECTIVE
To evaluate the accuracy of CT in identifying appendicitis in ultrasound negative cases.
To assess the efficacy of CT in identifying complications of appendicitis.
To identify the alternate diagnosis of right lower quadrant pain which mimic appendicitis.
To determine the average CT thickness of normal appendix in Indian population by measuring the appendix diameter in CT abdomen for other cases.
METHODOLOGY:
Patients who were admitted within the casuality surgical emergency ward inside the cohort of age 12-55 bestowed with clinical findings and symptoms of acute inflammation like right iliac fossa pain ,fever and vomiting were listed within the study. A complete study sample of two hundred was chosen. The clinical history concerning present history was taken within the prescribed proforma.
Informed consent was obtained from every taking part patient and also the protocol was approved by the institutional ethical committee. 64
Patients with negative ultrasound findings or with equivocal findings were proceed with CT examination and results were obtained.
RESULTS:
The study after statistical analysis brings to the conclusion of : Out of 200 patients in the study population with right lower quadrant pain and negative ultrasound findings, 77 patients were found to have appendicitis based on CT findings.
Based on this study, the patients with CT finding of an appendicular diameter of
>6mm (7-8mm in particular) were found to have Appendicitis, which was found in accordance with other corroborative findings, intra operative findings and histopathological correlation.
This brings us to the conclusion of CT having a more accurate role in the diagnosis of Appendicitis in patients with negative ultrasound findings with a significant sensitivity, specificity, positive and negative predictive value.
CONCLUSION:
The results of the study among patients with right lower quadrant pain, vomiting, fever and lowbackache and with equivocal /negative ultrasound findings, CT plays the next imaging modality of choice.
77 cases were found to have appendicitis in CT among the study population of 200. Among which 50 patients i.e. 25 % of cases have appendix diameter of 7-8mm with periappendiceal fat stranding and appendiceal wall enhancement and diagnosed as appendicitis.
Due to retrocaecal position of appendix obscured by gas shadows and obesity lead to non- visualization of appendix , thus giving USG negative picture for diagnosing appendicitis.
CT is the best modality of choice for diagnosing appendicitis with 7-8mm diameter of appendix along with periappendiceal fat stranding and wall enhancement. 7-8 mm diameter of appendix associated with adjacent CT changes was one of the findings of a major group of patients diagnosed as appendicitis in this study who had negative ultrasound findings.
Other mimics of appendicitis were mesenteric lymphadenitis, right distal ureteric calculus, ileo-caecal thickening, colitis , which were also made in CT images.
Thus coming to the conclusion of CT being the prime modality of choice in aiding clinicians diagnose appendicitis in patients with negative ultrasound findings,through correlation of appendicular diameter, periappendicular fat stranding and wall enhancement.
Thereby prompting early intervention, treatmentand reducing unnecessary complications. CT also helps us exclude the diagnosis of appendicitis therefore reducing the negative appendectomy rate.
TABLE OF CONTENTS
S.NO CONTENTS PAGE NO.
1. INTRODUCTION 12
2. REVIEW OF LITERATURE
HISTORY OF APPENDIX
ANATOMY OF APPENDIX
HISTOLOGY OF APPENDIX
PATHOPHYSIOLOGYOF APPENDIX
DIAGNOSTIC IMAGING
X-RAY
USG
CT
13 17 18 27 28 37
3. AIMS AND OBJECTIVES 47
4. CASES 51
5. STATISTICAL ANALYSIS 56
6. DISCUSSION 79
7. CONCLUSIONS 84
8. BIBLIOGRAPHY 86
9. ANNEXURE
ETHICAL COMMITTEE CERTIFICATE
CONSENT FORM
PROFORMA
PLAGIARISM
MASTER CHART
96
LIST OF ABBREVIATIONS
CRP - C reactive protein WBC - White Blood Count PPV - Positive Predictive Value NPV - Negative Predictive Value PR - Perforation Rate
NAR - Negative Appendectomy Rate ED - Emergency Department
HPE - Histopathology
CT - Computed Tomography USG - Ultra sonogram
No - Number
n - Number of case
INTRODUCTION:
Appendicitis is the most common cause of abdomen pain in patients admitted at the emergency department. It may be associated with vomiting, fever and diarrhoea but the most distressing symptom is the pain. The various cause of the abdomen pain may vary from benign to life threatening disease.
Diagnosing the appendicitis in young male patient is made out easily, but at the same time, it becomes a problem in premenopausal women who presents with similar clinical history and symptoms. Few gynaecological symptoms in middle aged women can also present with symptoms mimicking appendicitis, so it becomes a real challenging for treating clinician to exclude the diagnosis.
The timely diagnosis and intervention of acute appendicitis is important due to its grave complication like perforation CT plays a major role in diagnosing appendicitis in ultrasound negative and equivocal cases to reduce the perforation rate and negative appendectomy rate.
Even if there is no proper clinical findings and appropriate diagnosis of appendicitis, few surgeons are in favour of early laparotomy, to minimize the risk of appendiceal perforation.
REVIEW OF LITERATURE:
HISTORY OF APPENDICITIS
History of appendicitis was made and written in the past two generations.The function of the appendix was not clearly made out in fifteenth century. It was recognised as an organ attached to the caecum with no role in digestion. The Natural Philosopher, Darwin classified appendix as the vestigial, and harmless organ that could be safely ignored.
Hippocrates has also given similar such description of an appendix of that of appendicitis and that of appendicitis with perforation, in his work “The Epidemics”
Appendix was first described by Leonardo Da Vinci in his art in western medicine.
In 1522, the surgeon,Berengaria Carpi, quoted that the organ was empty inside ,measuring 3 inches, present at the end of caecum .
Twenty-one years later ,the findings of Berengaria was augmented by Vesaliusabout the structure of appendix. There was confusion existed between the caecum and the appendix.Finally Versalius called it as vermiformis a “ blind ending pouch”.
In 1541,vesalius depicted fecolith is the route cause of appendiciticis, that obstructs the appendiceal lumen .
In 1561, Fallopius compared appendix to a worm like structure.
Jacopo Berengaria Carpi found that the pain in right iliac fossa was mainly due to appendix.
At the start of nineteenth century,the three coats of appendix along with the mucous glands,the meso-appendix was described .
In 1847, Gerlach found the mucous membrane of appendix and it function as a valve of appendix cause to occlude the appendiceal lumen.
In the year 1880,the appendix was first removed in a elective surgery by Dr.
Lawson Tait .
In 1886, Reginald H. Fitz of Boston was the first to use the term “appendicitis”
in his article and then the word appendix is universally used.
McBurney in 1889,decsribed three classical sign of pain in the right iliac fossa with fever , chills and peritonitis .He was the one who described , the Mc Burney’s point, the point withmaximum tenderness at the junction of a line drawn from anterior superior iliac spine to umbilicus .
In 1887 by Sand and later by Treves in 1888 treated Perforated appendix by suturing. Today we have multiplicity of symptoms and signs and imaging modality ,to diagnose appendicitis. 7
ANATOMY OF APPENDIX
Blind ending tubular structure from posteromedial aspect of caecum and inferior to ilieo caecal junction is called vermiform appendix. The length of appendix varies from 7.5 to 10mm.
The appendix base lies in a constant position and is formed by the confluence of taenia coli. Base of appendix lies roughly deep to the McBurneys point.
Localised right iliac fossa pain and guarding at McBurneys point is the most important clinical finding for the diagnosis of appendicitis.
The free end or the tip of the appendix position is variable. This different location of appendix sometimes gives false negative imaging diagnosis in USG.
The position of appendix also influence the clinical finding2.The position of appendix varies from retrocaecal ,post ileal or pre ileal , midinguinal ,pelvic and paracolic or subcaecal . 8
Fig: 1 Various position of appendix
The appendix is suspended by a peritoneal fold which is a part of mesentry of the terminal ileum and it is attached to the caecum and proximal part of appendix called “ mesoappendix”.It contains appendicular artery, a branch of ileocolic artery. The right colic and ileocolic vein drains in to the portal system.
Fig:2 Arterial Supply of appendix
The lymphatic drainage of appendix is via ileocolic node and through the superior mesenteric to celiac node and it ends in cisterna chyli. Nerve supply to appendix is through T10 spinal segment and it also explains the pain which is referred to the periumbilical region.
HISTOLOGY OF APPENDIX
There are 5 layers from outer to inner.They are
Adventitia,
Muscularis,
Sub mucosa,
Lamina propria,
Mucosa.
FIG :3 HISTOLOGY OF APPENDIX ROLE OF APPENDIX:
Appendix has no digestive glands or secretory ducts, which confirms vestigial nature of this organ and it has no digestive function.
Appendix has lymphoid aggregations in the sub mucosal layer and it plays a role in immunity and it explains the immense inflammatory response in acute appendicitis. The immune system of an individual will not loss or reduce in case of loss of this organ.
PATHOPHYSIOLOGY OF APPENDIX
Appendicular lumen obstruction is considered to be main pathophysiology of appendicitis. The obstruction may be due to parasite infection, foreign body, crohns disease ,gastroenteritis, fecolith and lymphoid hyperplasia and upper respiratory tract infection.
Increase in the mucous secretionseen within the obstructed appendicular lumen and hence is increase in intraluminal pressure leads to distension of appendix.
Overgrowth of bacteria within the distended appendix cause mucosal edema and ulceration. Then there is venous obstruction and vascular congestion occurs due to increase in luminal pressure of appendix and is seen extending up to serosal surface.
Increase in appendicular pressure cause stretching and stimulating the nerve endings of the visceral efferent and it is perceived as periumblical or epigastric pain by the patient.
When the peritoneum gets inflammedthe pain shifts to right lower quadrant.
Venous congestion and stasis leads to thrombosis and results in gangrene of appendix. The appendix get infarcted and perforated due to tissue ischemia in the end stage.
Rupture of appendicitis may leads to spread of inflammation into adjacent bowel loop which results in adjacent bowel loop thickening and abscess or collection formation at the ruptured site.
These process leads to generalised peritonitis and the collection sometimes gets walled off by the bowel loops and greater omentum causing a phlegmatous mass.
Fig:4 Representative algorithm of pathophysiology of Appendicitis
History and physical examination
Evaluation of history of acute abdominal pain,physical examination and combination of signs and symptoms may support the diagnosis of appendicities.
Four signs most predictive of acute appendicitis4,8
The right lower quadrant pain
Abdominal rigidity
Migrating pain to the right lower quadrant from periumblical region.
Most important predictor is the duration of pain5,8 .
Due to gynaecological problems like pelvic inflammatory disease, gastroenteritis, urinary tract infection, ruptured ovarian follicle and ectopic pregnancy6,8 ,misdiagnosis is most common among women.
Predictors of pelvic inflammatorydisease7,8 1. vaginal discharge,
2. Tenderness outside the right lower quadrant 3. Urinary symptoms,
4. Cervical-motion tenderness
Most of surgeons and physician follows various clinical scoring system for diagnosing acute appendicitis as it is a clinically diagnosing condition.
ALVARADO scoring system is commonly used in practice.
FIG:5 ALVARADO SCORE (ref:Alvarado et al 94) The ALVARADO Score (MANTRELS)
In 1986 ,Alvarado published clinical scoring system for appendicitis. He compared common clinical findings in suspected patients and the laboratory findings with histopathologically proven acute appendicitis.
The diagnostic scoring system includes eight criteria. Right lower quadrant pain and a left Shift of WBC count is most predictive andprevalent factor.
Leucocytosis and right lower quadrant pain was given 2 points and other criteria carries 1 point each and reaching a total of 10. Age ranging from 4 to 80 years are included in the scoring system.
An Alvarado Score of ≥7 considered as high risk for acute appendicitis with sensitivity of 81% and a specificity of 74%94,95.
The mean ALVARADO score for inflamed appendix in different categories are compared with each other and p value is found to be .001 (p<0.05), which is statistically significant.
Fig:5 Algorithm for suspected case of appendicitis
Laboratory testing
The laboratory investigations like complete blood count , c-reactive protein, is taken in patients admitted with right quadrant pain.
In middle aged female ( 20-40 years) blood investigation like β-HCG (Human Chorionic gonadotropins ) is taken to excluded ectopic pregnancy.
Nearly 70-90% of patients with acute appendicitis shows an elevated WBC count, which may be due to the mural inflammation of the appendix. Studies have revealed that the WBC count correlates with the severity of appendicitis.
The laboratory investigation of CRP has a similar role as that of WBC in appendicitis 15. Sensitivity of 40-90% and Specificity of 27-90%16 is reported in the diagnosis of appendicitis.
Amalesh et al17 stated “ The accuracy of CRP in diagnosing acute appendicitis is very low and it is not useful for surgeon for performing the surgery”.
Ortega-Deballon et al18 concluded that “ CRP level is the most useful laboratory parameter in diagnosing acute appendicitis, because CRP levels is strongly correlates with inflammation of the inflamed appendix ,gangrenous or perforated appendix”.
Few of Studies have shown that , the correlation of CRP level with CT findings could predict the probability of the patient going for perforation.
OBSERVATION AND LAPAROSCOPY
When the surgeons are in dilemma state & imaging findings are equivocal, diagnostic laparoscopy plays a vital role in those cases, to reduce the unnecessary appendectomy19.
Diagnostic laparoscopy plays a role ,when surgeons are not in favour of surgery and reluctant to keep patients in observation. Both the decision is double edged sword, were perforation risk in positive cases is if more and also increase the rate of unnecessary appendectomy 18 in false negative cases.
The observation practice has reduced the negative appendectomy rate ,without increasing the perforation rate22-24 .Any diagnostic method like diagnostic laparoscopydelays the time for final diagnosis.25,26
Diagnostic laparoscopy has some advantage like27
Accurate and rapid diagnosis
Reduce unnecessary laparotomy rate28
Additional colonic and caecal lesion also identified
Disadvantage of diagnostic laparoscopy includes27
Its invasive Procedure
Cost and increased expenditure .
Hof et al29 quoted “ Gold standard for diagnosis of patients with signs of suspected acute appendicitis is laparoscopy”. Acute appendicitis in the early stages can be diagnosed by laparoscopy as it lowers the appendectomy threshold 30.
Garbarino and Shimi et al31“In women the negative appendectomy rate reduced significantly to 5% in routine use of diagnostic laparoscopy” .
Lim et al.32 “The therapeutic course of the disease changed in 31% when diagnostic laproscopy is routinely used”
The specificity of CT and ultrasound is 72 and 63% respectively and it is high in diagnostic laproscopy of 95% and PPV of 85%-100%.
Improved diagnostic accuracy of ( CT) computed tomography and early use of CT has reduced use of hospital resources33 and cost than the observation strategy.
As diagnostic laparoscopy is being a invasive procedure it has added disadvantage of about approximately 5 % rate of complications, which is mostly associated with use of general anesthetic20.
DIAGNOSTIC IMAGING IN ACUTE APPENDICITIS
The most common symptom in most of the emergency department we encountered is acute abdominal pain. It is attributed to many cause among which, the appendicitis occupies first few of the causes. A case of appendicitis is evaluated mainly by clinical signs and also based on clinical scores .
But by correlating only clinical findings of patient ,the negative appendectomy rate is significantly increased. And also in patients with equivocal and atypical clinical findings imaging modalities helps surgeons for arriving diagnostic conclusion rather than keeping the patient under observation.
As observation practices increased the perforation rate in patient,the imaging techniques like CT and USG has plays a major role in diagnosing acute appendicitis in early periods.
Among the various imaging technique, there arise a question like of which one is the best or which one is the first modality to be considered. USG is the first primary imaging modality recommended as it is of low cost relatively and with no radiation .
But the pitfall is, being operator dependent and is highly based on the skill and experience of the radiologist. Other factors like various position of the appendix ,the built of the patient, makes it difficult for the radiologist to visualise the appendix .
USG sometimes gives a equivocal findings , in such case we are forced and switch over to CT and other modalities if needed. CT is more specific than USG and hence appendicitis could be ruled out easily.Both imaging technique could give other diagnosis if appendicitis is ruled out.
For diagnosing acute appendicitis many literature and studies have debated over the best modality ,fortunately most of them gave the same results. In recent years, negative appendectomy rate significantly reduced by both these imaging modalities.
ROLE OF X-RAY IN DIAGNOSIS OF APPENDICITES
Newer techniques like CT and USG advent in the imaging field, outdated the role of X ray in the diagnosis of appendicitis .But the presence of appendicolith is confirmed by x- ray in 80-100% ,which is one of the main findings of appendicitis, mostly perforated one.
X ray gives clues for other differential diagnosis of renal stone, ileocaecal tuberculosis, crohn's disease,malrotation of the gut and intussusceptions. Most patients with false-positive xray findings for acute appendicitis have other conditions like low-lying inflamed gallbladder ,ruptured ovarian cyst and leaking carcinoma of the caecum.
Abdominal X-ray is neither sensitive nor specific for diagnosing appendicitis but can gives clue to alternate diagnosis or other clue in favour of appendicitis.
Ellis34 recommends plain x-ray film of abdomen for all cases of acute abdomen.
Brooks and Killen listed some radiological signs for acute appendicitis:
RADIOLOGICAL FEATURES IN THE ABDOMINAL X-RAY
i) Air-fluid levels localised to caecum and/or terminal ileum are indicative of localised inflammation in right iliac fossa.
ii) Gas in the caecum, terminal ileum and ascending colon and localised adynamic ileus.
iii) Soft-tissue density increased in the right lower quadrant.
iv) The right flank stripe gets blurred.
v) Appendicolith in the right lower quadrant
vi) Blurring and alteration of the psoas outline at its distal third.
vii) A rare but valuable sign is gas – filled appendix.
viii) Free gas or extra luminal gasin the retroperitoneal or peritoneal space.
ix) Deformity of the caecum.
x) Blurring of psoas shadow in the right side.
ULTRASOUND IN THE DIAGNOSIS OF APPENDICITIS
USG is a simple procedure andnon-invasive technique .It iseasily available even at primary centres and is also cost effective.
In 1986,it was introduced by Puylaert which was ten decades after Fitz published his article on acute appendicitis.
First modality used in diagnosing acute appendicitis is ultrasound. CT scan of the abdomen is the next modality, only if the ultrasound is negative or equivocal.35-38 ultrasound also avoids excessive radiation.
In ultrasound ,the common technique used is graded compression and has advantage of displacing gas filled in thebowel loops between the abdominal
walls. This graded compression method helps in better visualization of appendix freely from the intestinal loops . Higher rates of detection of appendicitis seen in lean patients with USG.39-41
VARIOUS METHODS OF GRADED COMPRESSION Limitations in visualising normal appendix
Various factors like position of the appendix and obesity limit the visualisation of normal appendix .Patients should be put in left lateral position or posterior manual technique may help in visualising retrocaecal position of the appendix.
Sometimes non peristaltic ascending colon in right iliac fossa may mislead the scanning radiologist wrongly as appendix .
At these time,added techniques like the left lateral decubitus or posterior manual compression would be of use.
Posterior manual compression is done by giving additional compression to patient’s back in anterior direction by keeping a hand in posterior aspect of trunk in right lumbar region.
To visualise the region posterior to the caecum and also retrocaecal appendix ,lateral decubitus position is used.
FIG:6 Posterior manual compression
FIG:7 Left lateral decubitus position 33
VISUALISATION OF APPENDICITIS IN USG
“ Longitudinal axis that measures greater than 6 mm in diameter and lacks peristalsis”
FIG :8 Longitudinal scan
“Transverse view, the distended appendix has a target-like appearance”
FIG:9 Target sign in transverse scan
Inflamed appendix seen as A Non-compressible B Aperistaltic
C Blind loop
D Diameter greater than 6 mm
The wall of the inflamed appendix appears laminated. Appendicolith may be seen sometimes and is nothing but inspissated secretions of appendix in the very narrowed lumen. Appendicolith seen in USG as a white echogenic structure and gives post acoustic shadowing.
Contributory factor for diagnosis of appendicitis is appendicolith. Someother additional findings gives a clue to the diagnosis are the periappendiceal fat stranding and caecal wall thickening .
These minor details can be found by good and experienced radiologists that may point towards the diagnosis of appendicitis .
To diagnosis appendicitis main clue comes from the patient himself , the patient will have right iliac fossa tenderness and pain is localized by the patient himself.
LimHK and Quillin SP was presented color Doppler first time in the diagnosis of acute appendicitis.
Increased vascularity in the periphery of appendix in color Doppler is a favourable finding.This is due to increased flow in the periappendiceal region and in the inflamed wall of appendix .
Loss of peripheral vascularity of appendix should alert the radiologist , as the disappearance of Doppler signal in an inflamed appendix gives clue that it is going for gangrene or perforation.
These findings to be mentioned mainly in the report so that operating surgeon to make an urgent decision to operate the patient. Otherwise the perforated appendix going for complication which leading to long term morbidity and mortality .
Most of the times acute appendicitis presents in atypical manner, mimicking other disease process. So that evenmany experienced surgeon may remove normal appendix which leads to negative appendectomy rate of 20%. This is done to avoid the unnecessary delay in case of complications likeperforated appendix.
Hence Ultrasound is now recommended routinely by referring surgeon or physician to diagnose atypical and equivocal cases of appendicitis.
Puylaert was reported a sensitivity of 89% and specificity of 100% after introducing the graded compression technique. The same level of sensitivity and specificity also reported in many studies following Puylaert.
Doria lists the meta- analysis that “sensitivity of ultrasound as 83% and 88%
and its specificity as 93% and 94% for adults and children respectively”.
Among many studies in diagnosis of appendicitis and ultrasound usefulness,One study compared - two groups ,of which one group was diagnosed appendicitis based on only clinical findings and the other group was diagnosed appendicitis with the help of ultrasound.
Clinically diagnosed group had sensitivity of 93% and so had many false positive cases and hence atleast 10 more cases went for surgery without any reason or cause but only on clinical diagnosis.
The second group who were diagnosed based on USG only had sensitivity of 81%.Among usg based diagnosed cases few patients who needed surgery were misdiagnosed as normal and left untreated.
Due to low sensitivity of USG many cases left untreated lead to the complication of perforation. Hence patients diagnosed only on USG findings leads to more morbidity and complication in patients with inflamed appendix and left untreated .
All studies shows that the clinical judgment can never override the imaging findings. But picture changes when specificity is taken into account as USG shows specificity of 95% while that of clinical diagnosis is only 44%.
This concludes clinically diagnosed cases has greater number of false positive.
These patients most times underwent unnecessary appendectomy. This high number of false positive in clinically diagnosed cases is highly unacceptable.
The acceptability of unnecessary surgery in appendix is to a certain extend as it is being a vestigial organ but this could not be allowed in case of other grave disease .But unnecessary operation is significantly reduced by usg based diagnosed cases as it has greater specificity of 95%.
As seen earlier by using USG for diagnosing acute appendicitis , both NAR and PR has decreased which clearly shows the reciprocal relation of NAR and PR.
So to reduce the negative appendectomy rate without increasing the perforation rate, USG plays a significant role in diagnostic aspect.
Stefan pug et al showed a decrease in NAR from 36.6% to 3.2 with use of ultrasound. Negative appendectomy and PR both being an adverse outcome both dropped from 40.6% 22.4% . The study clearly shows the use of ultra sound in the diagnostic work up of acute appendicitis.
To achieve good clinical outcome,combining the ultrasound and clinical findings to be done. Some studies showAlvarado score of 8 seldom needs ultrasound and these patients were taken for appendectomy without subjecting the patient for ultrasound.
On the other hand clinical score of 4, patients were further evaluated on the basis of ultrasound finding.
USG usefulness mainly, lies in patients with clinical score of 4 – 8 and the clinician and surgeon find it difficult to decide based on only with the clinical findings .Use of ultrasound could show additional findings that gives added value to clinch the alternate diagnosis for patients with abdomen pain and help in excluding the diagnosis of appendicitis.
Works on USG based on graded compression techinque by Terasawa and co workers43 showed an overall “sensitivity 0.86% Specificity 0.81% PPV – 84%
NPV – 85%”.
Meta analysis in Korea 44showed “sensitivity of 86.7% and specificity of 80%
and reported accuracy of ultrasound to be 86% - 96%” .
Advantages of USG
Safe in pregnancy
No risk of radiation exposure
Short scan time
No need for contrast
Non invasive
Easily performed in small children
Added benefit of diagnosing other alternate cause of abdominal pain.
Though its usefulness has been well described it has its own disadvantage and pit falls.
First and the fore most is that it is an operator depended, hence the final diagnosis also depends on the experience of the radiologist, performing the scan.
Individual skill is important
It is inferior to other imaging techniques like CT , in sensitivity
It has low negative predictive value it could not confidently exclude the diagnosis of appendicitis
Difficult in female population because of overlap of symptoms46-50.
Difficulty in getting adequate good graded compression in obese patient and in patients who had previous abdominal surgery
Sometimes the location of the appendix also leads to misdiagnosis
Most of the false positive is due to non-visualizations or only the tip of the appendix is inflamed45-47.
While positive ultrasound findings have a relatively high positive-predictive value, identification of a normal appendix is sometimes difficult.
Excellent results have been achieved at select centres. No visualization of the appendix, being reported to have a negative-predictive value of 90% 51.
Graded-compression USG remains our first-line method. It can be performed at any time, regardless of specific patient’s preparation. But in some equivocal cases subsequently they should undergo Computed Tomography assessment 52,53. However it is non-invasive ,non ionising, less expensive and also repeatable.
CT AND ITS ROLE IN DIAGNOSING ACUTE APPENDICITIS
The role of CT in diagnosing appendicitis is high yielding because of its excellent sensitivity, specificity and accuracy. The benefit of CT is still controversy. There are greater number of patient who are subjected to CT imaging and were still not operated.
Improved CT technology, its wide spread availability, the recent trend where the clinical diagnosis is becoming imagedependent, there has been increasing use of CT technique. CT has the advantage of helping to exclude the diagnosis of appendix and also gives an alternative diagnosis wherever applicable.
Various CT techniques are in use including
Unenhanced Helical CT57-59.
Targeted are focused appendiceal techniques using rectal contrast54-56
IV contrast enhanced CT
IV contrast with oral or without oral contrast CT61,62
Low dose CT
IV contrast with caecal air insufflations60
There is always debate over which technique is appropriate or good The IV contrast technique has its owndrwabacks as in,
Allergic reaction to contrast63
Expensive
Extravasation of contrast material64
Tissue injury due to the above leakage
Added to all is the patient’s inconvenience
Use of oral contrast68has as the added disadvantage of
Patient discomfort.
Increased duration of scan procedure.
Sometimes, if the contrast fails to reach the caecum due to various factors – the imaging becomes a total failure.
Advantages of oral contrast65
When ceacum and ileum fills with contrast, appendix is visualized well behind the background of contrast.
The appendix filling with contrast material doesnot rule out appendicitis
Many studies favour ,and some have found no difference in accuracy rate on using oral contrast. Anderson et al66and Keyzer etal67 quoted “No difference in sensitivity, specificity, positive predictive value or negative predictive value if oral is used or not”.
Unenhanced CT :
Unenhanced scan has the merit of being fast.It negates the risks associated with iv contrast. Ege et al concluded that Unenhanced CT has a “ sensitivity of 96%, specificity of 98%, positive predictive value of 97%, and negative predictive value of 98%”69. Heaston et al. showed a “sensitivity of 84% and a specificity of 92%”70 for unenhanced CT.
Non-focused Technique :
Non-focused Technique gave a higher diagnostic accuracy where larger population sample were used with average prevalence of acute appendicitis.
This is the most commonly used CT technique .
Rao et al used and reported cases with use of oral and colon contrast with prevalence of 53%54 of acute appendicitis with diagnostic accuracy of 98%55”.
This is based on the routine body imaging technique used in early days. It uses both IV and oral contrast.
It has the advantage of finding both normal and inflamed appendix with added advantage of finding other extra appendiceal pathologies. Though helical CT with iv or oral or only rectal or other combination is available this non-focused technique is widely used due to the fact that other technique in due course reduces the accuracy rate.
Focused technique or the Appendiceal CT :
Appendiceal CT is a focussed CT Technique and is advised for patients when the clinician strongly suspects acute appendicitis to be the sole cause for the
patient’s pain. Helical Scanning with 5 mm collimation and 5mm thickness is used.
Upper abdomen is left out covering only 15 cm of the lower abdomen and the upper pelvis centered at the tip of the caecum. Small rectal catheter is used to instill contrast into the colon with average volume of 900 ml of contrast. No iv or oral contrast is used in this technique. The scan is done in 20 – 30 minutes .
Negative was reported if the contrast filled the lumen or the lumen is filled with air . A positive diagnosis is given if the appendix is enlarged > 6 mm or if the appendix is not opacified with contrast. Other specific signs like arrow head and cecal bar sign steers in favour of a positive diagnosis. Appendicolith is another positive sign of appendicitis.
The main limitation of this technique is that other alternate diagnosis may be missed as the entire abdomen is not covered in the scan. But this technique can confidently confirm or exclude the diagnosis of acute appendicitis.
Rhea et al quoted “Focused appendiceal CT may lower both fixed and variable cost in caring the patient with appendicitis”72 .
Rho et al “Focused technique reduces the use of hospital resource”73
Fefferman et al reported high “sensitivity (97%), specificity (93%), positive predictive value (90%), and negative predictive value(98%) 71” in focussed technique.
The highest, for a CT accuracy for diagnosing acute appendicitis is also from this technique of about 93 to 98%.As only limited section is covered, the radiation dose to the patient is also minimal with reduced exposure and cost.
This technique also reduces the appendiceal perforation rate from 22 to 14%
and the negative appendectomy rate from 20 to 7%73.
Focussed techniques depend on expert interpretations and may not always provide an alternate diagnosis for pain in patients with acute symptoms.
Imaging every patient with suspected appendicitis may be impractical at many centres , because helical CT facilities and on-site radiologists, experienced in interpretation are not readily available.
Low dose protocol
Taking intoaccount the radiation from standard dose, CT low dose protocol with no use of iv or oral contrast was considered. This technique may be adequate for diagnosing acute appendicitis. It is in the hands of the radiologist to bring a change. Many studies based on low dose CT are being done.
KeyZer at al quoted “No difference in sensitivity and specificity value in diagnosing acute appendicitis on using standard does and simulated low does” 67 Seo et al after having made studies with low does technique and came up with the same results.
Contradicting KeyZer et al, studies have shown compromise in low dose technique like
Alternate diagnosis and finding normal appendix
Loss of reader confidence
Loss of accuracy and diagnostic confidence.
But still noise reducing post processing algorithm can be used to increase the diagnostic accuracy in low dose technique. This kind of improvement in post processing will decrease the noise and increase the image quality. The next
issue in low does technique is the explanation of alternate diagnosis, in case that had been reported negative for appendicitis.
To be reported as false positive it had to be “unequivocal diagnosis of the disease with no differential diagnosis”.
CT scans to be reported as true negative “ the image must give either an alternate diagnosis or must report it has normal findings”.
CT has been increasingly incorporated in most institutions because of high accuracy rate, an easy available range at present time.
It has the advantage of decreasing the NAR without increasing the perforation rate .
CT CRITERIA FOR DIAGNOSIS OF ACUTE APPENDICITIS : The primary diagnostic criteria for acute appendicitis is visualization of a
Thickened and distended appendix width >6 mm
Mural thickening and enhancement
Wall thickening of appendix >2mm
Periappendiceal stranding65
Secondary diagnostic criteria are
Appendicolith,
Periappendiceal abscess,
Small-bowel obstruction,
Pericaecal inflammation
Target appearance - Concentric inflammatory thickening of appendix
Presence of air either intraluminal or extraluminal.
The sensitivity and specificity of a pelvic and abdominal CT scan are 94 percent and 95 percent, respectively 43.
The additional benefit of CT is that alternative diagnoses are made in up to 15 percent of patients 74 .
A definitive CT diagnosis of acute appendicitis can be ruled out if there is air or contrast in the appendiceal lumen.
If rectal contrast is given two signs help in identifying appendicitis.
They are, 53
The caecal bar sign:
The contrast filled caecum is seen distinctly due the interface created by the inflammatory soft tissue thickening at the base of the appendix.
The arrow head sign79 :
It is the contrast filling in the caecum, with the arrow pointing to the point of occlusion in the appendix. It is not seen in all the films. Thin sections are needed to depict this sign better. And it is also a necessary pre requisite that the caecum must be well distended with contrast.
Caecal apical thickening:
Though both CT and USG have a synergistic value ,many radiologist are in favour of CT, as they are more confident in interpreting CT than sonography.80 Routine imaging is ,cost-effective and would also result in less delay before proper treatment. 54
Effect of CT imaging on false positive :
Surgically Accepted False Positive and Negative appendectomy rate among the surgeons is 20% 82which has dramatically decreased in the recent years by the liberal use of preoperative imaging studies like CT and USG.
The False Positive rate is more in females compared to men due to the overlap of gynaecological symptoms which is as high as 42% while many studies have shown reduction in the above rate with increased use of imaging. Some large scale studies have shown no improved clinical outcome81.
Various studies have shown that there has been increase in use of CT by the physicians and surgeon, as the first line imaging modality. There is a decline in the USG imaging. However USG may play its role in some diagnosis, mainly in female patients like fibroid, ovarian cyst and pelvic inflammatory disease.
And also with increased CT usage, an overall decrease in the appendiceal perforation has been noted with statistical significance of p < 0 .001.
There is also a significant decrease in the false positive diagnosis with preoperative use of CT. 55
Negative Appendectomy – Effect of Imaging :
NAR was defined “as the portion of pathologically normal appendices removed surgically in patients suspected of having acute appendicitis”. Literature shows that 15-25% of such normal appendix was removed82,83.
The need to reduce the unnecessary appendectomy is due the fact, to avoid the risk of surgical complication and the cost. But it itself is double edged sword.
Surgeons have the upper limit of negative appendectomy rate of 20%84. This is to avoid the negative and grave consequence of delayed diagnosis and perforation. The diagnostic accuracy of clinical findings is about 80%85.
This my fall to 60% to 68% percent in women population due to the overlap of the gynaecological symptoms84-86. There has been an increase in diagnostic accuracy to above 83% to 98% percent if in addition to the clinical findings the imaging findings from CT and ultrasound are combined73,75,88. There has been marked increase in the clinical outcome by using these imaging modalities.
Studies have show there has been significant decrease in NAR value in women who have gone with preoperative imaging. One such study have shown the overall sensitive of CT 96% and PPV (Positive predictive value) 96% and correctly diagnostic in 89%. Same studies showed ultrasound sensitive to be 86% and PPV 95% with correct diagnosis in 79%90.
Prior studies have reported NAR of 5 to 16 % in men and 11 to 34% in women87.
The most common misdiagnosis in women is the pelvic inflammatory disease which is the prime cause of increase in negative appendectomy rate.
The studies also showed a decrease (27%) in the negative appendectomy rate from 34% to 7% in CT and to about 8% with USG imaging90.
“Rao et al” showed a significant (P<0.001) decrease in NAR for women from 35% to 11% in CT imaging89. Studies showed low NAR value in males and boys regardless of preoperative imaging.
Coming to the perforation rate, literature shows perforation rate of 14-31%
inpatients who underwent CT imaging when compared to those who had not. It was later proposed that delay in the time of CT imaging may be the cause of increased perforation rate in the study group that undergo CT Examination.
Karakas et al reported “ PR of 54% in children who underwent CT to PR of 20% with no imaging done”91 ,possibly due to delay in imaging. But most of the surgeons resort to imaging technique, only when clinical findings are equivocal.
Perforation rate and NAR are inversely relative, in that any increase in negative appendectomy rate, usually decrease the PR and decrease the number of study people who are kept under observation.
Studies also implicated thatthe delay from the patient’s side play a major role in the perforation rate rather than the imaging technique performed.
Another study showed that the preoperative CT has significant decreased in the NAR in age group of < 45 years in women,but did not have any effect in male and women in > 45 years. The study has the similar conclusion as the study seen early in literature.
Raman et al showed that with the increase in the percentage of patients who undergo CT imaging from 18.5 to 94.2% ( P< .00001) ,NAR decreased from 16.72 – 8.7% with a statically significant p value < 0.000189,92.
“Rhea at al” showed a decrease in NAR from 20 to 7% while Rao et al quoted
“11 to 5% CT imaging showed false positive of 1.7 to 10% and false negative of 0 to 2.4%”89.
Another study by “Raja et al” showed with increase usageof CT from 1% to 97.5% (P < 0.0001), NAR decrease from 23% to 1.7% (P < 0.0001), with decrease from 29.8% to 1.6% in female population and a decrease from 15.5 to 1.8 in male population , with both having P Value of < 0.0001 being statistically significant93.
AIM AND OBJECTIVE
To evaluate the accuracy of CT in identifying appendicitis in ultrasound negative cases.
To assess the efficacy of CT in identifying complications of appendicitis.
To identify the alternate diagnosis of right lower quadrant pain which mimic appendicitis.
To determine the average CT thickness of normal appendix in Indian population by measuring the appendix diameter in CT abdomen for other cases.
STUDY DESIGN:
Hospital based observational study.
STUDY POPULATION:
Patients with right lower quadrant pain & negative USG findings.
SAMPLE SIZE: 200
STUDY DURATION: January 2018 – June 2019; 18 months.
METHODOLOGY:
Observational study to be carried out in the Department of Radiology in collaboration with the Department of Surgery in Coimbatore Medical College Hospital.
Those patients suspected to have appendicitis who show negative findings in ultrasound are subjected to non-enhanced and contrast enhanced CT.
INCLUSION CRITERIA:
All patients suspected to have appendicitis and show negative findings in ultrasound.
EXCLUSION CRITERIA:
Patients who show typical findings of appendicitis in ultrasound.
Patients who are medically unfit to undergo contrast study like renal failure patients.
Patients with hypersensitivity reactions.
Pregnant patients.
METHODOLOGY:
patients who were admitted within the casuality surgical emergency ward inside the cohort of age 12-55 bestowed with clinical findings and symptoms of acute inflammation like right iliac fossa pain ,fever and vomiting were listed within the study. A complete study sample of two hundred was chosen.
The clinical history concerning present history was taken within the prescribed proforma. Informed consent was obtained from every taking part patient and also the protocol was approved by the institutional ethical committee. 64
USG PROTOCOL
A routine USG was done in SONOSCAPE machine for the abdomen and pelvis employing a 3-5–MHz convex transducer to rule out various
abnormalities associated with solid organs and to rule out free fluid. Then ranked compression and color Doppler ultrasound of the right lower quadrant giving attention to the location of maximal tenderness was performed employing a linear transducer.
The normal appendix was envisioned as a blind ended loop with no vermiculation. The graded compression technique is employed to displace the intestine loops, permitting differentiation between incompressible inflamed appendix and compressible normal intestine loops.
The presence of appendicitis is diagnosed as a tubular blind-ended structure seen anterior to the iliac vessel and it is non compressible with diameter greater than 6mm. Increased peripheral vascularity seen in the wall of the appendix on doppler study due to the mural inflammation.
Periappendicular fat stranding, appendicolith and peritoneal fluid and someother additional findings were also identified. 65
On average of total time of 15-20 min was taken for a single study.The USG findings was reported as positive or negative for acute appendicitis. Other findings or diagnosis when achieved, was also reported.
CT PROTOCOL
Examinations were performed on a 16 – slice MDCT using ( TOSHIBA ) at 120 kVp and 100 mAs . CT abdomen and pelvis were taken from xiphoid process to the pubic symphysis, with 80 mL of non-ionic contrast material Iohexol 350 (Omnipaque 350).
The contrast material was injected in the volar aspect elbow in the cubital vein through a 18- gauge cannula at a flow rate of 4 ml/s and delay of 50 sec.Axial reconstructions from the raw data were done at 3 mm thickness.No oral contrast was used.
In reporting format normal appendix when visualised was reported . The CT report was positive, negative, or inconclusive. The criteria for appendicitis is similar to that of USG. Alternative diagnoses or otherfindings if any when achieved were reported .66
CASE 1
54 year old male with H/O abdominal pain for 4 days with H/O fever, total counts were 14,000 cells/cumm.
USG - shows right lower quadrant probe tenderness with other findings
CT showed an appendix of 7 -8mm(7.52mm) with periappendiceal fat stranding and is retrocaecal in position.
CASE 2
19 years female
c/o vague abdominal pain for 5 days with no evidence of fever ,vomiting.
USG shows no evidenvce of abdominal findings.
CT shows appendix of diameter 7.5mm with peripancreatic fatstranding.
CASE 3
35 years male
c/o right lower quadrant pain on and off for past 3 months.
TLC-4400cells/mm3.
USG – not significant.
CT – thickened appendix of diameter 11.2mm with no evidence of fat stranding and no evidence of wall enhancement.(Thickened appendix).
CASE 4 13 years male
C/o severe abdominal pain and abdominal distension for 4 days.
TLC – 14000 cells/mm3.
USG - fluid filled bowel like structure with no peristalsis with no evidence of peristalsis in adjacent bowel loops.
CT – appendicitis with appendicolith and appendicular abscess in RIF.
CASE 5
18 years female.
c/o lower abdominal pain for 3 days with h/o fever 3 days.
h/o vomiting and loose stools for 2 days.
USG – shows fluid filled collection in right lower quadrant pain with adjacent bowel loops shows mild dilatation and shows mild peristalsis. Appendix not separately visualised.
CT – shows appendix perforation in tip and appendicolith with periappendiceal fluid collection noted. Appendix is pelvic in position.
STATISTICAL ANALYSIS:
AGE DISTRIBUTION:
AGE IN YEARS NO OF PATIENTS PERCENTAGE
12 TO 19 46 23.00%
20 TO 24 91 45.50%
MORE THAN 25 63 31.50%
P VALUE – 0.08
TABLE:1 shows the age distribution of patients with right lower quadrant pain with negative ultrasound findings for appendicitis. The age group affected predominantly are between 20 to 24 years which is about 45.8% , i.e 91 out of 200 patients included in the study population, irrespective of sex.
AGE GROUP 20-24 HAS HIGHER INCIDENCE
This piechart shows graphic representation of the age group involved.
12 TO 19, 46
20 TO 24, 91 MORE THAN 25,
63
AGE DISTRIBUTION
SEX DISTRIBUTION
SEX NO OF PATIENTS PERCENTAGE
MALE 133 66.50%
FEMALE 67 33.50%
P VALUE -0.001
TABLE: 2 shows the sex distribution of the study population. 66.5 % of males &
33.5% of females presented with Right lower quadrant pain, indicating a male predominance.
MALE POPULATION HAS HIGHER INCIDENCE
Shows graphic representation of the percentage of male & female population in the study group.
MALE, 133 FEMALE, 67
SEX DISTRIBUTION
AGE VS SEX
AGE IN YEARS
SEX
MALE FEMALE
12 TO 19 29 17
20 TO 24 56 35
MORE THAN 25 47 16
P VALUE – 0.920
TABLE: 3 shows comparison between age and sex of the study population. It has P value of 0.920 indicating no significant relation between the age and sex of the patients presenting with right lower quadrant pain.
NO SIGNIFICANT RALATION BETWEEN AGE AND SEX
29
56
47
17
35
16
12 TO 19 20 TO 24 MORE THAN 25
AGE VS SEX
SEX MALE SEX FEMALE
FEVER
FEVER NO OF PATIENTS PECENTAGE
PRESENT 99 49.50%
ABSENT 101 50.50%
TABLE 4: shows patients with right lower quadrant pain presenting with fever which is about 49.5%. nearly 50% of the patients in study population presented with fever.
49%
51%
FEVER
PRESENT ABSENT
PRESENTING COMPLAINTS
PRESENTING COMPLAINTS PRESENT ABSENT
ABDOMINAL PAIN 200 0
FEVER 99 101
VOMITTING 25 175
CONSTIPATION 6 194
LOOSE STOOL 8 192
LOW BACK ACHE 26 174
PAINFUL MICTURATION 30 170
TABLE 5: shows in patients with the right lower quadrant pain, fever being the other major symptom (49.5%) followed by vomiting (12.5%) and painful micturition (13.5%).
The above bar diagram is the diagrammatic representation of overall presenting complaints in the study group.
200
99
25
6 8
26 30
0
101
175
194 192
174 170
PRESENTING COMPLAINTS
PRESENT ABSENT
DURATION OF PAIN IN RIF
DURATION OF PAIN NO OF PATIENTS PERCENTAGE
< 4 HRS 56 28%
4-8 HRS 62 28%
> 8 HRS 82 28%
P VALUE – 0.562 NOT MUCH DIFFERENCE IN DURATION OF PAIN AT TIME OF PRESENTATION
TABLE6: Shows the duration of right lower quadrant pain among the patients.
The p value is 0.562 indicating there is not much of a statistical significance.
shows the graphical representation of the duration of right lower quadrant pain among the patients.
28%
31%
41%
DURATION OF PAIN
< 4 HRS 4-8 HRS > 8 HRS
ON ULTRASOUND
ON USG NO OF PATIENTS PERCENTAGE
FREE FLUID 34 17.00%
MESENTRIC LYMPHADENITIS 53 26.50%
NORMAL 113 56.50%
TABLE 7: shows among study population, 56.5 % had normal ultrasound findings, and in the rest, 26.5 % had findings of mesenteric lymphadenitis & 17 % had findings of free fluid.
Bar diagram shows distribution of ultrasound findings among the study group.
34
53
113
FREE FLUID MESENTRIC
LYMPHADENITIS
NORMAL
ON ULTRASOUND
ON COMPUTED TOMOGRAPHY
POSITION OF APPENDIX NO OF PATIENTS PERCENTAGE
RETROCEACAL 155 77.50%
PELVIC 27 13.50%
PRE & POST ILEAL 11 5.50%
REST 7 3.50%
P VALUE – 0.001
TABLE: 8 shows position of appendix of the study population ,with 77.5% of patients having retrocaecal appendix with significant P value of 0.001.
RETROCEACAL IS COMMONEST POSITION ON CT SIGNIFICANTLY
The above schematic diagram shows position of appendix of the study population identified on Computed Tomography.
RETROCEACAL PELVIC PRE & POST ILEAL
REST 155
27
11 7
POSITION OF APPENDIX - ON CT
DIAMETER OF APPENDIX
DIAMETER OF APPENDIX NO OF PATIENTS PERCENTAGE
< 6 MM 112 56.00%
6 - 7MM 20 10.00%
7-8 MM 50 25.00%
>8 MM 18 9.00%
TABLE 9: Shows diameter of appendix among study groups. 56% of patients have appendix diameter of <6mm and 25 % of patients have a diameter of 7-8 mm.
In appendix diameter , less than 6MM, the mean appendix diameter was 5.7MM DIAMETER OF APPENDIX NO OF PATIENTS PERCENTAGE
4-5 MM 48 42%
5-6 MM 64 58%
The diagram shows the distribution of diameter of appendix in the study population.
56%
10%
25%
9%
DIAMETER OF APPENDIX
< 6 MM 6 MM 7 MM >8 MM
PERIAPPENDICIAL FAT STRANDING WITH WALL ENHANCEMENT PERIAPPENDICIAL FAT STRANDING WITH WALL ENHANCEMENT
ENHANCEMENT NO OF PATIENTS PERCENTAGE
PRESENT 77 38.50%
ABSENT 123 61.50%
TABLE :10 showsabout 38.5% of the study group has periappendiceal fat stranding with wall enhancement.
The bar diagram shows periappendiceal fat stranding with wall enhancement.
PRESENT ABSENT
77
123
PERIAPPENDICIAL FAT STRANDING
WITH WALL ENHANCEMENT
APPENDICITIS
APPENDICITIS NO OF PATIENTS PERCENTAGE
PRESENT 77 38.50%
ABSENT 123 61.50%
TABLE 11: shows 38.5 % among study group has appendicitis , diagnosed on Computed Tomography.
Bar diagram shows distribution of acute appendicitis diagnosed on Computed Tomography.
77
123
PRESENT ABSENT
ACUTE APPENDICITS ON CT
AGE VS ACUTE APPENDICITIS
AGE IN YEARS
ACUTE APPENDICITIS
PRESENT ABSENT
12 TO 19 0 46
20 TO 24 67 24
MORE THAN 25 10 53
P VALUE -0.001
TABLE 12: shows that the age group 20-24 years have a higher incidence of acute appendicitis with a significant P value of 0.001 among study population.
AGE GROUP 20-24 HAS HIGHER INCIDENCE IN OUR STUDY GROUP
The bar diagram shows distribution of Age vs Appendicitis.
0
67
10 46
24
53
12 TO 19 20 TO 24 MORE THAN 25
AGE VS APPENDICITIS
ACUTE APPENDICITIS PRESENT ACUTE APPENDICITIS ABSENT
