Suspected acute appendicitis: nonenhanced helical CT in 300 consecutive patients

Elevated total and direct bilirubin are associated with acute complicated appendicitis: a single-center based study in Saudi Arabia

BACKGROUND

Appendicitis is the most common abdominal surgical emergency and up to our knowledge no previous studies have been conducted in Saudi Arabia particularly at Qassim region and this study aimed to determine a total and direct bilirubin as a predictor of acute complicated appendicitis.

METHODS

Observational retrospective study that included patients admitted under the general surgery department with a diagnosis of acute appendicitis at King Saud Hospital, Unaizah, Saudi Arabia. Data on age, gender, BMI, diabetes mellitus, total and direct bilirubin, AST, ALT, sodium, and WBCs levels were obtained.

RESULT

Among the overall study population of 158 patients, the age median [IQR] was 24.5 [19-31], males were 99 (62.7%), and complicated appendicitis was 33 (20.9%). The multivariable analysis revealed that both elevated total and direct bilirubin are associated with complicated appendicitis (aOR = 3.79, 95% CI: 1.67-8.48, P = 0.001) and (aOR = 4.74, 95% CI: 2.07-10.86, P < 0.001) respectively. A receiver operating characteristic curve showed the best cutoff value of total and direct bilirubin as ≥ 15 µmol/L and ≥ 5 µmol/L respectively, with a sensitivity of 57.6%, and specificity of 73.6% for elevated total bilirubin, and a sensitivity of 54.6%, and specificity of 80% for elevated direct bilirubin.

CONCLUSION

Elevated total and direct bilirubin are associated with acute complicated appendicitis in this setting. However, it should be supportive factor for acute complicated appendicitis and not considered as standalone diagnostic test.

Imaging of Gastrointestinal Tract Ailments

Gastrointestinal (GI) disorders comprise a diverse range of conditions that can significantly reduce the quality of life and can even be life-threatening in serious cases. The development of accurate and rapid detection approaches is of essential importance for early diagnosis and timely management of GI diseases. This review mainly focuses on the imaging of several representative gastrointestinal ailments, such as inflammatory bowel disease, tumors, appendicitis, Meckel's diverticulum, and others. Various imaging modalities commonly used for the gastrointestinal tract, including magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT), and photoacoustic tomography (PAT) and multimodal imaging with mode overlap are summarized. These achievements in single and multimodal imaging provide useful guidance for improved diagnosis, staging, and treatment of the corresponding gastrointestinal diseases. The review evaluates the strengths and weaknesses of different imaging techniques and summarizes the development of imaging techniques used for diagnosing gastrointestinal ailments.

Diagnostic Algorithm Based on Machine Learning to Predict Complicated Appendicitis in Children Using CT, Laboratory, and Clinical Features

To establish a diagnostic algorithm for predicting complicated appendicitis in children based on CT and clinical features.

METHODS

This retrospective study included 315 children (<18 years old) who were diagnosed with acute appendicitis and underwent appendectomy between January 2014 and December 2018. A decision tree algorithm was used to identify important features associated with the condition and to develop a diagnostic algorithm for predicting complicated appendicitis, including CT and clinical findings in the development cohort (n = 198). Complicated appendicitis was defined as gangrenous or perforated appendicitis. The diagnostic algorithm was validated using a temporal cohort (n = 117). The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) from the receiver operating characteristic curve analysis were calculated to evaluate the diagnostic performance of the algorithm.

RESULTS

All patients with periappendiceal abscesses, periappendiceal inflammatory masses, and free air on CT were diagnosed with complicated appendicitis. In addition, intraluminal air, transverse diameter of the appendix, and ascites were identified as important CT findings for predicting complicated appendicitis. C-reactive protein (CRP) level, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and body temperature also showed important associations with complicated appendicitis. The AUC, sensitivity, and specificity of the diagnostic algorithm comprising features were 0.91 (95% CI, 0.86-0.95), 91.8% (84.5-96.4), and 90.0% (82.4-95.1) in the development cohort, and 0.7 (0.63-0.84), 85.9% (75.0-93.4), and 58.5% (44.1-71.9) in test cohort, respectively.

CONCLUSION

We propose a diagnostic algorithm based on a decision tree model using CT and clinical findings. This algorithm can be used to differentiate between complicated and noncomplicated appendicitis and to provide an appropriate treatment plan for children with acute appendicitis.

Approach to Abdominal Imaging in 2022

Abdominal pain represents 5% to 7% of all emergency department presentations. Many patients require imaging for diagnosis, and choosing the appropriate imaging modality is a crucial decision point. Modern medicine offers a fantastic array of options including abdominal radiograph, computed tomography, MRI, and ultrasonography, but the plethora of alternatives can be paralyzing. This article introduces the commonly available modalities, discusses the advantages and disadvantages, and presents current recommendations for commonly diagnosed conditions.

Abdominal Ultrasound and Its Diagnostic Accuracy in Diagnosing Acute Appendicitis: A Meta-Analysis

Background: Acute appendicitis (AA) is a common cause of abdominal pain encountering unnecessary surgeries in emergency departments. The present meta-analysis aims to assess the accuracy of abdominal ultrasound in suspected acute appendicitis cases in terms of sensitivity, specificity, and post-test odds for positive and negative results.

Materials and Methods: An extensive and systematic search was conducted in Medline (via PubMed), Cinahl (via Ebsco), Scopus, and Web of Sciences from 2010 till the end of March 2021. Two authors analyzed studies for inclusion, collected results, and conducted analyses separately. Examination of the histopathological tissue collected during appendectomy served as a gold standard for determining the final diagnosis of appendicitis. The accuracy was determined by evaluating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio.

Results: Out of 3,193 references, a total of 18 studies were selected. Overall sensitivity of 77.2% (95% CI – 75.4–78.9%) and specificity of 60% (95% CI – 58–62%) were observed. The diagnostic odds ratio of 6.88(95% CI 1.99–23.82) was obtained.

Conclusion: Abdominal ultrasound shows significant accuracy of diagnosis in patients with suspected acute appendicitis.

Analysis of CT characteristics in the diagnosis of Schistosoma japonicum associated appendicitis with clinical and pathological correlation: a diagnostic accuracy study

PURPOSE

To clarify unique non-contrast CT (NCCT) characteristics for early recognition of Schistosomal associated appendicitis (SAA) differentiating from Non-schistosomal associated appendicitis (NSA).

MATERIAL AND METHODS

Clinical and pathological data of 50 cases with SAA and 60 cases with NSA who underwent emergency appendectomy were retrospectively compared to pre-surgical NCCT features such as direct and indirect signs of acute appendicitis as well as appendicoliths, colon calcifications as diagnostic criteria. Statistical methods such as Chi-square (χ²), t-tests, Principal component analysis (PCA), Binary Logistic regression (LR) and Factor Analysis (FA) were utilized to observe differences and isolate recognizable CT features of SAA. Pre and post hoc diagnostic performance of all criteria was calculated as sensitivity, specificity, and the Odds Ratio (OR).

RESULTS

Age > 50 years, diameter > 13 mm, pneumatosis, peri appendiceal abscess, focal wall defect, perforation; Orbital, linear and point types of appendicular wall calcifications; sigmoid colon and cecal curvilinear calcifications were observed as unique characteristics with a sensitivity of 84-95% and specificity of 91-98% in predicting SAA by OR of 6.2 times. Pre and post hoc hypothetical analysis did not show any significance for all other factors.

CONCLUSION

Factors such as elderly age, CT features such as larger appendicular diameter, appendicular wall calcifications along with sigmoid colon, and cecal calcifications, signs of perforation or abscess are characteristic for early recognition of SAA.

Computed tomography for diagnosis of acute appendicitis in adults

BACKGROUND

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not.

OBJECTIVES

Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy.

SEARCH METHODS

We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status.

SELECTION CRITERIA

We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity.

MAIN RESULTS

We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery.

AUTHORS' CONCLUSIONS

The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Falling through the worm hole: an exploration of the imaging workup of the vermiform appendix in the pediatric population

Despite the thousands of articles discussing appendicitis in the literature, the dilemma of how to best diagnosis and manage pediatric appendicitis remains unsettled. Over the past decade, evidence has been mounting about the use of antibiotics as the sole therapy in uncomplicated appendicitis in the adult population. This debate has even recently bled over into the lay press. While this change in practice pattern is still in its infancy for the pediatric population, radiologists should be aware of this change in therapy and how it can impact the imaging work-up and relevant findings. This article concisely summarizes the imaging findings and various imaging pathways to arrive at the diagnose of appendicitis with an emphasis of how to best be of use to our surgical colleagues in this evolving paradigm. It also highlights venues for further research, namely increasing accuracy of differentiating complicated from uncomplicated appendicitis.

Focused CT for the evaluation of suspected appendicitis

PURPOSE

To determine the diagnostic accuracy of focused appendiceal CT as a feasible alternative to the standard CT of the abdomen and pelvis (CT-AP) in patients with suspected acute appendicitis.

METHODS

Retrospective review of 200 adults with suspected acute appendicitis between January and October 2016 were included in this study. Each patient underwent CT-AP with oral and intravenous (IV) contrast. A subset of axial images starting at the top of L4 vertebral body to the roof of the acetabula were obtained from each study which served as the focused appendiceal CT. After review of the focused CTs, the non-focused CT-AP scans were reviewed, each patient acting as their own control. Images were assessed for ability to identify the appendix, assess for appendicitis, or identify alternative diagnoses that could account for the presenting symptoms.

RESULTS

Of 200 cases, the appendix was visualized in the focused CT in 191 patients. In nine studies, the appendix was not visualized in focused or standard CT-AP. Using focused CT, 42 cases were positive for acute appendicitis. This result was identical when reviewing standard CT-AP. Alternative diagnoses were present in 38 patients. Using focused CT, 14 of these were not fully covered but the readers were able to make the diagnoses confidently on the focused CTs. Only one patient had acute non-appendiceal pathology mostly outside of the field of view.

CONCLUSIONS

Focused appendiceal CT with IV and oral contrast in the setting of clinically suspected appendicitis is a suitable alternative to conventional CT-AP.

Ingested metallic foreign body impacted in the vermiform appendix presenting as acute appendicitis: Case report

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Foreign body appendicitis in children may be caused by a variety of ingested foreign bodies.

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Pins are the most common cause of foreign body appendicitis.

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The reported incidence of bowel perforation is less than 1%, especially with sharp, thin, pointed or long objects.

Introduction

Ingestion of foreign bodies and their impaction at the lumen of the appendix is a very rare finding and only few cases have been reported all over the world. A variety of metallic foreign bodies when ingested may be lodged in the lumen of the appendix such as screws, bird shots, and needles. This is called in most literatures as foreign body appendicitis.

Case presentation

A 4-year-old boy with history of an accidental ingestion of a metallic nail presented to the emergency department one week later with right iliac fossa pain and one attack of vomiting. During abdominal examination there was tenderness and rebound tenderness at the right iliac fossa. Plain abdominal X-ray showed the metallic nail in the region of the right iliac fossa. Ultrasound examination was normal apart from tenderness of putting the probe on the right lilac fossa. The white blood cell counts were 14,000 cell per microliter.

During surgery the nail was found to be impacted inside the lumen of the vermiform appendix causing inflammation of the appendix. Appendicectomy done and the patient discharged on the third day in a good general condition.

Conclusion

Acute appendicitis may be caused by a variety of causes including ingested foreign bodies if impacted in its lumen. When the patient has signs of generalized peritonitis it is important to exclude bowel perforation. The surgery can be done by the open surgery or laparoscopically.

First-Line Diagnostic Evaluation with MRI of Children Suspected of Having Acute Appendicitis

Background Advances in abdominal MRI have enabled rapid, free-breathing imaging without the need for intravenous or oral contrast material. The use of MRI as the primary imaging modality for suspected appendicitis has not been previously studied. Purpose To determine the diagnostic performance of MRI as the initial imaging modality in children suspected of having acute appendicitis. Materials and Methods The study included consecutive patients 18 years of age and younger presenting with acute abdominal pain at a tertiary care institution from January 2013 through June 2016 who subsequently underwent an unenhanced MRI examination as the primary diagnostic imaging modality. Electronic medical records and radiology reports were retrospectively evaluated for the feasibility and diagnostic performance of MRI, with surgical pathology and follow-up electronic records as reference standards. Statistical analyses were performed by using simple binomial proportions to quantify sensitivity, specificity, and accuracy, and exact 95% confidence intervals (CIs) were obtained. Results After exclusions, 402 patients (median age: 13 years; interquartile range [IQR], 9-15 years; 235 female patients; 167 male patients) were included. Sedation for MRI was required in 13 of 402 patients (3.2%; 95% CI: 1.7%, 5.5%). The appendix was visualized in 349 of 402 patients (86.8%; 95% CI: 83.1%, 90%); for the remaining patients, a diagnosis was provided on the basis of secondary signs of appendicitis. The sensitivity, specificity, and accuracy of MRI as the primary diagnostic imaging modality for the evaluation of acute appendicitis were 97.9% (95 of 97; 95% CI: 92.8%, 99.8%), 99% (302 of 305; 95% CI: 97.2%, 99.8%), and 98.8% (397 of 402; 97.1%, 99.6%), respectively. Among patients with negative findings for appendicitis at MRI, an alternate diagnosis was provided in 113 of 304 patients (37.2%; 95% CI: 31.7%, 42.9%). Conclusion When performed as the initial imaging modality in children suspected of having acute appendicitis, MRI examinations had high diagnostic performance for the diagnosis of acute appendicitis and in providing alternative diagnoses. © RSNA, 2019 See also the editorial by Dillman and Trout in this issue.

MRI of the Nontraumatic Acute Abdomen: Description of Findings and Multimodality Correlation

Obtaining a specific diagnosis in the nontraumatic acute abdomen can be clinically challenging, because a wide range of disease processes affecting a number of different organ systems may have very similar presentations. Although computed tomography and ultrasound examination are the imaging tests most commonly used to evaluate the acute abdomen, MRI can often offer comparable diagnostic performance, and may be considered when other modalities are equivocal, suboptimal, or contraindicated. In some circumstances, MRI is emerging as an appropriate first-line imaging test.

Comprehensive review of typical and atypical pathology of the appendix on CT: cases with clinical implications

Acute appendicitis is the most common abdominal surgical emergency in the United States with approximately 250,000 cases annually. Computed Tomography (CT) has emerged as the most accurate diagnostic test to triage these patients for emergent surgery. Although the radiology search pattern is prioritized to detect an inflamed appendix, not all appearances equate to a typical surgical appendicitis. There are a select set of atypical pathologies involving the appendix that have subtle differences on CT, but can have catastrophic complications if treated with emergent appendectomy. This paper will review the spectrum of CT appearances and clinical management for typical and atypical appendiceal pathologies.

Minimally Invasive Treatment for Appendiceal Mass Formed After Acute Perforated Appendicitis

The optimal treatment for appendiceal mass formed after appendiceal rupture due to acute appendicitis is surrounded with controversy. The treatment strategy ranges from open surgery (emergency or interval appendectomy), laparoscopic appendectomy, and image-guided drainage, to conservative treatment with or without antibiotics. Nonsurgical treatment (including conservative and drainage treatment), followed by interval appendectomy to prevent recurrence, is the traditional management of these patients. The need for interval appendectomy after a successful conservative or/and image-guided drainage treatment, has recently been questioned as the risk of recurrence is relatively small. Several authors consider that even in cases involving only ambulatory follow-up observation, without interval surgery after conservative management, the recurrence rate and risks of missing underlying pathologies were not high. This article evaluates the minimally invasive treatment modalities in the management of appendiceal mass, risk of undetected serious disease, and the need for interval appendectomy to prevent recurrence.

Diagnostic Efficiency of Multidetector Computed Tomography in the Evaluation of Clinically Equivocal Cases of Acute Appendicitis with Surgical Correlation

Acute appendicitis is one of the most frequent causes of lower abdominal pain and requires immediate surgical intervention. The diagnosis often poses a lot of challenge even to experienced surgeon. Those patients with equivocal symptoms may require different imaging modalities like radiography, contrast examination and ultrasound with limited utility. Multidetector computed tomography (MDCT) used in suspected acute appendicitis has, however, resulted in improved diagnostic accuracy and also reduction of negative surgeries. Objective We intend to determine the diagnostic efficiency of MDCT in clinically equivocal cases of acute appendicitis correlating it with surgical/histopathological findings. Materials and methods A group of 116 patients was included in this study. Spiral MDCT was performed in all these cases after administration of oral and intravenous contrast. All these patients underwent surgery and the CT findings were correlated with histopathology. Out of these 116 patients, 60 patients were male and 56 female. The age range was from three to seventy years and mean age was 28+1 years. Results The results proved that MDCT had a sensitivity of 97.5%, specificity of 97.0%, and accuracy of 97.4% for the diagnosis of appendicitis with one false positive and two false negative cases. The study showed 100% accuracy in diagnosing acute appendicitis in children. In 33 patients, an alternate cause was identified with CT. The alternate diagnosis made on CT findings was consistent with the final diagnosis in 27 (81.8%) of 33 patients in whom there was no evidence of acute appendicitis. The clinical diagnosis disagreed with the CT diagnosis in six patients (18.18%). Conclusion Our study verifies that MDCT plays an important role in evaluation and consequent management of equivocal cases of acute appendicitis. MDCT is also able to diagnose appendicitis or detect alternative diagnosis in pediatric population.

Efficacy of Strain Elastography in Diagnosis and Staging of Acute Appendicitis in Pediatric Patients

Background

In the present study, the role and efficiency of strain elastography (SE) were evaluated in diagnosis and staging of acute appendicitis in pediatric patients.

Material/Methods

We enrolled 225 pediatric patients with suspected clinical and laboratory findings of acute appendicitis. Gray-scale sonographic findings were recorded and staging was made by the colorization method of SE imaging. Appendectomy was performed in all patients and the results of the surgical pathology were compared with the imaging findings. The sensitivity, specificity, and accuracy of SE imaging were determined in terms of evaluating the “acute appendicitis”.

Results

Sonographic evaluation revealed acute appendicitis in 100 patients. Regarding the SE analysis, cases with appendicitis were classified into 3 groups as: mild (n=17), moderate (n=39), and severe (n=44). The pathological evaluation revealed 95 different stages of appendicitis and normal appendix in 5 cases: acute focal (n=10), acute suppurative (n=46), phlegmonous (n=27), and perforated (n=12), regarding the results of surgical pathology. Five patients with pathologically proven “normal” appendix were noted as “mild stage appendicitis” based on gray scale and SE analysis. In total, when gray-scale and SE results were compared with pathology results regardless of the stage of appendicitis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates were 96%, 96%, 95%, 96.8%, and 96%, respectively. No statistically significant difference was detected between other groups (P<0.05).

Conclusions

In acute appendicitis, the use of SE imaging as a supportive method for the clinical approach can be useful in diagnosis, and its results are closely correlated with the histopathologic stage of appendix inflammation.

Acute appendicitis in childhood: oral contrast does not improve CT diagnosis

INTRODUCTION

We compared the diagnostic accuracy of CT performed without and with oral contrast for suspected appendicitis in children.

METHODS

In this retrospective cohort study, we reviewed abdomen/pelvis CT scans with IV contrast performed between 2011 and 2015 for suspected appendicitis. Oral contrast was used routinely before August 2013 and eliminated from the CT protocol thereafter. Diagnostic accuracy of CT was compared with operative/pathology reports, and included a 30-day follow-up period for non-surgical patients. For a secondary analysis, the oral contrast group was subdivided into "complete" (contrast extending into the cecum) or "partial" contrast. We also compared groups for CT turnaround time, the frequency of appendiceal perforation and abscess, and the potential influence of a prior appendix ultrasound.

RESULTS

Five hundred fifty-eight patients were included: 51.6% (n = 288) without oral contrast and 48.4% (n = 270) with oral contrast (of which 52% (n = 140/270) had "complete" contrast). There was no difference in diagnostic accuracy between the oral contrast and non-contrast groups (p = 0.903), with sensitivity/specificity of 93.8% (95% CI 84.8-98.3)/98.5% (CI 95.8-99.7) and 94.6% (CI 84.9-98.9)/98.3% (CI 95.7-99.5), respectively. Similarly, there was no difference in accuracy when comparing only "complete" contrast vs. non-contrast groups (p = 0.755). CT turnaround time for the non-contrast group was significantly faster (43.8 ± 37.6 min), on average, than the oral contrast group (137.4 ± 47.5 min).

CONCLUSION

For children evaluated by CT with IV contrast for suspected appendicitis, administering oral contrast increased wait time by > 90 min, did not reach the cecum in 48% of cases, and did not improve diagnostic accuracy. Oral contrast for pediatric CT appendicitis evaluation is not warranted.

Anatomic Reasons for Failure to Visualize the Appendix With Graded Compression Sonography: Insights From Contemporaneous CT

OBJECTIVE

The purpose of this study is to identify the anatomic locations of appendixes on CT when graded compression sonography fails to visualize the appendix.

MATERIALS AND METHODS

The study included 197 patients with suspected appendicitis whose appendixes were not visualized on graded compression sonography performed with typically used transducers of at least 10 MHz, who underwent CT within 48 hours following graded compression sonography, and who had available either pathologic examination following surgery or 6-week follow-up if surgery was not performed. Appendixes were retrospectively localized using four transverse quadrants (including the posteromedial quadrant) centered on the ileocecal valve and projected vertically, the craniocaudal level relative to the iliac crests, and the depth of the appendix as measured from the surface of the skin. Data were assessed using the Fisher exact test, t test, multinomial test, binomial distribution, ANOVA, and linear regression.

RESULTS

Appendixes were most frequently located in the posteromedial quadrant (123 of 197 patients [62.4%]; 95% CI, 55.3-69.2%) at a statistically significantly greater frequency than that expected by chance (p < 0.00001). Appendixes were located above the iliac crests in 19.8% of patients (39/197; 95% CI, 14.5-26.1%) and at depths exceeding the penetration of typical transducers of at least 10 MHz in 19.3% of patients (38/197; 95% CI, 14.0-25.5%). All appendixes (95% CI, 98.1-100.0%) were located within the range of 6-MHz transducers.

CONCLUSION

Appendixes that are not visualized on graded compression sonography are most frequently located in the posteromedial quadrant and are often located above the iliac crests or at depths too great for visualization with typically used transducers of at least 10 MHz. Accordingly, when the appendix is not visualized on graded compression sonography, targeted scanning of the posteromedial quadrant and the region above the iliac crests, and scanning with 6-MHz transducers, may enable visualization of the appendix and are recommended additions to scanning protocols.

A new technique for the diagnosis of acute appendicitis: abdominal CT with compression to the right lower quadrant

OBJECTIVE

To determine the diagnostic accuracy of abdominal CT with compression to the right lower quadrant (RLQ) in adults with acute appendicitis.

METHODS

168 patients (age range, 18-78 years) were included who underwent contrast-enhanced CT for suspected appendicitis performed either using compression to the RLQ (n = 71) or a standard protocol (n = 97). Outer diameter of the appendix, appendiceal wall thickening, luminal content and associated findings were evaluated in each patient. Kruskal-Wallis, Fisher's and Pearson's chi-squared tests were used for statistical analysis.

RESULTS

There was no significant difference in the mean outer diameter (MOD) between compression CT scans (10.6 ± 1.9 mm) and standard protocol (11.2 ± 2.3 mm) in patients with acute appendicitis (P = 1). MOD was significantly lower in the compression group (5.2 ± 0.8 mm) compared to the standard protocol (6.5 ± 1.1 mm) (P < 0.01) in patients without appendicitis. A cut-off value of 6.75 mm for the outer diameter of the appendix was found to be 100% sensitive in the diagnosis of acute appendicitis for both groups. The specificity was higher for compression CT technique (67.7 vs. 94.9%).

CONCLUSION

Normal appendix diameter was significantly smaller in the compression-CT group compared to standard-CT group, increasing diagnostic accuracy of abdominal compression CT.

KEY POINTS

• Normal appendix diameter is significantly smaller in compression CT. • Compression could force contrast material to flow through the appendiceal lumen. • Compression CT may be a CT counterpart of graded compression US.

The 100 most cited manuscripts in emergency abdominal surgery: A bibliometric analysis

BACKGROUND

The number of citations a scientific article receives provides a good indication of its impact within any given field. This bibliometric analysis aimed to identify the 100 most cited articles in Emergency Abdominal Surgery (EAS), to highlight key areas of interest and identify those that have most significantly shaped contemporary clinical practice in this newly evolving surgical specialty. This is of increasing relevance as concerns grow regarding the variable and suboptimal outcomes in Emergency General Surgery.

MATERIALS AND METHODS

The Thomson Reuters Web of Science database was used to search using the terms [Emergency AND Abdom* AND Surg*] to identify all English language, full manuscripts. Results were ranked according to citation number. The top 100 articles were further analysed by subject, author, journal, year of publication, institution, and country of origin.

RESULTS

The median (range) citation number of the top 100 out of 7433 eligible papers was 131 (1569-97). The most cited paper (by Goldman et al., Massachusetts General Hospital, New England Journal of Medicine; 1569 citations) focused on cardiac risk stratification in non-cardiac surgery. The Journal of Trauma, Injury, Infection and Critical Care published the most papers and received most citations (n = 19; 2954 citations. The majority of papers were published by centres in the USA (n = 52; 9422 citations), followed by the UK (n = 13; 1816 citations). The most common topics of publication concerned abdominal aneurysm management (n = 26) and emergency gastrointestinal surgery (n = 26).

CONCLUSION

Vascular surgery, risk assessment and gastrointestinal surgery were the areas of focus for 59% of the contemporary most cited emergency abdominal surgery manuscripts. By providing the most influential references this work serves as a guide to what makes a citable emergency surgery paper.

Intravenous and Oral Contrast vs Intravenous Contrast Alone Computed Tomography for the Visualization of Appendix and Diagnosis of Appendicitis in Adult Emergency Department Patients

Purpose

The study sought to compare radiologist's ability to 1) visualize the appendix; 2) diagnose acute appendicitis; and 3) diagnose alternative pathologies responsible for acute abdominal pain among adult patients undergoing computed tomography (CT) scan with 3 different protocols: 1) intravenous (IV) contrast only; 2) IV and oral contrast with 1-hour transit time; and 3) IV and oral contrast with 3-hour transit time.

Methods

We collected data of 225 patients; 75 consecutive patients with a clinical suspicion of appendicitis received oral contrast for 3 hours and IV contrast, 75 received oral contrast for 1 hour and IV contrast, and 75 trauma patients received IV contrast only. Three independent reviewers, blinded to final pathology, retrospectively analysed the cases and documented visualization of the appendix, periappendiceal structures, and their confidence in diagnosing appendicitis. Clinical diagnoses were derived from a combination of clinical, surgical, pathologic, or radiologic follow-up.

Results

Frequency of visualizing the appendix within IV group alone was 87.3%, IV with oral for 1 hour was 94.1%, and IV with oral for 3 hours was 93.8%. Both oral contrast groups had 100% sensitivity and negative predictive value in diagnosis of acute appendicitis. Specificity for the 1- and 3-hour oral contrast groups was 94.1% and 96.1%, respectively and positive predictive value for both groups was 92%.

Conclusions

Our findings suggest that reader confidence in visualizing the appendix improved with addition of oral contrast as compared to IV contrast alone. One- and 3-hour oral regimens have a similar diagnostic performance in diagnosing appendicitis.

Acute Appendicitis: The Reliability of Diagnosis by Clinical Assessment Alone

Background and Aims:

This prospective study aimed to review the trustworthiness of the initial clinical assessment in acute appendicitis without employment of imaging modalities, laparoscopy or any other adjunct diagnostic test.

Patients and Methods:

717 patients were operated on for appendicitis by six different surgeons. Initial clinical and laboratory examination were evaluated in relation to the intraoperative and the pathological appreciation of the appendiceal inflammation.

Results:

598 patients were found to have appendicitis, 34 a different condition, 41 had both appendicitis and an additional condition and 44 no pathology. 6% of the laparotomies and 11 % of the appendectomies were unnecessary. The severity of the inflammation correlated significantly with periumbilical pain, pain migrating to right lower quadrant, loss of appetite, fever, rebound tenderness, local rigidity, polymorphonuclear predominance on deferential, polymorhonucleosis and leukocytosis. Leukocytosis was less frequent in aged patients. All the six surgeons were found to be equally reliable, although they all underestimated the setting compared to the pathologists. Patients with a long duration of symptoms had milder forms of inflammation and increased percentage of unanticipated abdominal conditions.

Conclusions:

Appendicitis can be reliably diagnosed clinically without employment of adjunct tests. These can be reserved for equivocal cases.

From esophagus to rectum: a comprehensive review of alimentary tract perforations at computed tomography

Gastrointestinal (GI) tract perforation is a life-threatening condition that can occur at any site along the alimentary tract. Early perforation detection and intervention significantly improves patient outcome. With a high sensitivity for pneumoperitoneum, computed tomography (CT) is widely accepted as the diagnostic modality of choice when a perforated hollow viscus is suspected. While confirming the presence of a perforation is critical, clinical management and surgical technique also depend on localizing the perforation site. CT is accurate in detecting the site of perforation, with segmental bowel wall thickening, focal bowel wall defect, or bubbles of extraluminal gas concentrated in close proximity to the bowel wall shown to be the most specific findings. In this article, we will present the causes for perforation at each site throughout the GI tract and review the patterns that can lead to prospective diagnosis and perforation site localization utilizing CT images of surgically proven cases.

Enteric Distribution of Oral Contrast in Emergency Department Patients Undergoing Abdominal-Pelvic Computed Tomography

PURPOSE

The study sought to assess the gastrointestinal (GI) distribution of oral contrast (OC) among emergency department (ED) patients and determine if contrast reaches the terminal ileum or site of pathology to assist in diagnosis.

METHODS

Retrospectively, adults undergoing abdominal-pelvic computed tomography (APCT) in the ED at 2 hospitals were identified over a 3-month period. APCTs were reviewed for location of OC. Presence, site, type of bowel pathology, and prior gastrointestinal surgery were documented. When applicable, the site of bowel pathology was evaluated for the presence or absence of OC.

RESULTS

There were 1349 exams with mean age 50.5 years (range 18-97 years), 41% male, with 530 (39%) receiving OC. In 271 of 530 (51%), OC reached the terminal ileum (TI). Bowel pathology was present in 31% of cases (165 of 530). When bowel pathology was present, 47% (77 of 165) had OC present at the pathology site. The GI tract was divided into 4 anatomic segments: OC most frequently reached pathology in stomach and duodenum (84%), but was present less frequently at sites of pathology from jejunum to TI (35%), proximal colon (57%), and distal colon (28%). In only 84 of 530 OC cases (16%) did contrast extend from the stomach to distal colon. OC administration contributed to longer mean APCT order to final report of 0.5 hours and longer mean ED length of stay of 0.8 hours compared with all patients who received APCT.

CONCLUSIONS

Optimal OC distribution is not achieved in more than half of ED patients, raising questions about the continued use of OC in the ED.

ACR Appropriateness Criteria® Right Lower Quadrant Pain--Suspected Appendicitis

The most common cause of acute right lower quadrant (RLQ) pain requiring surgery is acute appendicitis (AA). This narrative's focus is on imaging procedures in the diagnosis of AA, with consideration of other diseases causing RLQ pain. In general, Computed Tomography (CT) is the most accurate imaging study for evaluating suspected AA and alternative etiologies of RLQ pain. Data favor intravenous contrast use for CT, but the need for enteric contrast when intravenous contrast is used is not strongly favored. Radiation exposure concerns from CT have led to increased investigation in minimizing CT radiation dose while maintaining diagnostic accuracy and in using algorithms with ultrasound as a first imaging examination followed by CT in inconclusive cases. In children, ultrasound is the preferred initial examination, as it is nearly as accurate as CT for the diagnosis of AA in this population and without ionizing radiation exposure. In pregnant women, ultrasound is preferred initially with MRI as a second imaging examination in inconclusive cases, which is the majority.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The utility of acoustic radiation force impulse imaging in diagnosing acute appendicitis and staging its severity

PURPOSE

The aim of this study was to investigate the feasibility of using acoustic radiation force impulse (ARFI) imaging to diagnose acute appendicitis.

METHODS

Abdominal ultrasonography (US) and ARFI imaging were performed in 53 patients that presented with right lower quadrant pain, and the results were compared with those obtained in 52 healthy subjects. Qualitative evaluation of the patients was conducted by Virtual Touch™ tissue imaging (VTI), while quantitative evaluation was performed by Virtual Touch™ tissue quantification (VTQ) measuring the shear wave velocity (SWV). The severity of appendix inflammation was observed and rated using ARFI imaging in patients diagnosed with acute appendicitis. Alvarado scores were determined for all patients presenting with right lower quadrant pain. All patients diagnosed with appendicitis received appendectomies. The sensitivity and specificity of ARFI imaging relative to US was determined upon confirming the diagnosis of acute appendicitis via histopathological analysis.

RESULTS

The Alvarado score had a sensitivity and specificity of 70.8% and 20%, respectively, in detecting acute appendicitis. Abdominal US had 83.3% sensitivity and 80% specificity, while ARFI imaging had 100% sensitivity and 98% specificity, in diagnosing acute appendicitis. The median SWV value was 1.11 m/s (range, 0.6-1.56 m/s) for healthy appendix and 3.07 m/s (range, 1.37-4.78 m/s) for acute appendicitis.

CONCLUSION

ARFI imaging may be useful in guiding the clinical management of acute appendicitis, by helping its diagnosis and determining the severity of appendix inflammation.

Evaluating the Patient with Right Lower Quadrant Pain

Right lower quadrant pain is one of the most common indications for imaging evaluation of the abdomen in the emergency department setting. This article reviews important imaging findings associated with acute appendicitis as well as major differential considerations including: mesenteric adenitis, Meckel diverticulum, neutropenic colitis, right-sided diverticulitis, epiploic appendagitis, omental infarction, and inflammatory bowel diseaseRight lower quadrant pain is one of the most common indications for imaging evaluation of the abdomen in the emergency department setting. This article reviews important imaging findings associated with acute appendicitis as well as major differential considerations including: mesenteric adenitis, Meckel diverticulum, neutropenic colitis, right-sided diverticulitis, epiploic appendagitis, omental infarction, and inflammatory bowel disease.

Three-step sequential positioning algorithm during sonographic evaluation for appendicitis increases appendiceal visualization rate and reduces CT use

OBJECTIVE

The purpose of this article is to examine the rates of appendiceal visualization by sonography, imaging-based diagnoses of appendicitis, and CT use after appendiceal sonography, before and after the introduction of a sonographic algorithm involving sequential changes in patient positioning.

MATERIALS AND METHODS

We used a search engine to retrospectively identify patients who underwent graded-compression sonography for suspected appendicitis during 6-month periods before (period 1; 419 patients) and after (period 2; 486 patients) implementation of a new three-step positional sonographic algorithm. The new algorithm included initial conventional supine scanning and, as long as the appendix remained nonvisualized, left posterior oblique scanning and then "second-look" supine scanning. Abdominal CT within 7 days after sonography was recorded.

RESULTS

Between periods 1 and 2, appendiceal visualization on sonography increased from 31.0% to 52.5% (p < 0.001), postsonography CT use decreased from 31.3% to 17.7% (p < 0.001), and the proportion of imaging-based diagnoses of appendicitis made by sonography increased from 63.8% to 85.7% (p = 0.002). The incidence of appendicitis diagnosed by imaging (either sonography or CT) remained similar at 16.5% and 17.3%, respectively (p = 0.790). Sensitivity and overall accuracy were 57.8% (95% CI, 44.8-70.1%) and 93.0% (95% CI, 90.1-95.3%), respectively, in period 1 and 76.5% (95% CI, 65.8-85.2%) and 95.4% (95% CI, 93.1-97.1%), respectively, in period 2. Similar findings were observed for adults and children.

CONCLUSION

Implementation of an ultrasound algorithm with sequential positioning significantly improved the appendiceal visualization rate and the proportion of imaging-based diagnoses of appendicitis made by ultrasound, enabling a concomitant decrease in abdominal CT use in both children and adults.

Enteral contrast in the computed tomography diagnosis of appendicitis: comparative effectiveness in a prospective surgical cohort

OBJECTIVE

Our goal was to perform a comparative effectiveness study of intravenous (IV)-only versus IV + enteral contrast in computed tomographic (CT) scans performed for patients undergoing appendectomy across a diverse group of hospitals.

BACKGROUND

Small randomized trials from tertiary centers suggest that enteral contrast does not improve diagnostic performance of CT for suspected appendicitis, but generalizability has not been demonstrated. Eliminating enteral contrast may improve efficiency, patient comfort, and safety.

METHODS

We analyzed data for adult patients who underwent nonelective appendectomy at 56 hospitals over a 2-year period. Data were obtained directly from patient charts by trained abstractors. Multivariate logistic regression was utilized to adjust for potential confounding. The main outcome measure was concordance between final radiology interpretation and final pathology report.

RESULTS

A total of 9047 adults underwent appendectomy and 8089 (89.4%) underwent CT, 54.1% of these with IV contrast only and 28.5% with IV + enteral contrast. Pathology findings correlated with radiographic findings in 90.0% of patients who received IV + enteral contrast and 90.4% of patients scanned with IV contrast alone. Hospitals were categorized as rural or urban and by their teaching status. Regardless of hospital type, there was no difference in concordance between IV-only and IV + enteral contrast. After adjusting for age, sex, comorbid conditions, weight, hospital type, and perforation, odds ratio of concordance for IV + enteral contrast versus IV contrast alone was 0.95 (95% CI: 0.72-1.25).

CONCLUSIONS

Enteral contrast does not improve CT evaluation of appendicitis in patients undergoing appendectomy. These broadly generalizable results from a diverse group of hospitals suggest that enteral contrast can be eliminated in CT scans for suspected appendicitis.

Differentiation of early perforated from nonperforated appendicitis: MDCT findings, MDCT diagnostic performance, and clinical outcome

To determine the CT findings and assess their diagnostic performance in differentiating early perforated appendicitis from nonperforated appendicitis, and to compare therapeutic approaches and clinical outcomes between two types of appendicitis. Our retrospective study was approved by our institutional review board and informed consent was waived. From July 2012 to July 2013, 339 patients [mean age 40.8 years; age range 19-80 years; 183 male (mean age 40.5 years; age range 19-79 years) and 156 female (mean age 41.2 years; age range 19-80 years)] who underwent appendectomy with preoperative CT examination for suspected acute appendicitis were included, with exclusion of 37 patients with specific CT findings for advanced perforated appendicitis. And they were categorized into nonperforated and early perforated appendicitis groups according to surgical and pathologic reports. The following CT findings were evaluated by two radiologists blinded to pathologic and surgical findings: transverse diameter of the appendix, thickness of the appendiceal wall, the depth of intraluminal appendiceal fluid, appendiceal wall enhancement, presence or absence of focal defect in the appendiceal wall, intraluminal appendiceal air, appendicolith/fecalith, periappendiceal changes, cecal wall thickening, and free fluid. The type of surgical procedures, performance of surgical drainage, and the length of hospital stay were recorded. Univariate and multivariate logistic regression analysis were used to determine the CT findings for differentiating early perforated appendicitis from nonperforated appendicitis, a total of 75 (22%) of the 339 patients was diagnosed with early perforated appendicitis. Focal wall defect [adjusted odds ratio (aOR), 23.40; p < 0.001], circumferential periappendiceal changes (aOR, 5.63; p < 0.001), appendicoliths/fecaliths (aOR, 2.47; p = 0.015), and transverse diameter of the appendix (aOR, 1.22; p = 0.003) were independently differentiating variables for early perforated appendicitis. The transverse diameter of the appendix (≥11 mm) had the highest sensitivity (62.7%) and focal wall defect in the appendiceal wall showed the highest specificity (98.8%). The prevalence of surgical drainage was higher (p = 0.001) and the mean hospital stay was approximately one day longer (p < 0.001) in the early perforated group than nonperforated group. CT can be helpful in differentiating early perforated appendicitis from nonperforated appendicitis, although the sensitivity of the evaluated findings was somewhat limited.

Computed tomography: revolutionizing the practice of medicine for 40 years

Computed tomography (CT) has had a profound effect on the practice of medicine. Both the spectrum of clinical applications and the role that CT has played in enhancing the depth of our understanding of disease have been profound. Although almost 90 000 articles on CT have been published in peer-reviewed journals over the past 40 years, fewer than 5% of these have been published in Radiology. Nevertheless, these almost 4000 articles have provided a basis for many important medical advances. By enabling a deepened understanding of anatomy, physiology, and pathology, CT has facilitated key advances in the detection and management of disease. This article celebrates this breadth of scientific discovery and development by examining the impact that CT has had on the diagnosis, characterization, and management of a sampling of major health challenges, including stroke, vascular diseases, cancer, trauma, acute abdominal pain, and diffuse lung diseases, as related to key technical advances in CT and manifested in Radiology.

Can outer-to-outer diameter be used alone in diagnosing appendicitis on 128-slice MDCT?

AIM: To assess the frequency of visualization, position and diameter of normal appendix on 128-slice multidetector computed tomography (MDCT) in adult population.

METHODS: Retrospective cross sectional study conducted at Radiology Department, Dallah Hospital, Riyadh, Saudi Arabia from March 2013 to October 2013. Non-enhanced computed tomography scans of abdomen and pelvis of 98 patients presenting with hematuria (not associated with abdominal pain, fever or colonic disease) were reviewed by two radiologists, blinded to patient history. The study group included 55 females and 43 males with overall mean age of 54.7 years (range 21 to 94 years). The coronal reformatted images were reviewed in addition to the axial images. The frequency of visualization of appendix was recorded with assessment of position, diameter and luminal contents.

RESULTS: The appendix was recorded as definitely visualized in 99% of patients and mean outer-to-outer diameter of the appendix was 5.6 ± 1.3 mm (range 3.0-11.0 mm).

CONCLUSION: MDCT with its multiplanar reformation display is extremely useful for visualization of normal appendix. The normal appendix is very variable in its position and diameter. In the absence of other signs, the diagnosis of acute appendix should not be made solely on outer-to-outer appendiceal diameter.

Important CT findings for prediction of severe appendicitis: involvement of retroperitoneal space

Background

Determination of the severity of appendicitis and differentiation between complicated and uncomplicated appendicitis are clinically important. Severe appendicitis frequently affects extraperitoneal spaces. We have investigated CT findings of retroperitoneal space (RPS) in patients with appendicitis to create a model for identification of complicated appendicitis.

Method

CT images of 223 patients with pathologically proven appendicitis were reviewed. The total number of the segments in RPS where inflammatory changes were located (RPS count) was obtained as well as appendiceal diameter, appendicolithiasis, WBC count, and CRP level. Data were analyzed to identify factors indicating complicated appendicitis. Univariate analysis was conducted to identify statistically significant variables. A multivariable logistic regression analysis was performed in order to find independent predictors of complicated appendicitis.

Results

Patients with complicated appendicitis were more likely to have higher RPS count (P < 0.001), appendicolithiasis (P = 0.002), higher CRP level (P < 0.001), and greater appendix diameter (P < 0.001) than patients with uncomplicated appendicitis. Statistical analysis showed RPS count was the most helpful predictor of complicated appendicitis.

Conclusion

Radiologists and surgeons should be aware of the importance of CT findings in RPS when treating patients with appendicitis. Complicated appendicitis can be predicted by RPS count, diameter of the appendix, appendicolithiasis, and CRP level.

Better visualization of vermiform appendix with tissue harmonic imaging compared to conventional sonography

BACKGROUND

Surgery of appendicitis carries 7-11% negative appendectomy rates. Sonographically visualized normal appendix precludes unnecessary computed tomography (CT) examination and may reduce negative appendectomy rates. Tissue harmonic imaging (THI) has been reported to improve the overall image quality.

OBJECTIVE

We aimed to assess whether THI is more successful than conventional ultrasonography (US) in detecting normal and pathologic appendices.

PATIENTS AND METHODS

The study was performed on 185 patients who applied for routine US examinations in whom clinical findings of appendicitis were detected in 25. We searched for the appendix; applying both THI and conventional US to each patient, one before and the other after the routine US examinations. Patients were divided into two groups; one was evaluated first with conventional US and the other first with THI. When the appendix was found, localization, diameter and time spent for visualization were recorded. Twelve patients were operated; all of whom had appendicitis pathologically. Two methods were compared for: 1. Success rates in all patients; female, male and child groups separately; 2. Visualization of pathologic and normal appendices; 3. Time for visualization of appendix; 4. Comparison of success rates in the adult and child population. The relationship between the rate of visualization and body mass index was evaluated.

RESULTS

The appendix was visualized better by THI in all patients, and in the female and male groups (P < 0.001). In children, both methods were more successful compared to adults (P < 0.001, compared to male group, P < 0.001, compared to female group), with no difference between the methods (P = 0.22). When only the normal appendices were concerned, there was significant difference between both methods (P < 0.000). Both methods detected pathologic appendices better than normal ones, with a higher ratio for THI (P = 0.022 for the THI group, and χ(2) = 7.22, P = 0.07 for the conventional US group). THI visualized the appendix faster. Both methods were more successful in lean patients (P = 0.004 for THI, P = 0.001 for conventional US imaging).

CONCLUSIONS

THI visualizes appendix better than conventional US. It is a simple and time saving method that may eliminate further diagnostic imaging, and it may decrease negative appendectomy rates and related complications.

Cystic fibrosis: unenhanced CT description of the appendix in asymptomatic adults

OBJECTIVE

The purpose of this study was to describe the unenhanced CT appearance of the appendix in adults with cystic fibrosis.

SUBJECTS AND METHODS

Among adults with cystic fibrosis undergoing follow-up at our hospital, 71 patients (35 women, 36 men; mean age, 33 years; range, 18-59 years) without a history of appendectomy or current abdominal pain were prospectively included in this study and underwent unenhanced abdominopelvic MDCT. Two readers coded visualization of the appendix, measured the diameter of the appendix, and described the attenuation of its contents in relation to the intestinal wall. They also coded the presence of colonic wall redundancy, pancreatic fatty replacement, and cirrhosis. Lung transplant status and CFTR gene mutations were recorded. Analysis of variance, linear regression analysis, Student t test, and Pearson test were used.

RESULTS

The appendix was detected in all patients. The mean diameter was recorded as 10.6 ± 3.5 mm. The mean diameter was larger when the appendix contained hyperattenuating material (p = 0.001). There was no association between diameter and the other coded CT findings (p = 0.076-0.466), transplant status (p = 0.788), or CFTR mutation (p = 0.078). In 75% of the patients, the appendix contained hyperattenuating material with a higher proportion in homozygous ΔF508 mutation (p = 0.029) without any significant effect of the other CT features (p = 0.056-0.392), or transplant status (p = 1.000).

CONCLUSION

The appendix is larger in adults with cystic fibrosis than in those without it and appears hyperattenuating at unenhanced CT in 75% of patients, more commonly in those with ΔF508 homozygous mutation.

The normal appendix on CT: does size matter?

PURPOSE

(1) To evaluate the frequency of visualisation and measurements of the normal appendix. (2) To correlate Body Mass Index (BMI) and gender with visualisation of the normal appendix. (3) To correlate age, gender and body length with appendiceal length.

MATERIALS AND METHODS

A retrospective review of 186 patients undergoing abdominal CT without suspicion of acute appendicitis was done. Frequency of visualisation and measurements (including maximal outer diameter, wall thickness, length, content, location of base and tip) of normal appendices were recorded.

RESULTS

Prevalence of appendectomy was 34.4%. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of visualisation of the normal appendix were 76%, 94%, 96%, 67%, and 82% respectively. The mean maximal diameter of the appendix was 8.19 mm±1.6 (SD) (range, 4.2-12.8 mm). The mean length of the appendix was 81.11 mm±28.44 (SD) (range, 7.2-158.8 mm). The mean wall thickness of the appendix was 2.22 mm±0.56 (SD) (range, 1.15-3.85 mm). The most common location of the appendiceal tip was pelvic in 66% appendices. The most common location of the appendiceal base was inferior, medial, and posterior in 37%. The normal appendix contained high-density material in 2.2%. There was a significant correlation between gender and appendiceal length, with men having longer appendices than women.

CONCLUSION

Most normal appendices are seen at multislice CT using i.v. contrast. The maximal outer diameter of the normal appendix overlaps with values currently used to diagnose appendicitis on CT.

Unenhanced CT for the detection of renal cell carcinoma: effect of tumor size and contour type

PURPOSE

To evaluate effect of tumor size and contour type for the detection of renal cell carcinoma (RCC) on unenhanced CT.

METHODS

This retrospective institutional review board approved study that includes 111 patients with RCC and 100 patients without RCC who underwent unenhanced CT. Two readers performed a blinded and independent review of the presence of RCC on unenhanced CT. The area under the receiver operating characteristic curves (AUC) was compared by tumor size (<3 cm: small, or ≥3 cm: large) and contour type (endophytic, mesophytic, or exophytic).

RESULTS

For tumor size, the AUC for small RCC (0.70 and 0.78, for reader 1 and reader 2) was significantly lower than that for large RCC (0.97 and 0.99, for reader 1 and reader 2) (p < 0.001). As for contour type of tumor, the AUC for endophytic RCC (0.60 and 0.71, for reader 1 and reader 2) was significantly lower than that for mesophytic RCC (0.95 and 0.98, for reader 1 and reader 2) and exophytic RCC (0.98 and 0.99, reader 1 and reader 2) (p < 0.001).

CONCLUSION

On unenhanced CT, tumor size and contour type can affect the detection of RCC. While most large or exophytic RCC can be easily detected, the detection of small and endophytic RCC is highly limited.

Improvement in the diagnosis of appendicitis

Our attempts to systematically improve accuracy in the evaluation of patients with suspected appendicitis are, in some ways, hindered by the fact that the condition is so frequently straightforward to diagnose. Careful history-taking and physical examination are reliable in most patients. However, establishing the diagnosis with these skills alone remains vulnerable to conditions that masquerade as acute appendicitis. A substantial body of clinical research over the last quarter-century has shown that improved accuracy is possible. Strategies for improvement include the use of diagnostic scoring systems, laboratory makers such as CRP, diagnostic laparoscopy, and advanced imaging modalities such as CT, MRI, and US. How clinicians use these strategies depends on many factors related to practice setting, the population served, and clinical goals. In children, for instance, the desire to limit exposure to ionizing radiation competes with the greater anatomic detail that a CT scan can provide; at the same time, many hospitals that treat children do not have the resources to maintain the sort of full-time, highly sophisticated abdominal US programs that achieve the highest rates of diagnostic accuracy in clinical studies. Trade-offs have to be made, but improvement is possible in almost all groups of patients: the clinical community should no longer settle for a 15% NA rate when 5% is clearly possible without adverse consequences. Many clinicians will be faced with the task of evaluating patients suspected of having acute appendicitis. A deliberate, proactive, and, ideally, benchmarked strategy for improving diagnosis should be the standard to which we hold ourselves and the promise we deliver to our patients.

Acute appendicitis: investigating an optimal outer appendiceal diameter cut-point in a pediatric population

BACKGROUND

Acute appendicitis is the most common cause of abdominal pain in children requiring operative intervention. Among a number of sonographic criteria to aid in the diagnosis of appendicitis, an outer diameter >6 mm is the most objective and widely accepted. However, there is a lack of evidence-based standards governing this consensus.

STUDY OBJECTIVES

The aim of this study was to determine the outer appendiceal diameter that maximizes sensitivity and specificity in a pediatric population.

METHODS

A retrospective review of all urgent diagnostic ultrasounds (US) was performed over 2 years in children aged <18 years. The diagnostic accuracy of various cut-points was assessed by calculating the sensitivity and specificity and plotting a receiver operating characteristic (ROC) curve.

RESULTS

The study sample consisted of 398 patients in whom the appendix was visualized on US. The median outer appendiceal diameter was significantly higher in the surgical group compared to the nonsurgical group (9.4 mm; range = 8.1-12.0 vs. 5.5 mm; range = 4.4-6.5, p < 0.01). The optimal cut-point with the greatest area under the ROC curve was determined to be an outer appendiceal diameter of 7.0 mm.

CONCLUSIONS

In our patients, adopting a 7-mm rather than a 6-mm appendiceal diameter threshold would balance a greater number of missed cases of acute appendicitis for a reduction in the number of unnecessary surgeries.