CT Evaluation of Appendicitis and Its Complications: Imaging Techniques and Key Diagnostic Findings

Multidetector computed tomography in large bowel lesions-a study of 100 cases

This study aims to evaluate the role of multidetector computed tomography (MDCT) in detecting and classifying the large bowel lesions. A prospective study of 100 adult patients was conducted from June 2007 to October 2009. Rectal and IV contrast were used for three dimensional reconstruction. Angiography was performed in cases of suspected ischemic pathology. CT colongraphy was done to evaluate adenomas. CT findings were correlated and confirmed by either colonoscopy, biopsy, postoperative findings or follow-up CT. The pathologies were common in 50-70 yrs (44%). M: F ratio was 2:1. Malignant lesions were seen in (55%) followed by inflammatory lesions in 26%, diverticulitis and ischemic colitis in 6% each. Miscellaneous conditions like polyps, volvulus and intussusceptions were seen in 7%. Adenocarcinoma was the common malignancy (81.2%). Present study showed that adenocarcinomas were associated with marked thickening of bowel wall (>1.5 cm) in 85.4% of patients, asymmetrical wall thickening (96.4%), focal involvement (length <10 cm) in 85.5% with heterogeneous post contrast enhancement (96.3%). Inflammatory lesions showed mild thickening (69%),segmental or diffuse involvement (77%), symmetrical wall thickening (89%) and homogenous post contrast enhancement (81%). Ischemic lesions showed marked thickening (83.4%), symmetrical thickening (100%) and homogenous enhancement (100%). Diverticulitis showed marked thickening (100%), asymmetrical wall thickening (66.7%) with heterogeneous post contrast enhancement (100%), with pericolic fluid. Arterial/venous thrombosis was diagnosed in 66.66%. Three per cent had benign adenomatous polyps on CT colonographic studies. MDCT was accurate in 98.2% cases for differentiating between benign and malignant etiology and is the modality of choice.

Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis: an open-label, non-inferiority, randomised controlled trial

BACKGROUND

Researchers have suggested that antibiotics could cure acute appendicitis. We assessed the efficacy of amoxicillin plus clavulanic acid by comparison with emergency appendicectomy for treatment of patients with uncomplicated acute appendicitis.

METHODS

In this open-label, non-inferiority, randomised trial, adult patients (aged 18-68 years) with uncomplicated acute appendicitis, as assessed by CT scan, were enrolled at six university hospitals in France. A computer-generated randomisation sequence was used to allocate patients randomly in a 1:1 ratio to receive amoxicillin plus clavulanic acid (3 g per day) for 8-15 days or emergency appendicectomy. The primary endpoint was occurrence of postintervention peritonitis within 30 days of treatment initiation. Non-inferiority was shown if the upper limit of the two-sided 95% CI for the difference in rates was lower than 10 percentage points. Both intention-to-treat and per-protocol analyses were done. This trial is registered with ClinicalTrials.gov, number NCT00135603.

FINDINGS

Of 243 patients randomised, 123 were allocated to the antibiotic group and 120 to the appendicectomy group. Four were excluded from analysis because of early dropout before receiving the intervention, leaving 239 (antibiotic group, 120; appendicectomy group, 119) patients for intention-to-treat analysis. 30-day postintervention peritonitis was significantly more frequent in the antibiotic group (8%, n=9) than in the appendicectomy group (2%, n=2; treatment difference 5·8; 95% CI 0·3-12·1). In the appendicectomy group, despite CT-scan assessment, 21 (18%) of 119 patients were unexpectedly identified at surgery to have complicated appendicitis with peritonitis. In the antibiotic group, 14 (12% [7·1-18·6]) of 120 underwent an appendicectomy during the first 30 days and 30 (29% [21·4-38·9]) of 102 underwent appendicectomy between 1 month and 1 year, 26 of whom had acute appendicitis (recurrence rate 26%; 18·0-34·7).

INTERPRETATION

Amoxicillin plus clavulanic acid was not non-inferior to emergency appendicectomy for treatment of acute appendicitis. Identification of predictive markers on CT scans might enable improved targeting of antibiotic treatment.

FUNDING

French Ministry of Health, Programme Hospitalier de Recherche Clinique 2002.

Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003-2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Diagnosis and Management of Complicated Intra-abdominal Infection in Adults and Children: Guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003–2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Epiploic appendagitis: an entity frequently unknown to clinicians--diagnostic imaging, pitfalls, and look-alikes

OBJECTIVE

Epiploic appendagitis is an ischemic infarction of an epiploic appendage caused by torsion or spontaneous thrombosis of the epiploic appendage central draining vein. When it occurs on the right side of the abdomen, it can mimic appendicitis and right-sided diverticulitis; whereas when it occurs on the left side of the abdomen, it is often mistaken for sigmoid diverticulitis. The purpose of this article is to review the diagnostic imaging of this entity.

CONCLUSION

Epiploic appendagitis is self-limited and spontaneously resolves without surgery within 5-7 days. Therefore, it is imperative for radiologists to be familiar with this entity.

Diagnosis of acute appendicitis with sliding slab ray-sum interpretation of low-dose unenhanced CT and standard-dose i.v. contrast-enhanced CT scans

OBJECTIVE

The purpose of this study was to compare low-dose unenhanced CT with standard-dose i.v. contrast-enhanced CT in the diagnosis of appendicitis.

MATERIALS AND METHODS

Two hundred seven adults with suspected appendicitis underwent CT with mean effective doses of both 4.2 and 8.0 mSv. Two radiologists retrospectively reviewed thin-section images by sliding a 5-mm-thick ray-sum slab. They rated the likelihood of appendicitis and appendiceal visualization on 5- and 3-point scales, respectively, and proposed alternative diagnoses. Likelihood > or = 3 was considered a positive diagnosis. Receiver operating characteristics analysis, the McNemar test, and the Wilcoxon's signed-rank test were used.

RESULTS

Seventy-eight patients had appendicitis. The values of the area under the receiver operating characteristics curve were 0.98 for the low-dose unenhanced acquisition and 0.97 for the standard-dose contrast-enhanced acquisition for reader 1 (95% CI for the difference, -0.02 to 0.03) and 0.99 and 0.98 (-0.02 to 0.02) for reader 2. Sensitivity was 98.7% for low-dose unenhanced CT and 100% for standard-dose contrast-enhanced CT for reader 1 (p = 1.00) and 100% for both techniques for reader 2. Specificity was 95.3% and 93.0% (p = 0.25) and 96.9% and 96.9%. The interpretation was indeterminate (score 3) in 0.5% and 1.4% of cases for reader 1 (p = 0.63) and 0.5% and 0% for reader 2 (p = 1.00). A normal appendix was not visualized in 5.4% and 3.9% of cases by reader 1 (p = 0.63) and 3.9% and 2.3% of cases by reader 2 (p = 0.50). None of the patients whose appendix was not visualized had appendicitis. Diagnostic confidence, visualization score for a normal appendix, and correct alternative diagnosis tended to be compromised with use of low-dose unenhanced CT, showing a significant difference for a reader's confidence in the diagnosis of appendicitis (p = 0.004). The two techniques were comparable in the diagnosis of appendiceal perforation.

CONCLUSION

Low-dose unenhanced CT is potentially useful in the diagnosis of appendicitis.

Noncontrast and contrast enhanced computed tomography for diagnosing acute appendicitis: A retrospective study for the usefulness

Abdominal computed tomography (CT) provides great benefits for the differential diagnosis in patients complaining of acute abdominal pain. However, the use of diagnostic X-rays is associated with the cumulative risk of cancer development. In order to determine the relative usefulness of noncontrast and enhanced CT with intravenous contrast material for diagnosing acute appendicitis, the retrospective analysis was performed using 247 patients (46 children and 201 adults) with clinically suspected appendicitis, who were admitted to our hospital from 2002 to 2006 and underwent noncontrast or combined noncontrast and enhanced CT examination. Of 185 patients who were diagnosed to have acute appendicitis with appendiceal thickening (167 cases) or normal-sized appendix (18 cases), 73 cases underwent noncontrast CT alone and these 73 cases could be retrospectively diagnosed to have appendicitis on noncontrast CT. On the other hand, 112 cases of these 185 patients underwent noncontrast CT followed by enhanced CT, and vermiform appendix was detected in 86 cases of them (86/112, 76.8%) on noncontrast CT. These 86 cases could be retrospectively diagnosed to have acute appendicitis on noncontrast CT, whereas enhanced CT was required to detect vermiform appendix and to obtain the final diagnosis of appendicitis in the remaining 26 cases (26/112, 23.2%). Enhanced CT was superior to noncontrast CT in diagnosing appendicitis in all age and any gender groups. We suggest that enhanced, but not noncontrast, CT should be primarily performed for diagnosing acute appendicitis in all patients to minimize the radiation exposure unless intravenous administration of contrast material is contraindicated.

Infection of a malignant appendiceal mucocele masquerading as an appendiceal abscess: role of preoperative sonography and CT

We report the case of a 71-year-old lady with a suspected appendiceal abscess in whom preoperative sonography and CT demonstrated an infected appendiceal mucocele. The lesion was surgically removed and final pathologic examination revealed malignancy. Correct recognition of the mucocele prevented a potentially disastrous percutaneous drainage.

Identification of the normal appendix in healthy adults by 64-slice MDCT: the value of adding coronal reformation images

The aim of this study was to assess retrospectively the value of adding coronal reformation images to the identification of the normal appendix using 64-slice multidetector CT (MDCT). 200 consecutive healthy adults with no history of abdominal surgery underwent abdominal CT using 64-slice MDCT without oral contrast administration and were enrolled in the study. Two gastrointestinal radiologists first interpreted the axial images only; after a 2-week interval, they then interpreted both the axial and the coronal images while blinded to the first interpretation. The identification of the normal appendix was interpreted using a four-point scale: 1, not identified; 2, identified with low confidence; 3, probably identified; 4, definitely identified. Agreement between the readers was determined with the use of weighted kappa statistics. Differences in confidence ratings for identification of the appendix were determined with the Wilcoxon signed rank test. The agreement between the readers was higher when both axial and coronal images were reviewed (kappa = 0.85) than when only the axial scans images were reviewed (kappa = 0.43). The mean confidence scores for the identification of the normal appendix by the two readers were significantly higher when both the axial and coronal images were reviewed (mean, 3.81+/-0.498 and 3.83+/-0.485 for the two readers, respectively) than when only the axial images were reviewed (mean, 3.27+/-0.819 and 3.47+/-0.856, respectively) (all p<0.01). Therefore, adding coronal reformation images to 64-slice MDCT significantly improves inter-reader agreement and confidence in the identification of the normal appendix.

Subhepatically located appendicitis due to adhesions: a case report

INTRODUCTION

Acute appendicitis occurs frequently and is a major indication for acute abdominal surgery. Subhepatic appendicitis has rarely been reported and is more difficult to diagnose.

CASE PRESENTATION

A 71-year-old man with multiple medical comorbidities presented with undifferentiated right abdominal pain. Diagnostic difficulty was encountered due to subhepatic mal-location of the appendix and subsequently atypical presentation for acute appendicitis.

CONCLUSION

Subhepatic anatomical location of the appendix makes it more difficult to diagnose acute appendicitis at any age, including in older adults.

Evaluation of optimized inversion-recovery fat-suppression techniques for T2-weighted abdominal MR imaging

PURPOSE

To test the theoretical benefits of a spectral attenuated inversion-recovery (SPAIR) fat-suppression (FS) technique in clinical abdominal MRI by comparison to conventional inversion-recovery (IR) FS combined with T2-weighted (T2W) partial Fourier single shot fast spin echo (SSFSE).

MATERIALS AND METHODS

1.5T MRI studies of the abdomen were performed in 28 patients with liver lesions (hemangiomas n = 14; metastases n = 14). T2W sequences were acquired using IR and SPAIR SSFSE. Measurements included retroperitoneal and mesenteric fat signal-to-noise (SNR) to evaluate FS; liver lesion contrast-to-noise (CNR) to evaluate bulk water signal recovery effects; and bowel wall delineation to evaluate susceptibility and physiological motion effects.

RESULTS

SPAIR-SSFSE images produce significantly improved FS and liver lesion CNR. The mean SNR of the retroperitoneal and mesenteric fat for SPAIR SSFSE was 20.5 +/- 10.2 (+/-1 SD) and 12.7 +/- 6.2, compared to 43.2 +/- 24.1 (P = 0.000006) and 29.3 +/- 16.8 (P = 0.0000005) for IR-SSFSE. SPAIR-SSFSE images produced higher CNR for both hemangiomas CNR = 164 +/- 88 vs. 126 +/- 83 (P = 0.00005) and metastases CNR = 75 +/- 27 vs. 53 +/- 19 (P = 0.007). Bowel wall visualization was significantly improved using SPAIR-SSFSE (P = 0.002).

CONCLUSION

The theoretical benefits of SPAIR over conventional IR FS translate into significant multiple improvements that can be measured on clinical abdominal MRI scans.

The ectopic appendicolith from perforated appendicitis as a cause of tubo-ovarian abscess

Acute appendicitis is a common surgical cause of abdominal pain in the pediatric population. History and physical examination are atypical in up to a third of patients. Known potential complications of untreated or delayed management of acute appendicitis include appendiceal perforation, periappendiceal abscess formation, peritonitis, bowel obstruction and rarely septic thrombosis of mesenteric vessels. We report an unusual complication of perforated appendicitis. A tubo-ovarian abscess developed secondary to appendicolith migration into the right fallopian tube in a patient who had undergone interval laparoscopic appendectomy for perforated appendicitis. The retained appendicolith was visualized within the obstructed and dilated fallopian tube on contrast-enhanced CT. We discuss the CT imaging features of this unusual complication of perforated appendicitis.

Acute appendicitis--a benign disease?

INTRODUCTION

Appendicitis is the most common cause of the acute abdomen and can affect all age groups. Most patients recover quickly but a minority can suffer postoperative complications. This case-note review was undertaken to assess the frequency of these complications.

PATIENTS AND METHODS

Adult patients (> 16 years) undergoing an emergency appendicectomy at a University teaching hospital between February 2004 and January 2005 were identified from pathology records. Details of operative procedure, histology and postoperative complications were noted from the hospital case notes

RESULTS

A total of 199 patients with a median age of 31 years (range, 16-89 years) were identified. Of these, 58 (29%) patients experienced a postoperative complication. Eight (4%) patients were admitted to the surgical high dependency unit or intensive care unit postoperatively and there was one death (0.5%). Re-operation for a postoperative complication was required in 9 (4.5%) patients and there was a 13% re-admission rate (26 patients). Comparison between patients with histologically proven appendicitis (164 patients; 82%) and those patients having a negative appendicectomy (35 patients; 18%) showed no significant difference in the rate of complications as defined (43 of 164, 26% versus 15 of 35, 43%; P = 0.08). However, patients with positive histology were more likely to experience a septic complication (29 of 164, 18% versus 1 of 35, 3%; P = 0.028) and all re-operations came from this group. Despite this, patients with a negative appendicectomy were more likely to be re-admitted (12 of 35, 34% versus 14 of 164, 8.5%; P = 0.0002), predominantly with persistent abdominal pain.

CONCLUSIONS

Appendicectomy is associated with a significant morbidity. Patients with an inflamed appendix were more likely to experience a septic complication but re-admission was more common in patients with a histologically normal appendix because of unresolved abdominal pain.

Torsion of vermiform appendix with fecalith: a case report

Introduction

Torsion of the vermiform appendix is a rare disorder, which causes abdominal symptoms indistinguishable from acute appendicitis and is found by chance during the laparotomy.

Case presentation

We report a case (a 76-year-old male) suffering of torsion of the vermiform appendix with fecalith. It was twisted 540 degrees in an anti-clockwise direction. Appendectomy was done.

Conclusion

Appendiceal torsion may be assocated with the presence of fecalith. This case is the oldest one among the patients with appendiceal torsion reported to literature.

Bowel wall thickening in children: CT findings

A wide variety of bowel diseases, some of which are unique to or more prevalent in pediatric patients, may manifest with intestinal wall thickening at computed tomography (CT). Common causes of bowel wall thickening include edema, hemorrhage, infection, graft-versus-host disease, and inflammatory bowel disease; more unusual causes include immunodeficiencies, lymphoma, hemangioma, pseudotumor, and Langerhans cell histiocytosis. Radiologists must be familiar with the CT signs of bowel disease and should take careful note of the bowel characteristics (eg, extent and distribution of disease involvement, bowel dilatation, mural stratification, perienteric findings) to generate an adequate differential diagnosis. The study should be tailored and optimized in advance according to the clinical scenario to decrease radiation exposure due to repeated or delayed scanning. With spiral CT scanners, studies can be performed quickly, thereby eliminating the need for sedation, and multiple reconstructed images can be generated. CT is an invaluable diagnostic tool in the evaluation of pediatric diseases involving the bowel, in spite of the use of ionizing radiation.

Added diagnostic value of multiplanar reformation of multidetector CT data in patients with suspected appendicitis

Computed tomography (CT) is an accurate and effective modality for the diagnosis and staging of appendicitis. CT provides rapid and complete evaluation of patients with suspected appendicitis and clearly demonstrates the typical findings of appendicitis, including a distended appendix, periappendiceal fat stranding, an appendicolith, and focal thickening of the cecum. Identification of an inflamed appendix at CT may be difficult in certain patients (eg, patients with scanty intraabdominal fat, an unusual location of the cecum and appendix, prominent cecal wall thickening and pericecal fat stranding, small bowel dilatation, or abscess formation adjacent to the right adnexa). In such cases, multiplanar reformation (MPR) of multidetector CT data may provide improved appendiceal visualization and increase the physician's confidence in diagnosing appendicitis. Moreover, the use of MPR in addition to conventional CT may provide improved visualization of the normal appendix and thereby enhance confidence in excluding appendicitis and diagnosing diseases that mimic appendicitis. Consequently, the radiologist should obtain MPR images in the evaluation of patients with suspected appendicitis to help ensure the correct diagnosis.

Computed tomography evaluation of the normal appendix: comparison of low-dose and standard-dose unenhanced helical computed tomography

OBJECTIVE

To determine the visualization rate of the normal appendix on low- and standard-dose unenhanced computed tomography (CT) and to evaluate the variables that may influence the identification of the appendix.

METHODS

The study population was derived from the previous study, approved by the internal review board, investigating the effectiveness of low-dose CT (LDCT) in diagnosis of urolithiasis. Sixty-eight patients presenting with acute flank pain underwent 2 unenhanced dual-slice CT examinations. Standard-dose CT (SDCT) scans were obtained using 2 x 5-mm collimation, 120 kVp, and 170 effective mAs and followed by LDCT using 30 or 50 effective mAs. Two independent board-certified radiologists retrospectively recorded the visualization, outer diameter, and the wall thickness of normal appendices. The diameters, circumference, and cross-sectional area of the abdomen were measured.

RESULTS

The prevalence of appendectomy was 8.8% (6 of 68 patients). The means of the 2 reviewers' sensitivity, specificity, positive and negative predictive values, and accuracy for visualization of normal appendix at SDCT versus LDCT respectively were 78% versus 73%, 100% versus 92%, 100% versus 99%, 31% versus 24%, and 80% versus 74% (P = 0.39-0.75). The interobserver agreement was good at both SDCT (kappa = 0.61) and LDCT (kappa = 0.74). Overall 40% to 58% of appendices at LDCT and 33% to 47% at SDCT was larger than 6 mm. There was no significant correlation in the appendix visualization neither with abdominal dimensions nor with visceral or pericecal fat at both dose sets. The calculated mean effective radiation dose at LDCT was 70% to 82% less than SDCT.

CONCLUSIONS

Low- and standard-dose nonenhanced helical CT can visualize a normal appendix with high accuracy and good interobserver agreement. The diameter of normal appendix overlaps with that of appendicitis at CT. A diameter of 10.0 mm should be considered as the upper limit of normal in the absence of any other CT signs of appendicitis.

Imagem radiográfica de acúmulo fecal no ceco, como sinal diagnóstico de apendicite aguda

OBJETIVO: Apesar de os achados radiográficos de apendicite aguda serem bem documentados, o valor da radiografia simples ainda não foi completamente determinado. O objetivo do presente estudo foi estabelecer a freqüência da associação de apendicite aguda a um sinal radiográfico caracterizado por imagem de acúmulo fecal ocupando todo o ceco. MATERIAIS E MÉTODOS: Foram realizadas radiografias simples de abdome de 100 pacientes consecutivos com apendicite aguda, comprovada por operação e exame anatomopatológico. Pesquisou-se, nas radiografias, a presença de imagem de acúmulo fecal no ceco, caracterizada por hipotransparência ocupando todo o ceco e, eventualmente, também o cólon ascendente. RESULTADOS: A imagem de acúmulo fecal no ceco foi encontrada em 97% dos doentes, independentemente de idade, sexo, cor da pele ou estádio da apendicite. CONCLUSÃO: Este estudo sugere que a presença de imagem radiográfica de acúmulo fecal no ceco pode ser um sinal útil no diagnóstico de apendicite aguda.

A retrospective study of CT findings in cases undergoing appendectomy at a single hospital

The purpose of this study was to determine which clinical information or computed tomography (CT) features can distinguish perforated from nonperforated appendicitis. We collected data from 102 patients (62 men, 40 women; mean age, 49.6 years; age range, 16-85 years) who presented to the emergency department with acute abdominal pain or suspicion of acute appendicitis and underwent appendectomy. In the clinical information, there was no significant factor to predict appendiceal perforation. As for CT features, significant imaging factors for predicting appendiceal perforation included abscess, phlegmon, and thickening of lateroconal fascia. The treatment strategy of acute appendicitis varies according to the integrity of the appendiceal wall. Besides clinical findings, CT features can distinguish perforated from nonperforated appendicitis, facilitating proper decision making in ER.

Direct visualization of perforation sites in patients with a non-traumatic free pneumoperitoneum: added diagnostic value of thin transverse slices and coronal and sagittal reformations for multi-detector CT

The incremental diagnostic value of adding 1.25-mm slices and coronal and sagittal reformatting to 5-mm axial reconstructions for direct visualization of the perforation site in patients with non-traumatic free pneumoperitoneum was assessed. Forty patients with non-traumatic bowel perforation and free pneumoperitoneum underwent computed tomography (CT). The perforation was gastroduodenal in 18 patients and involved the small or large bowel in 22 patients. Transverse scans were reconstructed with 5-mm thick sections at 5-mm intervals and 1.25-mm-thick sections at 1.25-mm intervals. The second data set was reformatted coronally and sagittaly with 3-mm-thick sections at 3-mm intervals. Three independent blinded readers interpreted 5-mm transverse scans, then combined 1.25-mm and 5-mm-transverse scans, and then combined transverse, coronal and sagittal scans. The rate of identification of the perforation site ranged from 43% to 53% with the combined axial, sagittal and coronal scans, from 28% to 48% with the 1.25- and 5-mm transverse scans, and from 5% to 20% only with the 5-mm thick transverse scans. The agreement between readers was significantly higher with thin slices and reformatting. The use of 1.25-mm axial slices and reformations intrinsically contained more useful diagnostic information than 5-mm axial slices alone for diagnosis of the perforation site in patients with pneumoperitoneum.

Length of Stay by Route of Contrast Administration for Diagnosis of Appendicitis by Computed-tomography Scan

OBJECTIVES

Studies show equivalent accuracy of abdominal computed tomography (CT) using rectal contrast compared with oral contrast for diagnosing appendicitis. The authors evaluated whether emergency department (ED) length of stay and satisfaction differed by route of contrast administration for abdominal CT.

METHODS

This before-and-after intervention evaluated adult patients in an urban academic ED who were undergoing abdominal CT to screen for suspected appendicitis. Phase 1 subjects had a CT after oral contrast. Phase 2 patients had a CT after rectal contrast infused by gravity drip. Patients were interviewed after CT scan to assess satisfaction and discomfort. The primary outcome was ED length of stay. Medians, 95% binomial confidence intervals (CI), and Wilcoxon rank sum test of differences were calculated.

RESULTS

One hundred twelve patients were enrolled; half received rectal contrast. There was a significant decrease in length of stay for patients who were administered rectal contrast (261 min, 95% CI = 236 to 305 min) vs. oral contrast (332 min, 95% CI = 299 to 362 min), p = 0.009. Although subjects in the rectal-contrast group waited 65 minutes longer than did oral-contrast patients before receiving contrast after the CT order, the time from contrast administration to CT was 13 minutes, vs. 150 minutes for patients receiving oral contrast (p < 0.001). Patient satisfaction and discomfort did not differ by route of contrast administration.

CONCLUSIONS

Rectal contrast for patients undergoing abdominal CT to rule out appendicitis reduced ED length of stay by more than an hour and did not affect patient satisfaction or discomfort. Rectal-contrast administration for abdominal CT may significantly shorten patient throughput time for individuals undergoing evaluation for appendicitis.