CT evaluation of the acute abdomen: bowel pathology spectrum of disease

CT has become the primary imaging modality for the evaluation of the patient with clinical symptoms of an acute abdomen and a confusing clinical picture. Because these patients may have a range of various pathologies, CT has been used successfully to define the presence of disease and localize it to a specific organ or organ system. In this article, we review the various processes that resulted in acute abdomen focusing on the small bowel and colon. Specific entities discussed include appendicitis, diverticulitis, Crohn disease, and ulcerative colitis. Other less common processes, including pseudomembranous colitis, intussusception, and bowel ischemia are also discussed. The specific role of CT scanning and specific CT signs are discussed and addressed. The value of CT in relationship to other modalities and clinical evaluation is discussed and key statistics provided.

Colouterine fistula: computed tomography and vaginography findings

Colouterine fistulas are difficult to demonstrate radiologically. The authors present a case in which such a fistula was observed with computed tomography and confirmed by vaginography.

Septic thrombophlebitis of the inferior mesenteric vein associated with diverticulitis CT diagnosis

Septic thrombophlebitis of a mesenteric vein can occur as a rare complication of diverticulitis. We report a case of septic thrombophlebitis of the inferior mesenteric vein diagnosed with computed tomography, in a patient with sigmoid diverticulitis.

[Contribution of Doppler sonography in inflammatory pathology of the large bowels]

At the end of the eighties, Doppler equipment added to conventional ultrasonography a new dynamic dimension. On the basis of radiological (US, CT, barium studies), clinical, biological, surgical and/or pathological correlations in 30 cases, the following considerations were emphasized. In case of intestinal obstruction, viability of the obstructed segment is compromised when Doppler parietal flow remains undetectable. In Crohn's disease or ulcerative colitis, as well as in acute appendicitis, presence of Doppler parietal flow throughout the affected thickened segment indicates an acute condition; similarly, abnormally high mean portal velocity (30-48 cm/sec; normal: 15 +/- 7 cm/sec), and abnormally low resistive index in the superior mesenteric artery (0.58-0.78; normal: 0.908 = 0.026) are detected. In colonic diverticulitis, similar characteristics can be observed, but are subtle and usually predominant at the mesenteric side of the affected segment in moderate diverticulitis. These abnormal Doppler findings disappear with successful therapy.

[The computed tomography of acute sigmoid diverticulitis]

PURPOSE

To study the ranking of CT in the diagnosis of sigma diverticulitis. Comparison of results of the colon monocontrast enema with those obtained via CT and histopathology as gold standard.

MATERIAL AND METHODS

32 patients were included who were operated on for sigma diverticulitis. In 30 patients both CT and monocontrast enema were performed and in two patients CT only.

RESULTS

Acute inflammatory wall alterations are identified by CT with a sensitivity of 89.7% vs 96.3% via contrast enema. Pericolic reactions of the environment were seen via CT with 89.7% sensitivity. In case of covered perforations CT yielded a sensitivity of 76.5% vs 46.7% via contrast enema. Sensitivity for abscesses and fistulas was in each case 100% with CT.

RESULTS

CT may help to identify extraluminal inflammatory changes and complications in diverticulitis. The degree of the inflammation can be classified and the surgical approach suitably influenced, respectively modified.

Diagnosis of acute flank pain: value of unenhanced helical CT

OBJECTIVES

The purpose of our study was to determine the value of unenhanced CT in the diagnosis of acute flank pain. We determined the accuracy of unenhanced Ct for stone detection as well as the detection of abnormalities unrelated to stone disease.

MATERIALS AND METHODS

During an 18-month interval, 292 patients with acute flank pain were imaged with unenhanced CT. Confirmation of the CT diagnosis was obtained for 210 patients: One hundred patients were proved to have ureteral stones based on other imaging studies (58 patients), lithotripsy (seven patients), ureteroscopic stone extraction (five patients), and stone recovery (30 patients). One hundred ten patients were proved not to have ureteral stones based on other imaging studies (24 patients), failure to recover a stone (56 patients), or a confirmed diagnosis unrelated to stone disease (30 patients). This latter group of 30 patients included diagnoses of adnexal masses (eight patients), appendicitis (five patients), diverticulitis (four patients), and common bile duct stones (three patients), as well as other diagnoses.

RESULTS

Unenhanced CT findings were falsely negative for stone disease in three patients and falsely positive for stone disease in four patients. These data yield a sensitivity of 97%, a specificity of 96%, and an accuracy of 97% for diagnosing ureteral stone disease. Of 31 patients with a CT abnormality unrelated to stone disease, there was one false-negative diagnosis of acute appendicitis.

CONCLUSION

Unenhanced CT is a valuable technique for examining patients with acute flank pain in whom a clinical diagnosis is uncertain. It can accurately determine the presence or absence of ureteral stones as well as extraurinary causes of acute flank pain. In most cases, other imaging studies are not required.

[Effect of intestinal ultrasound on choice of surgical procedure in acute abdominal pain]

Differential diagnosis in patients with acute abdominal pain represents a difficult assignment in surgery involving the indication for urgent operation and the operation technique.

AIM

The value of sonography in diseases of the bowels for correct indication for early laparotomy was investigated.

METHOD

In a retrospective analysis we compared the result of sonography on 159 patients with acute abdominal pain with the first clinical assessment.

RESULTS

The sensitivity of this technique was found to be 38.9% for acute appendicitis, 57.1% for diverticulitis and 76.9% for obstructive ileus. The specificity ranged above 90% in each case. In consideration of more than two sonomorphological criterias for pathological alterations of the intestines the positive predictive value achieved 100%.

CONCLUSION

Low diagnostic sensitivity with high specificity implies the necessity to intensity routine ultrasonic investigation of the gut.

Technetium-99m-pyrophosphate scintigraphic findings of intestinal perforation in dermatomyositis

Gastrointestinal complications are more common in children than in adults and present a serious problem with dermatomyositis. We report on a 66-yr-old man with dermatomyositis who suffered from intestinal perforation. The abdominal plain radiograph revealed only dilatation of the intestinal loops; increased radioactivity, however, was clearly demonstrated in the early 5-min and delayed 3-hr 99mTc-pyrophosphate images.

A combined flexible sigmoidoscopy and double-contrast barium enema service: initial experience

BACKGROUND

A service has been instituted offering a combined single-stage procedure of flexible sigmoidoscopy and double-contrast barium enema (FS/DCBE). The results have been reviewed in the first 80 patients to undergo this examination (45 male: 35 female; mean age 61.4 years).

METHODS

Indications for investigation were abdominal pain or suspected diverticular disease (22 patients), altered bowel habit (19), rectal bleeding (17), iron deficiency anemia (6), and miscellaneous (16). FS was followed immediately by DCBE. Radiographs were reviewed by two radiologists unaware of the FS findings.

RESULTS

The extent of FS was to the proximal sigmoid or sigmoid descending colon or splenic flexure in 12.5%, and mid or distal sigmoid in 37.5%. Biopsies were performed at FS in 26 patients (33%). In 67 (84%) of DCBEs the barium coating was assessed as satisfactory or better. FS yielded pathological findings not seen at DCBE in 21 patients (26%). DCBE demonstrated additional abnormalities within the range of the FS examination in 15 patients (19%), almost entirely due to its increased sensitivity for diverticular disease.

CONCLUSION

FS/DCBE is feasible as a one-stage combined procedure. The quality of DCBE following FS is satisfactory, and the extra yield of FS and its potential for biopsy make the combined FS/DCBE a useful technique in the investigation of large bowel disease.

Transvaginal sonographic diagnosis of sigmoid diverticulitis

The development of the transvaginal technique has allowed for high-resolution, detailed evaluation of the female pelvis. Although not previously emphasized, gut pathology can also be recognized with this technique. We report two cases of sigmoid diverticulitis which were prospectively diagnosed using endovaginal sonography. In both patients, pelvic sonogram was the first imaging study performed for evaluation of nonspecific abdominal pain.

[Radiological and endoscopic diagnosis of sigmoid diverticulitis]

In emergency, the most commonly used examination, other than plain radiographs of the abdomen, is the water-soluble contrast enema (Gastrografin). It demonstrates three different pictures, which may be more or less associated one to the other: "peridiverticulitis", featuring serrate lesions, abnormal stiffness and fixity and, in some cases, a long narrowing or stricture of the colon; diverticula, mainly in the sigmoid colon, becoming sharp-pointed or spark-liked; spillage of contrast material out of the colic lumen or into a neighbouring organ (fistula). Ultrasonography may be a useful emergency procedure to secure a hesitating diagnosis in a patient with a febrile abdominal pain or with a abdominal-pelvic mass, especially in women. Colonoscopy and barium enema are both usually contra-indicated in the acute setting of diverticulitis because of their potential hazards. On the other hand, after resolution of the acute event, these tests may allow to rule out carcinoma or associated adenomas (which coexist in more than 15% of the patients). Endoscopic control appears more especially important as initial accurate diagnosis in sometimes impossible to assess between adenocarcinoma and diverticulitis. CT scan has found an increasing place in both diagnosis and evaluation of infectious complications of diverticular disease. It is most recommended to assess the diagnosis of severe episodes, failing to clearly improve after medical treatment, and most particularly when an abscess in suspected. CT scan may demonstrate a thickening of the colic wall, high densities of pericolic fat and a tissular mass which may enclose gas bubbles.

CT of inflammatory disease of the colon

CT plays an important role in the evaluation of patients with suspected colonic inflammation. High-resolution, thin-section imaging of the gastrointestinal tract allows assessment of both the intraluminal and extraluminal components of colonic disease, thereby enabling radiologists to detect and stage colonic pathology accurately. In addition, CT can be used to guide percutaneous drainage of abscess collections, often obviating the need for surgical intervention. This article describes CT techniques for diagnosing inflammatory diseases of the colon as well as the typical CT appearances.

[Hydrocolonic sonography in the study of colonic diseases. Comparison with double-contrast enema]

This study was aimed at assessing the diagnostic value of hydrocolonic sonography (HS), a new technique of US examination of the colon during water enema, in colonic diseases. HS was performed on 120 clinically selected patients and was followed by double contrast barium enema (DCBE) in all patients, by endoscopy in 85, by pathology in 50 and by surgery in 36 patients. We obtained good quality images in 86% of cases, middle quality findings in 10% and poor results in 4% of cases. HS allowed the 5 layers of the colonic wall to be visualized. Forty of 50 polyps bigger than 1 cm, 9/10 cases of granulomatous colitis and diverticulitis were recognized and distinguished from cancer and 31/32 carcinomas were found--3 of them were locally invasive tumors, even though endoscopic biopsy had diagnosed them as adenomas. Compared with DCBE, HS exhibited lower sensitivity in recognizing small polyps (80% vs. 92%) but higher specificity (100% vs. 92.8%); in the diagnosis of carcinoma, HS exhibited higher sensitivity (96.8% vs. 90.6%) and the same specificity (about 100%); the depiction of parietal layers allowed also tumor staging. At present, HS cannot be proposed as the examination of choice to study polyps because of its limitations in recognizing them; nevertheless, HS appears to exhibit some advantages over DCBE in tumor detection and staging. HS is a simple, fast and safe technique which is well tolerated and easily repeatable, which calls for further investigation of its potentials, also because improved operator's experience is sure to increase HS reliability.

Serial assessment of adnexal masses with transvaginal color Doppler sonography

Transvaginal color Doppler sonography (TV-CDS) was performed on 64 women with adnexal masses at 3, 6 and 12 weeks after initial presentation. In 47 (72% of patients studied), the pelvic mass demonstrated a decrease in size and increase in pulsatility index (PI) after 12 weeks. Of the patients undergoing surgery in this group, one had a tubo-ovarian abscess, one diverticular abscess and one hydrosalpinx. In seven patients (10%), there was no change in size or PI. Three in this group had an endometrioma, whereas two had a peritoneal cyst. In five (7%), there was no change in size and an increase in PI. One of these patients had a mucinous cystadenoma. In three (5%), there was a decrease in size and PI. Two of these patients had a tubo-ovarian abscess. In two (3%) patients studied, the mass showed an increase in size and decrease in PI; both had corpora luteum cysts with acute hemorrhage. Seventy-two percent of masses with high impedance underwent regression, whereas only 21% of lesions with low impedance did. Only 20% of masses demonstrating low impedance or morphologically complex structure regressed. Sixty-five percent of lesions that regressed had a significant drop in PI, whereas all the lesions that showed no change in size or enlargement had either no change or decrease in PI. Probability of regression was the greatest in young women (less than 40 years of age) and in masses < 5 cm. Ninety-three percent of women with persistent masses that underwent progestational suppression demonstrated regression with decrease of PI and peak systolic velocity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Diagnosis of acute colonic diverticulitis: comparison with echography and tomodensitometry]

The sensitivity of ultrasonography (US) as the initial imaging procedure in acute diverticulitis of the left colon was retrospectively compared with that of computed tomography (CT) in 34 patients. Final diagnosis was based on clinical findings and follow-up in a first group of 20 patients with mild diverticulitis, and was proved by surgery in a second group of 14 patients with severe diverticulitis. In the first group, US showed findings consistent with diverticulitis in 19 patients, as did CT. The image of an inflamed diverticulum was shown by US in 10 patients. In the surgical group, findings consistent with diverticulitis were shown by US in 11 cases, and by CT in 13 cases. An inflamed diverticulum was not detected at US in this group of patients, presumably because the diverticulum was incorporated in the inflammatory process. These results suggest that US is a valuable technique in the initial evaluation of patients suspected of having acute diverticulitis, especially when the disease is not severe. The image of an inflamed diverticulum shown at US strongly suggests the diagnosis of mild diverticular disease. When diverticulitis is severe, CT should be performed in addition to US.

[Ultrasonography of acute diverticulitis of the colon]

Ultrasonographic findings in two patients with acute diverticulitis of the left colon are described. Echographic identification of diverticula and thickened (> 4 mm) hypoechoic bowel wall were common findings. The final diagnosis was confirmed by contrast enema and colonoscopy. Patients had clinical signs and symptoms of acute diverticulitis. Diverticula were visualized as echogenic shadowing foci in thickened bowel wall (1 case) or as outpouches of the intestinal wall in the pericolonic soft tissues (1 case). One patient had edema of the pericolic fat. Additional studies are needed to confirm the usefulness of ultrasounds in the diagnosis of colonic diverticulitis.

CT of appendicitis and diverticulitis

CT scans have made a significant impact on the diagnosis and staging of those gastrointestinal disorders that are associated with perienteric inflammatory extension. Appendicitis and diverticulitis are examples of such diseases, and this article reviews the current role of CT scans in the diagnosis and management of patients with these conditions.

Sonography of appendicitis and diverticulitis

Graded compression sonography has gained widespread acceptance as a useful technique to evaluate patients with atypical signs and symptoms of appendicitis. When positive, early surgery can be performed prior to perforation. When there is no sonographic evidence of appendicitis, other alternative diagnoses may be established. CT scans and the contrast enema remain the primary imaging modalities to evaluate suspected diverticulitis; however, sonography may be useful in selected patients with an atypical clinical presentation.

[Radiologic diagnosis of inflammatory complications of colonic diverticulosis]

The authors analyze x-ray findings in 194 patients with colonic diverticulosis and its inflammatory complications. Clinical, x-ray, and morphologic studies helped the authors to specify the x-ray semeiotics of diverticulitis, paraintestinal infiltrates, intestinal fistulas. An optimal complex of radiological methods to detect each of these complications has been developed. The authors claim that irrigoscopy supplemented, if necessary, with simultaneous fistulography, or oral enterography is the priority and basic method for the diagnosis of inflammatory complications of colonic diverticulosis.

Differentiating sigmoid diverticulitis from carcinoma on CT scans: mesenteric inflammation suggests diverticulitis

OBJECTIVE

The purpose of this study was to analyze the usefulness of two specific CT signs of sigmoid mesenteric inflammation (fluid at the root of the mesentery and vascular engorgement) for identifying and differentiating sigmoid diverticulitis from carcinoma.

MATERIALS AND METHODS

CT scans of 69 patients with surgically proved sigmoid diverticulitis were retrospectively reviewed and compared with CT findings in 29 patients with surgically proved sigmoid carcinoma. Two specific patterns of inflammation of the sigmoid mesentery were analyzed: fluid at the root of the sigmoid mesentery and engorgement of the sigmoid mesenteric vessels.

RESULTS

The CT findings were present more often in patients with sigmoid diverticulitis than in those with carcinoma (p < .001). Fluid at the base of the mesentery had a sensitivity, specificity, and positive predictive value for diverticulitis of 36%, 90%, and 89% respectively. Vascular engorgement alone had a sensitivity, specificity, and positive predictive value of 29%, 100%, and 100%, respectively.

CONCLUSION

Our results suggest that CT findings of fluid at the root of the mesentery and vascular engorgement are useful in distinguishing sigmoid diverticulitis from carcinoma of the sigmoid.

Acute left colonic diverticulitis: a prospective analysis of 226 consecutive cases

BACKGROUND

The purpose of this prospective study was to evaluate the immediate and late outcome of acute left colonic diverticulitis and to correlate it with age (younger and older than 50 years of age), gender, and initial computed tomography (CT) findings.

METHODS

Analysis was made of data collected prospectively from all patients admitted because of acute colonic diverticulitis between October 1986 and January 1992. Diagnosis relied on results of operation, CT, and Gastrografin enema. Two hundred twenty-six patients were urgently hospitalized for acute left colonic diverticulitis; 47 were younger than 50 years of age (21%).

RESULTS

Sixty-six patients (29%) were operated on during their first hospitalization. The remaining 160 patients treated conservatively underwent CT and an enema within 72 hours of admission. Fifty-nine of 179 patients (33%) older than 50 years of age required operation during their first attack, compared with 7 in 47 patients (15%) younger than 50 years of age (p = 0.02), although on CT severe diverticulitis was found in 36 of 141 patients (26%) older than 50 years of age and in 16 of 43 patients (37%) younger than 50 years of age (p = 0.13). Of the 160 patients treated conservatively, 11 of 40 patients (28%) younger than 50 years of age experienced recurrences or complications after their first discharge, compared with 16 in 120 patients (13%) older than 50 years of age (p = 0.04).

CONCLUSIONS

Patients younger than 50 years of age were significantly more prone to recurrences and complications after conservative treatment of their diverticulitis, whereas older patients required operation significantly more often during their first hospitalization.

Sigmoid diverticulitis presenting as unilateral iliofemoral vein thrombosis

The clinical and radiological findings in a patient presenting with unilateral iliofemoral vein thrombosis caused by psoas abscess secondary to diverticulitis of the sigmoid colon are described. The causes of iliofemoral vein thrombosis and psoas abscess are reviewed.

[The surgical treatment of perforated colonic diverticulitis]

The authors report a consecutive series of 52 patients who underwent urgent operation because of peritonitis by perforated diverticulitis. Urgent colonic resection achieves the best results.

[Acute diverticulitis. Primary diagnosis with ultrasonography in 4 cases presenting urologic disease (diverticulitis with urologic symptoms)]

Four men with clinical signs of left ureteric colic, bladder infection, prostatitis and sigmoid colon tumor with colo-vesical fistula, respectively, were echographically found to have very suggestive signs of acute diverticulitis. US suspicion was confirmed by clinical course, follow up examinations or surgery.

[Value of computerized tomography in acute diverticulitis of the left colon]

This prospective study focuses on the prediction of late outcome after acute left colonic diverticulitis successfully treated conservatively and in which the diagnosis was confirmed radiologically (computed tomography [CT] and gastrografin enema [GE]). Acute diverticulitis was diagnosed in 226 patients. Sixty-six patients (29%) were operated on during their first hospitalization, and 2 of them died (3% mortality). The remaining 160 patients, successfully treated conservatively, had a CT and a GE within 72 hours of admission and entered this study. Signs of severity on CT included the presence of abscess(es) and/or extraluminal air and/or extraluminal hydrosoluble contrast (Gastrografin). Follow-up averaged 25 months (range 1 month to 5.3 years). Twenty-seven of these 160 patients (17%) had a poor outcome (persistent diverticulitis in 12, colonic stenosis in 6, recurrences in 7, residual parasigmoid abscess and colovesical fistula in one each). When comparing these 27 patients with the 133 others it appeared that: (1) men up to 50 years of age were significantly more prone to develop such complications (p = 0.003); (2) the probability of developing a complication was significantly greater when the initial CT had revealed an abscess and/or extraluminal air and/or extraluminal Gastrografin (p = 0.005). These results support the view that elective colectomy can reasonably be proposed after a first attack of acute left diverticulitis treated conservatively in men up to 50 years of age, and/or in patients whose initial CT revealed findings of severe diverticulitis.

[Colon diverticulitis: imaging diagnosis with ultrasound--a prospective study]

In a prospective study, we investigated the value of high resolution sonography for the imaging diagnosis of colonic diverticulitis. A total of 161 patients with abdominal complaints on account of which acute diverticulitis entered into differential diagnosis were included in the study. 74 of these finally had proven colonic diverticulitis (prevalence, 46%). The results of intestinal sonography and the working diagnoses on admission were evaluated on the basis of final diagnoses. According to history, symptoms, and clinical findings on admission, the working diagnosis of diverticulitis was graded as being "highly suspect" in 26 (35.1%) of these 74 diverticulitis patients, as being "possible/equivocal" in 36 (48.6%), and as being "very unlikely" in in 12 (16.2%). In 7 (9.5%) patients with diverticulitis, the diagnosis was clinically unsuspected and primarily established by ultrasound. Overall accuracy, sensitivity, and specificity of intestinal sonography with regard to the diagnosis of diverticulitis were 97.5%, 98.6%, and 96.5%, respectively. There were three false positive ultrasonic diagnoses of diverticulitis which were made in two patients with perforated carcinoma of the sigmoid and in one case of sigmoid volvulus (positive predictive value, 96%). Ultrasound failed to visualize sigmoid diverticulitis with perforation in one patient (negative predictive value, 98%). In 19 out of 20 patients with abdominal abscesses (prevalence, 12.4%), the diagnoses were established by means of sonography. Nine of these patients with abscesses initially were treated by ultrasound guided percutaneous drainage enabling elective surgery. In 26 (70%) of 36 patients with morphological disorders other than diverticulitis, ultrasound findings substantially added for the definite diagnoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiological investigation in acute diverticulitis

Optimal management of acute sigmoid diverticulitis depends on evaluation of the severity of the inflammatory process, in which radiological investigation is a useful but probably underutilized adjunct to clinical assessment. Plain abdominal radiography shows abnormalities in 30-50 per cent of patients but these tend to be non-specific and more accurate information is obtainable from a contrast enema. Although the quality of images produced by a water-soluble contrast agent is inferior to that with barium, the former is less hazardous in the presence of perforation and provides sufficient information to permit rational management decisions to be made. Ultrasonography and computed tomography (CT) are particularly useful in visualizing abscesses. They may be helpful in following the progression or resolution of suppuration and in guiding percutaneous aspiration when appropriate. Despite early reports to the contrary, CT is no more specific than a contrast enema in the diagnosis of acute diverticulitis. Radionuclide scans have little role in the routine assessment of acute diverticulitis and magnetic resonance imaging has not been adequately evaluated. Water-soluble contrast enema is safe, widely available and probably the most useful early supplementary investigation.

Computed tomography in the initial management of acute left-sided diverticulitis

Computed tomography (CT) was used in place of contrast enemas as the initial imaging study to evaluate patients with the clinical diagnosis of acute sigmoid diverticulitis. This report attempts to clarify the role of CT in the management of acute sigmoid diverticulitis by reviewing its usefulness in the diagnosis and treatment of 59 patients. CT established that three patients (5 percent) were hospitalized with an incorrect clinical diagnosis. Thirty-seven patients (62.7 percent) were identified as having uncomplicated acute diverticulitis. These patients were all treated successfully with nonsurgical therapies and were discharged in an average of 6.8 days. In the remaining 19 patients (32.2 percent), CT revealed complicated acute diverticulitis by identifying abscess, fistula, peritonitis, or obstruction. Eleven of these 19 patients required urgent surgery or CT-guided percutaneous drainage of an abscess. The four patients whose abscesses were drained percutaneously responded favorably and underwent an elective single-stage resection. The average hospital stay for patients with complicated diverticulitis was 13.6 days. Computed tomography is a useful aid in the initial management of patients with acute diverticulitis. It is a noninvasive test that recognizes and stratifies patients according to the severity of their disease. It has the further advantage of providing information about extracolonic pathology and anatomic variation useful for surgical planning. Additionally, early CT-guided needle drainage allowed downstaging of complicated diverticulitis, avoided emergent surgery, and permitted single-stage elective surgical resection.

Sonography in acute colonic diverticulitis. A prospective study

The clinical value of high-resolution real-time sonography for the diagnosis of acute and complicated colonic diverticulitis was prospectively studied in 130 consecutive patients with abdominal complaints, because of which the disease entered into differential consideration. The results of ultrasound investigation were compared with those of clinical examination on admission. Regarding history and initial clinical evaluation, diverticulitis was graded as "highly suspected" in 19 (36.5 percent) out of a total of 52 patients with later proven colonic diverticulitis (prevalence 40 percent), as "possible but equivocal" in 24 (46.2 percent), and as "very unlikely" in the remaining nine (17.3 percent) patients. Ultrasonography enabled the diagnosis of diverticulitis with an overall accuracy of 97.7 percent, a sensitivity of 98.1 percent, and a specificity of 97.5 percent. The predictive values of positive and negative ultrasound examinations were 96.2 percent and 98.5 percent, respectively. The echomorphologic features of acute diverticulitis include visualization of a colon segment presenting with local tenderness on gradual compression, which showed hypoechogenic thickening of the wall and a targetlike appearance in transverse view due to inflammatory changes and muscular thickening. Sonographic signs of peridiverticulitis (hyperechoic halo) were found in 96 percent of patients, echogenic diverticula in 86 percent. Twelve (92 percent) of 13 abdominal abscesses were detected on initial ultrasound examination and could be treated by percutaneous drainage in seven cases, while six required surgical intervention. These results indicate that high-resolution sonography with graded compression is highly sensitive and specific for the imaging diagnoses of acute colonic diverticulitis and complicating abscess.

[Acute diverticulitis--radiological and endoscopic studies]

In patients with suspected acute diverticulitis, plain abdominal radiographs may demonstrate free gas in the abdomen. Ultrasound can indicate the nature of disease but is not sufficient to assess the extent of the inflammation. If perforation is suspected, a water-soluble contrast agent should be used to demonstrate diverticulitis and peridiverticular abscess. Computed tomography is ideally suited for the evaluation of the disease. it permits the radiologist to tell the clinician the exact extent of the extramucosal inflammation and the involvement of adjacent organs and structures.

Prognostic factors from computed tomography in acute left colonic diverticulitis

This prospective study examined factors which may predict a poor outcome (complications and recurrence) after a first attack of diverticulitis which has been successfully managed conservatively. Twenty-four of 107 patients who entered the study had a poor outcome: persistent diverticulitis (nine cases), recurrence (seven cases), colonic stenosis (six cases), residual parasigmoid abscess (one case) and colovesical fistula (one case). Eight of the 18 men aged 50 years or less had a poor outcome compared with 16 of the remaining 89 patients (P = 0.032). Twelve of 76 patients (16 per cent) with mild findings on computed tomography (CT) (localized thickening of colonic wall and inflammation of pericolic fat) had a poor outcome compared with 11 of 23 patients (48 per cent) whose CT was estimated as severe (abscess and/or extraluminal air and/or extraluminal Gastrografin) (P = 0.004). These results suggest that elective colectomy can be proposed after a first attack of acute left diverticulitis in men up to 50 years of age and/or in patients whose initial CT reveals findings of severe diverticulitis.

Early water-soluble contrast enema in the diagnosis of acute colonic diverticulitis

Acute colonic diverticulitis is usually suspected by typical clinical findings supported by laboratory tests. Investigations of the colon are usually delayed 1 to 2 months until the acute situation is resolved. We studied 53 patients with an initial clinical diagnosis of acute diverticulitis by performing early water-soluble contrast enema of the colon. The initial diagnosis proved to be uncertain, as 26 patients (49%) had acute colonic diverticulitis as their final diagnosis. There were ten patients who had diverticulosis of the colon, but without radiologic signs of acute diverticulitis. Four of these patients had some other disease responsible for their symptoms. Thirteen patients had normal findings at early water-soluble contrast enema. Three colonic carcinomas and one ischaemic colitis were diagnosed. There were no complications related to the radiologic studies. We conclude that early water-soluble contrast edema of the left colon is safe and useful in investigating patients with suspected acute colonic diverticulitis. If the finding is normal, investigations can be directed elsewhere without undue delay.

Diverticular complications of renal failure

Ten patients with chronic renal failure presented with complications of colonic diverticula. Five had acute diverticulitis, 4 perforated diverticula, and 1 lower gastrointestinal hemorrhage. Symptoms were less severe than expected. In 3 the diagnosis was first suspected when free intra-abdominal air was detected. Seven patients had laparotomy, 5 emergently. Radiologists should be aware of the potential for diverticular complication in patients with renal failure, even with minimal or absent symptoms. Suspicion of colonic pathology either clinically or radiographically should be evaluated promptly so that aggressive therapy can begin.

Tc-99m labeled leukocytes in imaging of patients with suspected acute abdominal inflammation

One hundred patients with suspected acute abdominal inflammation were imaged at 0.5, 2-3, 4-6, and 24 hours after the administration of Tc-99m HMPAO labeled autologous leukocytes. Scan findings were retrospectively compared with final diagnosis, serum C-reactive protein (CRP), and antibiotic treatment. Clinical findings were confirmed with surgery, barium enema, or sigmoidoscopy in 61 patients, and diagnosis was based only on clinical findings in 13 patients. In 26 patients, symptoms subsided before a final diagnosis was made. Tc-99m leukocyte images were positive in 45 of the 61 patients with a confirmed diagnosis, including all patients with acute cholecystitis (N = 4) and inflammatory bowel disease (N = 8). They were also positive in nineteen out of 25 patients who had acute colonic diverticulitis and in 6 out of 7 who had intra-abdominal abscesses. Abnormal activity was found in patients with colonic carcinoma, small bowel infarction, and acute appendicitis. Abnormal activity was visualized in 0.5-hour images in all but one of the positive cases. With the exception of two postoperative cases, malignant lymphoma, and a liver abscess, a CRP level of greater than 75 mg/L was associated with positive image findings. Antibiotic treatment did not affect imaging findings. Imaging with Tc-99m labeled leukocytes appears to be valuable for detecting and localizing abdominal inflammation, and three-phase imaging during the first 4-6 hours is recommended. In some cases, 24-hour images may be useful for distinguishing small bowel from large bowel inflammation.

Sigmoid diverticulitis: diagnostic role of CT--comparison with barium enema studies

The diagnostic value of computed tomography (CT) and barium enema (BE) studies was evaluated prospectively in hospitalized patients with the presumptive diagnosis of acute sigmoid diverticulitis based on the presence of left-lower-quadrant pain and tenderness, fever, and leukocytosis. Of 56 patients, 11 had sigmoid diverticulitis confirmed at surgery and 16 by clinical response to medical therapy. CT, performed in all diverticulitis patients, had positive results in 93% (25 of 27). These compared favorably with BE study results, of which 80% (20 of 25) were positive. Neither examination had false-positive results. In the 29 patients who did not have diverticulitis, an alternative diagnosis was made by means of CT in 20, but in only three by means of BE studies. Many of the extracolonic abnormalities recognized at CT were clinically unexpected and necessitated emergency surgery. The excellent sensitivity and specificity of CT coupled with its versatility in the detection of extracolonic disease give it an advantage over contrast enema studies for diagnosis of sigmoid diverticulitis. CT should be the initial study in acutely ill patients, especially when the clinical features are atypical for sigmoid diverticulitis.

Limitations in the CT diagnosis of acute diverticulitis: comparison of CT, contrast enema, and pathologic findings in 16 patients

Pitfalls in CT diagnosis of acute diverticulitis were investigated in 16 patients with the disease who had misleading or equivocal CT features. The CT appearance was correlated with contrast enemas (13 cases) and with surgical assessment and pathologic evaluation of resected specimens (12 cases). Limitations in the CT diagnosis were related to (1) marked thickening of the colonic wall, between 1 and 3 cm in cross section simulating colonic neoplasm (all patients); (2) inability to visualize small amounts of fibropurulent exudate in the absence of pericolic inflammatory changes (eight patients); (3) failure to detect discrete intramural abscess (five patients). Resected surgical specimens available in 12 cases proved that colonic wall thickening was caused by muscular hypertrophy and various degrees of submucosal inflammation, edema, fibrosis, or focal organized inflammatory tissue. Contrast enema was useful in 10 out of 13 patients by excluding carcinoma of the colon and confirming the diagnosis of acute diverticulitis.

[Computed tomography of colonic diverticulitis]

33 patients with clinically suspected diverticulitis of the colon were studied prospectively by CT. The predictive value of symptoms, such as thickening of the colonic wall (86.6%), inflammatory changes of the pericolic fatty tissue (87.5%), the presence of diverticula (73.3%) and abscess formation (100%), were examined separately and their significance was evaluated. Our study was performed mainly on clinically less severe cases of diverticulitis. True positive results by CT were reached in 20/21 cases (sensitivity = 95.2%), true negative findings in 9/12 (specificity = 75.0%). The results of CT examinations were compared with those of contrast enemas (n = 24) and/or endoscopy (n = 6). The number of cases was too low to achieve statistic significance; the relatively high percentage of questionably positive results shows the difficulties inherent in these methods. Our study shows that CT is a good means to demonstrate even less severe forms of colonic diverticulitis with sufficient reliability.

Comparison of computed tomography and contrast enema evaluation of diverticulitis

A total of 31 patients with diverticulitis were analyzed who had both computed tomography and contrast enema. There was almost equal sensitivity to abnormality of approximately 90 percent. Contrast enema produced a specific diagnosis of diverticulitis in 61 percent, using stringent positive criteria, and an additional 29 percent with suggestive findings. Comparative computed tomography specific diagnoses in those 31 cases was made in 65 percent, and suggestive in 23 percent. Computed tomography was particularly useful diagnostically in cases of retrograde obstruction on contrast enema. The authors conclude that contrast enema should be the primary mode of approach, while computed tomography can be a valuable follow-up when the diagnosis is still in doubt, or if it is possible that patient management might be altered by additional information.