Diagnosis of acute left-sided colonic diverticulitis by three radiological modalities

The limited role of ultrasound in the diagnostic process of colonic diverticulitis

BACKGROUND

Diverticulitis is commonly diagnosed using ultrasound (US), followed by computed tomography (CT). Our aim was to determine the diagnostic accuracy of US compared with CT for patients with uncomplicated and complicated diverticulitis.

METHODS

We reviewed medical records of 232 patients admitted with diverticulitis via the emergency department between January 2009 and January 2011. Patients who had undergone US and a CT scan were identified and further analyzed.

RESULTS

A total of 123 patients underwent an US and a CT scan. In 78/94 patients with uncomplicated diverticulitis, results of US and CT scan were compatible (83 %); in 6 of the remaining 29 patients both modalities showed a complicated diverticulitis (21 %). US misdiagnosed 17 % of patients with uncomplicated diverticulitis and 79 % with complicated diverticulitis.

CONCLUSIONS

US is insufficient for diagnosing a complicated diverticulitis. Missing a complicated diverticulitis can have important clinical implications, and if diverticulitis is suspected, we suggest obtaining a CT scan to confirm diagnosis and to exclude complications.

Preoperative CT staging in sigmoid diverticulitis--does it correlate with intraoperative and histological findings?

PURPOSE

This study was designed to evaluate whether the computed tomography (CT) reflects the extent of the inflammation in sigmoid diverticulitis (SD) in order to draw conclusions for selecting the appropriate treatment.

METHODS

Two hundred four patients who underwent resection for SD from January 2003 to December 2008 were included. The preoperative CT stage was compared with intraoperative and histological findings. Patients were classified into phlegmonous (Hansen-Stock IIa), abscess-forming (HS IIb), and free perforated (HS IIc) forms of SD. Patients with a recurrent type of diverticulitis were excluded.

RESULTS

In the phlegmonous type (HS IIa; n = 75), we found a correlation with the preoperative stage in 52% (intraoperative) and 56% (histological), an understaging in 12% (intraoperative) and 11% (histological), and an overstaging in 36% (intraoperative) and 33% (histological). In the abscess-forming type (HS IIb, Hinchey I/II; n = 87), we found conformity in 92% (intraoperative) and 90% (histological), understaging in 3% (intraoperative) and 0% (histological), and overstaging in 5% (intraoperative) and 10% (histological). In the presence of a free perforation (HS IIc, Hinchey III/IV; n = 42), we saw conformity in 100% (intraoperative and histological). The positive predictive value for correctly diagnosing of phlegmonous type (HS IIa), abscess-forming type (HS IIb), and free perforation (HS IIc) by CT was intraoperatively (histologically) 52% (56), 92% (90), and 100% (100), respectively.

CONCLUSIONS

The CT is one of the most accurate methods for staging in SD. However, in the phlegmonous type (HS IIa), it leads to an overestimation of the findings in every third patient. It must be clarified whether this pronounced low inflammation should really be regarded as a complicated form of SD. In contrast, the abscess-forming (HS IIb) and free perforated (HS IIc) type of complicated SD is very well reflected by CT.

Microscopic findings in sigmoid diverticulitis--changes after conservative therapy

INTRODUCTION

The indications for prophylactic surgery for phlegmonous and covered perforated type of acute sigmoid diverticulitis (SD) are currently matters of debate, and a more conservative approach has been advocated. However, it has not yet been clarified to what extent CT findings indicative of acute SD correlate with histological findings, and it is still uncertain how these findings change in the time interval between initial antibiotic treatment and late elective surgery. The aim of this study was to record time-course changes of inflammation in phlegmonous and abscess-forming diverticulitis after conservative treatment in order to check the indication for surgery.

MATERIAL AND METHODS

This study included all patients who underwent surgery for CT morphologically phlegmonous and covered perforated SD from January 2002 to June 2007. Two groups were formed to record time-course changes: early elective surgery (7-10 days after antibiotic treatment) and late elective surgery (4-6 weeks after conservative treatment). Exclusion criteria were emergency interventions, free perforations (Hinchey III and IV), recurrent inflammations, and contrast allergy. The extent of the inflammation recorded preoperatively by CT scan was compared with histological findings.

RESULTS

A total of 257 patients (142 male and 115 female; mean age, 56.6 years) underwent surgery (116 early elective and 141 late elective) for phlegmonous and covered perforated SD. Phlegmonous SD was seen in 127 cases and covered perforated SD in 130 cases. In the phlegmonous type of SD, early surgery led to conformity with the preoperative stage in 56%, to more extensive findings in 11%, and to subsided inflammation in 33%. Late surgery led to conformity in 0% and to signs of subsided inflammation in 100%. In the covered perforated type of SD, early surgery led to conformity in 90%, to subsided inflammation in 10%, and to milder manifestation in 0%. In contrast, late surgery here led to conformity in 26% of the cases and to subsided inflammation in 74%. Considerable histological changes can be detected under conservative therapy. The acute inflammation subsides under antibiotic therapy as awaited. It must be clarified whether the phlegmonous form of SD should, in principal, be regarded as an indication for surgery, since it shows early and nearly complete regression of the inflammation. Otherwise, the covered perforated type of SD still shows marked inflammatory changes after conservative therapy in a high percentage of patients and should thus preferably be treated by surgery. However, the clinical appearance of the patient with sigmoid diverticulitis still remains the most important part of decision making.

Graded compression ultrasonography and computed tomography in acute colonic diverticulitis: meta-analysis of test accuracy

The purpose was to investigate the diagnostic accuracy of graded compression ultrasonography (US) and computed tomography (CT) in diagnosing acute colonic diverticulitis (ACD) in suspected patients. We performed a systematic review and meta-analysis of the accuracy of CT and US in diagnosing ACD. Study quality was assessed with the QUADAS tool. Summary estimates of sensitivity and specificity were calculated using a bivariate random effects model. Six US studies evaluated 630 patients, and eight CT studies evaluated 684 patients. Overall, their quality was moderate. We did not identify meaningful sources of heterogeneity in the study results. Summary sensitivity estimates were 92% (95% CI: 80%-97%) for US versus 94% (95%CI: 87%-97%) for CT (p = 0.65). Summary specificity estimates were 90% (95%CI: 82%-95%) for US versus 99% (95%CI: 90%-100%) for CT (p = 0.07). For the identification of alternative diseases sensitivity ranged between 33% and 78% for US and between 50% and 100% for CT. The currently best available evidence shows no statistically significant difference in accuracy of US and CT in diagnosing ACD. Therefore, both US and CT can be used as initial diagnostic tool until new evidence is brought forward. However, CT is more likely to identify alternative diseases.

Acute colonic diverticulitis: a systematic review of diagnostic accuracy

OBJECTIVE

To appraise the literature on the diagnosis of acute colonic diverticulitis by ultrasound (US), computed tomography (CT), barium enema (BE) and magnetic resonance imaging (MRI).

METHOD

The databases of Pub Med, the Cochrane Library and EMBASE were searched for articles on the diagnosis of diverticulitis published up to November 2005. Studies where US, CT, BE, or MRI were compared with a reference standard on consecutive or randomly selected patients were included. Three examiners independently read the articles according to a prespecified protocol. In case of disagreement consensus was sought. The level of evidence of each article was classified according to the criteria of the Centre for Evidence-Based Medicine (CEBM), Oxford, UK.

RESULTS

Forty-nine articles relevant to the subject were found and read in full. Twenty-nine of these were excluded. Among the remaining 20 articles, only one study, evaluating both US and CT reached level of evidence 1b according to the CEBM criteria. Two US studies and one MRI study reached level 2b. The remaining studies were level 4.

CONCLUSION

The best evidence for diagnosis of diverticulitis in the literature is on US. Only one small study of good quality was found for CT and for MRI-colonoscopy.

CT in acute perforated sigmoid diverticulitis

BACKGROUND

To assess the value of computed tomography (CT) in patients with acute perforated sigmoid diverticulitis in correlation with the Hinchey classification of perforated diverticular disease.

METHODS

Thirty patients with acute perforated sigmoid diverticulitis underwent computed tomography prior to surgery. Computed tomography scans were compared with the surgical and histopathological reports, utilizing the Hinchey classification.

RESULTS

In 28 of the 30 (93%) patients examined, the Hinchey stage was correctly determined by means of computed tomography. One patient with Hinchey stage IV was falsely classified as Hinchey stage III, and one patient with Hinchey stage III as Hinchey stage II. Computed tomography revealed 12 out of 14 (86%) patients with perforation sites and 3 out of 3 (100%) patients with contained perforation. In one of 17 (6%) patients with surgically or histopathologically proven perforation or contained perforation, a bowel wall discontinuity was revealed by computed tomography. In 6 of the 17 (35%) patients with surgical or histopathological perforation or contained perforation, extraluminal contrast material was detected by computed tomography.

CONCLUSIONS

Computed tomography is a valuable imaging tool for determining the degree of acute perforated sigmoid diverticulitis, by means of which patients can be stratified according to the severity of the disease; furthermore, this tool is of assistance in surgical planning.

Suspected acute colon diverticulitis: imaging with low-dose unenhanced multi-detector row CT

PURPOSE

To prospectively compare the sensitivity and specificity of unenhanced low-dose multi-detector row computed tomography (CT) with those of contrast material-enhanced standard-dose multi-detector row CT in patients suspected of having acute diverticulitis.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. One hundred ten consecutive patients (40 men, 70 women; age range, 30-82 years; mean, 57 years) suspected of having acute diverticulitis underwent unenhanced multi-detector row CT with 4 x 2.5-mm collimation, 120 kVp, and 30 effective mAs, as well as contrast-enhanced standard-dose multi-detector row CT with the same parameters but with 120 mAs. All scans were independently read by four readers. Intra- and interobserver agreements were calculated with the kappa statistic. Contrast-enhanced standard-dose scans read by three other experts and considered together with results from colonoscopy, surgery, and pathologic evaluation were used as reference. Differences in sensitivity and specificity between readers, radiation doses, and reading sessions were investigated. Pearson exact test and logistic regression models were used.

RESULTS

Colon diverticulitis was present in 39 patients (34%) and was graded as mild in 22 patients (56%) and severe in 17 (44%). Agreement within and between readers was good to excellent. No significant difference was observed in sensitivity (P ranging from .081 to >.99) or in specificity (P ranging from .326 to >.99) for any sign or overall diagnosis between radiation doses by all readers, except wall thickening, which for one reader had a higher specificity at low dose than at standard dose (P = .025). No significant difference in misclassification was detected between doses, regardless of the reader (P ranging from .481 to >.99). At both doses, the most predictive sign for acute diverticulitis was retroperitoneal fat stranding (P < .001).

CONCLUSION

Low-dose unenhanced multi-detector row CT has a diagnostic performance similar to that of contrast-enhanced standard-dose multi-detector row CT in patients suspected of having acute diverticulitis.

The out-patient management of patients with acute mild-to-moderate colonic diverticulitis

BACKGROUND

There are no management criteria for optimum out-patient care in mild-to-moderate acute colonic diverticulitis.

AIM

To enable such patients to be managed in an out-patient setting, by establishing criteria and treatment protocols.

METHODS

We conducted an open trial and follow-up study from 1997 to 2002. On the basis of ultrasonography, we defined and categorized mild-to-moderate acute colonic diverticulitis ranging from limited inflammation within diverticulum to an abscess < 2 cm in diameter. Subjects were treated as out-patients and followed a 10-day treatment protocol consisting of an oral antibiotic and a sports drink for the first 3 days. Physical examination and laboratory testing helped determine whether or not a patient could resume a liquid diet on day 4, and a regular diet on day 7.

RESULTS

Of the 70 patients, 68 were successfully treated. Two patients required hospitalization. Of the 65 patients who were tracked over several months [median (intraquarter range) = 30.8 (11.9-44.2) months], 16 had one or more clinical recurrences. The medical cost per episode was 80% lower than in-patient treatment.

CONCLUSIONS

Patients with mild-to-moderate acute colonic diverticulitis can be safely and successfully treated as out-patients using this protocol.

Computed tomography evaluation of diverticulitis

Acute diverticulitis is a frequent and important diagnosis in gastrointestinal disease, most commonly involving the colon. It is estimated that approximately 15% to 30% of patients with diverticulosis develop symptomatic diverticulitis at some point in the natural history of the condition, often requiring medical and/or surgical therapy. The clinical diagnosis is often difficult to make, and several radiological studies have been used over the past decades to assist in the diagnosis of acute diverticulitis. These include barium enema, ultrasound, and computed tomography (CT). A number of studies over the past decade have shown CT to be the preferable initial examination because of its ability to demonstrate not only the extent of intramural inflammation but also the degree of pericolic disease, including intraperitoneal inflammation, perforation, and abscess formation. Additional benefits of CT imaging include guiding therapeutic interventions in complicated forms of diverticular disease and providing an alternative diagnosis in patients without diverticulitis. The accuracy, techniques, criteria for diagnosis, and staging and applications of CT imaging in acute diverticulitis are discussed.

Diverticular disease in adolescence

Diverticular disease is rare in the adolescent. Acute diverticulitis is almost never considered as a diagnosis for a young patient presenting with abdominal pain. Unfortunately, unrecognized it may be associated with significant morbidity and mortality. Also, when present, diverticulitis in the young adult is considered to be more aggressive compared to diverticulitis in older adults. Therefore, it is important to recognize, diagnose and manage diverticular disease appropriately in this age group. In tis chapter we will review the available literature on diverticula disease in the adolescent and young adult, discuss epidemiology, aetiology and pathogenesis and suggest guidelines for diagnosis and management.

Frequency, sensitivity, and specificity of individual signs of diverticulitis on thin-section helical CT with colonic contrast material: experience with 312 cases

OBJECTIVE

The aim of our study was to determine the frequency, sensitivity, and specificity of the individual signs of diverticulitis using helical CT with colonic contrast material.

MATERIALS AND METHODS

Between March 1997 and September 1999, 312 patients with suspected diverticulitis were examined on helical CT using rectally administered colonic contrast material. CT scans that were positive for diverticulitis or indeterminate were rereviewed by two radiologists; CT interpretations were correlated with patients' clinical courses and surgical findings.

RESULTS

One hundred fourteen (37%) of the 312 CT scans were interpreted as positive for diverticulitis; 192 scans (61%), as negative; six scans (2%), as indeterminate. Of the 114 scans that were positive for diverticulitis, 109 (96%; sensitivity 96%, specificity 91%) showed bowel wall thickening; 108 (95%; sensitivity 96%, specificity 90%), fat stranding; 104 (91%; sensitivity 91%, specificity 67%), diverticula; 57 (50%; sensitivity 50%, specificity 100%), fascial thickening; 51 (45%; sensitivity 45%, specificity 97%), free fluid; 49 (43%; sensitivity 43%, specificity 100%), inflamed diverticula; 34 (30%; sensitivity 30%, specificity 100%), free air; 18 (16%; sensitivity 16%, specificity 100%), "arrowhead" signs; nine (8%; sensitivity 8%, specificity 99%), abscesses; four (4%; sensitivity 4%, specificity 100%,), phlegmons; five (4%; sensitivity 4%, specificity 99%), intramural air; two (2%; sensitivity 2%, specificity 100%), intramural sinus tracts. Overall CT interpretation had a sensitivity of 99%, a specificity of 99%, a positive predictive value of 99%, a negative predictive value of 99%, and an overall accuracy of 99%.

CONCLUSION

The two most frequent signs of diverticulitis were bowel wall thickening (96%) and fat stranding (95%). Less frequent but highly specific signs were fascial thickening (50%), free fluid (45%), and inflamed diverticula (43%).

Diverticular abscess presenting as prostate abscess and missed by abdominal CT scan

This is a case report of sigmoid diverticular abscess presenting as prostate abscess. Helical computed tomography (CT) scan revealed the prostate abscess but failed to demonstrate the underlying diverticular abscess. Colonic diverticular abscess can have many unusual presentations, and multiple imaging modalities may be required to reveal the underlying pathology. Abdominal CT scan is not always a definitive and absolute imaging modality for abdominal pain evaluation and cannot supplant clinical judgment in the evaluation of confusing cases.

Diverticular disease in the elderly

Diverticular disease is common among the elderly. Because of the advanced age and muted symptoms and signs of many of those affected, diagnosis can be difficult. Consequently, great demands are placed on the physician to diagnose and treat clinically evident diverticular disease. Endoscopic, radiologic, and surgical advances have increased the availability of more definitive therapies for patients with complicated diverticular disease and diverticular hemorrhage.

Computed tomographic colonography and conventional colonoscopy for colon diseases: a prospective, blinded study

OBJECTIVES

Computed tomographic (CT) colonography or virtual colonoscopy is a new diagnostic method for the colon and rectum, developed on the basis of spiral computed axial tomography and employing virtual reality technology. The aim of this study was to determine the sensitivity, specificity, and diagnostic accuracy of CT colonography compared with colonoscopy in a prospective, blinded study in one single institution in Italy.

METHODS

Ninety-nine patients randomly selected among those attending the open-access endoscopy unit for diagnostic colonoscopy underwent colonoscopy and spiral CT. The images obtained were transmitted to generate the virtual colonoscopy pictures. A supervisor compared the results with the findings of conventional colonoscopy.

RESULTS

CT colonography diagnosed seven of eight tumors, one being missed because the patient had been inadequately prepared. In 28 patients, CT colonography identified 26 polyps of 45 (57.8% sensitivity, 92.6% specificity, 86.7% positive predictive value), regardless of their size. The sensitivity in detecting colonic polyps was 31.8% (7/22) in the first 25 cases and 91.6% (11/12) in the last 20 patients. CT colonography missed one flat adenoma, some angioectasias and colonic lesions because of portal hypertension in one patient, Crohn's disease ulcers in two patients, and ulcerative colitis lesions in three.

CONCLUSIONS

CT colonography shows poor sensitivity for identifying colonic polyps and does not always detect neoplastic lesions. Flat lesions are impossible to see by this method.

Diverticular disease of the colon

Diverticular disease of the colon is quite common in developed countries, and its prevalence increases with age. Although present in perhaps two thirds of the elderly population, the large majority of patients will remain entirely asymptomatic. Nonetheless, an estimated 20% of those affected may manifest clinical illness, mainly diverticulitis, with its potential complications of abscesses, fistulas, and obstruction, as well as lower intestinal hemorrhage. The purpose of this report is to review our understanding of the epidemiology, pathophysiology, clinical presentation, and treatment options for this disorder.