The Current Role of Radiologic and Endoscopic Imaging in the Diagnosis and Follow-Up of Colonic Diverticular Disease. AJR Am J Roentgenol. 2016;207:15-24. [PMID: 27082846 DOI: 10.2214/ajr.16.16138]

The Portal Vein: A Comprehensive Review

Radiologists are familiar with the appearances of a normal portal vein; variations in its anatomy are commonplace and require careful consideration due to the implications for surgery. These alterations in portal vein anatomy have characteristic appearances that are clearly depicted on CT, MR, and US images. Similarly, there are numerous congenital and acquired disorders of the portal vein that are deleterious to its function and can be diagnosed by using imaging alone. Some of these conditions have subtle imaging features, and some are conspicuous at imaging but poorly understood or underrecognized. The authors examine imaging appearances of the portal vein, first by outlining the classic and variant anatomy and then by describing each of the disorders that impact portal vein function. The imaging appearances of portal vein abnormalities discussed in this review include (a) occlusion from and differentiation between bland thrombus and tumor in vein and the changes associated with resultant hepatic artery buffer response changes, cavernous transformation of the portal vein, and portal biliopathy; (b) ascending thrombophlebitis of the portal vein (pylephlebitis); (c) portal hypertension and its causes and sequelae; (d) the newly described disease entity portosinusoidal vascular disorder; and (e) intra- and extrahepatic shunts of the portal system, both congenital and acquired (including Abernethy malformations), and the associated risks. Current understanding of the pathophysiologic processes of each of these disorders is considered to aid the approach to reporting. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Ultrasonographic and Functional Features of Symptomatic Uncomplicated Diverticular Disease

INTRODUCTION

To evaluate the ability of intestinal ultrasound (IUS) in discriminating symptomatic uncomplicated diverticular disease (SUDD) among patients with abdominal symptoms including irritable bowel syndrome (IBS).

METHODS

This observational, prospective study included consecutive patients classified into the following categories: (i) SUDD; (ii) IBS; (iii) unclassifiable abdominal symptoms; and (iv) controls, including asymptomatic healthy subjects and diverticulosis. The IUS evaluation of the sigmoid: assessed the presence of diverticula, thickness of the muscularis propria, and IUS-evoked pain, namely the intensity of pain evoked by compression with the ultrasound probe on sigmoid colon compared with an area of the left lower abdominal quadrant without underlying sigmoid colon.

RESULTS

We enrolled 40 patients with SUDD, 20 patients with IBS, 28 patients with unclassifiable abdominal symptoms, 10 healthy controls, and 20 patients with diverticulosis. Patients with SUDD displayed significantly ( P < 0.001) greater muscle thickness (2.25 ± 0.73 mm) compared with patients with IBS (1.66 ± 0.32 mm), patients with unclassifiable abdominal pain, and healthy subjects, but comparable with that of patients with diverticulosis (2.35 ± 0.71 mm). Patients with SUDD showed a greater (not significant) differential pain score than other patients. There was a significant correlation between the thickness of the muscularis propria and the differential pain score only for patients with SUDD ( r = 0.460; P : 0.01). Sigmoid diverticula were detected by colonoscopy in 40 patients (42.4%) and by IUS with a sensitivity of 96.0% and a specificity of 98.5%.

DISCUSSION

IUS could represent a useful diagnostic tool for SUDD, potentially useful in characterizing the disease and appropriately address the therapeutic approach.

When to Perform a Colonoscopy in Diverticular Disease and Why: A Personalized Approach

Colonoscopy is a crucial diagnostic tool in managing diverticular disease (DD). Diverticulosis can often be an unexpected diagnosis when colonoscopy is performed in asymptomatic subjects, generally for colorectal cancer screening, or it could reveal an endoscopic picture compatible with DD, including acute diverticulitis, in patients suffering from abdominal pain or rectal bleeding. However, alongside its role in the differential diagnosis of colonic diseases, particularly with colon cancer after an episode of acute diverticulitis or segmental colitis associated with diverticulosis, the most promising use of colonoscopy in patients with DD is represented by its prognostic role when the DICA (Diverticular Inflammation and Complication Assessment) classification is applied. Finally, colonoscopy plays a crucial role in managing diverticular bleeding, and it could sometimes be used to resolve other complications, particularly as a bridge to surgery. This article aims to summarize "when" to safely perform a colonoscopy in the different DD settings and "why".

Colonic Acquired Fistulae: The Potential of CT Colonography

The diagnosis of colonic fistulae is crucial in defining the best therapeutic approach. Fistulae can be suspected from clinical history or specific symptoms, but imaging plays a key role in confirming the diagnosis. Previous studies described conventional studies with barium as methods of choice for the diagnosis; more recently intestinal ultrasound, CT and MR have been considered promising tests. CT Colonography is the best radiologic test to evaluate the colon, but only few case reports described its role in this setting. Aim of this paper is to highlight the potentials of CT colonography in evaluating patients with suspected colonic fistulae.

Magnetic Resonance Imaging for the diagnosis and management of acute colonic diverticulitis: a review of current and future use

Diverticular disease is one of the most common causes of outpatient visits and hospitalisations across Australia, North America and Europe. According to the Gastroenterological Society of Australia (GESA, 2010), approximately 33% of Australians over 45 years of age and 66% over 85 years of age have some form of colonic diverticulosis. Patients with colonic diverticulosis are known to develop subsequent complications such as acute colonic diverticulitis (ACD), and when more than one attack of diverticulitis occurs, there is a 70-90% chance that the individual will experience ongoing problems and recurring infections throughout their lifetime. Medical imaging is fundamental in the diagnosis, treatment and ongoing management of ACD and its complications, with Computed Tomography (CT) identified as the prevailing gold standard in the last few decades. Cross-database searching highlighted a large gap in the literature regarding the effectiveness of Magnetic Resonance Imaging (MRI) as a non-ionising radiation alternative imaging tool for ACD imaging after the mid-2000s, despite ongoing technological advancements in this modality. This narrative review identified 13 key publications (11 primary prospective cohort studies, 1 systematic review and 1 meta-analysis) that evaluate MRI for ACD imaging, of which five were published within the last decade. Several existing MRI protocols are deemed suitable for ACD imaging, and it is recommended they be re-evaluated in larger cohorts. Future studies should consider the rapidly growing technological improvements of MRI, its cost efficiency and its applicability in modern day healthcare settings when addressing ACD management. This is especially important considering the gradual rise in radiation dose among the Australian population attributable to increased CT referrals, alongside increased reporting of ACD cases in younger individuals.

Accuracy of preoperative CT staging of acute colonic diverticulitis using the classification of diverticular disease (CDD) - Is there a beneficial impact of water enema and visceral obesity?

PURPOSE

We evaluated the accuracy of preoperative CT in staging colonic diverticulitis (ACD) by using the classification of diverticular disease (CDD) and investigated the diagnostic impact of water enema (WE) and visceral obesity.

METHODS

In this retrospective study, the radiological and hospital information system was searched for patients who underwent CT for clinically suspected ACD prior to surgery between 2009 and 2019. From the initial population (n = 164), we included 155 patients (94.5 %) (85 women; mean age: 58 ± 13 years) matching the following inclusion criteria: i.) clinically suspected ACD, ii.) i.v. contrast-enhanced CT, iii.) surgery for ACD within 1 week after CT, iv.) histopathological report that proved ACD. The remaining 9 patients (5.5 %) were excluded because histopathological reports were lacking (n = 3) or CT was performed without intravenous contrast agent (n = 6). WE (+ butylscopolamine i.v.) was performed in 93 patients (group A, 60 %). 62 patients (group B, 40 %) had no WE. Visceral-to-subcutaneous fat ratio (V/S) was determined for each patient. Two radiologists blinded for final diagnosis independently staged ACD according to CDD and assessed prevalence and confidence ratings of ACD-related CT-findings: pericolonic fat stranding, covered- and free-perforation, local and generalized peritonitis, abscess. Interobserver-agreement of CT-findings were assessed and effects of WE and V/S ratio on the diagnostic accuracy of CT with surgical and histopathological findings as reference were determined by calculating a logistic regression model.

RESULTS

CT-staging showed high accuracy (94 %) and excellent interrater-correlation (ICC 0.96) for staging ACD. WE had no positive impact neither on diagnostic accuracy of staging, nor on confidence ratings of ACD-related CT-findings (all p > 0.5). Confidence ratings were significantly higher in examinations without WE for perforation, peritonitis as well as abscesses (all p < 0.5). Confidence ratings for the assessment of local peritonitis improved significantly with higher V/S (p = 0.049). The increase of V/S significantly correlated with the probability for correct CDD staging of ACD in CT (p = 0.023).

CONCLUSION

Increase of visceral obesity significantly improves accuracy of CT in preoperative staging acute colonic diverticulitis. However, independently of the degree of visceral obesity, water enema has no diagnostic benefit and may therefore be omitted. Overall, CT proves high accuracy in preoperative staging ACD using the classification of diverticular disease.

LEVEL OF EVIDENCE

Retrospective study, observational study.

CT colonography followed by elective surgery in patients with acute diverticulitis: a radiological-pathological correlation study

Purpose

To perform a radiologic-pathologic correlation analysis of sigmoid colon in patients undergoing pre-operative CT Colonography (CTC) after an episode of acute diverticulitis (AD).

Methods

Fifty-nine consecutive patients (31/28 M/F; 58 ± 13 years) underwent CTC 55 ± 18 days after AD, 8 ± 4 weeks before surgery. Thirty-seven patients (63%) underwent conventional abdominal CT at time of AD. An experienced blinded radiologist retrospectively analyzed all images: disease severity was graded according to the Ambrosetti classification on conventional CT and according to the diverticular disease severity score (DDSS) on CTC. A GI pathologist performed a dedicated analysis, evaluating the presence of acute and chronic inflammation, and fibrosis, using 0–3 point scale for each variable.

Results

Of 59 patients, 41 (69%) had at least one previous AD episode; twenty-six patients (44%) had a complicated AD. DDSS was mild-moderate in 34/59 (58%), and severe in 25/59 (42%). All patients had chronic inflammation, while 90% had low-to-severe fibrosis. Patients with moderate/severe fibrosis were older than those with no/mild fibrosis (61 ± 13 versus 54 ± 13). We found a significant correlation between DDSS and chronic inflammation (p = 0.004), as well as DDSS and fibrosis (p = 0.005). Furthermore, fibrosis was correlated with complicated acute diverticulitis (p = 0.0.27), and with age (p = 0.067). At multivariate analysis, complicated diverticulitis was the best predictor of fibrosis (odds ratio 4.4). Patient age and DDSS were other independent predictors.

Conclusion

DDSS-based assessment on preoperative CTC was a good predictor of chronic colonic inflammation and fibrosis. In addition, the presence of complicated diverticulitis on CT during the acute episode was most predictive of fibrosis.

ACR Appropriateness Criteria® Left Lower Quadrant Pain-Suspected Diverticulitis

This review summarizes the relevant literature regarding imaging of suspected diverticulitis as an etiology for left lower quadrant pain, and imaging of complications of acute diverticulitis. The most common cause of left lower quadrant pain in adults is acute sigmoid or descending colonic diverticulitis. Appropriate imaging triage for patients with suspected diverticulitis should address the differential diagnostic possibilities and what information is necessary to make a definitive management decision. Patients with diverticulitis may require surgery or interventional radiology procedures because of associated complications, including abscesses, fistulas, obstruction, or perforation. As a result, there has been a trend toward greater use of imaging to confirm the diagnosis of diverticulitis, evaluate the extent of disease, and detect complications before deciding on appropriate treatment. Additionally, in the era of bundled payments and minimizing health care costs, patients with acute diverticulitis are being managed on an outpatient basis and rapid diagnostic imaging at the time of initial symptoms helps to streamline and triage patients to the appropriate treatment pathway. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Utility of point-of-care ultrasound in patients with suspected diverticulitis in the emergency department

In emergency department (ED) cases with clinically suspected diverticulitis, diagnostic imaging is often needed for diagnostic confirmation, to exclude complications, and to direct patient management. Patients typically undergo a CT scan in the ED; however, in a subset of cases with suspected diverticulitis, point-of-care ultrasound (POCUS) may provide sufficient data to confirm the diagnosis and ascertain a safe plan for outpatient management.We review the main sonographic features of diverticulitis and discuss the diagnostic accuracy and potential benefits of a POCUS First model.

Paradigm shift: the Copernican revolution in diverticular disease

Diverticular disease (DD) is an umbrella definition that includes different clinical conditions ranging from diverticulosis to severe and potentially life-threatening complications. In the last decade, new concepts regarding pathogenetic alterations have been developed, while the diagnostic, clinical and therapeutic approaches to the management of DD patients have changed. The protective role of dietary factors (i.e., fiber) has been questioned, whilst some drugs widely used in clinical practice have been found to have a deleterious effect. The use of antibiotics in all patients with acute uncomplicated diverticulitis was reconsidered, as well as the need for a surgical approach in these patients. Conflicting recommendations in different guidelines were proposed for the treatment of symptomatic uncomplicated DD. An endoscopic classification of DD was introduced, and a "curative" endoscopic approach has been pioneered. Based on these observations, which together amount to a kind of "Copernican revolution" in the management of DD patients, we performed a comprehensive and critical reappraisal of the proposed modifications, aiming to discriminate between certainties and doubts on this issue.

Diverticular Disease in the Elderly

PURPOSE OF REVIEW

While few diseases are limited solely to the elderly, diverticular disease is clearly more prevalent with increasing age and therefore the aim of this review is to focus on the clinical implications of diverticular disease in the elderly.

RECENT FINDINGS

Diverticulitis in the elderly is best managed with an individualized treatment approach including considerations for selective antibiotic usage even in uncomplicated disease. Furthermore, due to the increased prevalence of ischemic colitis in the elderly and the similarities in presentation with diverticular hemorrhage, there needs to be a high index of suspicion and appropriate evaluation for ischemic colitis in patients with hematochezia, particularly if they have abdominal pain. The elderly are a vulnerable population where the index of suspicion for complications of diverticular disease should be high.

Effects of Radiation Dose Reduction on Diagnostic Accuracy of Abdominal CT in Young Adults with Suspected Acute Diverticulitis: A Retrospective Intraindividual Analysis

RATIONALE AND OBJECTIVES

To assess the effects of radiation dose reduction on image quality and diagnostic accuracy of abdominal computed tomography (CT) in young adults with suspected acute diverticulitis.

MATERIALS AND METHODS

Fifty-four patients ≤40 years who received contrast-enhanced abdominal CT for suspected acute diverticulitis were included. Low-dose CT (LDCT) datasets (25%, 50%, and 75% of the original dose) were generated using sinogram synthesis and quantum noise modeling. A five-point scale was used to assess images qualitatively (overall image quality, noise, artefacts, and sharpness) and for diagnostic confidence (5 being the best possible outcome). Furthermore, the diagnostic accuracy was determined for the presence of acute diverticulitis.

RESULTS

Among 54 patients (mean age: 35.2 ± 5.3 years, 77.8% male), the prevalence of acute diverticulitis was high (57.4%). Subjective image quality was highest for original datasets and lowest for LDCT datasets with 25% of the original dose (median [interquartile range]: 5 [5] vs. 3 [2-3], p < 0.001). Diagnostic confidence was high for all datasets down to 50% of the original dose, while 25% LDCT datasets were associated with a significantly decreased diagnostic confidence (p < 0.001). Diagnostic accuracy was high for all LDCT and original datasets (sensitivity: 100%, negative predictive value [NPV]: 100% for 75% and 100% dose levels; sensitivity: 96.8%, NPV: 95.8% for 50% dose level; sensitivity: 93.6%, NPV: 91.7% for 25% dose level, respectively). Inter-rater agreement regarding the detection of diverticulitis was almost perfect at doses ≥50% (kappa: >0.81), while lower for datasets of 25% of the original radiation dose agreement (kappa: 0.67-0.78).

CONCLUSION

Radiation dose reduction down to 50% of the original radiation exposure permits high image quality, diagnostic confidence, and accuracy for the assessment of acute diverticulitis in abdominal CT in young adults without the use of iterative reconstruction algorithms.

The Multidisciplinary Management of Acute Complicated Diverticulitis

BACKGROUND

Acute complicated diverticulitis (ACD) is an important and increasing issue in Western countries that leads to a significant impact and burden for patients, but also for the society due to its effects on hospital costs. In recent years, essential progression has been made regarding the research and implementation of novel or improved treatment strategies for the various disease entities of ACD. Much debated topics in the multidisciplinary approach of patients with ACD, such as the choice for nonoperative treatment options, the role of percutaneous drainage for diverticular abscesses, the role of laparoscopic lavage for perforated diverticulitis with purulent peritonitis, and the role of sigmoidectomy with primary anastomosis for patients with perforated diverticulitis, require clinicians to attentively follow and participate in these discussions.

SUMMARY

The aim of this review article is to provide clinicians with a structured overview of the recent literature on the multidisciplinary management of complicated diverticulitis by a panel of experts on the topic. By performing an extensive literature search in the online medical databases MEDLINE (Ovid) and Embase, insights into nonoperative treatment, percutaneous drainage, minimally invasive and open surgical treatment of ACD are provided. Furthermore, a comprehensive algorithm for the treatment of ACD has been developed.

KEY MESSAGES

Accurate patient evaluation and selection based on patient and disease characteristics is of paramount importance to determine the appropriate treatment strategy for patients with complicated diverticulitis. The presence of an experienced surgeon with advanced skills in laparoscopic emergency colorectal surgery is crucial for the treatment of patients with perforated diverticulitis in order to properly evaluate, select and treat patients suitable for nonoperative or operative treatment with an open or laparoscopic approach.

Colorectal surgeon consensus with diverticulitis clinical practice guidelines

AIM

To determine the application of clinical practice guidelines for the current management of diverticulitis and colorectal surgeon specialist consensus in Australia and New Zealand.

METHODS

A survey was distributed to 205 colorectal surgeons in Australia and New Zealand, using 22 hypothetical clinical scenarios.

RESULTS

The response rate was 102 (50%). For 19 guideline-based scenarios, only 11 (58%) reached consensus (defined as > 70% majority opinion) and agreed with guidelines; while 3 (16%) reached consensus and did not agree with guidelines. The remaining 5 (26%) scenarios showed community equipoise (defined as less than/equal to 70% majority opinion). These included diagnostic imaging where CT scan was contraindicated, management options in the failure of conservative therapy for complicated diverticulitis, surgical management of Hinchey grade 3, proximal extent of resection in sigmoid diverticulitis and use of oral mechanical bowel preparation and antibiotics for an elective colectomy. The consensus areas not agreeing with guidelines were management of simple diverticulitis, management following the failure of conservative therapy in uncomplicated diverticulitis and follow-up after an episode of complicated diverticulitis. Fifty-percent of rural/regional based surgeons would perform an urgent sigmoid colectomy in failed conservative therapy of diverticulitis compared to only 8% of surgeons city-based (Fisher’s exact test P = 0.016). In right-sided complicated diverticulitis, a greater number of those in practice for more than ten years would perform an ileocecal resection and ileocolic anastomosis (79% vs 41%, P < 0.0001).

CONCLUSION

While there are areas of consensus in diverticulitis management, there are areas of community equipoise for future research, potentially in the form of RCTs.

Diagnosis of symptomatic uncomplicated diverticular disease and the role of Rifaximin in management

Patients with diverticulosis who develop persistent abdominal pain, bloating and changes in bowel habits not associated with overt inflammation may have symptomatic uncomplicated diverticular disease (SUDD). The severity and frequency of SUDD symptoms may have an impact on daily activities and severely affect quality of life. Effective management of SUDD should follow a three part strategy: divert, tackle and maintain. Divert to make the correct diagnosis: several symptoms of SUDD are common to other conditions that require different therapeutic approaches. However, several key differences should be used to diagnose SUDD. Pain in SUDD is normally in the iliac fossa, persistent, often lasting more than 24 hrs, and is not relieved by bowel movement, as is often the case with irritable bowel syndrome. Another difference is in the timing: the prevalence of SUDD increases with age, and patients under the age of 40 years are less likely to have diverticula. It is useful to establish whether a patient has diverticulosis, especially if the patient is relatively young; lack of diverticula excludes SUDD. Cross-sectional imaging is indicated; however, recent archival image data or ultrasonography may be useful alternatives. Laboratory tests should be ordered to exclude overt inflammation. Once the diagnosis of SUDD is made, the patient should receive effective therapy to tackle the condition. This should include dietary fibre supplementation and cyclic treatment with rifaximin 400 mg twice daily for 7 days per month. Once symptom control is achieved, it should be maintained by continuing therapy for at least 12 months.

Intestinal Ultrasonography in the Diagnosis and Management of Colonic Diverticular Disease

Diverticula of the colon and their symptomatic manifestations, including acute diverticulitis (AD), are frequent complaints and the cause of an increasing burden of ambulatory visits, diagnostic procedures, and hospital admissions. Endoscopic and radiologic diagnostic procedures have a well-known role in the diagnosis and management of the disease, but recently intestinal ultrasonography has been proposed as a complementary tool in the diagnosis and follow-up of diverticular disease. This review shows the main sonographic features of diverticula and discusses the potential role of ultrasound in suggesting the presence of symptomatic uncomplicated diverticular disease of the colon. Moreover, the sonographic features of AD, diagnostic accuracy, advantages, and limitations of the technique will be discussed. We place special emphasis on the present role of intestinal ultrasonography in patients with suspected AD. Owing to its high sensitivity and high positive predictive value in assessing AD, intestinal ultrasound is currently suggested by some European national consensus guidelines as the first-line examination in this setting. In fact, to minimize false-negative findings and avoid unnecessary radiation exposure in patients with suspected AD, intestinal ultrasound might be used as the first-line examination in a sequential diagnostic strategy, followed by computed tomography only in the case of negative or inconclusive findings.

Acute left-sided colonic diverticulitis: clinical expressions, therapeutic insights, and role of computed tomography

The diagnostic approach of patients with suspected acute diverticulitis remains debated. On the one hand, a scoring system with the best predictive value in diagnosing acute diverticulitis has been developed in order to reduce the use of computed tomography (CT) scan, while, on the other hand, patients with a high probability of acute diverticulitis should benefit from CT scan from a clinical viewpoint, ensuring that they will receive the most appropriate treatment. The place and classification of CT scan for acute diverticulitis need to be reassessed. If the management of uncomplicated acute diverticulitis, abscess, and fecal peritonitis is now well codified, urgent surgical or medical treatment of hemodynamically stable patients presenting with intraperitoneal air or fluid without uncontrolled sepsis is still under discussion. Furthermore, the indications for laparoscopic lavage are not yet well established. It is known for years that episode(s) of acute uncomplicated diverticulitis may induce painful recurrent bowel symptoms, known as symptomatic uncomplicated diverticular disease and irritable bowel syndrome-like diverticular disease. These two clinical expressions of diverticular disease, that may darken quality of life, are treated medically aimed at symptom relief. The possible place of surgery should be discussed. Clinical and CT scan classifications should be separated entities.