Sonography: first-line modality in the diagnosis of acute colonic diverticulitis?

Accuracy of "TICS" ultrasound protocol in detecting simple and complicated diverticulitis: A prospective cohort study

BACKGROUND

Point-of-care ultrasound (US) has been suggested as the primary imaging in evaluating patients with suspected diverticulitis. Discrimination between simple and complicated diverticulitis may help to expedite emergent surgical consults and determine the risk of complications. This study aimed to: (1) determine the accuracy of an US protocol (TICS) for diagnosing diverticulitis in the emergency department (ED) setting and (2) assess the ability of TICS to distinguish between simple and complicated diverticulitis.

METHODS

Patients with clinically suspected diverticulitis who underwent a diagnostic computed tomography (CT) scan were identified prospectively in the ED. Emergency US faculty and fellows blinded to the CT results performed and interpreted US scans. The presence of simple or complicated diverticulitis was recorded after each US evaluation. The diagnostic ability of the US was compared to CT as the criterion standard. Modified Hinchey classification was used to distinguish between simple and complicated diverticulitis.

RESULTS

A total of 149 patients (55% female, mean ± SD age 58 ± 16 years) were enrolled and included in the final analyses. Diverticulitis was the final diagnosis in 75 of 149 patients (50.3%), of whom 53 had simple diverticulitis and 22 had perforated diverticulitis (29.4%). TICS protocol's test characteristics for simple diverticulitis include a sensitivity of 95% (95% confidence interval [CI] 87%-99%), specificity of 76% (95% CI 65%-86%), positive predictive value of 80% (95% CI 71%-88%), and negative predictive value of 93% (95% CI 84%-98%). TICS protocol correctly identified 12 of 22 patients with complicated diverticulitis (sensitivity 55% [95% CI 32%-76%]) and specificity was 96% (95% CI 91%-99%). Eight of 10 missed diagnoses of complicated diverticulitis were identified as simple diverticulitis, and two were recorded as negative.

CONCLUSIONS

In ED patients with suspected diverticulitis, US demonstrated high accuracy in ruling out or diagnosing diverticulitis, but its reliability in differentiating complicated from simple diverticulitis is unsatisfactory.

Surgeon-Performed Point-of-Care Ultrasound in the Diagnosis of Acute Sigmoid Diverticulitis: A Pragmatic Prospective Multicenter Cohort Study

Background and purpose Early diagnosis and risk stratification of sigmoid diverticulitis rely heavily on timely imaging. Computerized tomography (CT), the gold standard diagnostic test, may be delayed due to resource constraints or patient comorbidity. Point-of-care ultrasound (POCUS) has an established role in trauma evaluation, and could potentially diagnose and stage acute diverticulitis, thus shortening the time to definitive treatment.  Aims This study aimed to benchmark the accuracy of surgeon-performed POCUS against CT in diagnosing and staging acute diverticulitis. A secondary aim was to evaluate the duration between the POCUS and the confirmatory CT scan report. Patients and methods A pragmatic prospective multicenter cohort study (ClinicalTrials.gov Identifier: NCT02682368) was conducted. Surgeons performed point-of-care ultrasound as first-line imaging for suspected acute diverticulitis. POCUS diagnosis and radiologic Hinchey classification were compared to CT as the reference standard. Results Of 45 patients with suspected acute diverticulitis, POCUS classified 37 (82.2%) as uncomplicated diverticulitis, four (8.8%) as complicated diverticulitis, and four (8.8%) as other diagnoses. The POCUS-estimated modified radiologic Hinchey classification was largely concordant with CT staging with an accuracy of 88.8% (95% CI, 75.95-96.2%), a sensitivity of 100% (95% CI, 90.2- 100%) and a specificity of 44.4% (95% CI, 13.7-78.8%). The positive predictive value (PPV) was 87.8% and the negative predictive value (NPV) was 100%. There was moderate agreement between CT and POCUS, with a Cohen's kappa coefficient of 0.56. The mean delay between CT and POCUS was 9.14 hours (range 0.33 to 43.5). Conclusion We examined the role of POCUS in the management of acute diverticulitis and our findings suggest that it is a promising imaging modality with the potential to reduce radiation exposure and treatment delays. Adding a POCUS training module to the surgical curriculum could enhance diagnosis and expedite the management of acute diverticulitis.

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.

A Prospective Evaluation of Point-of-Care Ultrasonographic Diagnosis of Diverticulitis in the Emergency Department

STUDY OBJECTIVE

We evaluate the sensitivity and specificity of point-of-care ultrasonography, performed by ultrasonographic fellowship-trained emergency physicians and physician assistants, compared with computed tomography (CT) scan in diagnosing acute diverticulitis in the emergency department (ED).

METHODS

This was a prospective observational study of a convenience sample of patients with suspected diverticulitis who were treated at an academic ED between 2017 and 2020. Sonographers were blinded to clinical data, laboratory results, and CT scan findings. A total of 19 ultrasonographic fellowship-trained emergency physicians and physician assistants performed the ultrasonographic examinations. Point-of-care ultrasonographic diagnosis of acute diverticulitis was defined as the presence of bowel wall thickening, greater than 5 mm, surrounding a diverticulum, enhancement of the surrounding pericolonic fat, and sonographic tenderness to palpation. The primary outcome measures were sensitivity, specificity, positive predictive value, and negative predictive value of point-of-care ultrasonography in the diagnosis of diverticulitis compared with CT, which was considered the criterion standard.

RESULTS

Data from 452 patients were analyzed. Median age was 60 years, 54% were women, and 36% had a diagnosis of diverticulitis based on CT scan. Of the 452 patients, there were 13 false-positive (3%) and 10 false-negative (2%) point-of-care ultrasonographic examinations. Overall, compared with CT, point-of-care ultrasonography had a sensitivity of 92% (95% confidence interval 88% to 96%), specificity of 97% (95% confidence interval 94% to 99%), positive predictive value of 94% (95% confidence interval 90% to 97%), and negative predictive value of 96% (93% to 98%) in the diagnosis of diverticulitis.

CONCLUSION

In a convenience sample of ED patients with suspected diverticulitis, point-of-care ultrasonography performed by ultrasonographic fellowship-trained emergency physicians and physician assistants could be used as an imaging modality for diagnosing acute diverticulitis, with high sensitivity and specificity compared with CT scan.

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.

Diagnostic accuracy of acute diverticulitis with unenhanced low-dose CT

Background

The aim of this study was to evaluate the diagnostic accuracy of unenhanced low‐dose CT (LDCT) in acute colonic diverticulitis in comparison with contrast‐enhanced standard‐dose CT (SDCT).

Methods

All patients with clinically suspected diverticulitis who underwent LDCT followed by SDCT between January and October 2017 were evaluated prospectively. CT examinations were assessed for signs of diverticulitis, complications and other differential diagnoses by three independent radiologists (two consultants and one fourth‐year resident) using SDCT as the reference method. Sensitivity and specificity were calculated and Cohen's κ coefficient was used for agreement analyses.

Results

Of the 149 patients included (mean age 66·7 years, M : F ratio 0·4), 107 (71·8 per cent) had imaging consistent with diverticulitis on standard CT. Sensitivity and specificity values for a diverticulitis diagnosis using LDCT were 95–99 and 86–100 per cent respectively, and respective values for identification of complications were 58–73 and 78–100 per cent. The corresponding κ values among the three readers for diagnosis were 0·984, 0·934 and 0·816, whereas κ values for complications were 0·680, 0·703 and 0·354. Of the 26 patients who presented with other causes of abdominal symptoms identified on standard CT, 23 were diagnosed correctly on LDCT. Missed cases included splenic infarction (1) and segmental colitis (2).

Conclusion

The diagnostic accuracy of LDCT was high for the presence of acute diverticulitis. However, as signs of complicated disease can be missed using the low‐dose protocol, use of LDCT as a primary examination method should not preclude SDCT when complications may be suspected.

Acute diverticulitis: Key features for guiding clinical management

Diverticular disease of the colon and small bowel is an important cause of pathology leading to emergency department visits and urgent gastrointestinal surgery. CT is a highly sensitive and specific modality for the diagnosis of acute diverticulitis and its complications as well as for the exclusion of alternate causes of pathology. Ultrasound, MRI and virtual CT colonoscopy have important adjunct roles for screening and workup of complications in specific patient populations. While diverticular disease most commonly involves the descending and sigmoid colon, it can also affect the proximal colon and small bowel. Acute diverticulitis may be categorized as uncomplicated or complicated according to the degree of inflammatory changes and related complications it induces, although some degree of overlap exists in clinical practice. Uncomplicated diverticulitis is classically characterized by localized inflammation surrounding a diverticulum ranging from wall thickening and phlegmonous change to the development of small, localized pericolic abscesses. Complicated forms of disease manifest with larger pericolic and distant abscesses, fistulae to adjacent organs, perforation, and peritonitis. Recurrent episodes of diverticulitis may lead to muscular hypertrophy of the bowel wall and luminal narrowing, potentially leading to bowel obstruction. Several imaging features may help to differentiate diverticulitis from colonic malignancy, however this remains a diagnostic imaging challenge that often requires further evaluation with colonoscopy. In this review, we discuss the pathophysiology and key imaging features of acute diverticulitis and its complications. We explore both common and uncommon presentations of the disease involving the colon and small bowel, acute and chronic manifestations of disease, and pitfalls to recognize when imaging alone may be insufficient to distinguish benign from malignant.

Nongynecologic Findings Seen at Pelvic US

Ultrasonography (US) is frequently the first imaging modality used to examine women with symptoms involving the pelvis. It is widely available and involves no exposure to ionizing radiation. Images can be acquired with a transabdominal, endovaginal, or translabial approach, and the use of video clips and three-dimensional reconstructions can be helpful. US is excellent for assessment of the uterus, ovaries, and adnexa. Occasionally, nongynecologic pelvic diseases arising from the gastrointestinal, genitourinary, and musculoskeletal systems and the pelvic peritoneal and extraperitoneal spaces may be detected and can be a source of diagnostic dilemma. US can be helpful not only in the detection but also occasionally in the characterization of such entities. Computed tomography and magnetic resonance imaging are useful in complicated cases. In this article, the normal US appearance of the bowel and US signs of bowel disease and specific entities, including appendicitis, diverticular disease, bowel obstruction, appendiceal mucocele, and intestinal tumors, are reviewed. The lower urinary tract is included in the field of view in every pelvic US examination; commonly encountered entities related to the urinary bladder, distal ureter, and urethra are illustrated. In addition to arising in the gastrointestinal and genitourinary tracts, pathologic conditions in the pelvis can arise in the peritoneal or extraperitoneal space. Although conditions of the pelvic peritoneal and extraperitoneal spaces are rare, it is important to recognize these entities and distinguish them from the more common gynecologic diseases. Owing to the implications for diagnosis and management, radiologists and other physicians who perform pelvic US should be aware of the spectrum of nongynecologic pathologic entities that can be detected. ©RSNA, 2017.

Benefits of sonography in diagnosing suspected uncomplicated acute diverticulitis

OBJECTIVES

Despite evidence demonstrating equivalent accuracy of sonography and computed tomography (CT) in the workup of mild/uncomplicated acute diverticulitis, CT is overwhelmingly performed as the initial diagnostic test, particularly in the acute setting. Our study evaluated potential radiation and turnaround time savings associated with performing sonography instead of CT as the initial diagnostic examination in the workup of suspected uncomplicated acute diverticulitis.

METHODS

We retrospectively reviewed medical records from January 2010 to December 2012 for patients presenting with clinical symptoms of acute diverticulitis. Patients were categorized as a whole and subgrouped by age (>40 and <40 years). A modified Hinchey classification (Am Surg 1999; 65:632-636) was used to stage the severity of the disease. The effective radiation dose was calculated by multiplying the dose length product from the scanner by the standard conversion coefficient (k= 0.0021 mSv/mGy × cm). The turnaround time for patients was calculated as the time the examination was ordered by the emergency department physician or staff to the time the report was finalized.

RESULTS

Our study included 253 patients (172 male and 81 female; mean age ± SD, 50.2 ± 11.7 years; 132 >40 years and 121 <40 years). The distribution of patients by the modified Hinchey classification was 210 (stages 0 and 1a), 26 (stages 1b and 2), 17 (stages 3 and 4), 0 (fistula), and 0 (obstruction). The estimated CT radiation dose per patient was 21 ± 5.2 mSv. Mean turnaround times for CT and sonography were 138.5 ± 76.9 and 51.3 ± 44 minutes, respectively.

CONCLUSIONS

Sonography is a lower-cost, faster, and radiation-free alternative that measures up to the diagnostic standards of CT for management of suspected mild or uncomplicated acute diverticulitis.