Contrast extravasation on computed tomography angiography in patients with hematochezia or melena: Predictive factors and associated outcomes

Localization and etiological stratification of non-neoplastic small bowel bleeding via CT imaging: a 10-year study

OBJECTIVES

The purpose of this study is to assess the diagnostic efficacy of contrast-enhanced CT scans for small bowel bleeding.

METHODS

This retrospective study evaluated patients diagnosed with non-neoplastic small intestinal bleeding (including duodenum) who underwent abdominal CT at our institution from December 2013 to March 2023. Patients were categorized into diverticulum and non-diverticulum groups based on the cause of bleeding. Active bleeding was defined on the CT images as extravasation of contrast material in the intestinal lumen during the arterial phase and/or progressive accumulation of contrast material during the venous phase. We have documented the original report (extracted from the medical record system and additional consultation opinions from senior radiologists), including the presence of active bleeding and its potential bleeding location. Furthermore, two radiologists reassessed the CT images, seeking consensus on the diagnosis between them.

RESULTS

The study included 165 patients, predominantly male, with a median age of 30 years. Active bleeding was identified in 48.3% of patients. Notably, all identified bleeding diverticula in the diverticulum group exhibited cul-de-sac termination. Among the identified causes of bleeding, Crohn's disease was most prevalent (46.7%, N of causes = 64). Significant differences were observed in the diagnostic methods between the diverticulum and non-diverticulum groups, with surgery predominantly applied in the diverticulum group, and endoscopy in the non-diverticulum group (n = 49 vs n = 15, p = 0.001). Contrast agent extravasation was significantly higher in the diverticulum group (n = 54 vs n = 16, p = 0.001), and Meckel's diverticulum cases appearing tubular were significantly higher than in other diverticulum cases (n = 25 vs n = 3, p < 0.001).

CONCLUSION

CT allows for a higher detection rate of diverticular bleeding, even if asymptomatic, guiding classification into multiple potentially clinically relevant categories.

CRITICAL RELEVANCE STATEMENT

Contrast-enhanced CT imaging is effective in determining the location and cause of non-neoplastic small bowel bleeding, especially diverticular bleeding. Therefore, the use of enhanced CT should be prioritized in the diagnosis and management of small bowel bleeding.

KEY POINTS

CT has potential value in the diagnosis of small bowel bleeding. CT imaging suggests possible surgical intervention for active bleeding detection. CT diagnoses and localizes small bowel bleeding, aiding in treatment and prioritizing in guidelines.

Cinematic Rendering of Gastrointestinal Stromal Tumours: A Review of Current Possibilities and Future Developments

Gastrointestinal stromal tumours (GISTs) are defined as CD117-positive primary, spindled or epithelioid, mesenchymal tumours of the gastrointestinal tract, omentum, or mesentery. While computed tomography (CT) is the recommended imaging modality for GISTs, overlap in imaging features between GISTs and other gastrointestinal tumours often make radiological diagnosis and subsequent selection of the optimal therapeutic approach challenging. Cinematic rendering is a novel CT post-processing technique that generates highly photorealistic anatomic images based on a unique lighting model. The global lighting model produces high degrees of surface detail and shadowing effects that generate depth in the final three-dimensional display. Early studies have shown that cinematic rendering produces high-quality images with enhanced detail by comparison with other three-dimensional visualization techniques. Cinematic rendering shows promise in improving the visualization of enhancement patterns and internal architecture of abdominal lesions, local tumour extension, and global disease burden, which may be helpful for lesion characterization and pretreatment planning. This article discusses and illustrates the application of cinematic rendering in the evaluation of GISTs and the unique benefit of using cinematic rendering in the workup of GIST with a specific emphasis on tumour characterization and preoperative planning.

CT and MRI of Gastrointestinal Stromal Tumors: New Trends and Perspectives

Gastrointestinal stromal tumors (GISTs) are defined as mesenchymal tumors of the gastrointestinal tract that express positivity for CD117, which is a c-KIT proto-oncogene antigen. Expression of the c-KIT protein, a tyrosine kinase growth factor receptor, allows the distinction between GISTs and other mesenchymal tumors such as leiomyoma, leiomyosarcoma, schwannoma and neurofibroma. GISTs can develop anywhere in the gastrointestinal tract, as well as in the mesentery and omentum. Over the years, the management of GISTs has improved due to a better knowledge of their behaviors and risk or recurrence, the identification of specific mutations and the use of targeted therapies. This has resulted in a better prognosis for patients with GISTs. In parallel, imaging of GISTs has been revolutionized by tremendous progress in the field of detection, characterization, survival prediction and monitoring during therapy. Recently, a particular attention has been given to radiomics for the characterization of GISTs using analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence with the aim of better characterizing GISTs and providing a more precise assessment of tumor burden. This article sums up recent advances in computed tomography and magnetic resonance imaging of GISTs in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning.

The Accuracy of Computed Tomography Angiography Compared With Technetium-99m Labelled Red Blood Cell Scintigraphy for the Diagnosis and Localization of Acute Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

Imaging tests are commonly used as an initial or early investigation for patients presenting with suspected acute gastrointestinal bleeding (AGIB). However, controversy remains regarding which of two frequently used modalities, computed tomography angiography (CTA) or technetium-99m labelled red blood cell scintigraphy (RBCS), is most accurate. This systematic review and meta-analysis was performed to compare the accuracy of CTA and RBCS for the detection and localization of AGIB. Five electronic databases were searched with additional manual searching of reference lists of relevant publications identified during the search. Two reviewers independently performed screening, data extraction and methodological assessments. Where appropriate, the bivariate model was used for meta-analysis of sensitivities and specificities for the detection of bleeding and Freeman-Tukey double-arcsine transformation used for meta-analysis of proportions of correctly localized bleeding sites. Forty-four unique primary studies were included: twenty-two investigating CTA, seventeen investigating RBCS and five investigating both modalities. Meta-analysis produced similar pooled sensitivities; 0.83 (95% CI 0.74-0.90) and 0.84 (0.68-0.92) for CTA and RBCS respectively. Pooled specificity for CTA was higher than RBCS; 0.90 (0.72-0.97) and 0.84 (0.71-0.91) respectively. However, differences were not statistically significant. CTA was superior to RBCS in correctly localizing bleeding; pooled proportions of 1.00 (0.98-1.00) and 0.90 (0.83-0.96) respectively (statistically significant difference, P < 0.001). There is no evidence that CTA and RBCS have different diagnostic performance with respect to the detection of AGIB. However, CTA is superior to RBCS in terms of correctly localising the bleeding site, supporting usage of CTA over RBCS as the first line imaging investigation.

Modified Appleby procedure for locally advanced pancreatic carcinoma: A primer for the radiologist

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent pancreatic neoplasm accounting for more than 90% of pancreatic malignancies. Surgical resection with adequate lymphadenectomy remains the only available curative strategy for patients with PDAC. Despite improvements in both chemotherapy regimen and surgical care, body/neck PDAC still conveys a poor prognosis because of the vicinity of major vascular structures, including celiac trunk, which favors insidious disease spread at the time of diagnosis. Body/neck PDAC involving the celiac trunk is considered locally advanced PDAC in most guidelines and therefore not eligible for upfront resection. However, a more aggressive surgical approach (i.e., distal pancreatectomy with splenectomy and en-bloc celiac trunk resection [DP-CAR]) was recently proposed to offer hope for cure in selected patients with locally advanced body/neck PDAC responsive to induction therapy at the cost of higher morbidity. The so-called "modified Appleby procedure" is highly demanding and requires optimal preoperative staging as well as appropriate patient preparation for surgery (i.e., preoperative arterial embolization). Herein, we review current evidence regarding DP-CAR indications and outcomes as well as the critical role of diagnostic and interventional radiology in patient preparation before DP-CAR, and early identification and management of DP-CAR complications.

Transcatheter arterial embolization for cancer-related non-variceal upper gastrointestinal bleeding: A multicenter retrospective study of 107 patients

PURPOSE

The purpose of this study was to retrospectively evaluate the outcome of transcatheter arterial embolization (TAE) in the treatment of cancer-related non-variceal upper gastrointestinal bleeding (UGIB).

MATERIALS AND METHODS

One-hundred and seven patients who underwent TAE for the treatment of cancer-related non-variceal UGIB at five institutions between June 2016 and May 2019 were retrospectively included. There were 78 men and 29 women, with a mean age of 60.6 ± 13.2 (SD) (age range: 31-87 years). Clinical success was defined as no rebleeding within 30 days after TAE. Rebleeding was defined as non-variceal UGIB resulting in a decrease in hemoglobin > 2 g/dL within 24 h. The Kaplan-Meier method was used to estimate actuarial probabilities of rebleeding and survival within 30 days after TAE. Univariable and multivariable analyses were performed to identify variables associated with clinical success and 30-day mortality.

RESULTS

Technical success was achieved in 106 out of 107 patients (99.1%). Positive angiographic findings (contrast extravasation and pseudoaneurysm) were observed in 30/107 patients (28.0%). Empiric embolization was performed in 77/107 patients (72.0%). Clinical success was achieved in 60/107 patients (56.1%). The 3-day, 7-day, and 30-day actuarial probabilities of rebleeding were 21.5%, 31.0%, and 44.6%, respectively. No variables were identified as predictors of clinical success. Nineteen patients (19/107; 17.8%) died within 30 days after TAE; of them, 14 (14/107; 13.1%) died due to bleeding-related causes. The 3-day, 7-day, and 30-day actuarial probabilities of survival were 91.6%, 88.8%, and 77.4%, respectively. A baseline hemoglobin level of ≤ 60 g/L (Odds ratio [OR]: 3.376; 95% confidence interval [CI]: 1.223-9.318; P = 0.019) and clinical failure (OR: 6.149; 95% CI: 2.113-17.893; P = 0.001) were identified as predictors of 30-day mortality. Major complications (gastrointestinal perforation) occurred in one patient (1/107; 0.9%). Minor complications (abdominal pain, fever, and vomiting) occurred in 19 patients (19/107; 17.8%).

CONCLUSION

TAE is a safe treatment option for patients with cancer-related non-variceal UGIB, and seems to be effective in more than half of these patients.

Gastrointestinal stromal tumors: a comprehensive radiological review

Gastrointestinal stromal tumors (GISTs) originating from the interstitial cells of Cajal in the muscularis propria are the most common mesenchymal tumor of the gastrointestinal tract. Multiple modalities, including computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography, ultrasonography, digital subtraction angiography, and endoscopy, have been performed to evaluate GISTs. CT is most frequently used for diagnosis, staging, surveillance, and response monitoring during molecularly targeted therapy in clinical practice. The diagnosis of GISTs is sometimes challenging because of the diverse imaging findings, such as anatomical location (esophagus, stomach, duodenum, small bowel, colorectum, appendix, and peritoneum), growth pattern, and enhancement pattern as well as the presence of necrosis, calcification, ulceration, early venous return, and metastasis. Imaging findings of GISTs treated with antineoplastic agents are quite different from those of other neoplasms (e.g. adenocarcinomas) because only subtle changes in size are seen even in responsive lesions. Furthermore, the recurrence pattern of GISTs is different from that of other neoplasms. This review discusses the advantages and disadvantages of each imaging modality, describes imaging findings obtained before and after treatment, presents a few cases of complicated GISTs, and discusses recent investigations performed using CT and MRI to predict histological risk grade, gene mutations, and patient outcomes.