Background
To train a machine-learning model to locate the transition zone (TZ) of adhesion-related small bowel obstruction (SBO) on CT scans.
Materials and methods
We used 562 CTs performed in ...2005–2018 in 404 patients with adhesion-related SBO. Annotation of the TZs was performed by experienced radiologists and trained residents using bounding boxes. Preprocessing involved using a pretrained model to extract the abdominopelvic region. We modeled TZ localization as a binary classification problem by splitting the abdominopelvic region into 125 patches. We then trained a neural network model to classify each patch as containing or not containing a TZ. We coupled this with a trained probabilistic estimation of presence of a TZ in each patch. The models were first evaluated by computing the area under the receiver operating characteristics curve (AUROC). Then, to assess the clinical benefit, we measured the proportion of total abdominopelvic volume classified as containing a TZ for several different false-negative rates.
Results
The probability of containing a TZ was highest for the hypogastric region (56.9%). The coupled classification network and probability mapping produced an AUROC of 0.93. For a 15% proportion of volume classified as containing TZs, the probability of highlighted patches containing a TZ was 92%.
Conclusion
Modeling TZ localization by coupling convolutional neural network classification and probabilistic localization estimation shows the way to a possible automatic TZ detection, a complex radiological task with a major clinical impact.
Objectives
To identify computed tomography (CT) findings associated with bowel necrosis in patients with surgically confirmed strangulating closed-loop small-bowel obstruction (CL-SBO) due to ...adhesions or internal hernia.
Methods
This retrospective study was approved by our institutional review board, and informed consent was waived. To identify CT signs of bowel necrosis, two gastrointestinal radiologists performed blinded, independent, retrospective reviews of 41 CT studies from consecutive patients who had CL-SBO due to adhesions or internal hernias and who underwent surgery within 48 h. On the basis of surgical and pathological findings, patients were classified as having reversible ischemia or histologically documented necrosis. Univariate statistical analyses were performed to assess associations between CT signs and bowel necrosis. Kappa statistics were computed to assess interobserver agreement.
Results
We included 25 (61%) women and 16 (39%) men with a median age of 79 years. Bowel necrosis was found in 25/41 (61%) patients and ischemic but viable bowel in 16/41 (39%) patients. Increased unenhanced bowel-wall attenuation was the only CT finding significantly associated with bowel necrosis (
p
= 0.0002). This sign had 58% (95% CI, 37–78) sensitivity and 100% (95% CI, 79–100) specificity for necrosis. Interobserver agreement was fair (0.59; 95% CI, 0.37–0.82).
Conclusion
Increased unenhanced bowel-wall attenuation is specific for bowel necrosis and should lead to prompt surgery for bowel resection.
Key Points
• Increased unenhanced bowel-wall attenuation is the only sign specific for necrosis
• Decreased bowel-wall enhancement is not relevant for differentiating reversible ischemia from necrosis
• Preoperative knowledge of bowel necrosis is helpful to plan adequate surgery
To evaluate performance of increased bowel-wall attenuation on unenhanced 64-section multidetector computed tomographic (CT) images for diagnosing bowel-wall ischemia in patients with mechanical ...small-bowel obstruction (SBO) and to evaluate the diagnostic accuracy of multidetector CT in detecting small-bowel ischemia complicating SBO, with surgical and histopathologic findings as reference standard.
The local institutional review board approved this retrospective study; informed consent requirement was waived. In 44 patients (10 men, 34 women; age range, 30-100 years) who were admitted because they were suspected of having SBO and treated surgically within the next 7 days, 45 multidetector CT scans were retrospectively reviewed. Two gastrointestinal radiologists performed independent blinded reviews of images to identify specific signs of ischemia; disagreements were resolved in consensus with a third gastrointestinal radiologist. Results were compared with both findings in prospective radiology reports and surgical and histopathologic findings. Fisher exact and χ(2) tests were used to assess associations between CT signs and ischemia, and the κ statistic was used to assess interobserver agreement.
In 19 of 45 (42%) multidetector CT scans, ischemia was confirmed at surgery and/or histopathologic examination. Increased bowel-wall attenuation on unenhanced images was significantly associated with ischemia (P < .0001); in this highly selected population, this sign had a 100% (24 of 24) specificity and a 56% (10 of 18) sensitivity. Sensitivity and specificity of multidetector CT for ischemia were 63% (12 of 19) and 92% (24 of 26), respectively, for the prospective reports and 84% (16 of 19) and 96% (25 of 26), respectively, for the consensus review. Decreased segmental bowel-wall enhancement was the most accurate 64-section multidetector CT sign for diagnosing ischemia (sensitivity, 78% 14 of 18; specificity, 96% 24 of 25; P < .0001). The small-bowel feces sign was significantly associated with ischemia (P = .0308).
Increased bowel-wall attenuation on unenhanced 64-section multidetector CT images is a specific sign for ischemia complicating SBO. Diagnostic accuracy of 64-section multidetector CT for ischemia associated with SBO was excellent.
Key Points
• Early in the pandemic, numbers of patients undergoing non-COVID-19 emergent CTs dropped sharply but diagnostic yield did not increase, suggesting potentially undiagnosed emergencies in ...patients not seen in healthcare institutions.
Purpose
To identify computed tomography (CT) findings associated with successful conservative treatment of closed loop small bowel obstruction (CL-SBO) due to adhesions or internal herniation.
...Material and methods
The local institutional review board approved this study while waiving informed consent. Clinical and CT data were collected retrospectively for 96 consecutive patients with a CT diagnosis of CL-SBO due to adhesions or internal herniation established by experienced radiologists who had no role in patient management. Mechanical obstruction with at least two transition zones on the bowel at a single site defined CL-SBO. Two radiologists blinded to patient data independently performed a retrospective review of the CT scans. The patient groups with successful versus failed initial conservative therapy were compared. Univariate and multivariate analyses were performed to look for CT findings associated with successful conservative therapy. Interobserver agreement was assessed for each CT finding.
Results
Of the 96 patients, 34 (35%) underwent immediate surgery and 62 (65%) received first-line conservative treatment, which succeeded in 19 (31%) and failed in 43 (69%). The distance between the transition zones was the only independent predictor of successful conservative therapy (odds ratio, 4.6 when ≥ 8 mm; 95% confidence interval 95% CI, 1.2–18.3). A distance ≥ 8 mm had 84% (95% CI, 60–97) sensitivity and 46% (95% CI, 31–62) specificity for successful conservative treatment. The correlation coefficient for the distance between transition zones between readers 1 and 2 was fair (
r
= 0.46).
Conclusion
CL-SBO can be resolved without surgery. When there is no CT sign of ischemia, the distance between the transition zones should be assessed.
Key Points
•
Twenty percent (19/96) of all cases of closed loop small bowel obstruction (CL-SBO) representing 31% of the patients given first-line conservative therapy, were resolved without surgery.
•
The distance between the transition zones may help to choose between conservative and surgical management in patients with a CL-SBO but no CT evidence of ischemia.
•
A distance < 8 mm between the transition zones suggests a need for emergent surgery.
Purpose
To compare clinical features, computed tomography (CT) findings, and outcomes of right vs. left colonic diverticulitis (CD) in Caucasians.
Methods
This single-center retrospective ...case–control study of patients seen between July 2005 and February 2013 included 30 consecutive cases of right CD and 70 controls taken at random from a consecutive cohort of patients with left CD. The final diagnosis was established by consensus between a gastrointestinal surgeon and a gastrointestinal radiologist. Clinical features, treatment, and follow-up data were collected. Two radiologists blinded to patient data reached a consensus about multiple CT criteria. Cases and controls were compared using appropriate statistical tests, and odds ratios (ORs) associated with clinically meaningful variables were computed using univariate logistic regression.
Results
Median age was significantly lower in cases than in controls (48.5 years IQR, 31–61 vs. 63.5 years 54–75,
P
< 0.0001). A body mass index <20 kg/m
2
compared to >30 kg/m
2
was associated with a higher risk of right than of left CD (OR 22.7, 95% confidence interval 95% CI, 2.6–200,
P
= 0.005). Compared to controls, cases more often had CT evidence of focal diverticular inflammation (86.7% 26/30 vs. 50% 35/70,
P
= 0.0006) and noncircumferential (≤180°) colonic wall thickening (66.7% 20/30 vs. 20% 14/70,
P
< 0.001). Complications were less common in the cases (6.7% 2/30 vs. 25.7% 18/70 than in controls,
P
= 0.03).
Conclusion
In Caucasians, right CD occurs in younger and thinner patients and carries a lower risk of complications compared to left CD. Focal diverticular inflammation by CT is more common in right than in left CD.
Renal arteriovenous malformation is a primarily congenital renal vascular abnormality. It is usually diagnosed incidentally on imaging, and the most common subtype is ‘cirsoid’, consisting of ...multiple, enlarged arterial feeders interconnecting with draining veins. We present a 74-year-old woman with an incidental finding of what was at first considered a hypervascularised kidney tumour but turned out to be a left intrarenal arteriovenous malformation associated with a left renal vein thrombosis. Selective endovascular embolisation was performed. The cause-consequence relationship between the arteriovenous malformation and the thrombosis is unique. To our knowledge, no such case has ever been reported.
Acceptance and commitment therapy (ACT) is a relatively new type of psychotherapy effective for treating depression and anxiety amongst family care partners of persons living with dementia PLWD. ...However, care partner engagement in mental health services is low and specific guidelines for designing ACT programs for care partners of PLWD do not exist. The purpose of this scoping review was to examine patterns in care partner engagement in ACT programs to identify program factors potentially influencing engagement.
A comprehensive scoping review according to Arksey and O'Malley's framework was followed. Databases and grey literature were searched for primary studies of ACT programs with care partners of PLWD. Data were charted and synthesized.
Ten studies met inclusion criteria and were analyzed. Amongst these, engagement was highest in three ACT programs that were delivered individually, remotely and were therapist-led or supported. Conversely, engagement was the lowest in two ACT programs that were self-directed, web-based and had minimal or no care partner-therapist interaction. Program factors perceived as influencing engagement included tailoring and personalization, mode of delivery and format, therapeutic support and connectedness, program duration and pace.
Findings from this review suggest that care partners engagement may be promoted by designing ACT programs that focus on the therapeutic client-therapist relationship, are delivered remotely and individually. Future research should focus on evaluation of best implementation practices for engagement and effectiveness.
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