Arterial and venous phase evaluation in fast kV-switching dual-energy CT for detecting acute small bowel ischemia caused by small bowel obstruction

Q: What was the study purpose?

To compare diagnostic performance of fast kV-switching dual-energy CT parameters (VMI and iodine mapping) in arterial and venous phases for detecting surgically confirmed acute small bowel ischemia in suspected cases.

Q: Which DECT parameters performed best and in which phase?

Iodine quantity showed the highest AUC in each phase. Arterial phase parameters generally had higher AUCs than venous phase parameters, with notable significant differences involving arterial 40 keV and iodine quantity and venous iodine quantity.

Sep 29, 2026

Uploaded by Jake

Purpose: Compare fast kV-switching dual-energy CT (DECT) parameters—virtual monochromatic imaging (VMI) and iodine mapping—in arterial versus venous phases for detecting surgically confirmed acute small bowel ischemia (ASBI) in patients suspected by conventional visual CT. Methods: Thirty-two patients with bowel obstruction and conventional visual CT findings underwent cursor-based measurements on hypo-perfused bowel wall regions at 70 keV, 40 keV, and iodine quantity, with ROC analysis and inter-observer reliability (ICC). Results: Arterial 40-keV CT value and iodine quantity, and venous iodine quantity, differed significantly between surgically confirmed and non-confirmed ASBI; iodine quantity showed the highest AUC. Conclusions: DECT parameters, especially iodine quantity and generally arterial-phase metrics, effectively differentiate ASBI and may support arterial-phase DECT detection.

LanguageEnglish

CategoryHealthcare

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Pages12

Reading Time30 min

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Materials and methods

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Japanese Journal of Radiology (2026) 44:126–137 [https://doi.org/10.1007/s1](https://doi.org/10.1007/s1) 1604-025-01873-8 Arterial and venous phase evaluation in fast kV‑switching dual‑energy CT for detecting acute small bowel ischemia caused by small bowel obstruction Masazumi Matsuda1 · Motoko Konno1 · Takahiro Otani1 · TomokiTozawa1 · Kento Hatakeyama1 · Toshiki Murata1 · Emika Murasawa1 · Daichi Sugawara1 · Junichi Arita2 · Hajime Nakae3 · Naoko Mori1 Received: 12 February 2025 / Accepted: 8 September 2025 / Published online: 13 September 2025 © The Author(s) 2025 Abstract Purpose To compare the diagnostic performance of fast kV-switching dual-energy CT (DECT) parameters, including virtual monochromatic imaging (VMI) and iodine mapping, in the arterial and venous phases for detecting surgically confirmed acute small bowel ischemia (ASBI) in cases suspected as ASBI on conventional visual CT findings. Materials and methods Thirty-two patients with conventional visual CT findings suggesting possible or suspected ASBI caused by small bowel obstruction (SBO) were included. Two radiologists independently placed ten cursors on visually hypo-perfused bowel wall regions to measure CT values at 70 keV, 40 keV, and iodine quantity. Patients were categorized into surgically confirmed ASBI (n = 12) and non-confirmed ASBI (n = 20) . ROC analysis assessed diagnostic performance, and inter-observer reliability was evaluated using intra-class correlation coefficients (ICC) . Results For both observers, the CT value at 40 keV and iodine quantity in the arterial phase, as well as iodine quantity in the venous phase, was significantly different between surgically confirmed ASBI and non-confirmed ASBI groups (p < 0.05) . Iodine quantity consistently yielded the highest AUC among the evaluated parameters in each phase although the differences compared to 70-keV VMI were not statistically significant. The parameters in the arterial phase tended to demonstrate higher AUCs than those in the venous phase. Inter-observer agreement was moderate to substantial (ICC 0.585–0.741), while intraobserver agreement was substantial to almost perfect (ICC 0.733–0.940) . Conclusions DECT parameters, such as the CT value at 40-keV and the iodine quantity, were effective in differentiating surgically confirmed ASBI from non-confirmed ASBI in SBO cases with suspected ischemia. Iodine quantity showed the highest diagnostic performance among all evaluated parameters. Although the differences were not statistically significant, arterial phase parameters generally yielded higher AUCs than those in the venous phase, suggesting the potential utility of arterial phase DECT in the detection of ASBI. Keywords Dual-energy CT · Acute small bowel ischemia · Small bowel obstruction · Arterial phase Introduction Acute small bowel ischemia (ASBI) is a complex condition caused by the interruption of blood flow to the small bowel, which can result from mesenteric artery occlusion, mesenteric vein thrombosis, non-occlusive mesenteric ischemia, and strangulated small bowel obstruction (SBO) [1] . The mortality rate of ASBI is high, exceeding 50%[2–5] . Prompt intervention is critical to avoid poor outcomes in cases of ASBI; however, clinical signs and laboratory findings alone Extended author information available on the last page of the article are insufficient to reliably predict ASBI, making CT imaging an essential diagnostic tool [6, 7] . In this study, the abbreviation SBO refers to small bowel obstruction in general, while the term'strangulated SBO'is used specifically to indicate cases of obstruction accompanied by compromised blood flow. In the diagnosis of ASBI, particularly in cases of strangulated SBO, vascular occlusion may not be visualized on CT. Instead, evaluation relies on assessing the bowel wall and associated findings. Conventional visual CT findings of ASBI include reduced bowel enhancement, mural thickening, bowel-wall edema, unusual

FAQs

What was the study purpose?

To compare diagnostic performance of fast kV-switching dual-energy CT parameters (VMI and iodine mapping) in arterial and venous phases for detecting surgically confirmed acute small bowel ischemia in suspected cases.

How were patients selected and measurements performed?

Thirty-two patients with conventional visual CT findings suggesting possible or suspected ASBI due to small bowel obstruction were included. Two radiologists placed ten cursors on visually hypo-perfused bowel wall regions to measure CT values at 70 keV, 40 keV, and iodine quantity.

Which DECT parameters performed best and in which phase?

Iodine quantity showed the highest AUC in each phase. Arterial phase parameters generally had higher AUCs than venous phase parameters, with notable significant differences involving arterial 40 keV and iodine quantity and venous iodine quantity.

Sep 29, 2026

Uploaded by Jake