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Dual-energy CT of acute bowel ischemia. Abdom Radiol (NY) 2022; 47:1660-1683. [PMID: 34191075 DOI: 10.1007/s00261-021-03188-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/17/2022]
Abstract
Acute bowel ischemia is a condition with high mortality and requires rapid intervention to avoid catastrophic outcomes. Swift and accurate imaging diagnosis is essential because clinical findings are commonly nonspecific. Conventional contrast enhanced CT of the abdomen has been the imaging modality of choice to evaluate suspected acute bowel ischemia. However, subtlety of image findings and lack of non-contrast or arterial phase images can make correct diagnosis challenging. Dual-energy CT provides valuable information toward assessing bowel ischemia. Dual-energy CT exploits the differential X-ray attenuation at two different photon energy levels to characterize the composition of tissues and reveal the presence or absence of faint intravenous iodinated contrast to improve reader confidence in detecting subtle bowel wall enhancement. With the same underlying technique, virtual non-contrast images can help to show non-enhancing hyperdense hemorrhage of the bowel wall in intravenous contrast-enhanced scans without the need to acquire actual non-contrast scans. Dual-energy CT derived low photon energy (keV) virtual monoenergetic images emphasize iodine contrast and provide CT angiography-like images from portal venous phase scans to better evaluate abdominal arterial patency. In Summary, dual-energy CT aids diagnosing acute bowel ischemia in multiple ways, including improving visualization of the bowel wall and mesenteric vasculature, revealing intramural hemorrhage in contrast enhanced scans, or possibly reducing intravenous contrast dose.
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Srisajjakul S, Prapaisilp P, Bangchokdee S. Comprehensive review of acute small bowel ischemia: CT imaging findings, pearls, and pitfalls. Emerg Radiol 2022; 29:531-544. [PMID: 35122558 DOI: 10.1007/s10140-022-02028-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 01/31/2022] [Indexed: 01/12/2023]
Abstract
Acute small bowel ischemia is a life-threatening condition with a high mortality rate due to its lack of specific symptoms and laboratory profile, which render difficulty in establishing early diagnosis. The etiology of acute small bowel ischemia includes occlusive forms (arterial embolism, arterial thrombosis, and venous thrombosis) and nonocclusive mesenteric ischemia, of which arterial causes are far more common than venous causes. CT, the mainstay of accurate diagnoses, allows the identification of the features of vascular abnormalities and intestinal ischemic injuries, and helps clinicians to restore intestinal blood flow. Without treatment, the prognosis for acute small bowel ischemia is poor. A high index of suspicion and familiarity with the CT spectral findings of bowel ischemia are required to ensure rapid recognition of this condition.
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Affiliation(s)
- Sitthipong Srisajjakul
- Department of Radiology, Faculty of Medicine, Division of Diagnostic Radiology, Siriraj Hospital, Mahidol University, 2 Wanglang Road, Bangkoknoi, Bangkok, 10700, Thailand.
| | - Patcharin Prapaisilp
- Department of Radiology, Faculty of Medicine, Division of Diagnostic Radiology, Siriraj Hospital, Mahidol University, 2 Wanglang Road, Bangkoknoi, Bangkok, 10700, Thailand
| | - Sirikan Bangchokdee
- Department of Internal Medicine, Pratumthani Hospital, 7 Ladlumkaew Muang District, Pratumthani, 12000, Thailand
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Fitzpatrick LA, Rivers-Bowerman MD, Thipphavong S, Clarke SE, Rowe JA, Costa AF. Pearls, Pitfalls, and Conditions that Mimic Mesenteric Ischemia at CT. Radiographics 2021; 40:545-561. [PMID: 32125953 DOI: 10.1148/rg.2020190122] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The diagnosis of AMI is challenging because patient symptoms and laboratory test results are often nonspecific. A high degree of clinical and radiologic suspicion is required for accurate and timely diagnosis. CT angiography of the abdomen and pelvis is the first-line imaging test for suspected AMI and should be expedited. A systematic "inside-out" approach to interpreting CT angiographic images, beginning with the bowel lumen and proceeding outward to the bowel wall, mesentery, vasculature, and extraintestinal viscera, provides radiologists with a practical framework to improve detection and synthesis of imaging findings. The subtypes of AMI are arterial and venoocclusive disease, nonocclusive ischemia, and strangulating bowel obstruction; each may demonstrate specific imaging findings. Chronic mesenteric ischemia is more insidious at onset and almost always secondary to atherosclerosis. Potential pitfalls in the diagnosis of AMI include mistaking pneumatosis as a sign that is specific for AMI and not an imaging finding, misinterpretation of adynamic ileus as a benign finding, and pseudopneumatosis. Several enterocolitides can mimic AMI at CT angiography, such as inflammatory bowel disease, infections, angioedema, and radiation-induced enterocolitis. Awareness of pitfalls, conditions that mimic AMI, and potential distinguishing clinical and imaging features can assist radiologists in making an early and accurate diagnosis of AMI. ©RSNA, 2020.
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Affiliation(s)
- Laura A Fitzpatrick
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
| | - Michael D Rivers-Bowerman
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
| | - Seng Thipphavong
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
| | - Sharon E Clarke
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
| | - Judy A Rowe
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
| | - Andreu F Costa
- From the Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 1276 S Park St, 3rd Floor, Halifax, NS, Canada B3H 2Y9 (L.A.F., M.D.R.B., S.E.C., J.A.R., A.F.C.); and Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, Women's College Hospital, and University of Toronto, Toronto, Ontario, Canada (S.T.)
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4
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Olson MC, Fletcher JG, Nagpal P, Froemming AT, Khandelwal A. Mesenteric ischemia: what the radiologist needs to know. Cardiovasc Diagn Ther 2019; 9:S74-S87. [PMID: 31559155 DOI: 10.21037/cdt.2018.09.06] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Acute mesenteric ischemia (AMI) is a life-threatening condition that often presents with abdominal pain. Early diagnosis with contrast-enhanced computed tomography and revascularization can reduce the overall mortality in AMI. This article reviews practical etiological classification, pathophysiology of imaging manifestations and common pitfalls in intestinal ischemia.
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Affiliation(s)
| | | | - Prashant Nagpal
- Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
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Bunch PM, Zamani AA. Anatomic Eponyms in Neuroradiology: Brain, Cerebral Vasculature, and Calvarium. Acad Radiol 2016; 23:730-42. [PMID: 26916250 DOI: 10.1016/j.acra.2016.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/02/2016] [Accepted: 01/02/2016] [Indexed: 10/22/2022]
Abstract
Medical eponyms are ubiquitous, numerous, and at times controversial. They are often useful for succinctly conveying complex concepts, and familiarity with eponyms is important for proper usage and appropriate communication. In this historical review, we identify 18 anatomic eponyms used to describe structures of the brain, cerebral vasculature, and calvarium. For each structure, we first offer a biographical sketch of the individual for whom the structure is named. This is followed by a description of the anatomic structure and a brief discussion of its clinical relevance.
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