Acute abdominal venous thromboses- the hyperdense noncontrast CT sign Poster No.: C-1095 Congress: ECR 2011 Type: Educational Exhibit Authors: M. Goldstein, K. Jhaveri; Toronto, ON/CA Keywords: Abdomen, Veins / Vena cava, CT, Acute DOI: 10.1594/ecr2011/C-1095 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 25
Learning objectives The purpose of this exhibit is to review the presentation of acute venous thromboses (VT) throughout the abdominal venous system at unenhanced multidetector computed tomography (CT) and improve radiologist awareness to detect this important finding. Background Acute abdominal venous thrombosis (VT) is an infrequent but potentially serious event requiring prompt treatment management and in some cases intervention. Many CT scans are performed without intravenous (IV) contrast either due to scan protocol or to reasons such as renal impairment, allergy or lack of IV access. As a consequence the scan must be interpreted within these limitations raising possible diagnostic difficulties. When VT occurs such as acute SMV thrombosis the mortality risk has been found to range from 7% (1) to 34% (2) with risk of mesenteric ischaemia, bowel gangrene and peritonitis and their early diagnosis and treatment has been shown to reduce mortality. Though not all pose imminent risk of serious morbidity acute abdominal VT may also lead to acute renal failure or acute pulmonary embolus with risk of sudden death and therefore, urgent treatments such as anticoagulation or thrombolysis may be implemented upon diagnosis to prevent this. Clotted blood is called thrombosis when found intra-luminally within a vessel and a haematoma when extra-luminally and in the early stages is typically of high attenuation with density ~40-80 HU (3, 4). Hyperattenuating signs may be seen in a variety of vascular diseases at unenhanced CT including acute arterial occlusion, acute arterial dissection, aneurysm rupture, and acute venous thrombosis leading to a hyperdense vessel and are usually a transient phenomenon (5). The presence of an acute abdominal VT may be detected by identifying a hyperattenuating venous segment on unenhanced CT or as a filling defect on contrastenhanced CT. The presence of an acute VT either intracranially such as venous sinus thrombosis or within the chest as a pulmonary embolus may present similarly with a hyperattenuating sign on a non-contrast CT (6, 7). Imaging findings OR Procedure details Page 2 of 25
Kanne et al, and Swenson et al found that narrowing the windows (width ~150 HU/ level 50 HU) improved the radiologists' ability to diagnose acute pulmonary emboli and extracranial haemorrhage at unenhanced CT (7, 8). This may also be utilised by radiologists when looking at unenhanced abdominal CT scans particularly in those with acute presentations. This is shown with examples of acute abdominal venous thromboses in six different patients (Figures 1-21) with both standard abdominal and narrowed window settings demonstrated. Images for this section: Fig. 1: Left portal vein thrombosis at unenhanced CT on standard abdominal windows (Figure 1) and narrowed windows (Figure 2) Page 3 of 25
Fig. 2: Left portal vein thrombosis at unenhanced CT on standard abdominal windows (Figure 1) and narrowed windows (Figure 2) Page 4 of 25
Fig. 3: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 5 of 25
Fig. 4: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 6 of 25
Fig. 5: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 7 of 25
Fig. 6: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 8 of 25
Fig. 7: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 9 of 25
Fig. 8: Splenic, portal and superior mesenteric vein thrombosis at unenhanced CT axial and coronal images on standard abdominal windows (Figures 3,5), narrow windows (Figures 4,6), and confirmed at axial and coronal (Figures 7,8) enhanced CT subsequently performed. Page 10 of 25
Fig. 9: Portal vein thrombosis in a patient day 1 post-liver transplant at axial unenhanced CT on standard abdominal windows (Figure 9) and narrowed windows (Figure 10) Page 11 of 25
Fig. 10: Portal vein thrombosis in a patient day 1 post-liver transplant at axial unenhanced CT on standard abdominal windows (Figure 9) and narrowed windows (Figure 10) Page 12 of 25
Fig. 11: Right gonadal vein thrombosis in a patient treated for hepatoma on coronal unenhanced CT standard abdominal (Figure 11), narrowed windows (Figure 12) and confirmed at enhanced CT subsequently performed (Figure 13) Page 13 of 25
Fig. 12: Right gonadal vein thrombosis in a patient treated for hepatoma on coronal unenhanced CT standard abdominal (Figure 11), narrowed windows (Figure 12) and confirmed at enhanced CT subsequently performed (Figure 13) Page 14 of 25
Fig. 13: Right gonadal vein thrombosis in a patient treated for hepatoma on coronal unenhanced CT standard abdominal (Figure 11), narrowed windows (Figure 12) and confirmed at enhanced CT subsequently performed (Figure 13) Page 15 of 25
Fig. 14: SMV branch thrombosis in a patient presenting with closed loop small bowel obstruction and ischaemic small bowel confirmed on subsequent surgery seen at axial unenhanced CT on standard abdominal windows (Figure 14) and narrowed windows (Figure 15) Page 16 of 25
Fig. 15: SMV branch thrombosis in a patient presenting with closed loop small bowel obstruction and ischaemic small bowel confirmed on subsequent surgery seen at axial unenhanced CT on standard abdominal windows (Figure 14) and narrowed windows (Figure 15) Page 17 of 25
Fig. 16: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 18 of 25
Fig. 17: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 19 of 25
Fig. 18: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 20 of 25
Fig. 19: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 21 of 25
Fig. 20: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 22 of 25
Fig. 21: Left renal vein, and IVC and bilateral common iliac, and left internal and external iliac vein thromboses in a patient post-ivc resection seen at axial and coronal unenhanced CT on standard abdominal windows (Figure 16,18,20) and narrowed windows (Figures 17,19,21) Page 23 of 25
Conclusion 1) Co-morbidities such as renal impairment particularly in the emergency setting mean many CTs are performed without IV contrast. Although not frequently seen, recognition of a hyperdense segment of a vein at unenhanced CT is important as it may indicate the presence of an acute VT which can pose significant adverse patient risk. 2) If uncertainty over the presence of an acute abdominal VT exists at unenhanced CT correlative imaging such as contrast enhanced CT or ultrasound should be performed. Personal Information References 1. Warshauer DM, Lee JK, Mauro MA, White GC,2nd. Superior mesenteric vein thrombosis with radiologically occult cause: a retrospective study of 43 cases. AJR Am J Roentgenol 2001; 177:837-841. 2. Alvi AR, Khan S, Niazi SK, Ghulam M, Bibi S. Acute mesenteric venous thrombosis: improved outcome with early diagnosis and prompt anticoagulation therapy. Int J Surg 2009; 7:210-213. 3. New PF, Aronow S. Attenuation measurements of whole blood and blood fractions in computed tomography. Radiology 1976; 121:635-640. 4. Mori H, Hayashi K, Uetani M, Matsuoka Y, Iwao M, Maeda H. High-attenuation recent thrombus of the portal vein: CT demonstration and clinical significance. Radiology 1987; 163:353-356. 5. Morita S, Ueno E, Masukawa A, Suzuki K, Machida H, Fujimura M. Hyperattenuating signs at unenhanced CT indicating acute vascular disease. Radiographics 2010; 30:111-125. 6. Leach JL, Fortuna RB, Jones BV, Gaskill-Shipley MF. Imaging of cerebral venous thrombosis: current techniques, spectrum of findings, and diagnostic pitfalls. Radiographics 2006; 26 Suppl 1:S19-41; discussion S42-3. 7. Kanne JP, Gotway MB, Thoongsuwan N, Stern EJ. Six cases of acute central pulmonary embolism revealed on unenhanced multidetector CT of the chest. AJR Am J Roentgenol 2003; 180:1661-1664. Page 24 of 25
8. Swensen SJ, McLeod RA, Stephens DH. CT of extracranial hemorrhage and hematomas. AJR Am J Roentgenol 1984; 143:907-912. Page 25 of 25