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Intra-arterial CT angiography: the new gold standard for mesenteric embolisation in acute gastrointestinal bleeding
S106
’
Wednesday
Scientific Session
Results: Averaged across all doses, MBIR reduced noise and improved contrast to noise ratio (CNR) compared to FBP by 73% and 232%, and reduced noise and improved CNR compared to ASIR by 69% and 110%, respectively. The effect was more pronounced in higher noise settings. Averaged across all doses, MBIR improved subjective image quality and diagnostic sensitivity for pulmonary embolism (PE) compared to FBP by 50% and compared to ASIR by 25%. Subjective improvements in image quality were most pronounced in higher noise settings. At 120 kVp/400 mA, readers scored FBP, ASIR, and MBIR images equally. At 100 mA/120 kVp, readers scored FBP and ASIR images as nondiagnostic for detection of PE, while MBIR images were considered of moderate quality but remained diagnostic for detection of PE. Conclusion: MBIR reduced image noise and improved CNR for the pulmonary arteries compared to ASIR and FBP across all dose levels. Furthermore, MBIR resulted in higher subjective image quality and improved diagnostic sensitivity for pulmonary embolism, particularly in higher noise settings.
4:10 PM
Abstract No. 228
Intra-arterial CT angiography: the new gold standard for mesenteric embolisation in acute gastrointestinal bleeding
WEDNESDAY: Scientific Sessions
Y. Yan, F.G. Irani, T. Teo, T. Yeow, A. Gogna, S. Ramamurthy, A. Patel, S.X. Chan, C. Too, R. Lo, B.S. Tan, K. Tay; Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore Purpose: There is limited evidence describing the role of IntraArterial CT Angiography (IACTA) in the investigation of acute bleeding of the gastrointestinal tract (BGIT). We aim to compare the sensitivity of IACTA with respect to conventional mesenteric digital subtraction angiography (DSA), in identifying the bleeding vessel (BV) and region of bleed (RB). We also aim to determine the complications and outcomes of IACTA, and positive predictors of IACTA. Materials and Methods: The hospital data of patients who underwent both DSA and IACTA for BGIT in our institution from September 2008 to February 2012 was reviewed. 34 procedures in 31 patients (16 males, 15 females), mean age 61.9 years (range 25 to 88 years), were included in the study. The comorbidities of the patients were compiled and graded using Charlson Comorbidity Index (CCI) (1). The DSA and IACTA images were compared to determine the BV and RB. Univariate analysis was performed to determine any relationship between the pre-procedural clinical parameter and the positive predictors for bleeding on DSA and IACTA. In 4 procedures, the bleeding spontaneously stopped on table prior to the patient undergoing IACTA and these were excluded from the analyses. There were 23 lower BGIT cases and 11 upper BGIT cases. Results: Out of 30 IACTAs, 19 identified the RB compared with 13 for DSA (p¼0.03), and 11 identified the BV compared with 8 for DSA (p¼0.25). Embolisation was performed in 11 (32.4%) procedures. Overall complication rate was 14.7% (n¼5) with all being minor. In the cohort, 11 patients made a full recovery, 10 required surgical intervention, 5 endoscopy and another 5 repeat
’
JVIR
mesenteric angiogram. 30 day mortality was 8.8% (n¼3). Higher CCI score, prolonged PT and lower systolic BP were associated with a positive DSA and IACTA (po0.05). Conclusion: IACTA has a superior sensitivity in detecting BGIT compared to DSA. A negative IACTA can reduce the amount of time and radiation expended in detecting BGIT. IACTA is a promising modality and prospective multicentre studies are needed to further establish its role in the management of BGIT.
4:18 PM
Abstract No. 229
Initial experience using non-contrast MR angiography for pre-procedural assessment in renal sympathetic denervation U. Pua1,2, C. Tan1, H. Ho3, P.J. Ong3; 1Diagnostic Radiology, Tan Tock Seng Hospital, Singapore, Singapore; 2Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; 3 Department of Cardiology, Tan Tock Seng Hospital, Singapore, Singapore Purpose: Respiratory and ECG-gated non-contrast MR angiography utilizing fast steady-state gradient echo (NC-MRA) is a novel MR technique in vascular imaging. We hereby describe our initial experience integrating NC-MRA as a pre-procedural assessment tool in patients referred for renal sympathetic denervation (RDN). Materials and Methods: All patients in our institution referred for RDN for the treatment of resistant hypertension were prospectively enrolled. NC-MRA was used as the primary renovascular imaging modality for assessment of anatomical suitability. Exclusion criteria for RDN included; i) significant renal artery stenosis (460% in diameter), ii) atrophied or solitary kidney, iii) renal artery length o20 mm, iv) renal artery diameter o5 mm. Other relevant parameters that aids RDN planning such as; i) early branching patterns, ii) presence of accessory renal arteries (diameter and numbers), iii) plaque location were also analyzed. NC-MRA were correlated with catheter angiography where available. Results: From November 2011 to September 2012, a total of 10 patients were referred for RDN. NC-MRA was successfully performed in all 10 patients. Three patients were deemed unsuitable for RDN due to severe renal artery stenosis (n¼1) and inadequate renal artery diameter (n¼2). Catheter angiographic correlation were available in 8 patients (7 RDN, 1 renal artery stenting) and showed good correlation for the recorded parameters. Relevant information such as plaque location (n¼2), early branching pattern (n¼1) and accessory renal arteries (n¼1) allowed for pre-procedural planning of ablation sites. RDN were successfully performed in all patients deemed suitable on NCMRA with no complications. Conclusion: Our early experience supports NC-MRA as a valuable assessment tool for anatomical suitability in RDN. Additionally, NC-MRA provides accurate anatomical information that aids pre-procedural planning. Larger scale studies are warranted to fully elucidate its potential as the main renovascular imaging modality in this new catheter based therapy.
’
Wednesday
Scientific Session
Results: Averaged across all doses, MBIR reduced noise and improved contrast to noise ratio (CNR) compared to FBP by 73% and 232%, and reduced noise and improved CNR compared to ASIR by 69% and 110%, respectively. The effect was more pronounced in higher noise settings. Averaged across all doses, MBIR improved subjective image quality and diagnostic sensitivity for pulmonary embolism (PE) compared to FBP by 50% and compared to ASIR by 25%. Subjective improvements in image quality were most pronounced in higher noise settings. At 120 kVp/400 mA, readers scored FBP, ASIR, and MBIR images equally. At 100 mA/120 kVp, readers scored FBP and ASIR images as nondiagnostic for detection of PE, while MBIR images were considered of moderate quality but remained diagnostic for detection of PE. Conclusion: MBIR reduced image noise and improved CNR for the pulmonary arteries compared to ASIR and FBP across all dose levels. Furthermore, MBIR resulted in higher subjective image quality and improved diagnostic sensitivity for pulmonary embolism, particularly in higher noise settings.
4:10 PM
Abstract No. 228
Intra-arterial CT angiography: the new gold standard for mesenteric embolisation in acute gastrointestinal bleeding
WEDNESDAY: Scientific Sessions
Y. Yan, F.G. Irani, T. Teo, T. Yeow, A. Gogna, S. Ramamurthy, A. Patel, S.X. Chan, C. Too, R. Lo, B.S. Tan, K. Tay; Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore Purpose: There is limited evidence describing the role of IntraArterial CT Angiography (IACTA) in the investigation of acute bleeding of the gastrointestinal tract (BGIT). We aim to compare the sensitivity of IACTA with respect to conventional mesenteric digital subtraction angiography (DSA), in identifying the bleeding vessel (BV) and region of bleed (RB). We also aim to determine the complications and outcomes of IACTA, and positive predictors of IACTA. Materials and Methods: The hospital data of patients who underwent both DSA and IACTA for BGIT in our institution from September 2008 to February 2012 was reviewed. 34 procedures in 31 patients (16 males, 15 females), mean age 61.9 years (range 25 to 88 years), were included in the study. The comorbidities of the patients were compiled and graded using Charlson Comorbidity Index (CCI) (1). The DSA and IACTA images were compared to determine the BV and RB. Univariate analysis was performed to determine any relationship between the pre-procedural clinical parameter and the positive predictors for bleeding on DSA and IACTA. In 4 procedures, the bleeding spontaneously stopped on table prior to the patient undergoing IACTA and these were excluded from the analyses. There were 23 lower BGIT cases and 11 upper BGIT cases. Results: Out of 30 IACTAs, 19 identified the RB compared with 13 for DSA (p¼0.03), and 11 identified the BV compared with 8 for DSA (p¼0.25). Embolisation was performed in 11 (32.4%) procedures. Overall complication rate was 14.7% (n¼5) with all being minor. In the cohort, 11 patients made a full recovery, 10 required surgical intervention, 5 endoscopy and another 5 repeat
’
JVIR
mesenteric angiogram. 30 day mortality was 8.8% (n¼3). Higher CCI score, prolonged PT and lower systolic BP were associated with a positive DSA and IACTA (po0.05). Conclusion: IACTA has a superior sensitivity in detecting BGIT compared to DSA. A negative IACTA can reduce the amount of time and radiation expended in detecting BGIT. IACTA is a promising modality and prospective multicentre studies are needed to further establish its role in the management of BGIT.
4:18 PM
Abstract No. 229
Initial experience using non-contrast MR angiography for pre-procedural assessment in renal sympathetic denervation U. Pua1,2, C. Tan1, H. Ho3, P.J. Ong3; 1Diagnostic Radiology, Tan Tock Seng Hospital, Singapore, Singapore; 2Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; 3 Department of Cardiology, Tan Tock Seng Hospital, Singapore, Singapore Purpose: Respiratory and ECG-gated non-contrast MR angiography utilizing fast steady-state gradient echo (NC-MRA) is a novel MR technique in vascular imaging. We hereby describe our initial experience integrating NC-MRA as a pre-procedural assessment tool in patients referred for renal sympathetic denervation (RDN). Materials and Methods: All patients in our institution referred for RDN for the treatment of resistant hypertension were prospectively enrolled. NC-MRA was used as the primary renovascular imaging modality for assessment of anatomical suitability. Exclusion criteria for RDN included; i) significant renal artery stenosis (460% in diameter), ii) atrophied or solitary kidney, iii) renal artery length o20 mm, iv) renal artery diameter o5 mm. Other relevant parameters that aids RDN planning such as; i) early branching patterns, ii) presence of accessory renal arteries (diameter and numbers), iii) plaque location were also analyzed. NC-MRA were correlated with catheter angiography where available. Results: From November 2011 to September 2012, a total of 10 patients were referred for RDN. NC-MRA was successfully performed in all 10 patients. Three patients were deemed unsuitable for RDN due to severe renal artery stenosis (n¼1) and inadequate renal artery diameter (n¼2). Catheter angiographic correlation were available in 8 patients (7 RDN, 1 renal artery stenting) and showed good correlation for the recorded parameters. Relevant information such as plaque location (n¼2), early branching pattern (n¼1) and accessory renal arteries (n¼1) allowed for pre-procedural planning of ablation sites. RDN were successfully performed in all patients deemed suitable on NCMRA with no complications. Conclusion: Our early experience supports NC-MRA as a valuable assessment tool for anatomical suitability in RDN. Additionally, NC-MRA provides accurate anatomical information that aids pre-procedural planning. Larger scale studies are warranted to fully elucidate its potential as the main renovascular imaging modality in this new catheter based therapy.