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Paul J Finn - One of the best experts on this subject based on the ideXlab platform.
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high resolution 3 dimensional ferumoxytol enhanced cardiovascular Magnetic Resonance Venography in central venous occlusion
Journal of Cardiovascular Magnetic Resonance, 2019Co-Authors: Puja Shahrouki, John M Moriarty, Sarah N Khan, Biraj B Bista, Stephen T Kee, Brian G Derubertis, Takegawa Yoshida, Kimlien Nguyen, Paul J FinnAbstract:Although cardiovascular Magnetic Resonance Venography (CMRV) is generally regarded as the technique of choice for imaging the central veins, conventional CMRV is not ideal. Gadolinium-based contrast agents (GBCA) are less suited to steady state venous imaging than to first pass arterial imaging and they may be contraindicated in patients with renal impairment where evaluation of venous anatomy is frequently required. We aim to evaluate the diagnostic performance of 3-dimensional (3D) ferumoxytol-enhanced CMRV (FE-CMRV) for suspected central venous occlusion in patients with renal failure and to assess its clinical impact on patient management. In this IRB-approved and HIPAA-compliant study, 52 consecutive adult patients (47 years, IQR 32–61; 29 male) with renal impairment and suspected venous occlusion underwent FE-CMRV, following infusion of ferumoxytol. Breath-held, high resolution, 3D steady state FE-CMRV was performed through the chest, abdomen and pelvis. Two blinded reviewers independently scored twenty-one named venous segments for quality and patency. Correlative catheter Venography in 14 patients was used as the reference standard for diagnostic accuracy. Retrospective chart review was conducted to determine clinical impact of FE-CMRV. Interobserver agreement was determined using Gwet’s AC1 statistic. All patients underwent technically successful FE-CMRV without any adverse events. 99.5% (1033/1038) of venous segments were of diagnostic quality (score ≥ 2/4) with very good interobserver agreement (AC1 = 0.91). Interobserver agreement for venous occlusion was also very good (AC1 = 0.93). The overall accuracy of FE-CMRV compared to catheter Venography was perfect (100.0%). No additional imaging was required prior to a clinical management decision in any of the 52 patients. Twenty-four successful and uncomplicated venous interventions were carried out following pre-procedural vascular mapping with FE-CMRV. 3D FE-CMRV is a practical, accurate and robust technique for high-resolution mapping of central thoracic, abdominal and pelvic veins and can be used to inform image-guided therapy. It may play a pivotal role in the care of patients in whom conventional contrast agents may be contraindicated or ineffective.
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abdominal Magnetic Resonance Venography
CardioVascular and Interventional Radiology, 1992Co-Authors: Paul J Finn, Esterbrook H LongmaidAbstract:With the refinement of fast gradient-echo imaging, it is now possible to perform abdominal Magnetic Resonance Venography completely noninvasively, without the use of oral or injected contrast agents. In this paper, we emphasize two-dimensional, time-of-flight angiographic techniques, as applied to the study of patency and flow in the veins of the abdomen. Magnetic Resonance Venography is routinely applicable to patients with portal disease, or suspected occlusion of the inferior vena cava, iliac veins or renal veins. Sequential, single-slice venographic images, acquired during breath holding, can be postprocessed to form projected venograms. Hemodynamic information is derived using presaturation schemes, bolus-tracking or phase imaging. These techniques can also be used to establish the integrity of surgical portosystemic shunts.
Puja Shahrouki - One of the best experts on this subject based on the ideXlab platform.
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high resolution 3 dimensional ferumoxytol enhanced cardiovascular Magnetic Resonance Venography in central venous occlusion
Journal of Cardiovascular Magnetic Resonance, 2019Co-Authors: Puja Shahrouki, John M Moriarty, Sarah N Khan, Biraj B Bista, Stephen T Kee, Brian G Derubertis, Takegawa Yoshida, Kimlien Nguyen, Paul J FinnAbstract:Although cardiovascular Magnetic Resonance Venography (CMRV) is generally regarded as the technique of choice for imaging the central veins, conventional CMRV is not ideal. Gadolinium-based contrast agents (GBCA) are less suited to steady state venous imaging than to first pass arterial imaging and they may be contraindicated in patients with renal impairment where evaluation of venous anatomy is frequently required. We aim to evaluate the diagnostic performance of 3-dimensional (3D) ferumoxytol-enhanced CMRV (FE-CMRV) for suspected central venous occlusion in patients with renal failure and to assess its clinical impact on patient management. In this IRB-approved and HIPAA-compliant study, 52 consecutive adult patients (47 years, IQR 32–61; 29 male) with renal impairment and suspected venous occlusion underwent FE-CMRV, following infusion of ferumoxytol. Breath-held, high resolution, 3D steady state FE-CMRV was performed through the chest, abdomen and pelvis. Two blinded reviewers independently scored twenty-one named venous segments for quality and patency. Correlative catheter Venography in 14 patients was used as the reference standard for diagnostic accuracy. Retrospective chart review was conducted to determine clinical impact of FE-CMRV. Interobserver agreement was determined using Gwet’s AC1 statistic. All patients underwent technically successful FE-CMRV without any adverse events. 99.5% (1033/1038) of venous segments were of diagnostic quality (score ≥ 2/4) with very good interobserver agreement (AC1 = 0.91). Interobserver agreement for venous occlusion was also very good (AC1 = 0.93). The overall accuracy of FE-CMRV compared to catheter Venography was perfect (100.0%). No additional imaging was required prior to a clinical management decision in any of the 52 patients. Twenty-four successful and uncomplicated venous interventions were carried out following pre-procedural vascular mapping with FE-CMRV. 3D FE-CMRV is a practical, accurate and robust technique for high-resolution mapping of central thoracic, abdominal and pelvic veins and can be used to inform image-guided therapy. It may play a pivotal role in the care of patients in whom conventional contrast agents may be contraindicated or ineffective.
Marc A Rodger - One of the best experts on this subject based on the ideXlab platform.
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the natural history of pelvic vein thrombosis on Magnetic Resonance Venography after vaginal delivery
American Journal of Obstetrics and Gynecology, 2012Co-Authors: Hisham Khalil, Andre Olivier, Leonard Avruch, Mark Walker, Marc A RodgerAbstract:Objective Venous thromboembolism constitutes the leading cause of direct maternal mortality in the developed world. To date, there are no studies using Magnetic Resonance Venography (MRV) to delineate the incidence and natural history of intraluminal filling defects in the postpartum period in patients with low thrombosis risk. Study Design This was a prospective cohort study of women at low thrombosis risk postvaginal delivery undergoing MRV in the early postpartum period. Results In 30 eligible and consenting participants, independently adjudicated MRV, conducted on a median of postpartum day 1, identified definite thrombosis in 30% (95% confidence interval [CI], 13.6–46.4%) of study participants. All episodes of definite thrombosis were identified in the iliac and ovarian veins. Probable thrombosis was identified in an additional 27% of study participants (95% CI, 10.3–41.7%), and possible thrombosis in an additional 10% (95% CI, 0–20.7%). Conclusion In this group of low-risk postpartum patients, we identified a high prevalence of definite pelvic vein intraluminal filling defects of uncertain clinical significance. This study suggests that some degree of pelvic vein intraluminal filling defect may be a normal finding after uncomplicated vaginal delivery.
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pelvic Magnetic Resonance Venography reveals high rate of pelvic vein thrombosis after cesarean section
Obstetrical & Gynecological Survey, 2006Co-Authors: Marc A Rodger, Leonard Avruch, Heather E Howley, Andre Olivier, Mark WalkerAbstract:Venous thromboembolism (VTE) not only remains the major cause of direct maternal mortality in developed countries worldwide, but reportedly causes more than half of direct maternal deaths in the United States. Although cesarean section increases the risk of pregnancy-associated VTE, postpartum thromboprophylaxis is not uniformly recommended. Magnetic Resonance Venography (MRV) appears to be a highly sensitive and specific means of detecting deep venous thrombosis (DVT) in the upper and lower extremities. The investigators report preliminary findings of an ongoing randomized, controlled trial that uses MRV to identify pelvic DVT after operative delivery. Observations were made during the run-in phase of a trial of thromboprophylaxis in women at moderate to high risk of DVT based on a family history of VTE or a personal history of superficial phlebitis, current major illness or infection, immobility for longer than 4 days, obesity, or age greater than 35 years. Other risk factors included gross varicose veins, preeclampsia, parity of 4 or more, emergency cesarean section, and extended surgery such as cesarean hysterectomy. The women were assigned to receive or not to receive open-label tinzaparin, a low-molecular-weight heparin, by subcutaneous injection. Two radiologists independently and blindly assessed the MRV studies. Participants included 15 women with a mean age of 33 years. None of them had compression leg ultrasound findings of DVT. The MRV findings were interpreted as showing definite thrombosis in 46% of women, all of whom were asymptomatic. Clots were found chiefly in the iliac veins, although one patient had thrombosis in the common femoral artery. All clots were less than 1 cm in size and only one occluded the affected vein. Nearly half of these moderate- or high-risk women were found to have definite pelvic DVT after cesarean delivery-many more than expected. The clinical significance of this finding remains to be determined. It is possible that pelvic vein thrombosis is a normal finding after cesarean delivery and also that DVT may be present in lower-risk women. MRV would seem to be a useful measure of outcome in studies evaluating postpartum measures intended to prevent DVT.
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pelvic Magnetic Resonance Venography reveals high rate of pelvic vein thrombosis after cesarean section
American Journal of Obstetrics and Gynecology, 2006Co-Authors: Marc A Rodger, Leonard Avruch, Heather E Howley, Andre Olivier, Mark WalkerAbstract:In the run-in phase of a thromboprophylactic trial in women at moderate to high risk of deep vein thrombosis postcesarean section, we used Magnetic Resonance Venography and found a surprisingly high rate of pelvic deep vein thrombosis (46% overall). Pelvic Magnetic Resonance Venography may be a useful surrogate outcome in obstetric thromboprophylaxis studies but the clinical significance is not known.
Alan R Moody - One of the best experts on this subject based on the ideXlab platform.
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iliac compression syndrome and recanalization of femoropopliteal and iliac venous thrombosis a prospective study with Magnetic Resonance Venography
Journal of Vascular Surgery, 2004Co-Authors: Douglas G W Fraser, Alan R Moody, Paul S Morgan, Anne L MartelAbstract:Abstract Objectives Poor iliac vein recanalization has been associated with compression of the left common iliac vein by the right common iliac artery (RCIA/LCIV compression); however, this finding has been difficult to confirm. In a baseline study, RCIA/LCIV compression was detected with Magnetic Resonance imaging in patients with deep venous thrombosis. We compared recanalization of left femoropopliteal and iliac thrombosis with and without RCIA/LCIV compression. Methods This was a prospective blinded study carried out in a 1355-bed university hospital. Thirty-one patients were recruited from consecutive cohorts of patients with iliofemoral and femoropopliteal DVT who underwent direct thrombus Magnetic Resonance imaging, venous enhanced peak arterial Magnetic Resonance Venography, and Magnetic Resonance arteriography as part of the baseline study relating RCIA/LCIV compression to extent of thrombosis. Magnetic Resonance Venography was performed 6 weeks, 6 months, and 1 year after diagnosis of deep venous thrombosis. Femoropopliteal and iliac venous segments that were occluded at diagnosis were classified as occluded, partially occluded, or patent on follow-up scans. Results At 6-week follow-up, recanalization of all segments was incomplete. At both 6-month and 1-year follow-up, recanalization of left iliac segments associated with RCIA/LCIV compression was poorer compared with recanalization of left iliac segments not associated with compression (6 of 6 occluded vs 1 of 6 occluded and 1 of 6 partially occluded at 6 months, P =.015; 6 of 6 occluded vs 5 of 5 patent at 1 year, P = .002). This was due to complete failure of recanalization of left common iliac veins associated with RCIA/LCIV compression in 6 of 6 cases. All other iliac and femoropopliteal segments including left external iliac veins associated with RCIA/LCIV compression had high rates of recanalization at both 6 months and 1 year. Conclusion RCIA/LCIV compression is associated with persistent occlusion of the left common iliac vein. The recanalization rate for all other femoropopliteal and iliac segments was high.
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anomalous inferior vena cava demonstrated by contrast enhanced Magnetic Resonance Venography
Journal of Magnetic Resonance Imaging, 2000Co-Authors: Philip J E Smart, Alan R MoodyAbstract:We discuss the technique of contrast-enhanced Magnetic Resonance Venography and its advantages over other methods of imaging the veins of the chest. An example is presented of the results of this technique in a patient with agenesis of the hepatic segment of the inferior vena cava and azygos continuation. J. Magn. Reson. Imaging 2000;11:327–329. © 2000 Wiley-Liss, Inc.
Mark Walker - One of the best experts on this subject based on the ideXlab platform.
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the natural history of pelvic vein thrombosis on Magnetic Resonance Venography after vaginal delivery
American Journal of Obstetrics and Gynecology, 2012Co-Authors: Hisham Khalil, Andre Olivier, Leonard Avruch, Mark Walker, Marc A RodgerAbstract:Objective Venous thromboembolism constitutes the leading cause of direct maternal mortality in the developed world. To date, there are no studies using Magnetic Resonance Venography (MRV) to delineate the incidence and natural history of intraluminal filling defects in the postpartum period in patients with low thrombosis risk. Study Design This was a prospective cohort study of women at low thrombosis risk postvaginal delivery undergoing MRV in the early postpartum period. Results In 30 eligible and consenting participants, independently adjudicated MRV, conducted on a median of postpartum day 1, identified definite thrombosis in 30% (95% confidence interval [CI], 13.6–46.4%) of study participants. All episodes of definite thrombosis were identified in the iliac and ovarian veins. Probable thrombosis was identified in an additional 27% of study participants (95% CI, 10.3–41.7%), and possible thrombosis in an additional 10% (95% CI, 0–20.7%). Conclusion In this group of low-risk postpartum patients, we identified a high prevalence of definite pelvic vein intraluminal filling defects of uncertain clinical significance. This study suggests that some degree of pelvic vein intraluminal filling defect may be a normal finding after uncomplicated vaginal delivery.
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pelvic Magnetic Resonance Venography reveals high rate of pelvic vein thrombosis after cesarean section
Obstetrical & Gynecological Survey, 2006Co-Authors: Marc A Rodger, Leonard Avruch, Heather E Howley, Andre Olivier, Mark WalkerAbstract:Venous thromboembolism (VTE) not only remains the major cause of direct maternal mortality in developed countries worldwide, but reportedly causes more than half of direct maternal deaths in the United States. Although cesarean section increases the risk of pregnancy-associated VTE, postpartum thromboprophylaxis is not uniformly recommended. Magnetic Resonance Venography (MRV) appears to be a highly sensitive and specific means of detecting deep venous thrombosis (DVT) in the upper and lower extremities. The investigators report preliminary findings of an ongoing randomized, controlled trial that uses MRV to identify pelvic DVT after operative delivery. Observations were made during the run-in phase of a trial of thromboprophylaxis in women at moderate to high risk of DVT based on a family history of VTE or a personal history of superficial phlebitis, current major illness or infection, immobility for longer than 4 days, obesity, or age greater than 35 years. Other risk factors included gross varicose veins, preeclampsia, parity of 4 or more, emergency cesarean section, and extended surgery such as cesarean hysterectomy. The women were assigned to receive or not to receive open-label tinzaparin, a low-molecular-weight heparin, by subcutaneous injection. Two radiologists independently and blindly assessed the MRV studies. Participants included 15 women with a mean age of 33 years. None of them had compression leg ultrasound findings of DVT. The MRV findings were interpreted as showing definite thrombosis in 46% of women, all of whom were asymptomatic. Clots were found chiefly in the iliac veins, although one patient had thrombosis in the common femoral artery. All clots were less than 1 cm in size and only one occluded the affected vein. Nearly half of these moderate- or high-risk women were found to have definite pelvic DVT after cesarean delivery-many more than expected. The clinical significance of this finding remains to be determined. It is possible that pelvic vein thrombosis is a normal finding after cesarean delivery and also that DVT may be present in lower-risk women. MRV would seem to be a useful measure of outcome in studies evaluating postpartum measures intended to prevent DVT.
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pelvic Magnetic Resonance Venography reveals high rate of pelvic vein thrombosis after cesarean section
American Journal of Obstetrics and Gynecology, 2006Co-Authors: Marc A Rodger, Leonard Avruch, Heather E Howley, Andre Olivier, Mark WalkerAbstract:In the run-in phase of a thromboprophylactic trial in women at moderate to high risk of deep vein thrombosis postcesarean section, we used Magnetic Resonance Venography and found a surprisingly high rate of pelvic deep vein thrombosis (46% overall). Pelvic Magnetic Resonance Venography may be a useful surrogate outcome in obstetric thromboprophylaxis studies but the clinical significance is not known.