Spoiled Liquidity - Fresh Blood Imaging In The Clinical Application Of Lower Extremity Arterial Disease

Flow Spoiled-Fresh Blood Imaging Combined with Three-Station Moving Table Technique of Low Extremity Arteries:Initial StudyPURPOSE:To evaluate the feasibility of flow-spoiled fresh blood imaging protocol combined with three-station moving table technique in low extremity arteries. MATERIALS AND METHODS:Fifteen healthy volunteers were included in this study. The scanning extent was 1160mm from infrarenal abdominal aorta to the dorsal artery. Flow-spoiled fresh blood imaging included three-station nonenhanced MR angiography in pelvis, thigh, calf. The pelvis were scaned twice in different phase-encoding direction. Two blinded readers separately analyzed original image, maximum-intensity-projection MR angiograms, and then made a consensus. The low extremity arteries were divided into 27 anatomic segments for review.The status of image quality was graded as excellent, fair, poor, invisible. RESULTS:On flow-spoiled fresh blood imaging which its read out direction was parallel to blood flow orientation, image quality was excellent or fair in 15(100%) of 15. And the image quality was invisible or poor in pelvis in 12(80%) of 15 when phase-encoding direction parallel to blood flow orientation. CONCLUSION:Flow-spoiled fresh blood imaging combined with three-station moving table technique is feasible to be performed in whole low extremity arteries tree.Read out direction should be parallel to blood flow orientation. Peripheral Arterial Disease:Flow Spoiled-Fresh Blood Imaging Compared with CTAPURPOSE:To evaluate nonenhanced flow-spoiled fresh blood imaging(FS-FBI) protocol in the assessment of low extremity arteries of patients with peripheral arterial disease (PAD) by using computed tomography angiography (CTA)as the reference standard. MATERIALS AND METHODS:Pretreatment flow-spoiled fresh blood imaging were performed in 39 consecutive patients at 1.5 T. And CTA were performed in 33 of them, DSA were performed in 1 of them. Flow-spoiled fresh blood imaging included three-station nonenhanced MR angiography in pelvis, thigh, calf.Two blinded readers separately analyzed original image, maximum-intensity-projection MR angiograms. Subjective image quality for FS-FBI was assessed by two radiologists on a five-point scale (from 1, nondiagnostic to 5, excellent). An agreement of image quality and results of CTA images were achieved by two radiologists. The peripheral vessels were divided into 37 anatomic segments for review. The status of each segment was graded as normal and stenosis less than 10% in diameter, stenosis greater than 10% and less than 50%, stenosis greater than 50%, or occluded. The sensitivity, specificity, and accuracy of FS-FBI for the detection of relevant (> or=50%) peripheral arteries stenosis and occlusion were calculated using CTA as the gold standard on a per-segment basis. Results of interobserver and intermethod comparisons were expressed as Kappa value. If there was a discrepancy in the image quality on FBI,the images were reviewed and a consensus arrived at. RESULTS:on Flow-spoiled fresh blood imaging, the mean image quality assessed by both readers was 4.27±1.07,4.60±1.11,4.18±1.42 for segments pelvis, thigh and calf, respectively.92 segments was excluded because FS-FBI failed to adequately visualize the peripheral vasculature owing to motion artifacts,wrong ECG delay time. As compared with DSA, among 1104 analyzed segments, the sensitivity, specificity, and accuracy of FS-FBI to help detect stenosis greater than 50% and occlusion of peripheral arteries were respectively 94.3%,93.9%,94.0% for reviewerl,93.1%,93.2%,93.2% for reviewer2. CONCLUSION:Preliminary data'strongly support flow-spoiled fresh blood imaging to be a screening method and a reliable supplement or alternative imaging technique for the assessment of peripheral arteries in patients for whom contrast-enhanced MR angiography (CE-MRA) and CTA is contraindicated. Flow Spoiled-Fresh Blood Imaging of Foot:Initial StudyPURPOSE:To evaluate the visibility of the pedal arteries with flow-spoiled fresh blood imaging protocol in healthy volunteers and abnomal performance of foot in patient with peripheral artery disease on FS-FBI.MATERIALS AND METHODS:Flow-spoiled fresh blood imaging with craniocaudal read out direction were performed in fifteen healthy volunteers and 12 PAD patients, the flow-spoiled gradient pulse was 35%. The scanning extent was from supramalleolar region to the top of foot. Two blinded readers separately analyzed original image, maximum intensity projection MR angiograms, and make a consensus. The pedal arteries were divided into 12 anatomic segments for review. The status of image quality of healthy volunteers was graded as excellent, fair, poor, invisible. The status of image quality of patients was assessed on a five-point scale (from 1, nondiagnostic to 5, excellent).RESULTS:On Flow-spoiled fresh blood imaging, distal anterior tibial artery,dorsalis pedis artery,distal posterior tibial artery,common plantar artery,lateral plantar artery,deep perforating artery were identified in 14 healthy volunteers who were examined succesfully, the average score of visibility of these vessels were greater than 3. 5。The pedal arch were identified in these 14 volunteers and had a score lower than doralis, pedis artery. The mean image quality assessed by both readers was 3.83±1.33 in patients with peripheral artery disease. And the anterior circulation or plantar circulation stenosis or occlusion appeared in PAD patients. CONCLUSION:Flow-spoiled fresh blood imaging facilitates precise visualization of anatomic features of pedal arteries without the use of contrast agents.