| Purpose:To evaluate visibility of the renal artery and its branches of young healthy adults using three-dimensional (3D) non-contrast enhanced MR angiography with a time-spatial labeling inversion pulse (Time-SLIP), and to provide an optimal value of the black blood inversion time (BBTI), and to evaluate the differences of the same BBTI between the axial and coronal sequences.Materials and Methods:. Time-SLIP were obtained in22young healthy volunteers (M:F=15:7; mean age25.0±2.0yrs) with a1.5T clinical system (Vantage XGV Power By Atlas, Toshiba, Japan). Four coronal sequences with different BBTI (700,900,1200,1500ms) and three axial sequences with different BBTI (900,1200,1500ms) were performed for each volunteer, referred to as sequence cor700, cor900, cor1200, cor1500, ax900, ax1200, ax1500, respectively. The renal artery were divided into3segments, and evaluated the images quanlities of the sequences. Relative signal intensity of the renal artery and visibility score (Rank1-4) and and the numbers of the branches were evaluated as the indexes of the Time-SLIP sequence image quality.Results:The mean relatively signal intensity value was21.53±9.64.4.70±1.61,1.92±0.63,1.10±0.32,5.86±3.65,1.84±0.43,1.14±0.26for sequence c cor700, cor900, cor1200, cor1500, ax900, ax1200, ax1500, respectively. The mean visibility score of the first segment were3.85±0.37,4.00±0.00,4.00±0.00,3.95±0.21,4.00±0.00,4.00±0.00,3.86±0.36for sequence cor700, cor900, cor1200, cor1500, ax900, ax1200, ax1500, respectively. The mean visibility score of the second segment were3.15±0.75,3.86±0.35,3.36±0.58,3.36±049,3.95±0.21,3.73±0.46,3.43±0.60for sequence cor700, cor900, cor1200, cor1500, ax900, ax1200, ax1500, respectively. The mean visibility score of the third segment were1.35±0.49,2.73±0.55,2.50±0.67,2.55±0.74,2.59±0.50,2.73±0.46,2.43±0.60for sequence cor700, cor900, cor1200, cor1500, ax900, ax1200, ax1500, respectively. The mean numbers of the branches were1.95±0.51,3.45±0.51,3.68±0.48,3.77±0.53,3.55±0.51,3.82±0.40,3.90±0.31, respectively. Among them, sequence cor700, cor900and ax900yielded significantly higher relatively signal intensity than the other four sequences (P<0.05); sequence cor900and ax900had better visibility scores of the first and second segment of the renal artery (P<0.05); The sequence cor700had the worst visibility score of the third segment of the renal artery (P<0.05), and there were no inter-sequence statistical differences in the other6sequences. There were no statistical differences visibility scores between the axial and coronal sequences with the same BBTI. Sequence ax1500had the best numbers of branches of the renal artery and it had statistical difference with the other6sequences (P<0.05).Conclusion:non-contrast-enhanced MR angiography using a Time-SLIP showed excellent visualization of the renal artery system in both coronal and the axial sequences. An coronal sequence with BBTI=900ms was considered to be the optimal choice for this purpose in young healthy adults. Purpose:To evaluate visibility of the renal artery and its branches using three-dimensional (3D) non-contrast enhanced MR angiography with a time-spatial labeling inversion pulse (Time-SLIP) in middle-aged subjects, and to provide an optimal value of the BBTI. To evaluate the difference of velocity of abdominal aorta in the levels of the beginning of the renal arteries between the young and middle-aged healthy subjects using two-dimensional phase contrast (2D-PC) MRI and to explore the instructional significance for choosing BBTI for Time-SLIP.Materials and Methods:.3D non-contrast enhanced MR angiography images with a Time-SLIP were obtained in22young healthy volunteers (M:F=15:7; mean age25.0±2.0yrs) and26middle-aged healthy volunteers(M:F=15:11; mean age52.8±1.9yrs) with a1.5T clinical system (Vantage XGV Power By Atlas, Toshiba, Japan). Three coronal sequences with different BBTI (900,1200,1500ms) were performed for each volunteer, referred to as sequence cor900, cor1200, cor1500, respectively. Relative signal intensity of the renal artery and visibility score (Rank1-4) and and the numbers of the branches were evaluated as an index of the Time-SLIP sequence image quality. Evaluate the mean velocity and peak velocity of the abdominal aorta in the levels of the beginning of the renal arteries using2D-PC MRI and divided all the subjects into two new groups by the median velocity, and compare the images qualities between the two groups.Results:1The mean relatively signal intensity value was5.06±3.65,1.79±0.59,1.13±0.42for sequence cor900, cor1200, cor1500, respectively. The mean visibility score of the first segment were3.85±0.46,3.96±0.20,3.81±0.40for sequence cor900, cor1200, cor1500, respectively. The mean visibility score of the second segment were3.54±0.81,3.50±0.58,3.23±0.65for sequence cor900, cor1200, cor1500, respectively. The mean visibility score of the third segment were2.08±0.63,2.35±0.49,2.00±0.49for sequence cor900, cor1200, cor1500, respectively. The mean numbers of the branches were2.88±0.91,3.38±0.70,3.35±1.02, respectively. Among them, sequence cor900yielded significantly higher relatively signal intensity than the other four sequences; sequence cor1200had better visibility scores of the three segments of the renal artery and the numbers of branches.2The mean velocity and peak velocity for the young volunteers were55.74±14.44.70.70±14.87,respectively and41.67±10.67,54.37±10.47, respectively for the middle-aged volunteers. There were no statistically difference between the two groups in all the Time-SLIP sequences.3There were53.8%of artery variations including accessory renal artery, early branching artery and multi renal arteries in unilateral or bilateral kidney.Conclusion:Balanced SSFP non-contrast-enhanced MR angiography showed excellent visualization of the renal artery system. An coronal sequence with BBTI=1200ms was considered to be the optimal choice for this purpose in middle-aged healthy subjects. Purpose:To evaluate three-dimensional (3D) non-contrast enhanced MR angiography with a time-spatial labeling inversion pulse (Time-SLIP) in the assessment of renal artery anatomy and variations compared with computer tomography angiography(CTA).Materials and Methods:. Time-SLIP and CTA were obtained in25subjects (M:F=13:12; mean age51.4±11.5yrs) with a1.5T clinical system. All the subjects received the coronal and axial orientation and firstly the coronal view, and adjust the BBTI according to the coronal images. Compare the anatomy and variant of renal artery and the degree of renal artery stenosis between the CTA and Time-SLIP sequences.Results:There were25patients enrolled in the study and59renal arteries totally. The results of reader1for the evaluation of the stenosis of CTA:grade1=42cases; grade2=9cases; grade3=7cases; grade4=1cases. The results of reader2for the evaluation of the stenosis of CTA:grade1=42cases; grade2=9cases; grade3=5cases; grade4=3cases. The Kappa value of the two readers were0.85. The results of reader1for the evaluation of the stenosis of Time-SLIP:grade1=42cases; grade2=11cases; grade3=4cases; grade4=1cases. The results of reader2for the evaluation of the stenosis of Time-SLIP:grade1=42cases; grade2=12cases; grade3=4cases; grade4=1cases. The Kappa value of the two readers were0.93.Conclusion:Both Time-SLIP and CTA can show the anatomy and variant of renal artery. The discrepancy between the two image modalities may related to the calcification of the renal artery and the change of the hemodynamic of the stenosis PURPOSE:To evaluate three-dimensional (3D) non-contrast enhanced MR angiography with a time-spatial labeling inversion pulse (Time-SLIP) in the assessment of renal artery anatomy and the assessment of renal artery stenosis: compared with digital subtraction angiography (DSA).MATERIALS AND METHODS:15patients (M:F=8:7,58.4±14.6yrs) were enrolled in this study who suspected coronary artery diseases and renal artery stenosis and to have DSA. all the informal consent were obtained. All the subjects received3D non-contrast enhanced MR angiography with a time-spatial labeling inversion pulse (Time-SLIP) with a1.5T clinical system (Vantage XGV Power By Atlas, Toshiba, Japan). All the subjects received both coronal and axial orientation. Firstly the coronal view, then adjust the BBTI according to the coronal images. Compare the anatomy and variant of renal artery and the degree of renal artery stenosis between the DSA and Time-SLIP sequences. The gap between the Time-SLIP and DSA ranged from1day to30days (average4.2±9.1days). Divide the renal artery into3parts, and the motion artifacts and image quality were evaluated by two radiologist independently. Evaluate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of Time-SLIP relative to DSA for the diagnosis of stenosis of50%or greater.RESULTS:There were12cases≥3of the score of motion artifact; all the first parts of the renal artery were of the image quality≥3;12cases≥3of the second part the renal artery;8cases≥3of the third part of the renal artery. There were103segments of renal arteries of DSA.90of them had no stenosis and3had relevant stenosis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of Time-SLIP relative to DSA for the diagnosis of a stenosis of50%or greater were100%(2/2),99%(100/101),66.7%(2/3),100%(100/100) and98.9%(102/103).CONCLUSION:3D SSFP with a Time-SLIP is a reliable alternative imaging technique for the assessment of renal artery stenosis, we recommend both coronal and axial sequences in each patient.
|
PDF Full Text Request