Rhee Thomas K, Park Jonathan K, Cashen Ty A, Shin Wanyong, Schirf Brian E, Gehl James A, Larson Andrew C, Carr James C, Li Debiao, Carroll Timothy J, Omary Reed A
Department of Radiology, Northwestern University, 448 East Ontario Street, Suite 700, Chicago, IL 60611, USA.
J Vasc Interv Radiol. 2006 Jul;17(7):1131-7. doi: 10.1097/01.RVI.0000228469.10687.2C.
To compare the accuracy of catheter-directed intraarterial (IA) magnetic resonance (MR) angiography at 3.0 T with that of x-ray digital subtraction angiography (DSA) for the measurement of renal artery stenosis (RAS) in swine.
Unilateral hemodynamically significant RAS (>50%) was induced surgically in six pigs with use of reverse cable ties. One to two weeks after surgery, each pig underwent x-ray DSA and MR angiography before and after percutaneous transluminal balloon angioplasty (PTA). X-ray DSA was performed before and after PTA of RAS by injection of iodinated contrast agent through a 5-F multiple-side hole angiographic catheter placed in the abdominal aorta under fluoroscopic guidance. MR angiography of RAS was performed before and after PTA of RAS on a 3.0-T clinical MR imager with use of gadolinium-based contrast agent. MR angiography and DSA images were analyzed with the full width at half maximum method. Percent stenosis measurements between x-ray DSA and MR angiography were compared with a paired t test and were correlated with linear regression and Bland Altman analysis (alpha = 0.05).
Six cases of RAS were induced and imaged successfully with DSA and MR angiography techniques before and after PTA. On x-ray DSA, median stenoses was 64% (95% CI 57%-80%) before PTA and 20% (95% CI 5%-32%) after PTA. Corresponding MR angiography median stenosis measurement was 69% (95% CI 58%-80%) before PTA and 26% (95% CI 16%-36%) after PTA. A paired t test comparison did not show a difference between DSA and MR angiography (P = .16). RAS measurements on MR angiography correlated closely (P < .01) with DSA measurements (r(2) = 0.92).
In swine, the accuracy of catheter-directed IA MR angiography with use of a clinical 3.0-T MR imaging unit for the measurement of RAS was similar to that of conventional x-ray DSA.
比较3.0 T导管导向动脉内（IA）磁共振（MR）血管造影与X线数字减影血管造影（DSA）测量猪肾动脉狭窄（RAS）的准确性。
使用反向束带对6头猪进行手术诱导单侧血流动力学显著的RAS（>50%）。术后1至2周，每头猪在经皮腔内球囊血管成形术（PTA）前后接受X线DSA和MR血管造影。通过在透视引导下将5F多侧孔血管造影导管置于腹主动脉内注射碘化造影剂，在RAS的PTA前后进行X线DSA。在3.0 T临床MR成像仪上使用钆基造影剂在RAS的PTA前后进行RAS的MR血管造影。采用半高宽法分析MR血管造影和DSA图像。通过配对t检验比较X线DSA和MR血管造影之间的狭窄百分比测量值，并与线性回归和Bland Altman分析相关（α = 0.05）。
6例RAS在PTA前后成功通过DSA和MR血管造影技术进行诱导和成像。在X线DSA上，PTA前的中位狭窄率为64%（95%CI 57%-80%），PTA后为20%（95%CI 5%-32%）。相应的MR血管造影中位狭窄测量值在PTA前为69%（95%CI 58%-80%），PTA后为26%（95%CI 16%-36%）。配对t检验比较未显示DSA和MR血管造影之间存在差异（P = 0.16）。MR血管造影上的RAS测量值与DSA测量值密切相关（P < 0.01）（r² = 0.92）。
在猪中，使用临床3.0 T MR成像单元进行导管导向IA MR血管造影测量RAS的准确性与传统X线DSA相似。
