Radiology, Northwestern Memorial Hospital, Chicago, IL, USA.
Radiology, Northshore University HealthSystem, Walgreen Building, G534, 2650 Ridge Avenue, Evanston, IL, 60201, USA.
J Cardiovasc Magn Reson. 2018 Aug 6;20(1):51. doi: 10.1186/s12968-018-0479-2.
Comparing cardiovascular magnetic resonance (CMR) angiography with computed tomography angiography (CTA), a major deficiency has been its inability to reliably image peripheral vascular calcifications that may impact the choice of interventional strategy and influence patient prognosis. Recently, MRI using a proton density-weighted, in-phase stack of stars (PDIP-SOS) technique has proved capable of detecting these calcifications. The goal of the present study was two-fold: (1) to determine whether magnetic field strength impacts the apparent size and conspicuity of ilio-femoral arterial calcifications; and (2) to determine whether the technique can be accurately applied to image aorto-iliac arterial calcifications.
Two patient cohorts were studied. For the first cohort, ilio-femoral arterial calcifications were imaged at 1.5 Tesla in 20 patients and at 3 Tesla in 12 patients. For the second cohort, aorto-iliac arterial calcifications were imaged in 10 patients at 3 Tesla and one patient at 1.5 Tesla. Qualitative image analysis as well as quantitative analysis using a semi-automated technique were performed using CTA as the reference standard. Qualitatively, most PDIP-SOS CMR images showed good-to-excellent confidence to detect vascular calcifications, with good-to-excellent inter-reader agreement (κ = 0.67 for ilio-femoral region, P < 0.001; κ = 0.80 for aorto-iliac region, P < 0.01). There was an overall excellent correlation (r = 0.98, P < 0.001) and agreement (intraclass correlation coefficient = 0.97, P < 0.001) between PDIP-SOS CMR and CTA measures of calcification volume in both regions, with no overt difference in performance at 1.5 Tesla vs. 3 Tesla for ilio-femoral calcifications. CMR lesion volumes were slightly lower than those measured for CTA.
Using PDIP-SOS CMR, aorto-iliac and ilio-femoral calcifications could be simultaneously evaluated at 3 Tesla in less than six minutes with excellent correlation and agreement to CTA. Our results suggest that PDIP-SOS CMR provides a reliable alternative to CT for pre-interventional evaluation of peripheral vascular calcium burden.
与计算机断层扫描血管造影（CTA）相比，心血管磁共振（CMR）血管造影的一个主要缺陷是无法可靠地成像外周血管钙化，这可能会影响介入治疗策略的选择并影响患者的预后。最近，一种使用质子密度加权、同相位叠加星（PDIP-SOS）技术的 MRI 已被证明能够检测到这些钙化。本研究的目的有两个：（1）确定磁场强度是否会影响髂股动脉钙化的表观大小和显影度；（2）确定该技术是否可以准确地应用于成像腹主动脉-髂动脉钙化。
研究了两个患者队列。对于第一个队列，20 名患者在 1.5 Tesla 下和 12 名患者在 3 Tesla 下进行髂股动脉钙化成像。对于第二个队列，10 名患者在 3 Tesla 下和 1 名患者在 1.5 Tesla 下进行腹主动脉-髂动脉钙化成像。使用 CTA 作为参考标准进行定性图像分析和半自动化技术的定量分析。定性地，大多数 PDIP-SOS CMR 图像显示出良好到极好的置信度来检测血管钙化，并且具有良好到极好的读者间一致性（髂股区域的κ=0.67，P<0.001；腹主动脉-髂动脉区域的κ=0.80，P<0.01）。总体上存在极好的相关性（r=0.98，P<0.001）和一致性（组内相关系数=0.97，P<0.001），PDIP-SOS CMR 与两个区域的钙化容积的 CTA 测量值之间，髂股钙化在 1.5 Tesla 与 3 Tesla 之间的性能没有明显差异。CMR 病变体积略低于 CTA 测量值。
使用 PDIP-SOS CMR，可以在不到六分钟的时间内在 3 Tesla 下同时评估腹主动脉-髂动脉和髂股钙化，与 CTA 具有极好的相关性和一致性。我们的结果表明，PDIP-SOS CMR 为外周血管钙负荷的介入前评估提供了一种可靠的 CT 替代方法。
