压缩感知不同加速倍数在平衡式快速场梯度回波对肾动脉图像质量的影响

Effect of different acceleration times of compression sensing on image quality of renal artery in balanced fast field gradient echo

目的 探讨压缩感知(CS)技术不同加速倍数在平衡式快速场梯度回波(B-TFE)对肾动脉图像质量的影响。方法收集2021年10月至2022年3月浙江省肿瘤医院肾肿瘤患者30例,术前接受肾动脉CT血管造影成像(CTA)检查,然后进行MRI并行采集(PI)B-TFE序列扫描和CS B-TFE序列扫描,其中CS加速倍数分别为3、6、9,记录扫描时间,每例患者获得PI、CS3、CS6、CS9 4组图像,在横轴面图像上测量左、右侧肾动脉信号强度,肾周脂肪信号强度,后背肌肉标准差为噪声,计算左、右侧肾动脉信号噪声比(SNR)、肾动脉与肾周脂肪的对比噪声比(CNR);并由2位放射科主治医师对肾动脉图像质量、分支显示情况进行评分;以肾动脉CTA为对照,对比B-TFE肾动脉显示副肾动脉情况。结果 PI、CS3、CS6、CS9组图像质量及分支显示差异均有统计学意义(均P<0.05);肾动脉分支显示CS9组图像不符合诊断要求。4组图像两两比较,CS9与其他3组图像质量及分支显示差异均有统计学意义(均P<0.05),CS6组与PI组、CS3组比较差异均无统计学意义(均P>0.05);4组左、右侧肾动脉SNR、CNR比较差异均有统计学意义(均P<0.05),4组图像的SNR和CNR两两比较,CS9组与其他3组比较差异均有统计学意义(均P<0.05),PI组与CS3、CS6组之间比较差异均无统计学意义(均P>0.05);以CTA为参照,CS3、CS6两组图像能清楚显示副肾动脉情况。结论 B-TFE肾动脉成像扫描中使用加速倍数为6的CS技术,能够在保证图像质量以及显示肾动脉分支情况的前提下减少扫描时间,可以作为肾肿瘤术前常规检查,同时可以减轻患者辐射及对比剂肾病风险。

Objective To explore the application of compressed sensing(CS) technique in balanced fast field gradient echo(B-TFE) renal artery imaging and compare the effects of different compression sensing accelerations on the images. Methods Thirty patients with renal tumors admitted in Zhejiang Cancer Hospital from October 2021 to March 2022were enrolled. Patients underwent renal artery CTA before operation, and then underwent magnetic resonance parallel acquisition(PI) B-TFE sequence scanning and CS B-TFE sequence scanning. The compression sensing addends were 3, 6and 9 respectively, and the scanning time was recorded. Each patient obtained four groups of images: PI, CS3, CS6 and CS9. The signal intensity of left and right renal arteries and the signal intensity of perirenal fat were measured on the horizontal axis image, The standard deviation of back muscle was noise, and the signal-to-noise ratio(SNR) of left and right renal arteries and the contrast-to-noise ratio(CNR) of renal artery and perirenal fat were calculated. Two attending radiologists rated the image quality and branch display of renal artery. Compared with renal artery CTA, B-TFE renal artery showed accessory renal artery. Results There were significant differences in image quality scores among PI, CS3, CS6and CS9 groups(P<0.05). There was a significant difference in the images of renal artery branch scores among the 4groups(P<0.05). The images of CS9 group did not meet the diagnostic requirements. The CS9 was significantly different from the other three groups(P<0.05);there was no significant difference among CS6, PI group and CS3 group(P>0.05). The SNR and CNR of the left and right renal arteries between the groups were significantly different(P<0.05). The SNR and CNR of the images in the four groups were compared in pairs. The difference between the CS9 group and the other three groups was statistically significant(P<0.05);while the difference among PI, CS3 and CS6 was not statistically significant(P>0.05). Taking CTA as a reference, the images of CS3 and CS6 clearly showed the accessory renal artery.Conclusion The use of CS technology with an acceleration factor of 6 in B-TFE renal artery imaging scanning can reduce the scanning time on the premise of ensuring the image quality and displaying the branches of renal artery. It can be used as a routine examination before renal tumor surgery, and can reduce the exposure to radiation and contrast-induced renal damage.