Foran Paul, Hwang Sinchun, Mazaheri Yousef, Panicek David
Departments of Radiology Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Medical Physics Memorial Sloan Kettering Cancer Center, New York, NY, USA.
BJR Open. 2019;1(1). doi: 10.1259/bjro.20180030. Epub 2019 May 29.
To determine the prevalence of high-signal bladder urine at T1-weighted MRI performed 1-7 days after injection of gadolinium-based contrast material and to assess for correlation with altered renal function.
The study group consisted of 267 patients who underwent MRI that included the bladder 1-7 days after a prior gadolinium-enhanced MRI. A control group consisted of 200 patients who underwent pelvic MRI and had not received gadolinium-based contrast material within the prior month. One reader recorded the relative T1-weighted signal intensity of bladder urine and calculated the eGFR for each patient. A positive scan was defined as one with bladder urine T1-weighted signal higher than that of muscle.
Twenty-five (9%) of 267 study group scans were positive; this included 68% (n=19) of scans obtained 12-24 hours after gadolinium-based contrast material administration, 21% (n=3) after 25-36 hours, 7% (n=2) after 37-48 hours, and 3% (n=1) after 49-72 hours. No positive scan occurred after 72 hours or in the control group. Mean eGFR in positive scans obtained more than 36 hours after gadolinium-based contrast material administration was significantly lower than in negative scans in the same timeframe (37 ml/min versus 76 ml/min, respectively; p = 0.01).
High T1-weighted signal in bladder urine occasionally is present on MRI performed up to 3 days after gadolinium-based contrast material administration, presumably reflecting residual excreted gadolinium-based contrast material. When visible more than 36 hours after gadolinium-based contrast material administration, such increased signal is associated with decreased eGFR.
Increased signal is occasionally present on bladder urine MRI performed up to 3 days post gadolinium-based contrast material administration. When higher signal is visible more than 36 hours after gadolinium-based contrast material administration it is associated with decreased eGFR.
确定在注射钆基对比剂后1 - 7天进行的T1加权磁共振成像（MRI）中高信号膀胱尿液的发生率，并评估其与肾功能改变的相关性。
研究组由267例患者组成，这些患者在先前的钆增强MRI后1 - 7天接受了包括膀胱的MRI检查。对照组由200例接受盆腔MRI且在前一个月内未接受钆基对比剂的患者组成。一名阅片者记录膀胱尿液的相对T1加权信号强度，并计算每位患者的估算肾小球滤过率（eGFR）。阳性扫描定义为膀胱尿液T1加权信号高于肌肉的扫描。
267例研究组扫描中有25例（9%）为阳性；这包括钆基对比剂给药后12 - 24小时获得的扫描中的68%（n = 19），25 - 36小时后的21%（n = 3），37 - 48小时后的7%（n = 2），以及49 - 72小时后的3%（n = 1）。72小时后或对照组中未出现阳性扫描。钆基对比剂给药后超过36小时获得的阳性扫描中的平均eGFR显著低于同一时间段的阴性扫描（分别为37 ml/分钟对76 ml/分钟；p = 0.01）。
在钆基对比剂给药后长达3天进行的MRI上，膀胱尿液中偶尔会出现高T1加权信号，推测反映了残留的经排泄的钆基对比剂。当在钆基对比剂给药后超过36小时可见时，这种信号增强与eGFR降低相关。
在钆基对比剂给药后长达3天进行的膀胱尿液MRI上偶尔会出现信号增强。当在钆基对比剂给药后超过36小时可见更高信号时，它与eGFR降低相关。
