Kang Kyuyong, Kim Kyeonga, Oh Donghyun, Choi Jeongwoo, Choi Mincheol, Yoon Junghee
College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea.
Vet Radiol Ultrasound. 2020 May;61(3):302-311. doi: 10.1111/vru.12849. Epub 2020 Feb 26.
Quantitative analysis of the normal retrograde urethrogram is well reported in radiography, but studies on CT urethrography are lacking. Recently, a method of retrograde CT urethrography using a power injector was described. The purpose of the current, prospective, analytical study was to quantify the urethral size of five, healthy, intact, male Beagle dogs using retrograde CT urethrography and a power injector. With the injection rate of the power injector set at 0.3 mL/s, 1 mL/kg of diluted contrast medium (15 mg I/mL) was injected, and a CT examination was performed. The state of the initial urethrogram taken was defined as "empty bladder." The same procedures were repeated with the injection of an additional 1 mL/kg of diluted contrast medium until the ureteral reflux was seen (distended bladder). There was a significant difference in volumes between the empty and distended bladder, but the membranous urethra showed the least difference (P = .0044) among the three regions (P < .0001 for the prostatic and penile urethra). Urethral diameters at six sites were measured from sagittal images, and the sites of measurements were adopted from the earlier radiographic studies. The most significant difference in the urethral diameters between the empty and distended bladder occurred at the cranial and middle prostatic urethra (P < .0001). The results of this study can be useful for interpreting the results of retrograde CT urethrography. Care must be taken when narrowing is suspected at the prostatic urethra, and if necessary, further distension of the urinary bladder should be tried.
X线摄影中对正常逆行尿道造影的定量分析已有充分报道，但关于CT尿道造影的研究尚少。最近，有人描述了一种使用动力注射器进行逆行CT尿道造影的方法。本前瞻性分析研究的目的是通过逆行CT尿道造影和动力注射器对5只健康、完整的雄性比格犬的尿道尺寸进行量化。将动力注射器的注射速率设定为0.3 mL/s，注入1 mL/kg稀释造影剂（15 mg I/mL），然后进行CT检查。最初拍摄的尿道造影状态定义为“膀胱空虚”。再额外注入1 mL/kg稀释造影剂并重复相同程序，直至出现输尿管反流（膀胱扩张）。膀胱空虚和扩张状态下的容积存在显著差异，但在三个区域中，膜部尿道的差异最小（P = 0.0044）（前列腺部和阴茎部尿道P < 0.0001）。从矢状图像测量六个部位的尿道直径，测量部位采用早期X线摄影研究中的部位。膀胱空虚和扩张状态下尿道直径的最大差异出现在前列腺部尿道的头侧和中部（P < 0.0001）。本研究结果有助于解释逆行CT尿道造影的结果。当怀疑前列腺部尿道狭窄时必须谨慎，如有必要，应尝试进一步扩张膀胱。
