Low R N, Francis I R
Sharp and Children's MRI Center, San Diego, CA, USA.
AJR Am J Roentgenol. 1997 Oct;169(4):1051-9. doi: 10.2214/ajr.169.4.9308464.
To determine an optimal MR imaging technique and pulse sequence for evaluating mural and serosal disease of the gastrointestinal tract, we administered 2% oral barium sulfate and obtained fat-suppressed gadolinium-enhanced breath-hold fast multiplanar spoiled gradient-recalled (FMPSPGR) MR images. We then compared these images with spin-echo T1-weighted and T2-weighted fast spin-echo MR images and with CT images.
Thirty-one patients with suspected diseases of the gastrointestinal tract were imaged with spin-echo T1-weighted, fast spin-echo T2-weighted, and fat-saturated gadolinium-enhanced FMPSPGR MR imaging. Before undergoing MR imaging, all patients received 1350 ml of 2% barium sulfate oral contrast media. For CT scans, patients received 120 ml of iodinated i.v. contrast material and 2% barium sulfate oral contrast material. CT and MR images were retrospectively and independently reviewed by two radiologists for ability to see normal bowel wall, for the presence of abnormal gastrointestinal tract mural thickening or enhancement, and for overall gastrointestinal tract visualization. Findings were correlated with surgical findings, endoscopy, and barium studies.
Ten patients had benign disease, 16 had malignant gastrointestinal tract disease, and five had no gastrointestinal tract abnormalities. In 94% of patients, the gadolinium- and barium-enhanced FMPSPGR MR images were superior to CT and spin-echo MR sequences for depicting the wall of the normal bowel (p < .001). For the two observers, the FMPSPGR MR images with i.v. and oral contrast material were seen as revealing 94% and 95% of bowel segments with malignant or inflammatory mural thickening or serosal tumor. In comparison, CT revealed 64% and 72% (p < .01 and p < .0001, respectively), fast spin-echo T2-weighted MR images revealed 21% and 28% (p < .0001), and T1-weighted MR images revealed 17% and 18% (p < .0001). The gadolinium- and barium-enhanced MR images were preferred for overall gastrointestinal tract visualization in 65% of patients compared with 1% for CT scans (p < .001). In 32% of patients, the enhanced MR images were equivalent to CT images.
MR evaluation of the gastrointestinal tract requires bowel distention with oral contrast material as well as motion reduction techniques, including glucagon and rapid gradient-echo pulses that allow breath-hold imaging. Fat-suppressed gadolinium-enhanced FMPSPGR MR imaging with diluted barium oral contrast media is effective for imaging benign and malignant mural and serosal abnormalities of the gastrointestinal tract.
为确定用于评估胃肠道壁层和浆膜疾病的最佳磁共振成像（MR）技术及脉冲序列，我们让患者口服2%的硫酸钡，并获取脂肪抑制钆增强屏气快速多平面扰相梯度回波（FMPSPGR）MR图像。然后将这些图像与自旋回波T1加权和T2加权快速自旋回波MR图像以及CT图像进行比较。
对31例疑似胃肠道疾病的患者进行自旋回波T1加权、快速自旋回波T2加权以及脂肪饱和钆增强FMPSPGR MR成像。在进行MR成像前，所有患者均接受1350毫升2%的硫酸钡口服对比剂。对于CT扫描，患者接受120毫升静脉注射碘对比剂以及2%的硫酸钡口服对比剂。两名放射科医生对CT和MR图像进行回顾性独立评估，以观察正常肠壁的显示情况、胃肠道壁层增厚或强化的存在情况以及整个胃肠道的可视化情况。将检查结果与手术结果、内镜检查及钡剂造影检查结果进行对照。
10例患者患有良性疾病，16例患有胃肠道恶性疾病，5例无胃肠道异常。在94%的患者中，钆和钡增强的FMPSPGR MR图像在显示正常肠壁方面优于CT和自旋回波MR序列（p < 0.001）。对于两位观察者而言，静脉注射和口服对比剂的FMPSPGR MR图像显示出94%和95%的存在恶性或炎性壁层增厚或浆膜肿瘤的肠段。相比之下，CT显示出64%和72%（分别为p < 0.01和p < 0.0001），快速自旋回波T2加权MR图像显示出21%和28%（p < 0.0001），T1加权MR图像显示出17%和18%（p < 0.0001）。65%的患者更倾向于使用钆和钡增强的MR图像进行整个胃肠道的可视化，而CT扫描仅为1%（p < 0.001）。在32%的患者中，增强MR图像与CT图像相当。
胃肠道的MR评估需要口服对比剂使肠管扩张以及采用包括胰高血糖素和允许屏气成像的快速梯度回波脉冲在内的减少运动的技术。使用稀释的钡剂口服对比剂进行脂肪抑制钆增强FMPSPGR MR成像对于胃肠道良性和恶性壁层及浆膜异常的成像有效。
