Mr prisma 3

MR Prisma 3.0 (SIEMENS, Germany) is used to conduct the scanning of 30 patients. During the scanning, the child lied on his/her back and was instructed to breathe steadily. For the child who did not cooperate, taking chloral hydrate orally was required and the doctor should inject chlorpromazine and Phenergan intramuscularly to sedate him/her. During examination, it is a must to ensure that the child maintains one posture all the time. First, cross-section and sagittal-section scans were performed to find the tracheal plane. Then, coronal-section scan was performed with the point lightly above the crotch of the trachea and bronchus as the central point. Scanning parameters were as follows: matrix is 251 × 251; layer thickness is 3.5 mm; vision is 25 × 25 cm; the flip angle is 15°; and the slice gap is 6.1 mm. After the scan, two experienced professional physicians in the imaging department performed manual segmentation and analysis of the image.

The MR Prisma 3.0 magnetic resonance machine produced by Siemens in Germany was utilized to examine the patients. The procedure was explained to the patient ahead of the scan, and the patient kept breathing calmly. During the examination, the patient was placed in the supine position, and axial and sagittal MRI images of the pelvic cavity were obtained. A high-pressure syringe was adopted to inject 0.2 mmol/L contrast enhancer Gd-DTPA (Bayer Healthcare, Berlin, Germany) into the dorsal hand vein at an injection rate of 2.5 mL/s, and then the same amount of normal saline was injected. Eight time-phases were collected consecutively, and the scanning time was 60 s. Scanning parameters: the matrix was 251 × 251, the layer thickness was 3.5 mm, the field of vision was 25 × 25 cm, the flip angle was 15°, and the layer spacing was 6.1 mm.

The MR Prisma 3.0 magnetic resonance instrument produced by Siemens (Germany) was used to evaluate patients. When scanning, the patient was required to keep a supine position, maintain steady breathing, tilt the head slightly back, and fully expose the neck. The patient was scanned with the linear array probe from the proximal end to the distal end and the examination procedure was introduced to them. The scanning parameters included the matrix of 251 × 251, the layer thickness of 3.5 mm, the field of view of 25 × 25 cm, the flip angle of 15°, and the layer spacing of 6.1 mm.