Immobilization Technique for High-Resolution MR Imaging of the Testes

Abstract

Techniques for testis immobilization can facilitate high-resolution MR imaging applications for testicular diseases by assuring good positioning of the testis on small radiofrequency coils and reducing motion artifacts. We tested negative pressure suction to immobilize the testis of rats during MR image acquisitions. Suction pressure between −5 and −10 kPa assured good positioning, suppressed motion artifacts, and allowed the observation of blood vessels and seminiferous tubules.

High Resolution MR Imaging of the Testis Using a Small Radiofrequency Coil

“…Yamaguchi and Fujii reported a technique for immobilization and correct positioning of the testis in their preclinical study. 7 They suctioned rat testes using a range of negative pressures from −25 to −10 kPa to immobilize them. Consequently, they High Resolution MR Imaging of the Testis acquired high-resolution spin-echo MR images with an inplane resolution of 78 µm, in which the seminiferous tubules and small blood vessels were clearly seen.…”

“…This is contradictory to the result of the above-mentioned previous paper that demonstrated almost complete suppression of testicular motion during MR scans in rats. 7 The cause of this inconsistency might stem from the difference in the consciousness level of the study subjects; the experimental animals were under general anesthesia and the human subjects were completely awake. From a physiological point of view, the dartos reflex is well known as a somato-autonomic reflex governed by the sympathetic segment between the 11th thoracic and 2nd lumbar spine levels.…”

“…The coil was encased (length, width, height: 126 × 50 × 15 mm), and a 21-mm aperture was created at the top and bottom of the case. The coil was the same type as that developed previously; 7 however, it was not the same one as was used in a preclinical research, since we purchased another coil from Takashima Seisakusho for this clinical research. We made sure that we were able to safely preform MR scans using this coil based on the following results: the coil passed a standard voltage proof test and a standard test on RF-induced heating according to the American Society for Testing and Materials (ASTM) F2182-11a.…”

“…They acquired MR images with 78-µm in-plane resolution and observed the seminiferous tubules in healthy rats. 7 However, to the best of our knowledge, there is no previous report of high-resolution MRI of human testes using this device combination. This could probably be due to the fact that adequate support and correct positioning of the human scrotum on such a small coil might be challenging.…”