Visualizing pelvic splanchnic nerve and hypogastric nerve with magnetic resonance neurography in rectal cancer patients.

PURPOSE: To evaluate the visualization rates of the hypogastric and pelvic splanchnic nerves using magnetic resonance neurography (MRN) and to identify associated factors.

MATERIALS AND

METHODS

This study included patients with rectal carcinoma who underwent preoperative MRN at our institution between December 2019 and September 2020. Two gastrointestinal surgeons evaluated the visibility of the hypogastric and pelvic splanchnic nerves on a per-nerve basis, with scores of "excellent" or "good" defined as successful visualization.

RESULTS

The visualization rates of the hypogastric and pelvic splanchnic nerves were 21.6% and 81.8%, respectively. A large visceral fat area at the umbilical level (p = 0.0150) was an independent factor affecting the visualization rate of the hypogastric nerves. Early clinical T stage (cT1-3) (p = 0.0255) and a large visceral fat area at the level of the upper edge of the femoral head (p = 0.0096) were independent factors affecting the visualization rate of the pelvic splanchnic nerves.

CONCLUSION

MRN demonstrated a high visualization rate for the pelvic splanchnic nerves but a low rate for the hypogastric nerves. Visualization appeared to be influenced by the visceral fat area and inflammatory responses or edema in surrounding structures.