Magnetic resonance imaging characteristics and changes in hemostatic agents after partial nephrectomy

Area of Science:

• Radiology
• Urologic Oncology
• Surgical Innovation

Background:

• Partial nephrectomy (PN) is a standard treatment for renal masses.
• Intra-operative hemostatic agents (HAs) are frequently used during PN to control bleeding.
• Post-operative imaging may reveal mass-like lesions (MLL) that require careful evaluation.

Purpose of the Study:

• To characterize magnetic resonance imaging (MRI) findings of MLL after PN.
• To assess the changes in MLL size during post-operative follow-up.
• To evaluate the relationship between HA use and MLL development.

Main Methods:

• Retrospective review of 47 patients who underwent PN with HA use.
• Analysis of diffusion and dynamic MRI scans at 2-4 and 12 months post-operatively.
• Morphological assessment of MLL, including size and signal characteristics.

Main Results:

• MLLs were defined as heterogeneous, intermediate-signal intensity masses with a pseudocapsule.
• MLLs demonstrated a decrease in size over the follow-up period (mean change -0.66 mm/month).
• No significant correlation was found between HA type/amount and MLL observation.

Conclusions:

• MLLs following PN with HAs typically show size reduction on serial MRI.
• Imaging characteristics and size changes aid in differentiating MLL from tumor recurrence.
• The use of specific hemostatic agents does not appear to influence MLL formation.