99mTechnetium-mercaptoacetyltriglycine scintigraphy with full bladder in patients with severe bladder dysfunction

Area of Science:

• Urology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Severe bladder dysfunction can lead to upper tract obstruction.
• Accurate detection of obstruction threshold is crucial for patient management.

Purpose of the Study:

• To evaluate 99mtechnetium-mercaptoacetyltriglycine scintigraphy for detecting threshold bladder volume causing upper tract obstruction.
• To assess the utility of this scintigraphic technique in patients with bladder dysfunction.

Main Methods:

• Retrospective study of 24 patients with severe bladder dysfunction.
• 99mtechnetium-mercaptoacetyltriglycine scintigraphy performed with a full bladder (mean instilled volume >850 ml).
• Dynamic imaging during saline drainage to identify obstruction relief volume; videocystometrogram used concurrently.

Main Results:

• 15 of 24 patients showed obstructed outflow at full bladder, relieved at <390 ml (median 300 ml).
• Only 2 obstructed patients had normal vesical end filling pressure (<20 cm H2O).
• Follow-up showed no renal function decrease in unobstructed patients, but a small decrease in obstructed ones.

Conclusions:

• A novel full bladder 99mtechnetium-mercaptoacetyltriglycine scintigraphic technique can detect obstructive outflow patterns at specific bladder volumes.
• This method aids in identifying the threshold bladder volume for upper tract obstruction in severe bladder dysfunction.