Small acoustic neuromas: detection by high resolution gas CT cisternography

Area of Science:

• Radiology
• Neurology
• Medical Imaging

Background:

• Acoustic neuromas require accurate diagnostic methods.
• Standard contrast-enhanced CT can be insufficient for detecting small tumors.

Purpose of the Study:

• To evaluate the efficacy of gas computed tomography (CT) cisternography in diagnosing acoustic neuroma.
• To assess the diagnostic yield of CT cisternography when standard CT is negative.

Main Methods:

• 81 gas CT cisternography procedures were performed in 79 patients.
• A high-resolution scanner with digital localization and zoom capabilities was utilized.
• Carbon dioxide was used as a substitute for air to reduce morbidity.

Main Results:

• 21 tumors were identified, including four exclusively intracanalicular tumors, in patients with negative standard CT scans.
• The high-resolution scanner improved image detail, visualizing the intracanalicular bundle in most normal patients.
• Using carbon dioxide significantly reduced the incidence of post-spinal tap headache.

Conclusions:

• Gas CT cisternography is a valuable tool for diagnosing acoustic neuromas, especially when standard CT is negative.
• The procedure is efficient (30-45 min), can be done outpatient, and offers improved visualization.
• It is recommended as the primary choice for suspected acoustic neuroma when initial CT scans are inconclusive.