Hepatopulmonary shunting on Tc99m-MAA liver mapping: correlation with dynamic cross-sectional imaging and description of different shunting patterns

• Published in: Abdominal imaging 2018-11, Vol.43 (11), p.3001-3008
• Main Authors: Bermo, Mohammed, Matesan, Manuela C., Itani, Malak, Behnia, Fatemeh, Vesselle, Hubert J.
• Format: Article
• Language: English
• Subjects: Abdomen; Adolescent; Adult; Aged; Aged, 80 and over; Arteriovenous Fistula - diagnostic imaging; Blood flow; Bypasses; Computed tomography; Correlation analysis; Female; Gastroenterology; Hepatic artery; Hepatic Artery - diagnostic imaging; Hepatic Veins - diagnostic imaging; Hepatology; Humans; Imaging; Informed consent; Liver; Liver Neoplasms - diagnostic imaging; Lungs; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Radiation; Radiology; Radiopharmaceuticals; Retrospective Studies; Shunts; Statistical analysis; Target recognition; Technetium; Technetium isotopes; Technetium Tc 99m Aggregated Albumin; Tomography, X-Ray Computed; Tumors; Veins & arteries
• ISSN: 2366-004X; 2366-0058
• DOI: 10.1007/s00261-018-1602-4

Purpose The purpose of the study was to correlate lung shunt fraction (LSF) calculated by intra-arterial injection of Technetium-99m (Tc-99m)-labeled macroaggregated albumin (MAA) in a hepatic artery branch with the presence of certain patterns of vascular shunts on dynamic CT or MRI of the liver. Methods This retrospective study was approved by the institutional review board and informed consent was waived. We reviewed 523 MAA scans in 453 patients (301 men, 152 women) performed from July 2007 to June 2015 and their correlative cross-sectional imaging. Patterns of vascular shunts on dynamic CT or MRI performed within 3 months of the MAA study and that potentially divert hepatic arterial inflow to the systemic venous return were defined as “target shunts.” Dynamic CT or MRI was classified into three groups with target shunt present, absent, or indeterminate. The mean LSF was compared across the first and second groups using paired t test. Results 342 CT and MRI studies met inclusion criteria: target shunts were present in 63 studies, absent in 271 studies, and 8 studies were indeterminate. When target shunts were visualized, the mean LSF on corresponding MAA scans was 12.9 ± 10.36% (95% CI 10.29–15.15%) compared to 4.3 ± 3.17% (95% CI 3.93–4.68%) when no target shunt was visualized. The difference was statistically significant ( p value