Published online Mar 14, 2020. doi: 10.3748/wjg.v26.i10.1088
Peer-review started: November 14, 2019
First decision: December 30, 2019
Revised: January 6, 2020
Accepted: January 19, 2020
Article in press: January 19, 2020
Published online: March 14, 2020
Processing time: 121 Days and 12 Hours
Hepatopulmonary syndrome (HPS) is a common complication of liver disease that impairs the lungs’ ability to oxygenate blood, leading to debilitating symptoms, such as shortness of breath. Intrapulmonary vascular dilations (IPVD), a hallmark of HPS, can be detected using technetium-99m-labeled macroaggregated albumin lung perfusion scan.
Of the two most commonly used methods of result interpretation (i.e., brain uptake and whole-body uptake) for macroaggregated albumin lung perfusion scan, it is unclear which is more accurate for detecting IPVD and diagnosing HPS.
This study aimed to compare brain and whole-body uptake of technetium for diagnosing HPS and establish the standard technique for calculating the shunt fraction for the future research.
Sixty-nine patients with chronic liver disease and/or portal hypertension were prospectively included. Brain uptake and whole-body uptake were calculated using the geometric mean of technetium counts in the brain and lungs and in the entire body and lungs, respectively.
Thirty-two (46%) patients had IPVD as detected by contrast-enhanced echocardiography. The area under the curve of whole-body uptake for detecting IPVD was significantly higher than that of brain uptake (0.75 vs 0.54; P = 0.025). The optimal cut-off values of brain uptake and whole-body uptake for detecting IPVD were 5.7% and 42.5%, respectively. The sensitivity, specificity, and accuracy of brain uptake > 5.7% and whole-body uptake > 42.5% for detecting IPVD were 23%, 89%, and 59% and 100%, 52%, and 74%, respectively.
Whole-body uptake is superior to brain uptake for diagnosing HPS.
Whole-body uptake is superior to brain uptake for diagnosing HPS. Further studies are needed to confirm the findings of the current study. For detecting IPVD and diagnosing HPS, whole-body uptake should be considered as the standard technique for calculating the shunt fraction from macroaggregated albumin lung perfusion scan.