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 an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) in the setting of liver disease and/or portal hypertension. This syndrome occurs most often in cirrhotic patients (4%–32%) and has been shown to be detrimental to functional status, quality of life, and survival. The diagnosis of HPS in the setting of liver disease and/or portal hypertension requires the demonstration of IPVD (i.e., diffuse or localized abnormally dilated pulmonary capillaries and pulmonary and pleural arteriovenous communications) and arterial oxygenation defects, preferably by contrast-enhanced echocardiography and measurement of the alveolar-arterial oxygen gradient, respectively.
To compare brain and whole-body uptake of technetium for diagnosing HPS.
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 demographics and clinical characteristics of the patients with and without IPVD were not significantly different with the exception of the creatinine level (0.71 ± 0.18 mg/dL vs 0.83 ± 0.23 mg/dL; P = 0.041), alveolar-arterial oxygen gradient (23.2 ± 13.3 mmHg vs 16.4 ± 14.1 mmHg; P = 0.043), and arterial partial pressure of oxygen (81.0 ± 12.1 mmHg vs 90.1 ± 12.8 mmHg; P = 0.004). Whole-body uptake was significantly higher in patients with IPVD than in patients without IPVD (48.0% ± 6.1% vs 40.1% ± 8.1%; P = 0.001). 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, based on Youden’s index. 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.
Core tip: Hepatopulmonary syndrome 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, a hallmark of hepatopulmonary syndrome, can be detected using technetium-99m-labeled macroaggregated albumin lung perfusion scan; however, of the two most commonly used methods of result interpretation (i.e., brain uptake and whole-body uptake), it is unclear which is more accurate. In this study of 69 patients with liver cirrhosis, we found that whole-body uptake is more accurate than brain uptake for detecting intrapulmonary vascular dilations.