Assessment of cross-sectional lung ventilation-perfusion imbalance in primary and passive pulmonary hypertension with automated V/Q SPECT

作者：Suga Kazuyoshi^*; Tokuda Osamu; Okada Munemasa; Koike Masahiro; Iwanaga Hideyuki; Matsunaga Naofumi

来源：Nuclear Medicine Communications, 2010, 31(7): 673-681.

DOI：10.1097/MNM.0b013e328339ea9b

• lung
• perfusion
• pulmonary hypertension
• single photon emission computed tomography
• ventilation

Purpose Cross-sectional lung ventilation (V)-perfusion (Q) imbalance in primary pulmonary arterial hypertension (PAH) and passive pulmonary hypertension (PH) was characterized by automated V/Q single-photon emission computed tomography (SPECT).
Materials and methods Technegas/macro-aggregated albumin SPECT-derived V/Q SPECT and V/Q profile were automatically built to characterize cross-sectional lung V-Q imbalance in 12 patients with primary (idiopathic or familial) PAH and 15 patients with passive PH associated with left ventricular dysfunction or failure. The abnormality of V/Q distribution in these patients was correlated with PaO(2) and pulmonary arterial pressure and with lung morphologic changes on computed tomography (CT).
Results Markedly low V/Q ratios (reverse V-Q mismatch) in the background lungs with heterogeneous V/Q distribution was seen in 12 of the 12 (100%) patients with primary PAH and in 10 of the 15 (66%) patients with passive PH, which were predominantly seen in the upper lung zone. Including these regions with reverse V-Q mismatch, the V/Q profile frequently showed flattened peaks with asymmetric and broadened V/Q distribution in all patients, with significant correlation between the standard deviation of V/Q ratios in the entire lungs and PaO(2) and mean pulmonary arterial pressure (both; P < 0.01). At the regions of the lungs with reverse V-Q mismatch, bronchial lumens compressed by dilated pulmonary arteries and heterogeneous lung attenuations were frequently seen on CT.
Conclusion Patients with primary PAH and passive PH seem to characteristically have a high prevalence of reverse V-Q mismatch indicative of an inadequate hypoxic vasoconstriction reflex on V/Q SPECT, frequently accompanied with heterogeneous lung attenuations and compressed airways on CT.

• 出版日期2010-7