Minimum-intensity projection of multidetector-row computed tomography for assessment of pulmonary hypertension in children with congenital heart disease

BackgroundThe present study aimed to assess the feasibility of minimum-intensity projection (minIP) images for the evaluation of pulmonary hypertension (PH) in children with congenital heart disease (CHD).MethodsA total of 70 consecutive patients (mean age, 4.6 ± 4.4 years; range, 6 months-16 years) underwent multidetector-row computed tomography (MDCT) angiography of the thorax prior to cardiac catheterization and lung perfusion scintigraphy. Contiguous axial, coronal and sagittal minIP images of 5-mm thickness were reconstructed from the contrast-enhanced CT datasets. Two reviewers evaluated the images in consensus and qualitatively graded lung parenchyma attenuation as homogeneous (Class I), slightly heterogeneous lung attenuation that does not conform to the anatomic boundaries of the secondary pulmonary lobule (Class II), and mosaic pattern (Class III). MinIP attenuation grading results were then compared with those of perfusion scintigraphy. Furthermore, the relationships between the results of these modalities and mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) were evaluated.ResultsIn 51 (73%) patients, concordant findings were observed between the modalities, although minIP showed a higher grade for heterogeneous images than did scintigraphy. mPAP and PVR showed significant difference among the minIP attenuation classes (p < 0.0001 for both). High-grade heterogeneous minIP images were associated with high mPAP, high PVR, presence of major aortopulmonary collateral artery, and chromosomal abnormality.ConclusionMinIP is a promising technique for depicting lung perfusion and can be used as superior alternative to scintigraphy in the evaluation of PH.