Gradient echo MRI for measurement of the pulmonary autograft diameter after transplantation to the aortic root: Validation and comparison with ultrasound

The purpose of this study was to s the value of MRI for measurement of pulm onary autograft diameters after transplantation to the aortic root in adult s. Thirtyeight adults underwent this operation. MRI and transesophageal ech ocardiography (TEE) were performed in 30 and 27 patients, respectively, aft er a mean followup period of 2.8 years, For internal validation of MRI, mea surements at the diastolic short and long axes of the sinus level were used . Pulmonary autograft diameters were measured and compared with MRI and TEE at five different levels: the subannular region (1), annulus (2), sinus (3 ), sinotubular junction (4), and the distal part of the autograft (5), The correlation coefficient r(2) between long- and short-axis measurements for corresponding sinuses was,.97. Diameters obtained with MRI were 1 to 3 mm l arger than those obtained with TEE (P < .05), except for the annulus at sys tole (P > .3), Cine gradient echo MRI is an appropriate technique to evalua te pulmonary autograft diameters during follow-up. Concordance with TEE was good, apart from a systematic difference of approximate to 2 mm.