MAGNETIC-RESONANCE-IMAGING EVALUATION OF PULMONARY VASCULAR MALFORMATIONS

Objective: The purpose of our study was to establish magnetic resonanc e imaging (MRI) criteria for the diagnosis of pulmonary vascular malfo rmations (PVMs).Materials and methods: Since 1987, 11 patients have be en referred for chest MRI at our institution because of findings sugge stive of a PVM. They were evaluated with a 1.5-T MRI system, incorpora ting a combination of spin-echo, gradient-recalled echo (GRE) cine, an d 2-D phase contrast (PC) cine sequences. We used the following MRI cr iteria to diagnose PVM: (1) flow void or intermediate gray signal on s pin-echo sequences; (2) bright signal on GRE cine sequences; and (3) b right signal consistent with flow detected on PC cine sequences using relatively low velocity ranges. Twelve patients not suspected of havin g a PVM served as controls; all had both MRI and pulmonary angiography to evaluate for central pulmonary embolus. Results: Eight patients in the study group had PVM as determined with MRI using these criteria. In four of these patients, a PVM was confirmed by subsequent pulmonary angiography. Three patients did not have PVM utilizing these criteria ; two had neoplasms and one had presumed mucus plugging and/or atelect asis that resolved spontaneously. The smallest vascular malformation d etected by MRI was 1 cm. None of the control patients had PVM by MRI o r pulmonary angiography. Conclusion: Utilizing these criteria, we beli eve that MRI is potentially an excellent noninvasive modality to evalu ate PVM, and we stress that some form of PC cine sequence must be perf ormed to determine if indeed there is blood flow within a suspicious l esion.