Quantitative human in vivo evaluation of high resolution MRI for vessel wall morphometry after percutaneous transluminal angioplasty

Visualization of the vessel wall after transluminal angioplasty is importan t to monitor the restenosis progress. Intravascular ultrasound proved its c apabilities as an invasive procedure in many studies. The aim of this study was to evaluate the feasibility of high-resolution MRI as a non-invasive t ool for follow-up after PTA. High-resolution magnetic resonance images (pix el size: 0.49 * 0.49 mm(2)) were acquired on a 1.0 T clinical scanner. Morp hometry was conducted after conversion of DICOM images into TIFF format usi ng ScionImage on a PC. In-vitro studies using a polyvinylchloride tube were evaluated by two independent investigators. Goldstandard was a caliper rul e and direct radiography. Five patients were monitored before and 24 h, six weeks, three months and six months after PTA. In vivo measurements promise d a good concordance for both investigators for area as well as for diamete r measurements. Area measurements showed correlations up to r = 0.86 (p < 0 .001) whereas the correlations of diameters were slightly inferior (r betwe en 0.58 and 0.84; p < 0.005). Relocation of the same slice position in the follow up studies could be guaranteed using anatomic landmarks in the image s. As a non-invasive tool to assess restenosis after PTA high-resolution MR I promises to be a reproducible technique. It is easy to identify the same vascular region in different studies due to neighboring anatomic landmarks. Progression of disease as well as success of pharmacologic treatment to pr event restenosis may be monitored. (C) 2000 Elsevier Science Inc. All right s reserved.