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M Cosottini

Publications and source records attributed to M Cosottini.

21 records · Page 2Linked to original sources

Identification of the feeding arteries of spinal vascular lesions via phase-contrast MR angiography with three-dimensional acquisition and phase display.

PURPOSE: To determine whether identification of the feeding arteries of spinal vascular lesions with phase-contrast MR angiography benefits from the higher spatial resolution of three-dimensional (volume) acquisitions and flow-direction information provided by the phase reconstruction of two-dimensional acquisitions. METHODS: Fifteen patients with high- or low-flow spinal vascular lesions proved by spinal arteriography underwent MR angiography with phase-contrast techniques. Arteriographic and MR angiographic studies were reviewed to identify the arterial feeders of spinal vascular lesions. RESULTS: On modulus reconstructions of coronal 2-D or 3-D acquisitions, three of four arteries feeding high-flow lesions and three of 14 arteries feeding low-flow lesions were identified as hypertrophic vessels joining the parent intercostal or cervical arteries. Of 11 intradural veins draining dural arteriovenous fistulas, three were identified on coronal 2-D acquisitions and six on coronal 3-D acquisitions as vessels that coursed from a neural foramen to a midline tangle of vessels. Phase reconstruction showed ascending and descending flow patterns in two patients with intramedullary arteriovenous malformations, and diverging flow in perimedullary veins draining a hemangioblastoma. In nine patients with dural arteriovenous fistulas, phase reconstruction provided information as to the level of the arterial feeders. Phase reconstruction in coronal plane acquisitions also provided evidence of centripetal flow. CONCLUSION: Three-dimensional acquisitions and phase display of 2-D acquisitions improved the visibility of arterial pedicles of spinal vascular lesions at phase-contrast MR angiography.

Adult↗

Contrast-enhanced time-resolved MR angiography of spinal vascular malformations.

PURPOSE: The purpose of this work was to assess the potential and limitations of a contrast-enhanced time-resolved MR angiography technique for evaluation of spinal vascular malformations. METHOD: Two patients with intramedullary arteriovenous (AV) malformations and three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to 2-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast agent. This was followed by coronal 3D and sagittal or coronal 2D phase contrast (PC) MR angiography. RESULTS: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nidus, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, whereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and persisted, although less conspicuous, in the fourth (late) series. Contrast-enhanced time-resolved MR angiography demonstrated the venous components of the lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identification of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. CONCLUSION: Contrast-enhanced time-resolved MR angiography is a useful complement to PC MR angiography for the evaluation of spinal vascular malformation.

Arteriovenous Fistula↗

[Usefulness of opposed-phase gradient-echo technique in the diagnosis of occult lesions of the knee and comparison with traditional T1-weight sequences (in-phase)].

PURPOSE: To investigate the usefulness of opposed-phase gradient-echo (GRE) technique in detecting occult posttraumatic bone injuries in the knee. Occult injuries account for pain and, if not properly treated, may progress to severe chondral and bone damage. An early diagnosis provided by MRI can help avoid interventional procedures. MATERIAL AND METHODS: We submitted to MRI of the knee 51 patients (32 men and 19 women) with negative plain radiographic findings and at least one traumatic bone injury at MRI. MR examinations were performed with a 0.5 T unit and included a conventional SE or GRE T1-weighted sequence and an opposed phase GRE sequence on the coronal or sagittal plane (2-3 minutes acquisition). To assess the lesion number and conspicuity, images were retrospectively reviewed by two readers. Injury conspicuity was graded as: 0 (poorly visible), 1 (visible), and 2 (well visible). Marrow-to-injury signal intensity ratio was calculated in 30 patients: a ROI was positioned in the site of highest signal intensity and adjacent bone marrow and the ratio analyzed with Student's "t"-test. RESULTS: In-phase and out-of-phase images showed 71 injuries in 51 patients. Conventional (in-phase) imaging missed 6/71 lesions. Injury conspicuity on out-of-phase images was of grade 2 in 58 cases (81.6%) and of grade 1 in 13 cases (18.3%), versus 23 (32.3%) and 42 (59.1%), respectively, on conventional images. Injury conspicuity was graded as 0 in 6 cases (8.4%) on conventional images. Quantitative analysis of marrow-to-injury signal intensity ratio showed higher values for out-of-phase GRE than conventional images. CONCLUSION: Opposed-phase GRE are quick sequences available on all MR systems which appear superior to conventional T1-weighted images in detecting occult injuries in the knee. Injuries are more conspicuous because their signal intensity is lower due to the simultaneous presence of fat and water protons, which is typical of bone trauma, GRE sequences make a useful and rapid complement to T1-/T2-weighted fat saturation acquisitions in the study of the post-traumatic knee.

Adolescent↗