Browsing by Author "Gambini, A"

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    Motor and language DTI Fiber Tracking combined with intraoperative subcortical mapping for surgical removal of gliomas
    (NEUROIMAGE, 2008) Bello, L; Gambini, A; Castellano, A; Carrabba, G; Acerbi, F; Fava, E; Giussani, C; Cadiolib, M; Blasi, V; Casarotti, A; Papagno, C; Gupta, AK; Gaini, S; Scotti, G; Falini, A
    Preoperative DTI Fiber Tracking (DTI-FT) reconstruction of functional tracts combined with intraoperative subcortical mapping (ISM) is potentially useful to improve surgical procedures in gliomas located in eloquent areas. Aims of the study are: (1) to evaluate the modifications of fiber trajectory induced by the tumor; (2) to validate preoperative DTI-FT results with intraoperative identification of functional subcortical sites through direct subcortical stimulation; (3) to evaluate the impact of preoperative DTI-FT reconstructions in a neuronavigational setup combined with ISM technique on duration and modalities of surgical procedures, and on functional outcome of the patients. Data are available on 64 patients (52 low-grade and 12 high-grade gliomas). DTI-FT was acquired by a 3-T MR scanner with a single-shot EPI sequence (TR/TE 8986/80 ms, b=1000 s/mm) with gradients applied along 32 non-collinear directions. 3D Fast Field Echo (FFE) T1-weighted imaging (TR/TE 8/4 ms) was performed for anatomic guidance. The corticospinal tract (CST), superior longitudinal, inferior fronto-occipital and uncinatus fasciculi were reconstructed. Data were transferred to the neuronavigational system. Functional subcortical sites identified during ISM were correlated with fiber tracts depicted by DTI-FT. In high-grade gliomas, DTI-FT depicted tracts mostly at the tumor periphery; in low-grade gliomas, fibers were frequently located inside the tumor mass. There was a high correlation between DTI-FT and ISM (sensitivity for CST=95%, language tracts=97%). For a proper reconstruction of the tracts, it was necessary to use a low FA threshold of fiber tracking algorithm and to position additional regions of interest (ROIs). The combination of DTI-FT and ISM decreased the duration of surgery, patient fatigue, and intraoperative seizures. Combination of DTI-FT and ISM allows accurate identification of eloquent fiber tracts and enhances surgical performance and safety maintaining a high rate of functional preservation. (C) 2007 Elsevier Inc. All rights reserved.
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    Structural and metabolic changes in the brain of patients with upper motor neuron disorders: A multiparametric MRI study
    (AMYOTROPHIC LATERAL SCLEROSIS, 2009) Charil, A; Corbo, M; Filippi, M; Kesavadas, C; Agosta, F; Munerati, E; Gambini, A; Comi, G; Scotti, G; Falini, A
    Our objective was to assess and compare the diagnostic sensitivity of conventional MRI (cMRI), magnetization transfer imaging (MTI), diffusion-weighted imaging (DWI), and proton magnetic resonance spectroscopic imaging (1H-MRSI) in patients with amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS). Thirty-eight ALS patients, nine PLS patients, and 22 healthy controls were enrolled. cMRI, MTI, DWI and (1)H-MRSI were obtained. ALS patients were classified as advanced phase (Ap)-ALS (definite + probable) and early phase (Ep)-ALS (possible + probable-laboratory supported). cMRI was highly sensitive in detecting corticospinal tract (CST) hyperintensities in Ap-ALS (63.4%) and PLS (71.9%), but it was poorly sensitive in Ep-ALS (17.1%). Hyperintensity on proton density-weighted images correlated with ALS severity (p = 0.02). CST apparent diffusion coefficient was significantly increased in ALS (p < 0.01) and PLS (p = 0.02) versus controls. The N-acetylaspartate/ creatine ratio was significantly reduced in the motor cortex of patients versus controls(p <= 0.01 in PLS, p = 0.02 in Ap-ALS). The study shows the utility of cMRI for diagnosing ALS. Nevertheless, MRI sensitivity is limited at the early stages of the disease. In these cases, DWI and (1)H-MRSI seem to have the potential to ameliorate the patients' work-up and estimate the nature and extent of the underlying pathological damage.