Prognostic value of preoperative diffusion restriction in glioblastoma.

INTRODUCTION: Although glioblastoma (GBM) has a very poor prognosis, overall survival (OS) in treated patients shows great difference varying from few days to several months. Identifying factors explaining this difference would improve management of patient treatment. AIM: To determine the relevance of diffusion restriction in newly diagnosed treatment-naïve GBM patients. METHODS: Preoperative magnetic resonance scans of 33 patients with GBM were reviewed. Regions of interest including all the T2 hyperintense lesion were drawn on diffusion weighted B0 images and transferred to the apparent diffusion coefficient (ADC) map. For each patient, a histogram displaying the ADC values within in the regions of interest was generated. Volumetric parameters including tumor regions with restricted diffusion, parameters derived from histogram and mean ADC value of the tumor were calculated. Their relationship with OS was analyzed. RESULTS: Patients with mean ADC value < 1415x10-6 mm2/s had a significantly shorter OS (p=0.021). Among volumetric parameters, the percentage of volume within T2 lesion with a normalized ADC value <1.5 times that in white matter was significantly associated with OS (p=0.0045). Patients with a percentage>23.92% had a shorter OS. Among parameters derived from histogram, the 50th percentile showed a trend towards significance for OS (p=0.055) with patients living longer when having higher values of 50th percentile. A difference in OS was observed between patients according to ADC peak of histogram but this difference did not reach statistical significance (p=0.0959). CONCLUSION: Diffusion magnetic resonance imaging may provide useful information for predicting GBM prognosis.

MRI contribution in minimally displaced lateral humerus condylar fractures in children.

INTRODUCTION: Diagnosis and treatment of displaced humerus lateral condylar fracture is well codified with open reduction and pinning. For non-displaced or minimally displaced lateral condylar (NMDLC) fractures, diagnosis can be challenging because of cartilaginous structures none visualized on radiographs. AIM: To determine the usefulness of MRI in evaluating articular extension of NMDLC fracture. METHODS: We reviewed consecutive NMDLC fractures during 6 years including children younger than 15 years old with displacement lesser than 2 mm (Rigault type I) at initial radiographs divided in two groups: only line fracture was viewed (R1a), displacement gap lesser than 2 mm (R1b). After elbow cast immobilization, children have got MRI. Surgery was performed in complete articular fractures. All children were seen after 1 mouth then at 6 month for elbow evaluation. RESULTS: Thirty-one fracture, including twenty-two (70.97%) boys. Average age was 6.24 years (3 to 11). Fifteen fractures was classified R1a and sixteen R1b .According to MRI, seven fractures (22,6%) were metaphyseal Gp1, eleven (35,5%) were metaphyso-epiphyseal with an intact hinge cartilage Gp2 ,nine (29%) were complete Salter IV Gp3 and MRI reveals a supracondylar fractures in four cases. Fracture was metaphyseal more often in R1a group (40.0%) compared to R1b (6.3%). Gp3 group was significantly higher in R1b (50.0%) compared to R1a group (6.7%). For the sixteen R1b cases, eight presented articular cartilage involvement on MRI (Gp3) with concordant operative findings. CONCLUSION: MRI is effective in assessing epiphyseal extension fracture providing accurate information for appropriate treatment.