Low-level laser therapy can be considered as an alternative physical modality in the management of temporomandibular disorder.

Purpose:To investigate the contribution of perfusionweighted MR imaging (PWI) by using the relative cerebral blood volume (rCBV) ratio in the differential diagnosis of various intracranial space-occupying lesions. Materials and Methods:This study involved 105 patients with lesions (high-grade glioma (N ϭ 26), low-grade glioma (Nϭ 11), meningioma (N ϭ 23), metastasis (N ϭ 25), hemangioblastoma (N ϭ 6), pyogenic abscess (N ϭ 4), schwannoma (N ϭ 5), and lymphoma (N ϭ 5)). The patients were examined with a T2*-weighted (T2*W) gradient-echo singleshot EPI sequence. The rCBV ratios of the lesions were obtained by dividing the values obtained from the normal white matter. Statistical analysis was performed with the Mann-Whitney U-test. A P-value less than 0.05 was considered statistically significant. Results:The rCBV ratio was 5.76 Ϯ 3.35 in high-grade gliomas, 1.69 Ϯ 0.51 in low-grade gliomas, 8.02 Ϯ 3.89 in meningiomas, 5.27 Ϯ 3.22 in metastases, 11.36 Ϯ 4.41 in hemangioblastomas, 0.76 Ϯ 0.12 in abscesses, 1.10 Ϯ 0.32 in lymphomas, and 3.23 Ϯ 0.81 in schwannomas. The rCBV ratios were used to discriminate between 1) high-and low-grade gliomas (P Ͻ 0.001), 2) hemangioblastomas and metastases (PϽ 0.05), 3) abscesses from high-grade gliomas and metastases (P Ͻ 0.001), 4) schwannomas and meningiomas (P Ͻ 0.001), 5) lymphomas from high-grade gliomas and metastases (P Ͻ 0.001), and 6) typical meningiomas and atypical meningiomas (P Ͻ 0.01).Conclusion: rCBV ratios can help discriminate intracranial space-occupying lesions by demonstrating lesion vascularity. It is possible to discriminate between 1) high-and low-grade gliomas, 2) hemangioblastomas and other intracranial posterior fossa masses, 3) abscesses from highgrade gliomas and metastases, 4) schwannomas and meningiomas, 5) lymphomas and high-grade gliomas and metastases, and 6) typical and atypical meningiomas.

ABSTRACT. The aim of this prospective study was to evaluate the value of unenhanced (three-dimensional constructive interference in steady state (3D-CISS)) and contrastenhanced MR cisternography (CE-MRC) in detecting the localisation of cerebrospinal fluid (CSF) leak in patients with rhinorrhoea. 17 patients with active or suspected CSF rhinorrhoea were included in the study. 3D-CISS sequences in coronal and sagittal planes and fat-suppressed T 1 -weighted spin-echo sequences in three planes before and after intrathecal contrast media adminstration were obtained. Images were obtained of the cribriform plate and sphenoid sinus. In addition, high-resolution CT (HRCT) was performed in order to evaluate the bony elements. The leak was present in 9/17 patients with 3D-CISS and 10/17 patients with CE-MRC. The leak from the cribriform plate to the nasal cavity in six patients and from the sphenoid sinus in four patients was nicely shown by CE-MRC. Eight of those patients were surgically treated, but spontaneous regression of the symptoms in two precluded any intervention. The leak localisations shown with CE-MRC were fully compatible with surgical results. The sensitivities of HRCT, 3D-CISS and CE-MRC for showing CSF leakage were 88%, 76% and 100%, respectively. In conclusion, 3D-CISS is a non-invasive and reliable technique, and should be the first-choice method to localise CSF leak. CE-MRC is helpful in conditions when there is no leak or in complicated cases with a positive b2-transferrin measurement.

PC-MRI is helpful in confirming the AS. However, positive flow does not necessarily exclude the existence of AS. 3D-CISS sequence provides excellent cerebrospinal fluid-to-aqueduct contrast, allowing detailed study of the anatomic features of the aqueduct. MRC should be performed on patients who demonstrate suspected AS findings on PC-MRI and/or 3D-CISS sequences.

Diffusion-weighted MR imaging findings of atypical/malignant meningiomas and typical meningiomas differ. Atypical/malignant meningiomas have lower intratumoral ADC values than typical meningiomas. Mean ADC values for peritumoral edema do not differ between typical and atypical meningiomas.