Bahattin Hakyemez

In the present study, the authors presented the intrathecal gadolinium enhanced MR-myelography findings of patients with spontaneous intracranial hypotension. Intrathecal gadolinium enhanced MR-myelography (Gd-MR-myelography) examinations between October 2012 and September 2018 in patients having clinical and radiological findings of spontaneous intracranial hypotension were evaluated retrospectively. Sites and types of contrast leakages in 20 patients who met inclusion criteria were reviewed. All patients had undergone T1-fat suppressed sagittal images of cervical, thoracic and lumbar region after the off label intrathecal injection of 1 ml gadolinium-based contrast agent. Patients (18 female, 2 male) are aged between 23 and 62 years-old (mean age: 41.1). Cerebrospinal fluid (CSF) leakages were cervical in 6 patients, thoracic in 5 patients, lumbar in 5 patients. One patient had leakage in multiple levels on both cervical and thoracic region and another patient on both cervical-thoracic and lumbar regions. No patients had adverse effects related to intrathecal injection of gadolinium. Gd-MR-myelography is effective imaging modality to reveal spinal CSF leakages in patients with spontaneous intracranial hypotension.

The aim of this prospective study was to evaluate the value of unenhanced (three-dimensional constructive interference in steady state (3D-CISS)) and contrast-enhanced 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 T1-weighted spin-echo sequences in three planes before and after intrathecal contrast media administration 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 beta2-transferrin measurement.

Intraventricular meningiomas have often been reported; however, literature reveals very few cases localized within foramen of Monro. Herein we report a 57-year-old woman admitted with obstructive hydrocephalus-related symptoms. Strikingly, the lesion was completely calcified in CT and had no marked solid component on MRI. The lesion was completely removed by surgical resection with a transfrontal intraventricular approach. The resected mass was histopathologically diagnosed as meningioma. The patient's symptoms resolved immediately after the operation.

Chloroma (myeloid or granulocytic sarcoma) is a rare type of tumour comprising immature granulocytic cells. It generally accompanies acute myeloid leukaemia and, rarely, other myeloproliferative disorders. When presenting as dural-based mass lesions, radiological differential diagnosis includes meningioma, metastasis and lymphoma. There is a limited number of descriptions of chloromas mimicking dural-based masses in the literature. We present preliminary diffusion-weighted MR, perfusion-weighted MR and MR spectroscopy findings of an intracranial myeloid sarcoma.

Introduction To investigate the contribution of perfusion-weighted MRI to the differentiation of meningiomas with atypical conventional MRI findings from intraaxial tumors. Methods We retrospectively analyzed 54 meningiomas, 12 glioblastomas and 13 solitary metastases. We detected 6 meningiomas with atypical features on conventional MRI resembling intraaxial tumors. The regional cerebral blood flow (rCBV) ratios of all tumors were calculated via perfusion-weighted MRI. The signal intensity-time curves were plotted and three different curve patterns were observed. The type 1 curve resembled normal brain parenchyma or the postenhancement part was minimally below the baseline, the type 2 curve was similar to the type 1 curve but with the postenhancement part above the baseline, and the type 3 curve had the postenhancement part below the baseline accompanied by widening of the curve. Student’s t-test was used for statistical analysis. Results On CBV images meningiomas were hypervascular and the mean rCBV ratio was 10.58±2.00. For glioblastomas and metastatic lesions, the rCBV ratios were 5.02±1.40 and 4.68±1.54, respectively. There was a statistically significant difference in rCBV ratios between meningiomas and glioblastomas and metastases (P<0.001). Only one of the meningiomas displayed a type 2 curve while five showed a type 3 curve. Glioblastomas and metastases displayed either a type 1 or a type 2 curve. None of the meningiomas showed a type 1 curve and none of the glioblastomas or metastases showed a type 3 curve. Conclusion Differentiating meningiomas with atypical conventional MRI findings from malignant intraaxial tumors can be difficult. Calculation of rCBV ratios and construction of signal intensity-time curves may contribute to the differentiation of meningiomas from intraaxial tumors.

Introduction Atypical/malignant meningiomas recur more frequently then typical meningiomas. In this study, the contribution of diffusion-weighted MR imaging to the differentiation of atypical/malignant and typical meningiomas and to the determination of histological subtypes of typical meningiomas was investigated. Methods The study was performed prospectively on 39 patients. The signal intensity of the lesions was evaluated on trace and apparent diffusion coefficient (ADC) images. ADC values were measured in the lesions and peritumoral edema. Student’s t-test was used for statistical analysis. PP0.05). Furthermore, the difference between the subtypes of typical meningiomas and atypical/malignant meningiomas was significant (P<0.001). Conclusion 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.

Our aim was to demonstrate lateralization morphometrically and volumetrically measuring the main limbic structures like hippocampus, amygdala, fornix and mamillary bodies in patients with temporal lobe epilepsy (TLE) and to establish the contribution of each anatomical structure to lateralizing the pathological site. Forty-two patients with complex partial seizures originating from the temporal lobe and 42 control healthy volunteers were included in the study. T2-weighted FSE sequences in axial and oblique coronal planes and T1-weighted SE sequences in the sagittal plane were used. A high-resolution IR sequence was used for the volumetric analysis of amygdala and hippocampus and for the measurement of fornix and mamillary body thickness. Intensity changes and atrophy of limbic structures were observed qualitatively and measurement of these structures was performed quantitatively. Student's t test and Mann-Whitney U-test were used for the statistical analysis. The p values <0.05 was taken as statistically significant. Ten out of 42 patients had intracranial masses and were excluded from the study. Qualitative analysis revealed atrophy in 84% and intensity increase in 60% of cases. Quantitative measurement demonstrated that control cases had a larger hippocampus than the patients (p0.05). According to the difference in the volumes of the right and left sides, there was unilateral atrophy in 34% of patients. Bilateral atrophy was not observed. There was a significant difference in fornix and mamillary bodies of the patients and control subjects (p<0.005). In 62.5% of cases, there were abnormalities in the fornix with bilateral involvement in 13% of cases. Mamillary bodies were abnormal in 37% of patients with bilateral involvement in 15%. Lateralization was accomplished in 65% of the patients according to the percentage difference ratios of fornix and in 38% of the patients according to the mamillary bodies. It is important to demonstrate hippocampus atrophy in patients with TLE. In the decision of lateralization of the epileptic side, evaluation of the fornix could be a good and practical solution. However, hippocampal volumetry is an indispensable criterion in demonstrating hippocampal atrophy more accurately. Atrophy of the amygdala and thickness of mamillary bodies have the least importance for lateralization.

We aimed to depict Broca's area and Wernicke's area by word generation and sentence formation paradigms in patients with various intracranial lesions adjacent to language areas using functional MRI technique and to evaluate the ability of functional MRI to lateralize the hemispheric dominance for language. Twenty-three right-handed patients were included in this study. Lesions were classified as low-grade glioma (n=8), high-grade glioma (n=9), metastasis (n=1), meningioma (n=1), arteriovenous malformation (n?2) and mesial temporal sclerosis (n=2). We performed blood-oxygenated-level-dependant functional MRI using a 1.5-T unit. Word generation and sentence formation tasks were used to activate language areas. Language areas were defined as Brodmann 44, 45 (Broca's area) and Brodmann 22 area (Wernicke's area). Laterality index was used to show the dominant hemisphere. Two poorly cooperative patients showed no activation and were excluded from the study. Broca's area was localized in 21 patients (100 %). Wernicke's area, on the other hand, could only be localized in eight of the 21 patients (38 %). The left hemisphere was dominant in 86% of patients while atypical language lateralization (right or bilateral) was demonstrated in 14% of the patients. Bilateral activation areas were shown in 10% of those patients while right cerebral hemisphere was dominant in 4% of the patients. Word generation and sentence formation tasks are especially helpful in localizing Broca's area. Wernicke's area could also be demonstrated in some of the cases. Functional MRI can be used as an important and useful means of demonstrating language areas in patients with lesions adjacent to those areas and depicting the hemispheric dominance.