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Background Intracranial lesions exhibit clear contrast enhancement in T1-weighted imaging, but the mechanism whereby contrast-enhanced susceptibility-weighted imaging (CE-SWI) generates signals remains unclear. Contrast enhancement patterns cannot be reliably predicted. Purpose To explore the mechanism of CE-SWI contrast enhancement. Material and Methods Fifty-five patients were retrospectively enrolled. All of the imaging employed a clinical 3T magnetic resonance imaging (MRI) system fitted with a 32-channel head coil. Minimum-intensity projection reformatted images were evaluated. Intracranial lesions and brain parenchymal intensities were explored using SWI and CE-SWI. signal intensity rates were calculated by dividing the lesional intensity by the white matter intensity, after which the SWI and CE-SWI signal intensity rate were compared. Two observers independently performed intralesional susceptibility signal analysis. Results After contrast medium administration, malignant and extra-axial tumors exhibited obvious contrast enhancement on CE-SWI ( P Conclusion Contrast media can either reduce or increase SWI signal intensities. The dual contrast feature of CE-SWI can be useful when exploring intracranial disorders.

The treatment options for high risk acute pulmonary embolism (PE) patients with failed systemic thrombolytic treatment (STT) is limited. The clinical use of catheter directed thrombolysis with the EkoSonic Endovascular System (EKOS) in this population has not been evaluated before. Catheter directed thrombolysis is an effective treatment modality for high risk PE patients with failed STT. Thirteen consecutive patients with failed STT were included in the study. EKOS catheters were placed and tissue plasminogen activator (t-PA) in combination with unfractionated heparin were given. Clinical and echocardiographic properties of the patients were collected before EKOS, at the end of EKOS and during the follow-up visit 6 months after discharge. The duration of EKOS treatment was 21.8 +/- 3.8 h and the total dose of tPA was 31.2 +/- 15.3 mg. One patient who presented with cardiac arrest died and the clinical status of the remaining subjects improved significantly. Any hemorrhagic complication was not observed. EKOS resulted in significant improvement of right ventricular functions and decrease of systolic pulmonary artery pressure. During a follow-up period of 6 months none of the patients died or suffered recurrent PE. In addition, echocardiographic parameters or right ventricular function significantly got better compared to in-hospital measurements. EKOS is an effective treatment modality for high risk PE patients with failed STT and can be applied with very low hemorrhagic complications.

True aneurysm of pancreaticoduodenal arcade (PDA) is usually accompanied by stenosis or occlusion of celiac trunk (CeT). The up-to-date and first choice treatment modality of PDA aneurysm is the endovascular approach in nearly all cases except few selected ones necessitating surgery. The main approach in endovascular treatment is embolization of the aneurysm by preserving the parent artery. A case with concomitant CeT occlusion and PDA aneurysm was treated with coil embolization by preserving inferior pancreaticoduodenal artery with retrievable Solitaire® stent. In our knowledge, this is the first case with PDA aneurysm treated with this technique.

WOS: 000371800700003, PubMed: 26493821, The aim of this study was to investigate the effect of stent cell geometry on midterm results of carotid artery stenting (CAS). One hundred fifty-five patients underwent CAS between February 2010 and December 2012. Ninety-one open- and 84 closed-cell stents were used in this non-randomized, retrospective study. Periprocedural complications were defined as the ones happened during the procedure or within 30 days afterwards. Starting from the 6th month after the procedure, in-stent restenosis was detected with multidetector computed tomography angiography and classified into four groups from focal restenosis to occlusion. Eleven complications were encountered in the periprocedural period (four on the open- and seven on the closed-cell group). Total complication rate was 6.3 % (11/175). No significant difference was detected in terms of periprocedural complications between two groups (p = 0.643). There was statistically significant difference between stent design groups in regard to radiological findings (p = 0.002). Sixteen of open-cell stents and three of closed-cell stents had focal restenosis. One closed-cell stent had diffuse proliferative restenosis and one open-cell stent had total occlusion. In-stent restenosis was more common in open-cell stent group, which have larger free cell area than closed-cell stents. Although our radiologic findings promote us to use closed-cell design if 'possible', no difference was detected in terms of clinical outcomes.

WOS: 000335276400002 PubMed: 24559748 Background and purpose: The purpose of this study is to investigate the relationship between Rosenthal basal vein (BVR) type and diameter and perimesencephalic nonaneurysmal subarachnoid hemorrhage (P-SAH). Materials and methods: Aneurysmal subarachnoid hemorrhage (A-SAH), P-SAH, and control groups were evaluated, and BVRs were classified by type. BVR diameters in patients were measured. Results: There was a statistically significant difference of BVR drainage types between groups (P=.002). BVR diameters of patients with normal drainage pattern in P-SAH group were significantly smaller than those in both other groups (P

The widespread use of immunosuppressive agents has significantly increased the rates of successful solid-organ and stem cell transplants, especially with liver and kidney. Cyclosporine and tacrolimus are most commonly used for this purpose. Although these agents have different mechanisms of action, both have various adverse effects, including nausea, vomiting, headache, hypertension, nephrotoxicity, and rarely epileptic seizures. In our first case, a patient presented with epileptic seizures and hemiparesis after a liver transplant, and posterior reversible encephalopathy syndrome related to cyclosporine toxicity was considered. Once cyclosporine levels in the blood decreased, the patient had both clinical and radiologic improvements. In our second case, a patient presented with delirium after a liver transplant. Again, when cyclosporine levels in the blood decreased, the patient showed improvement in clinical findings. Neurologic complications may develop after liver transplant, and these complications are encountered most frequently within the first postoperative month. Neurologic complications are multifactorial; insufficient graft function, intracranial bleeding, cerebral infarcts, infections, and immuno suppressive drug toxicity (tacrolimus and cyclosporine) may be considered among these factors. As shown in our presented cases, most neurologic complications can be successfully treated by correcting the underlying factor.

PURPOSE: We aimed to investigate the safety and functionality of tunneled transhepatic hemodialysis catheters in chronic hemodialysis patients. METHODS Thirty-eight patients (20 women aged 56±10 years and 18 men aged 61±11 years) with transhepatic tunneled hemodialysis catheters were evaluated. The date of the first transhepatic catheterization, indications, procedure details, functional time periods of catheters, reasons for the removal or revision of catheters, catheter-related complications, and current conditions of patients were retrospectively analyzed. RESULTS A total of 69 catheters were properly placed in all patients (100% technical success) under imaging guidance during the 91-month follow-up period. The functionality of 35 catheters could not be evaluated: five catheters were removed because of noncomplication related reasons (surgical fistulas were opened in two cases [2/35, 5.7%], transplantation was performed in three cases [3/35, 8.6%]), 18 patients died while their catheters were functional (18/35, 51.4%), and 12 catheters were still functional at the time of the study (12/35, 34.3%). The functionality of catheters was evaluated the remaining 34 catheters that necessitated revision because of complications. Furthermore, only half of the catheters were functional on day 136 when evaluated using Kaplan- Meier analysis. The four main complications were thrombosis (16/34, 47%; complication rate of 0.37 days in 100 catheters), infection (8/34, 23.5%; 0.18 days in 100 catheters), migration (8/34, 23.5%; 0.18 days in 100 catheters), and kinking (2/34, 6%; 0.04 days in 100 catheters). CONCLUSION Transhepatic venous catheterization is a safe and functional alternative route in chronic hemodialysis patients without an accessible central venou route. The procedure can be performed with high technical success and low complication rates under imaging guidance. © Turkish Society of Radiology 2016.

BACKGROUND: Meningioma is the most frequent intracranial tumor and is often an incidental finding on imaging. Some imaging-based scores were suggested for differentiating low- and high-grade meningiomas. The purpose of this work was to compare diffusion-weighted imaging findings of different meningiomas in a large multicenter study by using apparent diffusion coefficient (ADC) values for predicting tumor grade and proliferation potential. METHODS: Data from 7 radiologic departments were acquired retrospectively. Overall, 389 patients were collected. All meningiomas were investigated by magnetic resonance imaging (1.5-T scanner) by using diffusion-weighted imaging (b values of 0 and 1000 s/mm(2)). The comparison of ADC values was performed by Mann-Whitney U test. RESULTS: World Health Organization grade I was diagnosed in 271 cases (69.7%), grade II in 103 (26.5%), and grade III in 15 patients (3.9%). Grade I meningiomas showed statistically significant higher ADC values (1.05 +/- 0.39 x 10(-3) mm(2)s(-1)) in comparison with grade II (0.77 +/- 0.15 x 10(-3) mm(2)s(-1); P = 0.001) and grade III tumors (0.79 +/- 0.21 x 10(-3) mm(2)s(-1); P = 0.01). An ADC value of = 5%). CONCLUSIONS: The estimated threshold ADC value of 0.85 can differentiate grade I meningioma from grade II and III tumors. The same ADC value is helpful for detecting tumors with high proliferation potential.

Multiple myeloma (MM) is a hematologic malignancy characterized by lytic bone lesions and is usually with vertebral involvement. At the time of diagnosis, vertebral involvement is present in approximately 60% of patients (1). Pathologic vertebral fractures can easily occur in MM. Spinal instability, back pain, neurologic dysfunction and physical symptoms can be observed in patients with MM due to vertebral fractures. As a result, the quality of life of patients is affected significantly. A variety of contemporary therapeutic approaches are available for vertebral involvement in MM. These approaches are chemotherapy, radiotherapy, radioisotope therapy, bisphosphonate therapy, algological treatment and palliative/stabilization surgery. Risks of spinal instability and neural compression can be high with conservative treatment options. While surgery can be suitable for patients with neural compression, its complication rates are high (2). Percutaneous vertebroplasty (PV) is a minimally invasive treatment method. PV is used to treat back pain caused by vertebral involvement due to osteoporotic vertebral compression fractures, metastasis, multiple myeloma, and aggressive hemangioma (3). PV increases spinal stability by preventing vertebral collapse (2). PV was originally used for treatment of painful vertebral hemangioma by Galibert et al. (4). In several studies, it was reported that PV prevented vertebral height loss and reduced patient pain and need of analgesia use in patients with vertebral involvement due to osteoporosis and metastasis (5–8). PV usage is gradually increasing for vertebral involvement due to MM. However, data on PV usage for MM is limited in the literature (8). PV is preferred because it is more easily performed than surgery, more effective, and has lower rates of serious complications. The aim of this study was to assess the effectiveness, benefits, and reliability of PV in patients with vertebral involvement of MM.

The aim of this study was to examine the structural-neurochemical abnormalities of the frontal white matter (FWM), deep gray matter nuclei, and pons in patients with Wilson's disease (WD) using proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI). Nine patients with WD and 14 age-matched controls were examined with MRS. N-Acetylaspartate (NAA), choline (Cho), and creatine (Cr) peaks were calculated. DWI scans from six WD patients and six controls were also obtained. The relative metabolite ratios and apparent diffusion coefficient (ADC) values of the WD patients were compared to those of the control subjects by using statistical measures. Measurements in the thalamus and pons showed significantly lower NAA/Cho and NAA/Cr ratios in the WD group than in the control group (P < 0.05). Thalamic and pontine Cho/Cr ratios in the patient group were significantly higher than those of the control group (P < 0.05). No statistically significant relation was found between the patient and control groups as a result of the MRS examinations of FWM and all ADC measurements (P > 0.05). MRS is a noninvasive, valuable modality for detecting structural-neurochemical changes of the brain stem and deep gray matter in patients with WD. The contribution of DWI in these patients is limited.

We present a case of multiple intracranial abscesses caused by Cryptococcus neoformans in a patient who presented with no symptoms of immunodeficiency.

Vertebrobasilar junction fenestration is a rare congenital anomaly which is commonly seen with an aneurysm formation. Because of the complex anatomical structure of this area complicates the surgical intervention, endovascular coil treatment of aneurysm is an alternative method. Several fenestration-related aneurysms may not be detected by 2D conventional angiography imaging due to their considerably thin and short structure or small size. By 3D rotational digital subtraction angiography, small-sized fenestrations can be examined at the intended plane from various angles. This method enables us to plan the endovascular intervention in detail by revealing orientation, neck, origin of perforator arteries, and the relation between aneurysm and fenestration. In the present case, we present the angiographic results of the case with vertebrobasilar junction fenestration, along with endovascular treatment of the ruptured aneurysm. Vertebrobasilar bileşke fenestrasyonu nadir bir konjenital anomalidir ve anevrizma formasyonuyla birlikte sıktır. Bu bölgenin kompleks anatomisi nedeniyle cerrahi müdahale zor olduğundan, anevrizmanın endovasküler coil tedavisi alternatif bir metoddur. Bazı fenestrasyonların çok ince ve kısa olması ve bazı anevrizmaların küçük olması nedeniyle iki boyutlu konvansiyonel anjiografi görüntülerinde saptanamayabilir. 3D rotasyonel dijital subtraksiyon angiografi ile küçük boyutlardaki fenestrasyonların ve anevrizmaların istenilen düzlemde, değişik açılarda incelenebilmesi mümkün olmaktadır. Anevrizmanın oryantasyonu, boynu, perforan arterlerin orjini ve anevrizma ile fenestrasyon ilişkisi gösterilerek endovasküler girişimin planmasına olanak sağlar. Biz bu yazıda vertebrobaziler bileşke fenestrasyonlu olgunun anjiografik bulguları ve rüptüre olmuş anevrizmanın endovasküler tedavisini sunmaktayız.

Susac's syndrome is a vasospastic disease resulting from bilateral microangiopathy of the brain, cochlea and retina. It is characterized by encephalopathy, bilateral sensorineural fluctuating hearing loss and visual loss. It is very uncommon and usually affects women during young adulthood. Since all three symptoms of the triad may not be present, the clinical diagnosis is difficult. Therefore, neuroimaging, particularly magnetic resonance imaging, has an important role in establishing the diagnosis. In this case report, we present a young woman who had all the symptoms of Susac's syndrome. This is the first Susac's syndrome case reported in Turkey.

Purpose To investigate the contribution of perfusion-weighted 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 = 26), low-grade glioma (N= 11), meningioma (N = 23), metastasis (N = 25), hemangioblastoma (N = 6), pyogenic abscess (N = 4), schwannoma (N = 5), and lymphoma (N = 5)). The patients were examined with a T2*-weighted (T2*W) gradient-echo single-shot 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 ± 3.35 in high-grade gliomas, 1.69 ± 0.51 in low-grade gliomas, 8.02 ± 3.89 in meningiomas, 5.27 ± 3.22 in metastases, 11.36 ± 4.41 in hemangioblastomas, 0.76 ± 0.12 in abscesses, 1.10 ± 0.32 in lymphomas, and 3.23 ± 0.81 in schwannomas. The rCBV ratios were used to discriminate between 1) high- and low-grade gliomas (P < 0.001), 2) hemangioblastomas and metastases (P< 0.05), 3) abscesses from high-grade gliomas and metastases (P < 0.001), 4) schwannomas and meningiomas (P < 0.001), 5) lymphomas from high-grade gliomas and metastases (P < 0.001), and 6) typical meningiomas and atypical meningiomas (P < 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 high-grade gliomas and metastases, 4) schwannomas and meningiomas, 5) lymphomas and high-grade gliomas and metastases, and 6) typical and atypical meningiomas. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

Introduction: Differential radiologic diagnosis of cystic malformations of the posterior fossa is often difficult with conventional imaging techniques because of overlapping features of these entities. Posterior fossa cystic malformations occupy the cerebrospinal fluid (CSF) spaces. They may create secondary dynamic effects on the movements of CSF. The aim of this study was to investigate CSF flow alterations in posterior fossa cystic malformations with CSF flow MR imaging. Methods: The study included 40 patients with cystic malformations of the posterior fossa. The patients underwent cardiac-gated phase-contrast cine MR imaging. CSF flow was qualitatively evaluated using an in-plane phase-contrast sequence in the midsagittal plane. The MR images were displayed in a closed-loop cine format. Results: Twelve of the patients had communicating arachnoid cyst, seven had non-communicating arachnoid cyst, ten had mega cisterna magna, six had Dandy-Walker malformation, two had Dandy-Walker variant, and three had Blake's pouch cyst. CSF flow MR imaging indicated the regions of no, slow or higher flow, direction of flow, and abnormal cystic fluid motion. Each malformation displayed a distinct CSF flow pattern. Conclusion: Phase-contrast cine MR imaging for CSF flow evaluation may be a useful adjunct to routine MR imaging in the evaluation of the cystic malformations of the posterior fossa because it can improve the specificity in differentiating such malformations.

WOS: 000349660300009 PubMed: 25496683 This study describes the pen-procedural and late complications and angiographic follow-up results of 32 patients with 34 complex aneurysms treated with flow diverter Silk stents in a single centre. In this retrospective study, 40 Silk stents (SS) were implanted in 34 complex intracranial aneurysms in 32 patients. In our series, 20 (58.8%) carotid-ophthalmic internal carotid artery (ICA), six (17.6%) cavernous ICA, two (5.9%) supraclinoid ICA, two (5.9%) petrosal ICA (the same patient-bilateral) and four (11.8%) posterior circulation aneurysms were treated. One of the posterior circulation lesions was a fenestrated-type aneurysm. Twenty wide-necked, saccular; eight neck remnant; four fusiform and two blister-like aneurysms were included in our series. SS were successfully implanted in all patients (100%). Mis-deployment occurred in 17.6% of patients. In two of these patients adequate stent openness was achieved via Hyperglide balloon dilatation. Coil embolization in addition to SS placement was utilized in four aneurysms. One patient (3%) experienced transient morbidity due to a thromboembolic event and there was one mortality (3%) due to remote intraparenchymal haemorrhage. Complete occlusion of 27/33 (81.8 %) and 29/33 (87.9 %) aneurysms was achieved six and 12 months after the procedure, respectively. In-stent intimal hyperplasia was detected in 6.1 % patients. Flow-diverter Silk stent implantation is an effective method of treating complex aneurysms with acceptable mortality and morbidity rates. Complete occlusion is achieved in most of the complex aneurysms.

Mucormycosis is a rare, invasive and fatal disease that occurs mainly in diabetes mellitus patients with uncontrolled blood glucose levels or in immunocompromised patients. The mortality rate of this disease is as high as 25 to 80%, despite aggressive surgical treatment and antifungal therapy. This high mortality requires alternative treatment approaches. The accepted treatment modality of invasive mucormycosis are amphotericin B lipid formulations. Although echinocandins generally show no activity against Mucorales, it was shown that Rhizopus oryzae expressed the target enzyme for echinocandins, 1,3-beta-glucan synthase. Additionally, there are some experimental studies in a diabetic mouse model and case reports regarding the effects of caspofungin. In this report, we present a rhinocerebral mucormycosis case treated with liposomal amphotericin B and caspofungin. There was regression of the patient's clinical and radiological condition with the addition of caspofungin, but she died due to discontinuation of her treatment and reasons other than mucormycosis.

BACKGROUND/AIM: The limbic system, specifically the hippocampus, plays a key role in controlling the sleep-wake cycle. Changes in these particular structures of the central nervous system have been suggested to be related to obstructive sleep apnea syndrome (OSAS). We hypothesized that reduced hippocampal volume is a risk factor for excessive daytime sleepiness (EDS) in OSAS. PATIENTS AND METHODS: Twenty-two patients with newly diagnosed OSAS and 20 healthy controls were included in the present study. Polysomnography was performed for each participant to determine the presence of OSAS. EDS was defined based on the Epworth sleepiness scale (ESS) score, and patients were grouped as sleepy or non-sleepy according to this score. The hippocampal volume was calculated by MR volumetry using a manual tracing technique. RESULTS: There was no significant difference between groups in demographic variables. The hippocampus was markedly smaller in the OSAS groups than in controls (p < 0.001 Hippocampal volume was negatively correlated with the ESS score (r = - 0.631, p = 0.002). CONCLUSIONS: Our findings suggest that EDS is associated with reduced hippocampal volume in OSAS.

Syndrome is characterized by cerebral calcification andcyst formation (CRMCC), as defined in recent years,1and isdescribed in the published reports as Coats plus syndrome,Labrune syndrome and leukoencephalopathy calcification andcysts (LCC) syndrome.2Cerebral, ophthalmic, skeletal, intesti-nal involvement can be seen. CRMCC determined in lateadolescence is limited. Autosomal recessive inheritance isreported.3In the majority of patients, neurological findingsshowing progression have been reported, such as spasticity,dystonia, ataxia and loss of cognitive abilities. Imaging find-ings with laboratory data should support the diagnosis.

The aim of this study was to investigate the shape differences in the corpus callosum (CC) and cerebellum of female relapsing-remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS) patients compared with healthy controls. This study was conducted using the magnetic resonance imaging scans of 15 control subjects, 26 RRMS, and 14 SPMS patients. The data obtained from the landmark coordinates were analyzed with statistical shape analysis. The landmarks that were chosen to determine the shape differences of the CC and cerebellum have been identified and used in previous studies. In addition to these landmarks, constructed landmarks were determined and used to assess regional shape differences better. The shapes of the CC and cerebellum showed statistically significant differences from the controls when compared with both the RRMS and SPMS patients. It was found that the deformation observed from controls to SPMS was greater than the deformation from controls to RRMS, both for the CC and cerebellum. In conclusion, this study revealed CC and cerebellar shape change in RRMS and SPMS, and showed that deformations both in CC and cerebellum advances with the disease progression. Anat Rec, 2012. © 2012 Wiley-Periodicals, Inc.

Involvement of the iliac bone and a sacroiliac joint with malignant tumours is not uncommon, treatment is difficult due to the anatomy of the pelvis. Resection of the tumour mass must be extensive in order to achieve safe margins, but this may lead to instability and poor results. We present a new technique for reconstruction after resection of the iliac bone and sacroiliac joint including a sacral ala, and we present two illustrative cases, with 2 years follow-up. Following en bloc resection of a chondrosarcoma in the iliac bone, two or three polyaxial pedicle screws were placed transversly into the sacrum. Two polyaxial pedicle screws were also inserted into the remaining pubic and ischial bone respectively. After completion of the construct with rods, a cortical strut graft from the ipsilateral fibula was placed between the rods. Next a split mesh was placed around the implants and was filled with 60 cc bone chips allografts. Both patients were mobilized with crutches and partial weight bearing for 4 weeks and then fullweight bearing. After two years follow-up, they were ambulatory without external support and their radiological results remained satisfactory. This technique for reconstruction after type I pelvic resection is advantageous in that it saves mobile lumbar segments.

Proton magnetic resonance spectroscopy (MRS) complements conventional methods used to differentiate intracranial cystic lesions. We report MRS findings of three cases that were diagnosed as pyogenic, tuberculous, and Cryptococcus abscesses before instituting any medical or surgical therapy. The pyogenic brain abscess had typical specific spectral findings (i.e., the demonstration of amino acids). Lactate and lipid peaks were visible in the tuberculous abscess. Cryptococcus neoformans can appear differently in different brain regions, which may lead to different spectral findings.

Summary Purpose To compare the diagnostic efficacies of phase-contrast MRI (PC-MRI) and three-dimensional constructive interference in steady-state (3D-CISS) sequence for the detection of spontaneous third ventriculostomy (STV) on the basis of contrast-enhanced MR cisternography (MRC). Patients and methods Eleven obstructive hydrocephalus patients with clinically-radiologically suspected STV and ten controls were examined by PC-MRI, 3D-CISS and MRC. PC-MRI and 3D-CISS sequence were applied to view the third ventricle and basal cisterns. Following injection of 0.5-1 ml intrathecal Gd-DTPA injection, postcontrast MRC images were obtained in three planes. Presence of STV was scored as follows: grade 0, no existence of STV; grade 1, STV present. Results of PC-MRI and 3D-CISS were compared with the MRC findings. Results In PC-MRI, five patients were assessed as grade 0 and six cases grade 1. As a result of 3D-CISS sequence, eight cases were evaluated as grade 0 and three cases grade 1. Based on MRC, nine cases were assessed as grade 0 and two cases grade 1. False positivity was found in four cases by PC-MRI and in one case by 3D-CISS. The sensitivity, specificity and accuracy of PC-MRI and 3D-CISS sequence regarding demonstration of STV, were 100, 100, 56, 89, 64, and 91% respectively. Discussion PC-MRI and 3D-CISS are helpful in confirming the STV. PC-MRI and 3D-CISS should be the first preference. If PC-MRI and 3D-CISS give negative results, then MRC is not required. MRC should be performed on patients who demonstrate suspected STV findings on PC-MRI and 3D-CISS sequences. MRC may prevent false positive results.

Purpose: Obstructive sleep apnea syndrome (OSAS) is characterized by repetitive episodes of partial or complete obstruction of the upper airway during sleep and is associated with increasing respiratory efforts, with a consequent oxyhemoglobin desaturation, sleep fragmentation, and daytime symptoms, most commonly excessive sleepiness. The effectiveness of continuous positive airway pressure (CPAP) is undoubtedly high in treating those patients who use it regularly, but for those who refuse it, the success rate is 0. It is for this subset of patients that surgical therapy can be useful. The purpose of this study was to evaluate the effects of nasal surgery on nasal resistance, sleep apnea, sleep quality, and nasal volumetric measurement in adult male patients with OSAS. Methods: Twenty male patients with complaints of hypersomnia and snoring were included in the study. Polysomnography of patients with the prediagnosis of OSAS was planned. All patients underwent CPAP treatment before and after surgery. Patients, who had anatomic structural defects causing nasal valve shrinkage, were operated on at the Plastic Reconstructive and Aesthetic Department. Volumetric measurements of the nose were obtained before and after the operation. Results: In our study, it was observed that respiratory tract space of patients increased subsequent to the surgery, and thereby OSAS level decreased, and tolerating CPAP device was easier. Measurements of internal nasal valve vertex and fields and external nasal valve fields before and after operation were significant. Conclusions: Surgical relief of this nasal obstruction may improve quality of life in patients with OSAS.

Intracranial hypotension syndrome (IHS) is a rare disorder characterized by postural headache, low cerebrospinal fluid (CSF) pressure, dural thickening and pachymeningeal contrast enhancement as a consequence of decreased CSF volume. The present report is a case of spontaneous IHS due to dural leak at the level of T12-L1. The site of CSF leakage was not detectable on either conventional magnetic resonance imaging (MRI) or 12-weighted MR myelography. However, it was evident on contrast-enhanced MR myelography (CE-MRM). The present report discusses the efficacy of CE-MRM in the detection of CSF leaks according to the literature so far.

PURPOSE T1-weighted (T1W) magnetic resonance images with magnetization transfer (MT) are widely used in the evaluation of multiple sclerosis (MS) plaques. We aimed to evaluate the contribution of the subtraction technique with MT in the detection of acute MS plaques. MATERIALS AND METHODS Sixty-four patients during an MS attack were enrolled in the study. Axial T1W spin echo (SE) with MT, axial-sagittal T2W fast SE, axial FLAIR and postcontrast axial T1W SE magnetic resonance imaging sequence with MT were acquired from all patients. The subtraction (postcontrast-precontrast) images were obtained on the workstation. FLAIR and T2W images were used as reference for plaque imaging. Contrast material enhanced plaques were considered as acute plaques. Qualitatively, both subtracted and contrast-enhanced with MT images were evaluated visually. Quantitatively, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. RESULTS A total of 464 plaques were detected on T2W and FLAIR images. Thirty-five acute plaques were detected on both postcontrast MT and subtracted images. Additionally, 66 acute plaques were only detected on subtracted images visually. CNR and SNR values of acute MS plaques were significantly higher on subtracted MT images than on postcontrast MT images (P < 0.001). CONCLUSION The subtraction technique seems to facilitate the detection of acute MS plaques by intensifying the visibility of poorly enhanced plaques without use of high dose contrast medium. We suggest the use of subtraction technique in routine imaging work-up of MS patients with acute attacks.

A 23-year-old female patient presented with a 3-day history of dysarthria and gait impairment. Her medical history was significant for peptic ulcus for which she was receiving ornidazole (1 g/day), amoxicillin (2 g/day) and lansoprazol (60 mg/day) treatment for 5 weeks. After consumption of a total dose of 35 g ornidazole, her neurological signs and symptoms appeared. There was no family history of neurological or autoimmune disorders. On examination at admission to hospital, she was alert, oriented to person, place and time, but emotionally labile. She had moderate scanning dysarthria, horizontal gaze-evoked nystagmus and bilateral severe limb dysmetria and dysdiadochokinesia. Her gait was ataxic. The rest of the general and neurological examination was unremarkable. Routine biochemistry and urine analysis findings were unremarkable. The values for peripheral blood leucocytes, erythrocyte sedimentation rate and analysis of cerebrospinal fluid obtained by lumbar puncture were normal. A brain MRI demonstrated markedly increased signal intensity symmetrically involving the dentate nuclei, dorsal pontine tegmentum lying in the …

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 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 beta 2-transferrin measurement.

Rationale and Objectives: In this prospective study, we aimed to reveal the efficiency of phase-contrast magnetic resonance imaging (PC-MRI) in the diagnosis of idiopathic normal pressure hydrocephalus (INPH) and prediction of shunt response. Materials and Methods: The study group consisted of 43 patients with INPH diagnosis and 15 asymptomatic age-matched controls. PC-MRI studies were applied on cerebral aqueduct and superior sagittal sinus (SSS) in all the cases. Results: The maximum and mean cerebrospinal fluid (CSF) flow velocities were significantly higher in the INPH patients compared with the controls (P < .05). CSF stroke volume (43.2 +/- 63.8 mu L) and output/min (3921 +/- 5668 mu L) were remarkably higher in the NPH group compared with the control group (3.9 +/- 3.9 mu L, 439 +/- 487 mu L, respectively) (P < .05). Maximum and mean venous velocity values of the INPH patients (maximum, 19.2 +/- 4.3 cm/s; mean, 16 +/- 3.7 cm/s), were lower than those of the control group (maximum, 21.8 +/- 4.6 cm/s; mean, 18.9 +/- 3.9 cm/s) (P < .05). Stroke volume and venous output/min values of INPH patients in SSS, were significantly lower than those of the control group (P .05). Conclusion: The measurement of CSF venous flow velocities with PC-MRI is a noninvasive test that benefits INPH diagnosis, but remains inadequate in prediction of response against shunt treatment.

Purpose Methods and Materials Results Conclusion References Personal Information, Purpose: To evaluate neurochemical and structural changes in the newly diagnosed obstructive sleep apnea syndrome (OSAS) patients by MR spectroscopy (MRS), T2 relaxometry, and diffusion weighted imaging...

PURPOSE The aim of this study was to evaluate the efficiency of MR cisternography (MRC) in the diagnosis of idiopathic normal-pressure hydrocephalus (INPH) and in the prediction of the response to shunt treatment. MATERIALS AND METHODS Thirty-six patients with the diagnosis of "probable INPH" were included in the study group and 15 asymptomatic age-matched individuals were included in the control group. Pre-contrast T1-weighted (T1W) imaging was followed by intrathecal administration of 1 ml gadopentetate dimeglumine. Post-contrast T1W images were taken at the 12(th), 24(th) and 48(th) hours. The presence of contrast material in the lateral ventricles for more than 24 hours was accepted as a positive diagnosis of INPH. Data from both groups were compared statistically. Statistical significance was accepted for P < 0.05. RESULTS All of the INPH patients had remaining contrast material in their lateral ventricles at the 12(th) and 24(th) hours, while only 28 (78%) patients had contrast material remaining at the 48(th) hour after MRC. Only 3 (20%) of the control cases had remaining contrast material in their lateral ventricles at the 24(th) hour. No contrast material was present in the control cases at the 48(th) hour. The contrast material was found to be significantly more prevalent in the INPH patients at the 24(th) and the 48(th) hours compared with the control cases (P < 0.001). Shunt placement was performed in 14 INPH patients, and eight improved after shunt placement. All patients (100%) who improved after shunt placement had remaining contrast material in their lateral ventricles at the 24(th) and at the 48(th) hours. The sensitivity and specificity of MRC in the prediction of the response to shunt treatment were 100% and 17%, respectively. CONCLUSION MRC does not use ionizing radiation and is generally a useful procedure to diagnose NPH and to predict a positive response to shunt treatment; thus, we recommend MRC after routine MRI in patients with the presumed diagnosis of NPH.

Background/Objective: In this study, our purpose was to evaluate the thalamic magnetic resonance (MR) spectroscopic changes in multiple sclerosis (MS) patients. Patients and Methods: Forty-three relapsing-remitting MS (RRMS) patients and 23 control subjects were included in this study. Routine brain MR and MR spectroscopy (MRS) using single voxel technique were carried out in all the patients and the controls. The N-Acetylaspartate (NAA), choline (Cho) and creatine (Cr) peaks were calculated. The thalamic relative metabolite ratios of the RRMS patients were compared to those of the control subjects by using the statistical measures (Mann-Whitney U test). The level of statistical significance was set at 0.05. Results: The thalamic NAA/Cr and NAA/Cho ratios were lower while the thalamic Cho/Cr ratio was higher in the MS patients than those of the control subjects. But these differences in the spectroscopic relative metabolite ratios were not statistically significant between the groups (p=0.34, P=0.22 and p=0.1. respectively). Conclusion: The spectroscopic relative metabolite ratios were of limited value in determining the presence of metabolic changes in the deep grey matter of MS patients. New studies about the presence of the deep grey matter damage in MS patients are necessary.

Rationale and Objective. The aim of this study was to determine the distinctive features of normal-pressure hydrocephalus (NPH) and other dementias on routine T1-weighted and T2-weighted magnetic resonance (MR) images. Also, the contribution of these parameters to the diagnosis and treatment of NPH was investigated. Materials and Methods. Routine MR images were used to investigate the morphologic features (dilatation of Sylvian cisterns, narrowness of convexity sulci, thickness of corpus callosum (TCC), and dilatation of perihippocampal fissures) and the flow void phenomenon (FVP) in patients with idiopathic NPH (INPH) and other dementias. Routine MR images of 18 patients with INPH, 11 with dementias other than INPH, and 20 controls were retrospectively examined. Morphologic features and the FVP were graded subjectively. The TCC was measured quantitatively. Morphologic parameters, the FVP, and the shunt response were assessed using Kruskal-Wallis and Mann-Whitney U tests. Results. The mean FVP score was significantly higher in patients with INPH (2.89 +/- 0.75) than in controls and patients with other dementias (1.1 +/- 0.85 and 1.09 +/- 0.83, respectively) (P < .001). There was significant difference in terms of TCC between patients with INPH (3 +/- 0.7 mm), those with other dementias (1.9 +/- 0.7 mm), and controls (5.2 +/- 0.8 mm) (P < .001). Significant differences in terms of other morphologic features were found between patients with INPH and those with other dementias (P < .05). No significant difference was found between morphologic parameters and the FVP and the outcome of cerebrospinal fluid diversion (P > .05). Conclusions. Intense FVP is a signature of but is not pathognomonic for INPH. The morphologic analysis of MR images can be distinctive for the diagnosis of INPH or dementias other than INPH. Detailed evaluation of morphologic features and the FVP in routine MR workup of dementia will be useful for accurate diagnosis.

In the current study, we aimed to compare the diagnostic efficacies of phase-contrast magnetic resonance imaging (PC-MRI) and three-dimensional constructive interference in steady-state (3D-CISS) sequence over detection of aqueductal stenosis (AS) on the basis of contrast-enhanced magnetic resonance cisternography (MRC). Twenty-five patients with clinically and radiologically suspected AS were examined by PC-MRI, 3D-CISS, and MRC. Axial-sagittal PC-MRI and sagittal 3D-CISS were applied to view the cerebral aqueduct. Following injection of 0.5-1 ml intrathecal gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) injection, postcontrast MRC images were obtained in three planes in early and late phases. Aqueductal patency was scored as follows: grade 0, normal; grade 1, partial narrowing; and grade 2, complete obstruction. Results of PC-MRI and 3D-CISS were compared with the findings of MRC. In PC-MRI, seven cases were assessed as grade 0, 16 cases grade 1, and two cases grade 2. As a result of 3D-CISS sequence, eight cases were evaluated as grade 0, 12 cases grade 1, and five cases grade 2. Based on MRC, nine cases were assessed as grade 0, whereas nine and seven cases were evaluated to be grades 1 and 2, respectively. Five cases that demonstrated partial patency in PC-MRI or 3D-CISS showed complete obstruction by MRC. 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.

Serebral aspergilloz nadir bir durum olup konvansiyonel antifungal tedavilere genellikle kötü yanıt vermektedir. Bu raporda, 34 yaşında akut lenfoblastik lösemi tanısı olan bir erkek hastada agresif nörocerrahi, intrakaviter amfoterisin B tedavisi ve vorikonazol kombinasyonu ile başarıyla tedavi olan bir serebral aspergilloz olgusu sunulmuş ve nöroaspergillozun tedavisinde cerrahi tedavi, intrakaviter tedavi ve antifungal tedavinin rolleri tartışılmıştır. Amfoterisin B tedavisi altında dizartri ve sağ hemiparazi gelişen olgumuzda beyin manyetik rezonans görüntülemede sol paryeto-oksipital bölgede 7 cm çapında lezyon saptanmıştır. Tanı amaçlı yapılan cerrahi girişim aşırı kanama nedeniyle başarıyla gerçekleştirilememiştir. Lezyondan alınan aspirat örneğinin kültüründe Aspergillus flavus üremesi saptanmıştır. Tedavi kaspofungin ve vorikonazol kombinasyonu olarak değiştirilmiştir. Tedavi altında enfeksiyonun ilerleme göstermesi üzerine hastaya ikinci cerrahi girişim uygulanmış ve lezyonun boyutunda gerileme tespit edilmiştir. Cerrahi tedaviyi takiben vorikonazol ve kaspofungin kombinasyon tedavisine ek olarak intrakaviter amfoterisin B uygulaması yapılmıştır (0.3 mg/gün 15 gün). Kaspofungin tedavisine 42 gün devam edildikten sonra kesilmiştir. Vorikonazol tedavisine ise 100 gün devam edilmiştir. Bu dönemde beyindeki lezyon tama yakın düzelme göstermiştir. Ancak, hastanın takibi sırasında lösemi relapsı görülmüş ve kemoterapi sırasında aplazik dönemde gelişen nötropenik tiflitis tablosu ile hasta kaybedilmiştir. Serebral aspergillozlu olgularda erken dönemde radikal cerrahi uygulanması sonucunda daha iyi sonuçlar elde edildiği belirtilmektedir. Antifungal tedavide kullanılan ilaçların vorikonazolde olduğu gibi kan-beyin bariyerini geçebilme özelliğine sahip olması gerekmektedir. Tüm lezyonlar düzelinceye ve altta yatan predispozan faktörler geri dönünceye kadar tedaviye devam edilmelidir. Sonuç olarak, serebral aspergillozlu olgularda cerrahi girişim ve vorikonazol tedavisinin güvenilir ve etkin tedavi yaklaşımları olduğu düşünülmüştür. Cerebral aspergillosis is a rare condition that generally exhibits a poor response to conventional antifungal drugs. We report here a case of cerebral aspergillosis in a 34-years-old man with acute lymphoblastic leukaemia who was successfully treated with a combination of aggressive neurosurgery, intracavitary instillation of amphotericin B and voriconazole. We aimed to emphazise the roles of surgery, intracavitary therapy and antifungal therapy in the management of neuroaspergillosis. Under amphotericin-B therapy, the patient developed dysarthria and paralysis of the right side of his body. Brain magnetic resonance imaging demonstrated a lesion in the left parieto-occipital region, measuring 7 cm in the greatest dimension. Diagnostic surgery was interrupted due to abundant bleeding. The culture of the aspirate from the lesion yielded Aspergillus flavus. The therapy was switched to voriconazole and caspofungin combination. Due to disease progression during combination therapy, the patient had a second surgical resection resulting in a 75% reduction in lesion size. Following surgical intervention, intracavitary instillation of amphotericin B (0.3 mg/day for 15 days) was performed alongside with combination therapy (voriconazole and caspofungin). Caspofungin was stopped after 42 days, whereas the patient was continued on voriconazole for a total of 100 days. At this point, his brain lesion resolved almost completely. However, leukemia relapsed. The patient died during his treatment course because of neutropenic typhilitis occurring in the aplastic phase. It is stated that in patients with neuroaspergillosis radical neurosurgery leads to better outcomes if performed at an earlier stage. Antifungal treatment of cerebral aspergillosis requires that the drug must cross the blood brain barrier. Voriconazole has the ability to cross the blood brain barrier. The therapy should be prolonged beyond the resolution of all lesions and until reversal of the underlying predisposition. We conclude that the use of neurosurgery and voriconazole together appears to be a reliable and effective treatment modality in patients with cerebral aspergillosis.

We report a 34-year-old male neuroBehçet's Disease (NBD) patient with atypical magnetic resonance imaging (MRI) findings, whose behavioral problems were followed by progressive neurological symptoms. The patient was hospitalized due to forgetfulness, irritability, behavioral dyscontrol and a choking sensation. T2-weighted MRI showed prominent atrophy of cerebellar hemispheres, the cerebellar peduncle, the midbrain and the pons. He was diagnosed with NBD after an evaluation of his medical history together with neuropsychiatric and laboratory findings. There are few reports of NBD with only brainstem and cerebellar atrophy. We discuss our patient in the context of the four previously reported cases. In NBD without evident mucocutaneo-ocular symptoms, neurologists should always consider the medical and family history. Early diagnosis of NBD helps to initiate appropriate treatment, thereby modulating the course of the disease and preventing complications.

AIM: To evaluate the value of morphometric analysis and perfusion-weighted magnetic resonance imaging (MRI) in differentiating solitary metastases from high-grade gliomas. MATERIALS AND METHODS: Forty-eight tumours (22 high-grade gliomas and 26 solitary hemispheric metastases) were evaluated using conventional and perfusion-weighted MRI. T2-weighted, gradient-echo, echo-planar sequences were used for perfusion-weighted MRI. Relative cerebral blood volume (rCBV) ratios were calculated by dividing the rCBV of the intratumoural and peritumoural areas with the average CBV value of the normal white matter areas. Morphometric analysis was carried out by proportioning the area of peritumoural oedema to the mass area. Mann-Whitney U test and ROC Curve analysis were applied for statistical analysis. P < 0.05 was accepted as statistically significant. RESULTS: Mean rCBV ratios of intratumoural areas of high-grade gliomas and metastases were 5.02 +/- 2.47 and 4.62 +/- 2.46, respectively. No statistically significant difference was found (p = 0.515). rCBV ratios of peritumoural oedema were 0.89 +/- 0.51 in high-grade gliomas and 0.31 +/- 0.12 in metastases. The difference was statistically significant (p < 0.001). According to the results of morphometric analysis, a statistically significant difference was present between the two tumour types (p < 0.001). CONCLUSION: Measuring the oedema: mass and rCBV ratios of the oedema surrounding the tumour prior to operation in solitary masses proved to be useful for differentiating metastases from high-grade gliomas.

The objective of this study was to evaluate the role of phase-contrast cine magnetic resonance imaging (PC-MRI) in detecting possible communications between intraventricular arachnoid cysts (IV-ACs) and cerebrospinal fluid (CSF) spaces based on MR cisternography (MRC) comparison. Twenty-one patients with IV-AC were examined by PC-MRI and MRC. In order to determine the communication of IVAC with its neighbouring CSF spaces, PC-MRI was employed. The communication of IV-ACs with the ventricular system was examined on at least two anatomic planes. Precontrast images and PC-MRI were followed by the intrathecal administration of 0.5-1 ml gadopentetate dimeglumine. Early and delayed MRC were then carried out. Results of PC-MRI were compared with findings of MRC (McNemar's test). In seven IV-ACs, no communication was detected by PC-MRI. In 14 IVACs, a pulsatile CSF flow into the IV-ACs was observed. All the IV-ACs, which have been determined as non-communicating (NC) on the PC-MRI, showed NC character on MRC as well. Six cases suggesting a communication on PC-MRI showed no communication on MRC. MRC revealed eight communicating (38%) and 13 NC (62%) IV-ACs among a total of 21 cases. The sensitivity and specificity of PC-MRI imaging in demonstrating the communication between the IV-ACs and the CSF were 100% and 54%, respectively. PC-MRI is an effective method for evaluating NC IV-ACs. In order to decide about the management of IV-ACs, which are communicating according to the PC-MRI, the results should be confirmed with MRC if suspected jet flow is depicted.

Background: It is unusual to encounter hemorrhagic complications caused by arterial or venous damage during TSS. Problems with these structures can lead to permanent disability or death. Our aim was to quantitatively analyze anatomical and radiologic relationships among the BCS, the CCA, and the pituitary gland, as these structures are accessed during TSS. Methods: Forty-nine formaldehyde-fixed, sellar-parasellar tissue blocks from adult cadavers were used to simulate accessing the BCSs via TSS. In each specimen, size of the pituitary gland and specific characteristics of each BCS and the horizontal segment of each CCA were recorded. Nine other specimens were used for histologic investigation and microanatomical measurements. To attest correlation between clinical data and cadaveric measurements, coronal MRI scans of 22 healthy adults as well as of 28 patients with macroadenomas were analyzed. Results: In cadaveric specimens, distances between both CCAs in the BCS were 17.1 +/- 4.0 mm anteriorly, 20.3 +/- 4.2 mm medially, and 18.8 +/- 4.6 mm posteriorly. In this study, the anterior medial space of the BCS was dominant in 12 specimens on the right side and in 5 specimens on the left; the posterior medial space of the BCS was dominant in 23 specimens on the right side and in 9 specimens on the left side. The right medial BCS was dominant in 35 specimens. On histologic coronal sections, some part of the carotid artery's (CA's) diameter was located below the line passing from the basal dural layer ranging from 5.3% to 65.4%. In normal-sella images, distances between both CCAs were 15.4 +/- 1.8 mm anteriorly, 16.0 +/- 2.8 mm medially, 16.2 +/- 3.4 mm posteriorly. On coronal normal-sella images, some part of the CA's diameter was located below the line passing from the basal dural layer ranging from 16.4% to 66.7%. In macroadenomas, distances between both CCAs were 22.0 +/- 3.6 mm anteriorly, 21.5 +/- 3.8 mm medially, and 20.7.2 +/- 3.7 mm posteriorly. On coronal images, in only 6 of 28 macroadenomas, some part of the CA's diameter was located below the line passing from the basal dural layer ranging from 12.5% to 100%. Conclusions: Our results indicate that a working area of 15.0 +/- 2.6 x 10.3 +/- 2.1 mm is safe during TSS. The position of the CCA posterior segment was notably more caudal than the anterior segment with respect to the basal dura, which should be taken into account during extended exposure. Also, preoperative recognition of the anatomical variations is beneficial for detection of the boundaries of dissection, which is particularly important in the BCS, where variable course of CCAs may transform the anatomical configuration. Slowly growing pituitary adenomas stretch out both CCAs considerably from medial to lateral directions, and they cause widening of intercarotid distances in all segments. Processing of fixation, decalcification, and paraffin embedding for the cadaveric tissue in contrast to physiologically hydrated tissues may change the accuracy of measurements. These measurements are significantly different than those in the radiologic images when arterial blood under pressure is in the CCA as well as when venous blood fills the cavernous sinus as is the case in vivo. In clinical practice, these facts must be taken into consideration in the cadaveric measurements.

Purpose: The aims of the study are firstly, to determine the difference in diffusion-weighted imaging (DWI) in normal appearing white matter (NAWM) between patients with acute multiple sclerosis (MS) and controls; secondly, to determine whether there is a correlation between EDSS scores and DWI in acute plaques and also NAWM. Materials and method: Out of 50 patients with acute MS attack, 35 patients had active plaques with diffuse or ring enhancement on postcontrast images. Eighteen healthy volunteers constituted the control group. While 26 of 35 had relapsing-remitting, 9 had secondary progressive MS. Apparent diffusion coefficients (ADC) of the active plaques, NAWM at the level of centrum semiovale and occipital horn of lateral ventricle in the patients and NAWM in control group were measured. ADC values of active plaques were compared with WM of the patients and the control group. The relationship of ADC value of active plaques and WM in MS with expanded disability status scale (EDSS) was investigated by using Mann-Whitney U-test. Results: Of 63 plaques totally, 26 and 37 of the active plaques had diffuse and ring enhancement, respectively. There was no statistically significant difference between ADC value of active plaques and EDSS (p > 0.05). However, there was a statistically significant difference between ADC value of WM occipital horn and EDSS (p < 0.05). ADC value of active plaques were higher than WM in both groups (p < 0.001). The difference between ADC value of WM at the centrum semiovale (p < 0.05) and occipital horns (p < 0.001) in patients and controls was statistically significant. There was no statistically significant difference between EDSS scores, ADC value at centrum semiovale and WM around occipital horn and active plaques in subgroups (p > 0.05). Conclusion: Apparently normal tissue in MS patients may show early abnormalities when investigated carefully enough, and there is an even though moderate correlation between EDSS and ADC values and early alterations of ADC value are starting in the occipital white matter along the ventricles. This has to be verified in larger series.

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. P < 0.05 was considered statistically significant. Results: Mean ADC values in atypical/malignant and typical meningiomas were 0.75 +/- 0.21 and 1.17 +/- 0.21, respectively. Mean ADC values for subtypes of typical meningiomas were as follows: meningothelial, 1.09 +/- 0.20; transitional, 1.19 +/- 0.07; fibroblastic, 1.29 +/- 0.28; and angiomatous, 1.48 +/- 0.10. Normal white matter was 0.91 +/- 0.10. ADC values of typical meningiomas and atypical/malignant meningiomas significantly differed (P < 0.001). However, the difference between peritumoral edema ADC values was not significant (P > 0.05). 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.

Introduction Reversible posterior leukoencephalopathy syndrome (RPLS) is a recently described clinical and radiological entity comprising headache, seizures, altered level of consciousness and visual disturbances in association with transient posterior cerebral white-matter abnormalities. Method We report a young woman with Burkitt's lymphoma who developed RPLS after combined chemotherapy administered during the tumor lysis syndrome. Results The symptoms in this patient fitted well with those of RPLS; they included abrupt alterations in mental status, seizures, headache, visual changes and characteristic neuroradiological findings. She was given further combination chemotherapy without any neurological complications, at which time she had already recovered from both RPLS and tumor lysis syndrome. Conclusion Although many etiological factors have been reported in the development of RPLS, the underlying mechanism is not yet well understood. With prompt and appropriate management, RPLS is usually reversible, and chemotherapy can be continued after complete recovery from RPLS. We suggest that tumor lysis syndrome should be considered as a contributory factor to the development of RPLS in patients for whom treatment with combined chemotherapy for hematological malignancies is planned.

The aim of this study is to review the diffusion-weighted MRI findings of glioblastomas, to investigate those with atypical characteristics and to emphasise the reasons responsible for the atypical features on diffusion-weighted MR images. 48 cases of histologically proven glioblastomas were included in this study. In addition to conventional sequences of routine tumour protocol, diffusion-weighted MRI with spin-echo echoplanar sequence was performed. The cystic-necrotic components of the lesions, according to the conventional sequences, were determined on the diffusion-weighted MR images and were classified as typical or atypical. The presence of high signal intensity was accepted as an atypical feature while low signal intensity was accepted as typical. The apparent diffusion coefficient (ADC) values of the cystic components were calculated. The statistical significance of the typical and atypical glioblastomas was evaluated with the students t-test. In six of the cases apparent high signal intensity in diffusion weighted MR images was interpreted. In three cases the high signal intensity occupied all of the cystic component and in the other three most of the cystic component. The ADC values of the lesions varied between 0.86 x 10(-3) mm(2) s(-1) and 1.39 x 10(-1) mm(2) s(-1) (mean value 1.06 +/- 0.17 x 10(-3) mm(2) s(-1)). In 42 of the lesions the cystic-necrotic component demonstrated low signal intensity and the ADC values varied between 1.56 x 10(-3) mm(2) s(-1) and 3.32 x 10(-3) mm(2) s(-1) (mean value 2.36 +/- 0.46 x 10(-3) mm(2) s(-1)). The difference between ADC values of atypical and typical lesions was statistically significant (p < 0.001). The vast majority of glioblastomas do not exhibit restricted diffusion in diffusion-weighted MRI, but some of them display homogeneous or heterogeneous high signal intensity and decrease of ADC values. Diffusion-weighted MRI alone is not helpful in the differentiation of malignant tumours from abscesses with low ADC values and similar conventional MRI findings.

Purpose: To compare diffusion-weighted echo-planar imaging (DW) with spin-echo (SE), and fluid-attenuated inversion recovery (FLAIR) sequences in the evaluation of epidermoid cysts (ECs), and to evaluate T2 shine-through effect. Materials and methods: Fifteen patients were imaged prospectively in two different 1.5 T magnetic resonance (MR) units with standard head coils with SE, FLAIR and DW echo planar imaging sequences. The qualitative and quantitative assessments were performed by two radiologists in consensus. Apparent diffusion coefficient (ADC) values were obtained from all ECs. Exponential DW images are obtained in I I cases to eliminate T2 shine-through effects. The results are analyzed with variance analysis (ANOVA) and Bonferroni t method. Results: FLAIR sequence was superior to T1- and T2-weighted sequences in showing ECs. In U cases, the borders of the lesions could be delineated from the surrounding structures with only DW imaging where ECs were markedly hyperintense. The ADC values of ECs are significantly lower than CSF (P < 0.001), and significantly higher than deep white matter (P < 0.01). On exponential DW images, ECs had similar intensity with brain parenchyma showing that the real cause of the hyperintensity of the lesions on trace images is the enhanced T2 effect of the tissue. Conclusion: FLAIR sequence is superior to the conventional MR sequences in demonstrating the ECs and DW imaging is superior to other MR sequences in delineating the borders of the ECs. Exponential DW images had shown that the hyperintensity in the trace images are caused by increased T2 effect of the lesion rather than the decrease in ADC values. (c) 2004 Elsevier Ireland Ltd. All rights reserved.

In some instances conventional imaging techniques fail to differentiate meningiomas from isolated dural metastasis. This study aimed to evaluate the role of diffusion and perfusion-weighted MRI in differentiating meningiomas and dural metastasis. In this study, 14 metastasis and 26 meningiomas were involved. The imaging characteristics were analyzed using conventional MRI. Diffusion-weighted MRI was performed and ADC values were calculated from the solid components and the peritumoral edema. Perfusion-weighted MRI was performed and relative cerebral blood volume (rCBV) was calculated. Student's t test was used for the statistical analysis. Dural metastasis and meningiomas could not be differentiated by qualitative assessment of conventional and diffusion-weighted MRI. The mean intratumoral and peritumoral ADC values were not statistically significant (p > 0.05). The rCBV ratios for dural metastasis and meningiomas were 4.13 ± 2.32 and 7.32 ± 4.10 respectively and the difference between two was statistically significant (p = 0.003). Peritumoral rCBV ratios for dural metastasis and meningiomas were not statistically significant (p > 0.05). Conventional MRI findings of dural metastasis and meningiomas may overlap in some lesions. In differentiation of these lesions diffusion-weighted MRI yields no further information additional to conventional sequences. Perfusion-weighted MRI can be useful to distinguish these lesions by demonstrating high intratumoral rCBV ratios for meningiomas and low rCBV ratios for metastasis.

Purpose: The goals of this work were to measure the apparent diffusion coefficients (ADCs) for both hippocampus and amygdala of persons diagnosed with temporal lobe epilepsy (TLE) and unilateral hippocampus pathology on magnetic resonance imaging and to evaluate the sensitivity of diffusion-weighted (DW) images in determination of the lateralization of the epileptogenic focus. Methods: Thirteen cases with a TLE diagnosis and 21 healthy subjects were evaluated. Fluid-attenuated inversion recovery and T2W images of TLE cases revealed hippocampal volume loss and signal intensity changes. DW images were obtained by spin-echo echo-planar sequences vertical to the hippocampal axis. Qualitative and quantitative ADCs for left and right hippocampus and the amygdala of the controls and the patients were determined. Hippocampal ADCs were obtained independently at the head, body, and tail levels of the hippocampus. Statistical evaluation was conducted with Kruskal–Wallis and Mann–Whitney U tests. Predictive cutoff levels of hippocampal ADCs for identifying pathologic areas were established through receiver operating characteristic (ROC) curve analysis. Result On conventional images, 5 of 13 cases had right hippocampal pathology, and 8 of 13 cases had left hippocampal pathology. There were no bilateral hippocampal changes in signal intensity and no cases with bilateral atrophy. The amygdala was normal in all patients except one case of hyperintense signals. No statistical differences were found between the hippocampal and amygdaloid ADCs of the control subjects (P > 0.05). However, there was a significant difference between the ADCs for the side with hippocampal pathology and the ADCs for the contralateral side, and the control group (P < 0.001). No statistical difference was detected for the amygdala (P > 0.05). Hippocampal and amygdaloid ADCs of the contralateral lesion and the values of the control group were not statistically significantly different (P > 0.05). ROC curve analysis indicated 136 as the best cutoff level for hippocampal pathology. Conclusion DW trace images are insensitive in lateralization of hippocampal pathology; however, lateralization can be achieved through ADC measurements of the hippocampus. An increase in ADC on the affected side should be considered as indicating pathology. On the other hand, amygdaloid ADC values remain inaccurate.

Differentiating between brain abscesses and cystic brain tumors such as high-grade gliomas and metastases is often difficult with conventional MRI. The goal of this study was to evaluate the diagnostic utility of perfusion MRI to differentiate between these pathologies. MRI was performed in 19 patients with rim-enhancing brain lesions (4 pyogenic abscesses, 8 high-grade gliomas, 7 metastases). In addition to standard MR sequences, trace diffusion-weighted MRI with apparent diffusion coefficient (ADC) maps and perfusion-weighted MRI by using a first-pass gadopentetate dimeglumine T2*-weighted gradient echo single-shot echo-planar sequence were performed. Relative cerebral blood volume (rCBV) ratios were obtained via the values of the capsular portions of the lesions and the normal white matter. All the abscesses had markedly hyperintense signals in trace diffusion images, whereas they had significant hypointense signals in ADC images. In perfusion-weighted images, the capsular portions of the abscesses demonstrated low colored areas compared with the normal white matter and the rCBV ratio calculated was 0.76 +/- 0.12 (mean +/- SD). All but two of the cystic tumors showed low signal intensity on trace diffusion-weighted images and high signal intensity on ADC maps. Hyperintense signal was found in two brain tumors mimicking brain abscesses on trace diffusion images. The rCBV values in high-grade gliomas and metastases were 5.51 +/- 2.08 and 4.58 +/- 2.19, respectively. The difference between abscesses and cystic tumors was statistically significant (P = 0.003). Perfusion MRI may allow the differentiation of pyogenic brain abscess from cystic brain tumors, making it a strong additional imaging modality in the early diagnosis of these two entities.