Crystal storing histiocytosis forming a mass lesion in temporal lobe.

Crystal storing histiocytosis is a disorder characterized by local or diffuse infiltration of histiocytes containing crystalline inclusions. This entity has been reported in several organs, however the involvement of the central nervous system (CNS) is extremely rare and to date only 7 cases of crystal storing histiocytosis (CSH) of CNS have been reported in the English literature. More than 90% patients with CSH had an underlying lymphoproliferative or plasma cell disorders, especially multiple myeloma, lymphoplasmacytic lymphoma or monoclonal gammopathy. Radiologically and intraoperatively, CSH may mimic an infectious process or neoplasm, hence its histopathological confirmation is important to facilitate appropriate treatment. In this report, we describe an additional case of crystal storing histiocytosis in a 48 year old female who presented with a mass lesion in the right temporal lobe of the cerebrum.

Radiation Exposure in the Neonatal Intensive Care Unit in Newborns and Staff.

OBJECTIVE: Portable X-rays remain one of the most frequently used diagnostic procedures in neonatal intensive care units (NICU). Premature infants are more sensitive to radiation-induced harmful effects. Dangers from diagnostic radiation can occur with stochastic effects. We aimed to determine the radiation exposure in premature infants and staff and determine the scattering during X-ray examinations in the NICU. STUDY DESIGN: In this prospective study, dosimeters were placed on premature infants who were ≤1,250 g at birth and ≤30 weeks of gestational age who stayed in the NICU for at least 4 weeks. The doses were measured at each X-ray examination during their stay. The measurements of the nurses and the doctors in the NICU were also performed with dosimeters over the 1-month period. Other dosimeters were placed in certain areas outside the incubator and the results were obtained after 1 month. RESULTS: The mean radiation exposure of the 10 premature infants, monitored with dosimeters, was 3.65 ± 2.44 mGy. The mean skin dose of the six staff was 0.087 ± 0.0998 mSV. The mean scattered dose was 67.9 ± 26.5 µGy. CONCLUSION: Relatively high exposures were observed in 90% of the patients and two staff. The radiation exposure levels of premature infants and staff may need to be monitored continuously. KEY POINTS: · The premature infants are exposed to radiation due to the bedside X-rays.. · The radiation exposure levels of premature infants and staff may need to be monitored continuously.. · Measures and alternative methods to reduce radiation exposure should be encouraged..

Arterial transit artifacts observed on arterial spin labeling perfusion imaging of carotid artery stenosis patients: What are counterparts on symptomatology, dynamic susceptibility contrast perfusion, and digital subtraction angiography?

PURPOSE: To investigate possible relationships between the presence and location of arterial transit artifacts (ATA) and clinical symptoms, digital subtraction angiography (DSA), and dynamic susceptibility contrast (DSC) perfusion imaging abnormalities in patients with carotid artery stenosis (CAS). METHODS: Forty-seven patients who underwent arterial spin labeling (ASL) and DSC perfusion imaging in the same period diagnosed with > 50% unilateral internal carotid artery (ICA) stenosis by DSA performed 24 h after perfusion imaging were included. The presence of ATA, localization and hypoperfusion were evaluated using ASL interpretation. Maps derived from DSC perfusion, symptomatology, stenosis rates, and collateralization findings observed in DSA were investigated. Probable relationships were evaluated. RESULTS: ATA on ASL were detected in 68.1% (32/47); 40.6% (13/32) of ATAs were observed in the distal middle cerebral artery (MCA) trace, 50% (16/32) in the intracranial ICA and MCA traces, and 9.4% (3/32) in the intracranial ICA trace. When classifications based on the ATA presence and localization was made, qualitative and quantitative CBF, MTT, and TTP abnormalities, symptomatology, stenosis rates, and collateralization findings significantly differed between groups (p < 0.05). CONCLUSION: The presence and localization of ATA in patients with CAS may provide essential insights into cerebral hemodynamics and the CAS severity. ATAs observed only in the distal MCA trace may represent early-stage perfusion abnormalities and a moderate level of stenosis. ATA in the ICA trace may related to a more advanced level of perfusion abnormalities, critical stenosis rates, symptom or collateralization presence.

Morphological evaluation of the normal and hydrocephalic third ventricle on cranial magnetic resonance imaging in children: a retrospective study.

BACKGROUND: Third ventricle morphological changes reflect changes in the ventricular system in pediatric hydrocephalus, so visual inspection of the third ventricle shape is standard practice. However, normal pediatric reference data are not available. OBJECTIVE: To investigate both the normal development of the third ventricle in the 0-18-year age group and changes in its biometry due to hydrocephalus. MATERIALS AND METHODS: For this retrospective study, we selected individuals ages 0-18 years who had magnetic resonance imaging (MRI) from 2012 to 2020. We included 700 children (331 girls) who had three-dimensional (3-D) T1-weighted sequences without and 25 with hydrocephalus (11 girls). We measured the distances between the anatomical structures limiting the third ventricle by dividing the third ventricle into anterior and posterior regions. We made seven linear measurements and three index calculations using 3DSlicer and MRICloud pipeline, and we analyzed the results of 23 age groups in normal and hydrocephalic patients using SPSS (v. 23). RESULTS: Salient findings are: (1) The posterior part of the third ventricle is more affected by both developmental and hydrocephalus-related changes. (2) For third ventricle measurements, gender was insignificant while age was significant. (3) Normal third ventricular volumetric development showed a segmental increase in the 0-18 age range. The hydrocephalic third ventricle volume cut-off value in this age group was 3 cm3. CONCLUSION: This study describes third ventricle morphometry using a linear measurement method. The ratios defined in the midsagittal plane were clinically useful for diagnosing the hydrocephalic third ventricle. The linear and volumetric reference data and ratios are expected to help increase diagnostic accuracy in distinguishing normal and hydrocephalic third ventricles.

Neuroimaging of first seizure in the adult emergency patients.

The aim is to establish the role of head computed tomography (CT) and magnetic resonance imaging (MRI) in adults presenting to the emergency department (ED) with first-time seizure (FS) and to analyze the potential predictor variables for the adverse imaging outcome. We retrospectively reviewed the medical records of all adults who underwent cranial CT or MRI between January 1, 2011, and December 1, 2016, to an academic ED for FS. Patients were excluded if were under 18 years of age, had known recent intracranial pathology, known brain tumor or having a history of trauma. Important predictive variables to indicate pathology in either CT or MR scan in patients with FS were evaluated with logistic regression analysis. A total of 546 FS (293 men and 253 women; range, 18-81 years; mean, 47 years) were identified in patients receiving either cranial CT or MR scan. Of them, abnormal findings were observed in 22/451 (4.8%) patients on CT and 18/95 (18.9%) patients on MRI. Predictor variables of age greater than 50 years, focal neurologic deficit, hypoglycemia, and history of malignancy were identified on CT, whereas a history of malignancy, age greater than 50 years and focal neurological deficit were determined on MRI. Limiting neuroimaging to this population would potentially reduce head CT scans by 67% and would potentially reduce head MRI scans by 47%. Clinical suspicion should be heightened and the neuroimaging should be considered for advanced age, history of malignancy, hypoglycemia or focal neurological deficits in patients with FS.

Dural venous sinus thrombosis: The combination of noncontrast CT, MRI and PC-MR venography to enhance accuracy.

Aim The aim of this article is to determine whether a combination of noncontrast CT (NCCT), three-dimensional-phase contrast magnetic resonance venography (3D PC-MRV), T1- and T2-weighted MRI sequences can help to identify acute and subacute dural venous sinus thrombosis (DVST) with greater accuracy. Methods A total of 147 patients with DVST ( n = 30) and a control group ( n = 117) underwent NCCT, T1- and T2-weighted MRI sequences, and 3D PC-MRV from 2012 to 2016. Two experienced observers interpreted the images retrospectively for the presence of DVST. Nonvisualization of the dural venous sinuses on 3D PC-MRV and signal changes supporting acute or subacute thrombus on T2- and T1-weighted images were considered a direct sign of DVST. Also, using circle region of interest (ROI) techniques, attenuation measurement from each sinus was obtained on NCCT. Sensitivity and specificity were computed for these modalities separately and in combination for diagnosis of DVST using digital subtraction angiography as the reference standard. Results Nonvisualization of venous sinuses on 3D PC-MRV (sensitivity 100%, specificity 71%) in combination with both applying Hounsfield unit (HU) threshold values of greater than 60 on NCCT (sensitivity 70%, specificity 94%) and acquiring signal changes supporting DVST on T2- and T1-weighted images (sensitivity 83%, specificity 96%), were found to have 100% sensitivity and 100% specificity in the identification of acute or subacute DVST. Conclusion The combination of NCCT, T1- and T2-weighted MRI and 3D PC-MRV may allow the diagnosis of acute or subacute DVST and may obviate the need for contrast usage in patients with renal impairment or contrast allergies.

Predictor variables of abnormal imaging findings of syncope in the emergency department.

BACKGROUND: This study aimed to describe the pathological findings and to analyze clinical predictors of abnormal imaging findings in patients presenting to the emergency department (ED) with syncope. METHODS: The database was retrospectively reviewed for all patients who underwent cranial computed tomography (CT) or magnetic resonance imaging (MRI), having the symptom of syncope. Patients were included only if they were from the emergency department and excluded if were under 18 years of age, had known recent intracranial pathology, known brain tumor, or having a history of trauma. The primary outcome was assumed as abnormal head CT or MRI including intracranial hemorrhage, acute or subacute stroke, and newly diagnosed brain mass. Univariate and multivariate logistic regression analysis was utilized to determine the association between clinical variables and any significant pathology in either CT or MR scan. RESULTS: Total of 1230 syncope (717 men and 513 women; range, 18-92 years; mean, 54.5 years) as presenting symptoms were identified in patients receiving either cranial CT or MR scan in the ED. Abnormal findings related to the syncope were observed in 47 (3.8%) patients. The following predictor variables were found to be significantly correlated with acutely abnormal head CT and MRI: a focal neurologic deficit, history of malignancy, hypertension, and age greater than 60 years. CONCLUSIONS: Our data offer that the identification of predictor variables has a potential to decrease the routine use of head CT and MRI in patients admitting to the ED with syncope.

Massive cerebrovascular air embolism during posttraumatic cardiopulmonary resuscitation.

Air embolism is known to be a complicating factor in several clinical settings, including thoracic, cardiovascular, and neurosurgical operations; central line placement; and penetrating thoracic and cranial trauma. There are, however, only few case descriptions for cardiopulmonary resuscitation massive cerebral air embolism, and the frequency of this supposedly rare complication is unknown. Computed tomography is useful for showing cerebral air embolism. In this report, we present a 16-year-old adolescent girl with cerebrovascular air embolism on computed tomographic examination after a posttraumatic cardiopulmonary resuscitation and discuss the reasonable mechanisms of cerebrovascular air embolism.

Impaired aortic distensibility in hypothyroid patients with negative coronary angiograms: simultaneous evaluation with 128-slice multiple row detector computed tomography.

OBJECTIVE: To determine the relationship between arterial distensibility and hypothyroidism by simultaneous assessment of coronary angiography and aortic distensibility, measured using 128-slice retrospective electrocardiogram-gated multiple row detector computed tomography (MDCT). METHODS: Untreated hypothyroid patients and age-matched euthyroid patients, who underwent 128-slice retrospective electrocardiogram-gated MDCT to evaluate the coronary arteries, were assessed. Intraluminal aortic areas in systolic and diastolic phases of the cardiac cycle were measured with multiphase reformation at predefined locations including the ascending aorta, proximal descending aorta and distal descending aorta in the widest axial plane. RESULTS: The study included 21 hypothyroid and 21 euthyroid patients. Patients with hypothyroidism exhibited decreased aortic distensibility between each location in the thoracic aorta (ascending aorta, proximal descending aorta and distal descending aorta) compared with euthryoid patients. CONCLUSIONS: Hypothyroidism was associated with preclinical vascular alteration, characterized by impaired aortic distensibility at each location of the thoracic aorta, which has been shown to be related to increased cardiovascular risk. Monitoring of aortic distensibility is relevant for evaluating coronary artery disease progression and treatment choices.

MR cisternography: is it useful in the diagnosis of normal-pressure hydrocephalus and the selection of "good shunt responders"?

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 12th, 24th and 48th 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 12th and 24th hours, while only 28 (78%) patients had contrast material remaining at the 48th hour after MRC. Only 3 (20%) of the control cases had remaining contrast material in their lateral ventricles at the 24th hour. No contrast material was present in the control cases at the 48th hour. The contrast material was found to be significantly more prevalent in the INPH patients at the 24th and the 48th 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 24th and at the 48th 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.

Structural and neurochemical evaluation of the brain and pons in patients with Wilson's disease.

PURPOSE: 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). MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Imaging of active multiple sclerosis plaques: efficiency of contrast-enhanced magnetization transfer subtraction technique.

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.

The efficiency of PC-MRI in diagnosis of normal pressure hydrocephalus and prediction of shunt response.

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 + or - 63.8 microL) and output/min (3921 + or - 5668 microL) were remarkably higher in the NPH group compared with the control group (3.9 + or - 3.9 microL, 439 + or - 487 microL, respectively) (P < .05). Maximum and mean venous velocity values of the INPH patients (maximum, 19.2 + or - 4.3 cm/s; mean, 16 + or - 3.7 cm/s), were lower than those of the control group (maximum, 21.8 + or - 4.6 cm/s; mean, 18.9 + or - 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 < .001, P = .007, respectively). The response of INPH patients against shunt treatment showed no statistical correlation with any of the PC-MRI parameters (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.

Phase-contrast MRI and 3D-CISS versus contrast-enhanced MR cisternography on the evaluation of the aqueductal stenosis.

INTRODUCTION: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Morphologic features and flow void phenomenon in normal pressure hydrocephalus and other dementias: are they really significant?

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.

Phase-contrast cine MRI versus MR cisternography on the evaluation of the communication between intraventricular arachnoid cysts and neighbouring cerebrospinal fluid spaces.

INTRODUCTION: 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. MATERIALS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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.

MR imaging in the detection of diffuse axonal injury with mild traumatic brain injury.

PURPOSE: To evaluate the occurrence and distribution of mild traumatic brain injury (MTBI) caused by diffuse axonal injury (DAI) using magnetic resonance (MR) imaging and to attempt to correlate MR findings with post-concussion symptoms (PCS). PATIENTS AND METHODS: Forty MTBI patients (mean age: 32.5 years) with normal cranial computed tomography (CT) findings were examined with standard MR protocol including T(1)-weighted, T(2)-weighted, fluid attenuated inversion recovery (FLAIR), gradient echo (GRE) and diffusion-weighted (DW) sequences. MR imaging was performed within 24 hours of injury. The lesions were classified as DAI based on their location and morphologic appearance. RESULTS: In MR imaging of five (12.5%) of the patients, the lesions compatible with DAI were observed. Four patients (10%) had the foci of low signal intensity compatible with hemorrhagic shear injury on the GRE sequence, and five (12.5%) patients had high signal intensity on FLAIR and DW sequence. CONCLUSION: MR imaging can be helpful in revealing DAI lesions in patients with normal CT scan findings after MTBI. FLAIR, GRE and DW sequences are superior to conventional spin-echo images in detecting DAI lesions.

The contribution of diffusion-weighted MR imaging in multiple sclerosis during acute attack.

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.