Associating IDH and TERT Mutations in Glioma with Diffusion Anisotropy in Normal-Appearing White Matter.

BACKGROUND AND PURPOSE: IDH and TERT mutations might infiltratively manifest within normal-appearing white matter with specific phenotypes such as microstructural changes undetectable by standard MR imaging contrasts but potentially associable with DTI variables. The aim of this retrospective glioma study was to statistically investigate IDH and TERT associations and classifications with DTI reported microstructure in normal-appearing white matter. MATERIALS AND METHODS: Retrospective data from patients imaged between March 2012 and February 2016 were analyzed by grouping them as IDH-TERT subgroups and by IDH and TERT mutation status. DTI variables in the IDH-TERT subgroups were first identified by the Kruskal-Wallis test, followed by Dunn-Sidák multiple comparisons with Bonferroni correction. IDH and TERT mutations were compared with the Mann-Whitney U test. Classification by thresholding was tested using receiver operating characteristic analysis. RESULTS: Of 170 patients, 70 patients (mean age, 43.73 [SD, 15.32] years; 40 men) were included. Whole-brain normal-appearing white matter fractional anisotropy (FA) and relative anisotropy (RA) (P = .002) were significantly higher and the contralateral-ipsilateral hemispheric differences, ΔFA and ΔRA, (P < .001) were significantly lower in IDHonly patients compared with TERTonly, with a higher whole-brain normal-appearing white matter FA and RA (P = .01) and ΔFA and ΔRA (P = .002) compared to double positive patients. Whole-brain normal-appearing white matter ADC (P = .02), RD (P = .001), λ2 (P = .001), and λ3 (P = .001) were higher in IDH wild-type. Whole-brain normal-appearing white matter λ1 (AD) (P = .003), FA (P < .001), and RA (P = .003) were higher, but Δλ1 (P = .002), ΔFA, and ΔRA (P < .001) were lower in IDH mutant versus IDH wild-type. ΔFA (P = .01) and ΔRA (P = .02) were significantly higher in TERT mutant versus TERT wild-type. CONCLUSIONS: Axial and nonaxial diffusivities, anisotropy indices in the normal-appearing white matter and their interhemispheric differences demonstrated microstructural differences between IDH and TERT mutations, with the potential for classification methods.

Asociación entre la invasión perineural en la biopsia de próstata dirigida por RMmp y/o sistemática y los resultados patológicos adversos en la prostatectomía radical asistida por robot / The association between perineural invasion in mpMRI-targeted and/or systematic prostate biopsy and adverse pathological outcomes in robot-assisted radical prostatectomy

Introducción y objetivos: Este estudio tiene como objetivo investigar la relación entre la invasión perineural (IPN) en la biopsia de próstata con aguja dirigida (BD) y/o sistemática (BS) y las características patológicas adversas del cáncer de próstata (CaP) en los especímenes de prostatectomía.Materiales y métodos: Se incluyeron un total de 95 pacientes varones que recibieron una BD transperineal y/o una BS concomitante, tratados posteriormente con prostatectomía radical asistida por robot para CaP entre octubre de 2015 y junio de 2020. Se calculó el rendimiento de la IPN como prueba de clasificación (sensibilidad, especificidad, valores predictivos positivos y negativos) y su correlación con el CaP clínicamente significativo, la positividad del margen quirúrgico, la extensión extraprostática y la invasión de las vesículas seminales en la prostatectomía.Resultados: La edad media de los pacientes era 65 (60-70) años. Se realizó BD y BS concomitante en 78 (82,1%) pacientes, mientras que 16 (16,8%) pacientes recibieron solo BS y uno (1,1%) solo BD. La frecuencia de IPN en la BD y BS fue de 17 (21,5%) y 32 (34,0%), respectivamente. Los valores de especificidad/predictivos negativos de la IPN para positividad del margen quirúrgico, extensión extraprostática e invasión de las vesículas seminales fueron 79,7/88,7%, 92,5/79,0% y 83,3/96,8%, en la BD, y 71,1/87,1%, 80,7/74,2% y 69,5/91,9%, en la BS, respectivamente. También hubo una correlación estadísticamente significativa entre la IPN en la biopsia y la positividad del margen quirúrgico, la extensión extraprostática y la invasión de las vesículas seminales en la prostatectomía, así como en cuanto al grupo de grado ISUP y el estadio pT.Conclusiones: La ausencia de IPN en la biopsia de próstata con aguja puede predecir un CaP localizado con un estadio pT≤2c y márgenes quirúrgicos negativos; por el contrario, su presencia parece ser un indicador de factores desfavorables en la patología final (AU)

Introduction and objectives: This study aims to investigate the relationship between perineural invasion (PNI) in targeted (TBx) and/or systematic (SBx) prostate needle biopsy and adverse pathological features of prostate cancer (PCa) in prostatectomy specimens.Materials and methods: A total of 95 male patients who underwent transperineal TBx and/or concomitant SBx subsequently treated with robot-assisted radical prostatectomy for PCa between October 2015 and June 2020 were included. The performance of PNI as a classification test (sensitivity, specificity, positive and negative predictive values) and its correlation with clinically significant PCa, surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy were computed.Results: The median age of the patients was 65 (60-70) years. TBx and concomitant SBx were performed in 78 (82.1%) patients, while 16 (16.8%) patients underwent SBx alone and one (1.1%) patient underwent TBx alone. The frequency of PNI in TBx and SBx was 17 (21.5%) and 32 (34.0%), respectively. The specificity/negative predictive values of PNI for surgical margin positivity, extraprostatic extension, and seminal vesicle invasion were 79.7/88.7%, 92.5/79.0%, and 83.3/96.8%, in TBx, and 71.1/87.1%, 80.7/74.2%, and 69.5/91.9%, in SBx, respectively. There was also a statistically significant correlation between PNI in biopsy and surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy as well as the ISUP grade group and pT stage.Conclusions: The absence of PNI in prostate needle biopsy may predict localized PCa with a pT stage≤2c and negative surgical margins in contrast to its presence which appears to be an indicator of unfavorable factors in final pathology (AU)

Compressive strength, surface roughness, and surface microhardness of principle tricalcium silicate-based endodontic cements after universal adhesive application.

Aims and Background: It was aimed to evaluate compressive strength (CS), surface roughness, and microhardness of mineral trioxide aggregate (ProRoot MTA) and Biodentine (BD) after adhesive application. Materials and Methods: Tests was carried out according to international ISO standard. ProRoot MTA and BD were prepared in Teflon molds according to manufacturer's instructions: n = 210 for CS; n = 210 for microhardness. Samples were incubated for 7 days at 37°C in 100% humidity. Surfaces were smoothed with up to 2000 grits of silicon-carbide sandpaper on abrasive device at 150 rpm, randomly divided into seven groups (n = 15). Clearfil Universal Bond, All Bond Universal, and Single Bond Universal (SBU) were applied in both total-etch and self-etch (SE) modes. Adhesives were applied according to manufacturers' recommendations (no adhesive used in control). CS was performed at speed of 1 mm/min, microhardness at 100 gr for 15 s. The surface roughness of the samples was analyzed with atomic force microscopy. Two-way analysis of variance and post hoc Tukey tests were used for the evaluation of the data. Results: Man CS and microhardness values between ProRoot MTA and BD were as follows: 24.9 N, 72.6 HV; 59.8 N, 59.0 HV, respectively. In CS, BD was higher than ProRoot MTA (P < 0.05). In other comparisons except for SBU SE group (P < 0.05), BD and ProRoot MTA showed similar results (P > 0.05). However, ProRoot MTA was found higher than BD regarding microhardness (P < 0.05). As a result of the adhesive application in both BD and ProRoot MTA groups, a decrease in surface roughness was observed compared to the control group. Conclusion: BD exhibited better results than ProRoot MTA regarding CS. However, ProRoot MTA was found to be more successful than BD in terms of microhardness. BD and ProRoot MTA showed similar physical properties in terms of surface roughness. To improve regenerative procedures, besides the selection of bioceramic cements, the interaction between cements and materials applied during coronal restoration should be considered.

The association between perineural invasion in mpMRI-targeted and/or systematic prostate biopsy and adverse pathological outcomes in robot-assisted radical prostatectomy.

INTRODUCTION AND OBJECTIVES: This study aims to investigate the relationship between perineural invasion (PNI) in targeted (TBx) and/or systematic (SBx) prostate needle biopsy and adverse pathological features of prostate cancer (PCa) in prostatectomy specimens. MATERIALS AND METHODS: A total of 95 male patients who underwent transperineal TBx and/or concomitant SBx subsequently treated with robot-assisted radical prostatectomy for PCa between October 2015 and June 2020 were included. The performance of PNI as a classification test (sensitivity, specificity, positive and negative predictive values) and its correlation with clinically significant PCa, surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy were computed. RESULTS: The median age of the patients was 65 (60-70) years. TBx and concomitant SBx were performed in 78 (82.1%) patients, while 16 (16.8%) patients underwent SBx alone and one (1.1%) patient underwent TBx alone. The frequency of PNI in TBx and SBx was 17 (21.5%) and 32 (34.0%), respectively. The specificity/negative predictive values of PNI for surgical margin positivity, extraprostatic extension, and seminal vesicle invasion were 79.7/88.7%, 92.5/79.0%, and 83.3/96.8%, in TBx, and 71.1/87.1%, 80.7/74.2%, and 69.5/91.9%, in SBx, respectively. There was also a statistically significant correlation between PNI in biopsy and surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy as well as the ISUP grade group and pT stage. CONCLUSIONS: The absence of PNI in prostate needle biopsy may predict localized PCa with a pT stage ≤ 2c and negative surgical margins in contrast to its presence which appears to be an indicator of unfavorable factors in final pathology.

Structural signature of sporadic Creutzfeldt-Jakob disease.

BACKGROUND AND PURPOSE: Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive neurodegenerative disease caused by an abnormal isoform of the human prion protein. Structural magnetic resonance imaging in patients with pathologically confirmed sCJD was compared with cognitively normal individuals to identify a cortical thickness signature of sCJD. METHODS: This retrospective cross-sectional study compared patients with autopsy-confirmed sCJD with dementia (n = 11) with age- and sex-matched cognitively normal individuals (n = 22). We identified regions of interest (ROIs) in which cortical thickness was most affected by sCJD. Within patients with sCJD, the relationship between ROI cortical thickness and clinical measures (disease duration, cerebrospinal fluid tau and diffusion-weighted imaging abnormalities) was evaluated. RESULTS: Compared with cognitively normal individuals, patients with sCJD had significantly reduced cortical thickness in multiple ROIs, including the fusiform gyrus, precentral gyrus, precuneus and superior temporal gyrus bilaterally; the caudal middle frontal gyrus, superior frontal gyrus, postcentral gyrus, inferior temporal gyrus and transverse temporal gyrus in the left hemisphere; and the superior parietal lobule in the right hemisphere. Only one patient with sCJD had co-pathology consistent with Alzheimer's disease. Reduced cortical thickness did not correlate with disease duration, presence of diffusion restriction or elevated cerebrospinal fluid tau. CONCLUSION: Cortical signature changes in sCJD may reflect brain changes not captured by standard clinical measures. This information may be used with clinical measures to inform the progression of sCJD and patterns of prion protein spread throughout the brain. These results may have implications for prediction of symptomatic progression and plausibly for development of therapeutic strategies.

The effects of different irrigation protocols on removing calcium hydroxide from the root canals.

OBJECTIVE: The aim of this study was to evaluate the efficiencies of different irrigation protocols and solutions in the removal of calcium hydroxide (Ca[OH]2). MATERIALS AND METHODS: Sixty-eight maxillary incisors were used. Root canals were prepared and filled with Ca(OH)2. Two control (n = 4) and six experimental groups (n = 10) were adjusted: Group 1:1% peracetic acid (PAA) + master apical file (MAF); Group 2: 17% ethylenediaminetetraacetic acid (EDTA) + MAF; Group 3: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) + MAF; Group 4: 1% PAA + ultrasonic activation (UA); Group 5: 17% EDTA + UA; Group 6: 9% HEBP + UA. The cleanliness of root canal thirds were evaluated with scanning electron microscopy. Statistical analysis were performed (α = 0.05). RESULTS: At coronal thirds; PAA + UA was superior to EDTA + MAF, HEBP + MAF; and PAA + MAF was superior to EDTA + MAF, HEBP + MAF (P < 0.05). At middle thirds; PAA + MAF and PAA + UA were superior to EDTA + MAF and EDTA + UA; and, PAA + UA was superior to HEBP + MAF (P < 0.05). There were no significant differences among the rest of the experimental groups (P > 0.05). CONCLUSION: Complete removal of Ca(OH)2could not be achieved by none of the irrigants at all root thirds.

Deciphering H3K4me3 broad domains associated with gene-regulatory networks and conserved epigenomic landscapes in the human brain.

Regulators of the histone H3-trimethyl lysine-4 (H3K4me3) mark are significantly associated with the genetic risk architecture of common neurodevelopmental disease, including schizophrenia and autism. Typical H3K4me3 is primarily localized in the form of sharp peaks, extending in neuronal chromatin on average only across 500-1500 base pairs mostly in close proximity to annotated transcription start sites. Here, through integrative computational analysis of epigenomic and transcriptomic data based on next-generation sequencing, we investigated H3K4me3 landscapes of sorted neuronal and non-neuronal nuclei in human postmortem, non-human primate and mouse prefrontal cortex (PFC), and blood. To explore whether H3K4me3 peak signals could also extend across much broader domains, we examined broadest domain cell-type-specific H3K4me3 peaks in an unbiased manner with an innovative approach on 41+12 ChIP-seq and RNA-seq data sets. In PFC neurons, broadest H3K4me3 distribution ranged from 3.9 to 12 kb, with extremely broad peaks (~10 kb or broader) related to synaptic function and GABAergic signaling (DLX1, ELFN1, GAD1, IGSF9B and LINC00966). Broadest neuronal peaks showed distinct motif signatures and were centrally positioned in prefrontal gene-regulatory Bayesian networks and sensitive to defective neurodevelopment. Approximately 120 of the broadest H3K4me3 peaks in human PFC neurons, including many genes related to glutamatergic and dopaminergic signaling, were fully conserved in chimpanzee, macaque and mouse cortical neurons. Exploration of spread and breadth of lysine methylation markings could provide novel insights into epigenetic mechanism involved in neuropsychiatric disease and neuronal genome evolution.

Effects of ozone and photo-activated disinfection against Enterococcus faecalis biofilms in vitro.

OBJECTIVES: The purpose of this study was to compare the antibacterial effects of gaseous ozone (O3) and photo-activated disinfection (PAD) methods against Enterococcus faecalis (E. faecalis) biofilms. MATERIALS AND METHODS: Sixty-five human mandibular premolars with straight root canals were selected. After root canal preparation, the samples were sterilized and placed into eppendorf tubes with 1 mL brain heart infusion broth containing 1.5×10(8) colony-forming units (CFUs)/mL of E. faecalis. The contaminated samples were then divided into four groups (n=15) according to the disinfection method used: Group 1, Saline (positive control); Group 2, NaOCl (negative control); Group 3, Gaseous O3; and Group 4, PAD. Three non-contaminated teeth were used to control the infection and sterilization process. The CFUs were counted and the data were analyzed statistically. RESULTS: There was a statistically significant difference between the experimental and control groups (P<0.05). The saline group had the highest number of remaining microorganisms. Complete sterilization was achieved in the 2.5% NaOCl group. There were no statistically differences between PAD and gaseous O3 (P>0.05). CONCLUSION: Both PAD and gaseous O3 have a significant antibacterial effect on infected root canals. However, 2.5% NaOCl was superior in terms of its antimicrobial abilities compared with the other disinfection procedures.

Evaluation of apically extruded debris during root canal retreatment with several NiTi systems.

AIM: To compare the amount of debris extruded apically during root canal retreatment using ProTaper, Mtwo and Reciproc instruments with hand H-files. METHODOLOGY: In total, 60 freshly extracted human mandibular incisor teeth were used. All root canals were prepared with a Reciproc R25 file than filled with Gutta-percha and AH Plus sealer using cold lateral condensation before being assigned randomly to four groups (n = 15 each). In group 1, root fillings were removed with the Protaper Universal retreatment system; ProTaper Universal F3 and F4 instruments were used for the final preparation. In group 2, root fillings were removed with the Mtwo retreatment system; Mtwo size 30, .06 taper, size 35, .06 taper and size 40, .06 taper files were used for the final preparation. In group 3, root fillings were removed with Reciproc R25 instruments; Reciproc R40 instruments were used for the final preparation. In group 4, the root fillings were removed with Gates Glidden burs and sizes 35, 30 and 25 H-files; for final preparation, a size 40 H-file was used. Glass vials were used for debris collection. The vials were weighed before and after Gutta-percha removal. Additionally, the times required for the retreatment procedures were recorded. Data were analysed statistically using one-way analysis of variance. RESULTS: The Reciproc system produced significantly smaller amounts of apical extruded debris than the other groups (P < 0.05). There was no significant difference between the Mtwo, H-file and ProTaper groups. The ProTaper and Reciproc groups required significantly less time than the Mtwo and H-file groups (P < 0.001). CONCLUSIONS: Use of the reciprocating single file system resulted in the extrusion of significantly less debris compared with the full-sequence rotary NiTi instruments and hand filing. Use of the ProTaper and Reciproc instruments required less time for retreatment procedures than use of the Mtwo or H-file.

Evaluation of apically extruded debris associated with several Ni-Ti systems.

AIM: To evaluate the apical extrusion of debris associated with several root canal preparation systems in vitro. METHODOLOGY: Forty-five extracted human mandibular premolars with single canals and similar lengths were used. The root canals were instrumented using ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland), Twisted File (SybronEndo, Orange, CA, USA) or WaveOne (Dentsply Maillefer, Ballaigues, Switzerland). Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70 °C for 5 days. The Eppendorf tubes were weighed to obtain the final weight of the Eppendorf tubes plus extruded debris. Three consecutive weights were obtained for each tube. The groups were compared using the Kruskal-Wallis one-way analysis of variance on Ranks and Tukey's test. RESULTS: The ProTaper Next group produced the highest mean extrusion value whilst WaveOne produced less debris compared with all the other instruments (P > 0.05). There was a significant difference between the ProTaper Next and WaveOne group (P < 0.05). CONCLUSIONS: Apically extruded debris was associated with all instrumentation techniques. The WaveOne system extruded less debris compared with the Twisted File and ProTaper Next.

Diffusion-Weighted MR Imaging Findings of Cortical Vein Thrombosis at 3 T.

PURPOSE: Diagnosis of cortical vein thrombosis (CVT) on the basis of clot hyperintensity on diffusion-weighted imaging (DWI) has been reported as limited. Our aim was to evaluate different DWI findings of CVT either in isolated form or in combination with sinus thrombosis. METHODS: In this review-board-approved study, patients with the diagnosis of CVT on magnetic resonance venography (MRV) between 2004 and 2011 were evaluated, and 13 patients with 26 CVT (3 isolated and 23 combined CVT) sites were recruited. The evaluated DWI findings were as follows: (1) the hyperintense clot signal (CS) itself, and (2) clot susceptibility signal (CSS) that appears next to the CVT. Two blinded radiologists evaluated the data. Kappa (κ) statistics was applied for interobserver agreement. RESULTS: Both readers reported CS within the vascular clot itself in 6 of 26 (23%) CVT sites on DWI. CSS was reported in 16 of 26 (61.5%) CVT sites by reader 1, and in 14 of 26 (54%) of the CVT sites by reader 2. At four CVT sites with thrombosed veins on MRV, both readers reported no DWI findings. When both CS and CSS were evaluated together, reader 1 reported a positive DWI finding in 22 of 26 (84%) of the CVT sites, and reader 2 reported in 20 of 26 (79%) of the sites. κ Statistics showed a very good agreement (κ: 0.87). CONCLUSIONS: Besides the hyperintense CS, with additional evaluation of the presence of CSS, DWI can provide an additional clue in CVT patients and may suggest its diagnosis, which is important in clinically unsuspected patients.

Human brains found in a fire-affected 4000-years old Bronze Age tumulus layer rich in soil alkalines and boron in Kutahya, Western Anatolia.

Undecomposed human bodies and organs always attracted interest in terms of understanding biological tissue stability and immortality. Amongst these, cases of natural mummification found in glaciers, bog sediments and deserts caused even more attention. In 2010, an archeological excavation of a Bronze Age layer in a tumulus near the Western Anatolia city Kütahya revealed fire affected regions with burnt human skeletons and charred wooden objects. Inside of the cracked skulls, undecomposed brains were discernible. To analyze the burial taphonomy of the rare phenomenon of brain preservation, we analyzed brains, bone, teeth and surrounding soils elements using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Adipocere formation or saponification of postmortem tissue fat requires high levels of alkalinity and especially potassium. Indeed, ICP-MS analysis of the brain, teeth and bone and also of the surrounding soil revealed high levels of potassium, magnesium, aluminum and boron, which are compatible with the famous role of Kütahya in tile production with its soil containing high level of alkalines and tile-glazing boron. Fatty acid chromatography revealed simultaneous saturation of fats and protection of fragile unsaturated fatty acids consistent with soil-presence of both pro-oxidant and anti-oxidant trace metals. Computerized tomography revealed protection of diencephalic, metencephalic and occipital tissue in one of the best-preserved specimens. Boron was previously found as an intentional preservative of Tutankhamen and Deir el Bahari mummies. Here, in natural soil with its insect-repellant, anti-bacterial and fire-resistance qualities it may be a factor to preserve heat-affected brains as almost bioporcellain specimens.

Hydrocephalus in patients with neurofibromatosis type 1: MR imaging findings and the outcome of endoscopic third ventriculostomy.

Although hydrocephalus associated with NF-1 is not rare, up to now the MR imaging findings in these patients and the role of ETV in the treatment of hydrocephalus associated with NF-1 have not been investigated thoroughly. We present the MR imaging findings of hydrocephalus associated with NF-1 in 7 of 54 patients with NF-1. Although the types of obstruction were various, including aqueductal web, superior velum medullary synechia, periaqueductal/tectal hamartomas, cerebellar and pontine tegmentum hamartomas, brain stem glioma, or a combination, the presence of hamartomas was a consistent finding in patients with NF-1 with hydrocephalus. In 5 cases, 8 ETV procedures were performed and followed for up to 53 months. All children treated with ETV were shunt-free at their most recent examinations. ETV may be the primary procedure for the treatment of hydrocephalus associated with NF-1, regardless of the cause and the level of the obstruction.

Is all "communicating" hydrocephalus really communicating? Prospective study on the value of 3D-constructive interference in steady state sequence at 3T.

BACKGROUND AND PURPOSE: 3D-constructive interference in steady state (3D-CISS) sequence has been used to assess the CSF pathways. The aim of this study was to investigate the additive value of 3D-CISS compared with conventional sequences in the diagnosis of obstructive membranes in hydrocephalus. MATERIALS AND METHODS: A total of 134 patients with hydrocephalus underwent MR imaging examination with a 3T unit consisting of turbo spin-echo, 3D-CISS, and cine phase-contrast (cine PC) sequences. 3D-CISS was used to assess obstructive membranes in CSF pathways compared with other sequences. Cine PC, follow-up imaging, and surgical findings were used to confirm obstructive membranes. RESULTS: Comparing the number of noncommunicating cases by using the conventional and 3D-CISS images, we found 26 new cases (19.4%) of 134 cases that were previously misdiagnosed as communicating hydrocephalus by conventional images. 3D-CISS sequence identified obstructive membranes invisible in other sequences, which facilitated selection of neuroendoscopy in the treatment of 31 patients (23.1%) in total who would have been otherwise treated with shunt insertion. These patients included 26 newly diagnosed noncommunicating cases after demonstration of intraventricular and/or fourth ventricular outlet membranes and 5 cases of communicating hydrocephalus with obstructing cisternal membranes. There were obstructions of the foramina of Luschka in 22 of 26 newly found noncommunicating cases. CONCLUSIONS: Conventional sequences are insensitive to obstructive membranes in CSF pathways, especially in the fourth ventricular exit foramina and the basal cisterns. 3D-CISS sequence, revealing these obstructive membranes, can alter patient treatment and prognosis.

Two cases with progressive cystic leukoencephalopathy.

Leukoencephalopathies with cystic changes in the white matter on magnetic resonance imaging are aetiologically heterogeneous neurological disorders seen in children. A group of leukoencephalopathies characterised by white matter lesions progressing to multifocal cystic degeneration has been reported in various disorders, including mitochondrial enzyme deficiencies, leukodystrophies, and infectious processes. We report two patients with leukoencephalopathy showing progressive cystic changes on serial MRI, and magnetic resonance spectroscopy resembling progressive cavitating leukoencephalopathy.

Acute ischemic infarction defined by a region of multiple hypointense vessels on gradient-echo T2* MR imaging at 3T.

BACKGROUND AND PURPOSE: During the hyperacute phase of stroke, multiple hypointense vessels were identified specifically in the ischemic territory on gradient-echo T2*-weighted MR images (GRE-T2* WI) at 3T. The area was named a "region of multiple hypointense vessels (RMHV)." The aim of this study was to assess the usefulness of RMHV for the diagnosis of acute ischemic stroke (AIS) and to establish the relationship of this finding to other MR imaging studies. MATERIALS AND METHODS: Twenty patients with AIS underwent MR imaging at 3T consisting of GRE-T2*, diffusion-weighted images (DWI), and perfusion-weighted images (PWI) within 6 hours of symptom onset and follow-up images at 72 hours. RMHV was defined as an area containing multiple hypointense vessels strictly in the region of the ischemic territory on GRE-T2*. The RMHV volume on GRE-T2*, initial ischemic lesion volumes on DWI, PWI maps, and on follow-up images were measured and compared with the RMHV volume. RESULTS: RMHV on GRE-T2* was identified in 20 patients. There was no significant difference between the ischemic lesion volumes on mean transit time (247.3 +/- 88.1 mL), time-to-peak (228.6 +/- 88.8 mL), cerebral blood flow (200.6 +/- 89.7 mL), RMHV on GRE-T2* (214.4 +/- 86 mL), and the infarct volume at 72 hours (210.3 +/- 90.4 mL) (P = .975). CONCLUSIONS: RMHV on GRE-T2* can be used as a supportive imaging finding for the diagnosis of hyperacute ischemic stroke. RMHV volume provides information that is in accordance with the infarct volume at 72 hours and the data supplied by PWI.

Extrapontine Myelinolysis in a Child: a Rare Case with MRI, DWI and MRS Follow-up.

We describe a case of extrapontine myelinolysis in a child presenting with chorea and parkinsonian symptoms after treatment for hyponatremic dehydration. Although both extrapontine myelinolysis (EPM) in childhood and extrapyramidal presentation of EPM are very rare in children, the patient presented with pure extrapyramidal symptoms. Besides basal ganglia involvement and sparing brain stem, MRI demonstrated involvement of the amygdala bilaterally hitherto never reported in EPM patients. While single voxel proton spectroscopy (MRS) of the basal ganglia at the beginning was normal, the follow-up MRS showed moderate to severe NAA and mI decrease. Diffusion-weighted imaging abnormalities appeared relatively late during the disease course, also an unexpected finding. In addition, there were apparent increases in apparent diffusion coefficient (ADC) values of the affected basal ganglia instead of diffusion restriction.

Intraoperative MR imaging: preliminary results with 3 tesla MR system.

UNLABELLED: Aim of this study is to present the initial clinical experience with 3 tesla intraoperative MR (ioMR). MATERIAL AND METHODS: The 3T MRI suite is built adjacent to the neurosurgical operation theatre. The magnet room and the operation theatre are interconnected by a door and both RF-shielded. Before the operation, the magnet (3T Trio, Siemens) and the console rooms are disinfected. Whenever imaging is needed during the operation, the door is opened and the patient is transferred from the operation table to the magnet cradle. Axial, sagittal and/or coronal TSE T2, SE T1 and 3D Flash T1 weighted images (4-6 mm section thickness, 1 mm interslice gap) are obtained according to the lesion. Total examination time is approximately 10 minutes. RESULTS: Twenty-six patients were examined with ioMR. There were ten female and seven male patients. Lesions were pituitary adenoma in 10, low grade glial tumor in 9, meningioma and high grade glial tumor in 2 each and metastasis, haemangioblastoma and chordoma in one each. Follow-up time was 1 to 9 months. In 16 patients the first intraoperative examination revealed gross total tumor excision. However, in 10 patients due to tumor remnants surgical intervention was continued and a second examination revealed gross total tumor excision in all. Postoperative routine MR examinations confirmed total tumor excision in all patients. No complication occurred in this series. CONCLUSION: This small group of patients examined with ioMR demonstrated that the procedure is simple, helpful in achieving gross total tumor excision without complications.