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-Šidák 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.

Patients characteristics in Behçet's Syndrome and their associations with major organ involvement: a single-centre experience of 2118 cases

Objectives: To evaluate the demographic and clinical characteristics of patients with Behçet's syndrome (BS), and to define their associations with the presence of major organ involvement (MOI).Method: Medical records of 2118 patients (964 males, 1154 females) were analysed retrospectively. MOI was defined as the presence of at least one of vascular, eye, nervous, or gastrointestinal system involvement. Univariable and multivariable binary and ordinal logistic regression analyses were applied to assess the factors that were potentially associated with MOI.Results: The mean ± sd age at diagnosis was 30.5 ± 9.4 years. Genital ulcer and joint involvement were more common in females (both p < 0.001), while MOI was more frequent in males (p < 0.001). Genital ulcer (p < 0.001) and vascular involvement (p = 0.006) were more common in patients with a younger age at diagnosis, while joint involvement was more common in older patients. A total of 1097 patients (51.8%) had at least one MOI, 322 (15.2%) at least two MOIs, and 48 (2.3%) at least three MOIs. Male gender, smoking history, and absence of genital ulcer were significantly associated with MOI in multivariable binary logistic regression. Multivariable ordinal regression analyses confirmed the association between MOI and male gender and smoking, but not the protective effect of genital ulcers. In both regression analyses, we found no significant effects of age, human leucocyte antigen-B51, skin involvement, or joint involvement on MOI.Conclusion: Male gender and positive smoking history have a significant influence on the presence of MOI in patients with BS.

P14.95 Is the pathological-grade relevant in “IDH-wild type, TERT-mutant” diffuse-gliomas? An analysis in 147 patients

BACKGROUND

Although the word “glioblastoma” still denotes a grade-IV pathology, basic molecular studies have clearly indicated that a significant proportion of lower-grade gliomas harbor genetic alterations typical of glioblastomas. Based on these findings cIMPACT-NOW update 3 has defined an entity called the “diffuse astrocytic glioma, IDH-wildtype, with molecular features of glioblastoma, WHO grade IV”. A TERT-promoter mutation is one of these typical molecular markers of glioblastomas. In this study we analyzed IDH-wild type, TERT-mutant diffuse gliomas of different pathological grades to look for differences in demographic, clinical and survival characteristics.

MATERIAL AND METHODS

147 adult hemispheric diffuse-gliomas with wild-type IDH1/2 and mutant TERT-promoter (C228T or C250T) were retrospectively analyzed. Primary thalamic, cerebellar brainstem or spinal cases were excluded. 126 (86%), 16(11%) and 5(3%) patients were WHO grade IV, III and II respectively. After surgical treatment or stereotactic biopsy all patients underwent chemoradiation. Median follow-up was 16mo (1–110). Tumors of different grades were compared for age, gender, multifocality, gliomatosis pattern, Ki-67 index, progression-free survival and overall-survival.

RESULTS

Mean age at presentation for grade II, III and IV were comparable (58.1, 58 and 58.1; ANOVA, p=0.72). There was a slight male predominance in both lower-grades and WHO-grade IV (M:F ratios 1.625 and 1.74). Mean Ki-67 index was significantly higher in higher grades (0.06, 0.14 and 0.25 for grades II, III and IV; ANOVA, p=0.001). Multifocality was comparable (chi-sq, p=1) in lower-grades (3/21; 14.3%) vs. WHO-grade IV (18/126; 14.3%). Gliomatosis pattern was comparable (chi-sq, p=0.095) in lower-grades (2/21; 9.5%) vs. (3/126; 2.3%). Median recurrence free survival (RFS) was 16 months (0–63) in lower-grades and 8months (1–50) in WHO-grade IV. PFS was significantly different between 3 WHO-grades (Log rank, p=0.007) and also between lower-grades and WHO-grade IV (Log rank, p=0.002). Median overall survival was 26 months(2–110) in lower-grades and 15mo(1–91) in WHO-grade IV. OS was significantly different between 3 WHO-grades (Log rank, p=0.014) and also between lower-grades and WHO-grade IV (Log rank, p=0.007).

CONCLUSION

Increasing pathological grades of hemispheric “IDH-wild type, TERT-mutant diffuse gliomas” have similar demographic and clinical characteristics but incrasing proliferation indices, decrasing progression free survival and shorter overall survival. The findings may be suggesitve of different grades of one common tumor entity.

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.

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.

Intraoperative MR imaging: preliminary results with 3 tesla MR system

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.

Purification and characterization of catalase from chard (Beta vulgaris var. cicla)

Catalase is a major primary antioxidant defence component that primarily catalyses the decomposition of H(2) O(2) to H(2) O. Here we report the purification and characterization of catalase from chard (Beta vulgaris var. cicla). Following a procedure that involved chloroform treatment, ammonium sulfate precipitation and three chromatographic steps (CM-cellulose, Sephadex G-25, and Sephadex G-200), catalase was purified about 250-fold to a final specific activity of 56947 U/mg of protein. The molecular weight of the purified catalase and its subunit were determined to be 235 000 and 58 500 daltons, indicating that the chard catalase is a tetramer. The absorption spectra showed a soret peak at 406 nm, and there was slightly reduction by dithionite. The ratio of absorption at 406 and 275 nanometers was 1.5, the value being similar to that obtained for catalase from other plant sources. In the catalytic reaction, the apparent Km value for chard catalase was 50 mM. The purified protein has a broad pH optimum for catalase activity between 6.0 and 8.0. The enzyme had an optimum reaction temperature at 30 degrees C. Heme catalase inhibitors, such as azide and cyanide, inhibited the enzyme activity markedly and the enzyme was also inactivated by ?-mercaptoethanol, dithiothreitol and iodoacetamide.

Serial MRI and MRS studies with unusual findings in Rasmussen's encephalitis

Rasmussen's syndrome is characterized by intractable seizures and progressive neuropsychiatric deterioration secondary to unilateral cortical inflammation and tissue destruction. Diagnosis of Rasmussen's syndrome in the early phase depends mainly on the clinical features. Neuroimaging and histopathologic examinations may not be specific during this period. We report a case of Rasmussen's syndrome followed by serial MRI and magnetic resonance spectroscopy (MRS) studies over a 3- to 16-month period. A healthy 6-year-old boy presented with focal motor seizures. An MRI study demonstrated prominent enlargement and T2 hyperintensity of the left mesial temporal lobe and perisylvian region. This early finding evolved to volume loss and later progressive atrophy of the ipsilateral hemisphere when epilepsia partialis continua occurred. Being aware of those early MRI features in a patent with increasing frequency of focal motor seizures should suggest Rasmussen's syndrome. In addition, we found prominently increased myoinositol concentration in atrophic cortex which might reflect increased gliosis in the late period of the disease.

MRI and MRS in HMG-CoA lyase deficiency

3-Hydroxy-3-Methylglutaryl coenzyme A lyase (HMG-CoA) deficiency is a rare inborn error of leucine catabolism. The disease is characterized by recurrent episodes of metabolic acidosis, hyperammonemia without ketosis, hypoglycemia, lethargy, hepatomegaly, and seizures. This study has evaluated the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings of three patients with HMG-CoA deficiency. The common findings on all of the MRI scans were multiple, coalescent, marked lesions in periventricular white matter and arcuate fibers, most prominently in frontal or periatrial regions that were superimposed on diffuse, slightly hyperintense subcortical white matter signal. Involvement of the caudate nucleus and the dentate nucleus were observed in the reported patients. MRS studies by both STEAM and PRESS spectra of all patients revealed a decrease in N-acetylaspartate and elevation in both myoinositol and choline. A pathologic peak at 1.33 ppm, which is compatible with lactate, and a particular peak at 2.42 ppm in all patients were also found. The combination of both MRI and MRS findings could be considered as being specific in patients with HMG-CoA lyase deficiency.

High intensity signal of the posterior pituitary. A study with horizontal direction of frequency-encoding and fat suppression MR techniques

PURPOSE

To evaluate the consistency of fat in the high intensity signals of the normal neurohypophysis and to differentiate the high signal of posterior pituitary from that of dorsum sella. Sagittal SE T1-weighted images with frequency encoding in the horizontal direction were used in order to differentiate the high signal of posterior pituitary and dorsum sella by the vertically-oriented chemical shift artifact.

MATERIAL AND METHODS

The sellae of 46 normal volunteers were imaged with a commercially available fat suppression technique and SE sequences with frequency encoding in vertical (25 cases) and horizontal (21 cases) axes.

RESULTS

The high signal intensity was absent in 9% of the normal volunteers with no predilection to any specific age group. None of the cases with posterior pituitary high intensity signals showed suppression of the signal with fat suppression technique. A fat suppression technique was helpful in documenting the hyperintensity in 7% of normal volunteers. Nineteen of the 21 (90%) cases with high signal intensity were detected by routine SE T1-weighted images, whereas 18 of the 19 (95%) cases were detected by imaging with frequency encoding in the horizontal direction.

CONCLUSION

The high signal does not indicate the presence of fat. Fat suppression technique and a horizontal direction of frequency encoding help in differentiating the high signal of the neurohypophysis from that of dorsum sella.

Liver hydatid disease: long-term results of percutaneous treatment

PURPOSE

To evaluate the long-term effectiveness of percutaneous treatment of liver hydatid cysts.

MATERIALS AND METHODS

Thirty-one patients (19 female patients and 12 male patients; age range, 8-78 years; mean age, 41 years) with 57 liver hydatid cysts underwent percutaneous treatment. The cysts were treated with hypertonic saline (15% NaCl) and/or absolute alcohol. Sonographic and/or fluoroscopic guidance was used.

RESULTS

Repeated sonography revealed a gradual decrease in cyst size. Volume reduction was 18%-99% (mean, 83%). With the disappearance of the fluid component, pseudotumor appearance occurred. In all treated cases, the cyst wall became irregular and thicker during follow-up. No mortality occurred. No abdominal dissemination was encountered during follow-up. Major complications were infection of the cavity, hypersensitivity reaction, and development of biliary fistula. One cyst recurred 11 months after primary drainage.

CONCLUSION

Long-term results indicate that percutaneous treatment of liver hydatid cysts is an effective and safe method in selected cases.

Percutaneous treatment of pulmonary hydatid cysts

PURPOSE

To evaluate the safety and efficacy of percutaneous drainage of pulmonary hydatid cysts.

METHODS

Eleven pulmonary hydatid cysts in eight patients were drained percutaneously after 1-2 years of treatment with mebendazole (50 mg/kg/day). Percutaneous needle aspiration was carried out under ultrasound (US) in six patients and computed tomography (CT) in two patients. Nine cysts were close to, and two cysts were distant from the thoracic wall. After aspiration, hypertonic (15%) saline solution was instilled for up to 35% of the estimated volume of the cyst and aspirated 5-10 min later. Follow-up ranged from 8 to 31 months (mean 16.3 months).

RESULTS

Neither anaphylactic shock nor death occurred in any of the eight patients. One patient developed fever, ipsilateral hydropneumothorax, and contralateral pleural effusion. One patient suffered from fever, pneumothorax, and abscess and was treated surgically; one developed fever and dyspnea. The volume reduction during follow-up was 47%-93%. The cystic contents turned into a pseudotumor appearance with a thick irregular contour on CT and higher Hounsfield units. On US, the cysts showed a heterogeneous content with internal echoes representing detached and degenerated membranes, and the fluid content almost completely disappeared.

CONCLUSION

We believe that percutaneous therapy of pulmonary hydatid disease is an effective alternative to surgical treatment in patients who have failed medical therapy.