PBRM1 and BAP1: novel genetic mutations in malignant transformation of craniopharyngioma-a case report.

Malignant craniopharyngioma is especially rare, so the causes and genetic mutations associated with the malignant transformation have not been explained in detail. We investigated the molecular genetic characteristics of malignant transformation in craniopharyngioma. A 53-year-old man with a history of adamantinomatous craniopharyngioma presented with complaints of subcutaneous swelling. Magnetic resonance imaging showed a less enhanced intradural supra-sellar lesion and a heterogeneously well-enhanced extradural invasive lesion infiltrating the dura mater, brain, frontal bone, and subcutaneous tissue. Histopathological examination of the recurrent tumor revealed typical findings of both craniopharyngioma (intradural supra-sellar lesion) and malignant transformation, such as marked nuclear atypia with mitosis (invasive extradural lesion), which were not present in the primary tumor. A genetic panel test with the Oncopanel system was performed to investigate the genetic mutations responsible for the malignant transformation. Four genetic mutations were identified: CTNNB1 c.C98T, TP53 p.C135fs*35(PLS = 3 UPD/LOH), PBRM1 p.R1000*(PLS = 3 UPD/LOH), and BAP1 p.L650fs*5(PLS = 3 UPD/LOH). Sanger sequencing showed CTNNB1 in both the intradural supra-sellar and extradural invasive lesions, but TP53, PBRM1, and BAP1 only in the extradural invasive lesion. The genetic mutations of PBRM1 and BAP1 may be genetic factors in the malignant transformation of adamantinomatous craniopharyngioma.

T2-fluid-attenuated inversion recovery mismatch sign in lower grade gliomas: correlation with pathological and molecular findings.

After the new molecular-based classification was reported to be useful for predicting prognosis, the T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign has gained interest as one of the promising methods for detecting lower grade gliomas (LGGs) with isocitrate dehydrogenase (IDH) mutations and chromosome 1p/19q non-codeletion (IDH mut-Noncodel) with high specificity. Although all institutions could use T2-FLAIR mismatch sign without any obstacles, this sign was not completely helpful because of its low sensitivity. In this study, we attempted to uncover the mechanism of T2-FLAIR mismatch sign for clarifying the cause of this sign's low sensitivity. Among 99 patients with LGGs, 22 were T2-FLAIR mismatch sign-positive (22%), and this sign as a marker of IDH mut-Noncodel showed a sensitivity of 55.6% and specificity of 96.8%. Via pathological analyses, we could provide evidence that not only microcystic changes but the enlarged intercellular space was associated with T2-FLAIR mismatch sign (p = 0.017). As per the molecular analyses, overexpression of mTOR-related genes (m-TOR, RICTOR) were detected as the molecular events correlated with T2-FLAIR mismatch sign (p = 0.020, 0.030. respectively). Taken together, we suggested that T2-FLAIR mismatch sign could pick up the IDH mut-Noncodel LGGs with enlarged intercellular space or that with overexpression of mTOR-related genes.

[A Case of Anterior Cranial Fossa Dural Arteriovenous Fistula Involving Uncontrolled Seizures Diagnosed Based on Characteristic Findings on Arterial Spin-labeling Imaging].

We report a case of anterior cranial fossa dural arteriovenous fistula(ACF-DAVF)in a patient whose diagnosis was made according to characteristic findings on arterial spin labeling(ASL)MRI. CASE:A 68-year-old man was admitted to our hospital because of intractable epilepsy. Based on the initial MRI findings, an initial diagnosis of limbic encephalitis was made. Steroids and anticonvulsant drugs were administered;however, the seizures could not be controlled. A second MRI with ASL revealed abnormal vessel signals in the base segments of the left frontal and temporal lobes toward the basal vein of Rosenthal. Digital subtraction angiography(DSA)revealed an arteriovenous shunt in the left anterior cranial fossa, which drained toward the medial side of the left temporal lobe. A diagnosis of ACF-DAVF with status epilepticus was made, and the main drainer was cauterized. After the surgical procedure, the epilepsy was controlled with antiepileptic drugs, and postoperative MRI revealed obliteration of ACF-DAVF, disappearance of the high-intensity area on FLAIR sequences, and disappearance of the high-intensity signal area on ASL.

Anatomical and metabolic assessment of prostate using a 3-Tesla MR scanner with a custom-made external transceive coil: healthy volunteer study.

PURPOSE: To examine the possibility of using a 3 Tesla (T) magnetic resonance (MR) scanner with a custom-made external coil to obtain ductal details of the prostate, high-quality spectra, and metabolite mapping corresponding to prostate zonal anatomy in healthy volunteers. MATERIALS AND METHODS: MRI and two-dimensional (2D) chemical shift imaging (CSI) were performed in 16 healthy volunteers using a 3T scanner with a custom-made external transmit-receive (transceive) coil. Visualization of the prostatic duct-like structure was analyzed on T2-weighted (T2W) images. The resolution of the metabolite peaks and the distribution of metabolites in CSI were also assessed. RESULTS: In the axial plane, 3-mm-thick images were better than 4-mm-thick images with the same voxel volume for assessing duct-like structures and prostatic urethra. Differentiation between inner and outer citrate (Cit) peaks was frequently observed (29 out of 30). The mean peak area ratio of choline (Cho) plus creatine (Cr) over Cit in the peripheral zone (PZ) was significantly lower than in the transition zone (TZ) (P = 0.014). CONCLUSION: 3T MR examinations of the prostate using an external coil allow information to be collected about the details of duct-like structures, the high-quality spectra of Cit, and the zone-specific distribution of metabolites.

Delayed gadolinium-enhanced MR to determine glycosaminoglycan concentration in reparative cartilage after autologous chondrocyte implantation: preliminary results.

PURPOSE: To prospectively evaluate delayed gadolinium-enhanced magnetic resonance (MR) imaging of cartilage for assessment of glycosaminoglycan (GAG) concentration in reparative cartilage after autologous chondrocyte implantation (ACI). MATERIALS AND METHODS: The study was approved by the ethics review committee of the National Institute of Radiological Sciences, and informed consent was obtained from all patients. The study group comprised nine knees of nine patients (six male, three female; mean age at ACI, 21.2 years +/- 7.5 [standard deviation]; age range, 13-35 years) who had undergone ACI and second-look arthroscopy with biopsy. MR imaging was performed at 1.5 T before and after intravenous injection of anionic gadopentetate dimeglumine. The precontrast R1 (R1(pre)), postcontrast R1 (R1(post)), and difference between R1(pre) and R1(post) (DeltaR1) were measured in reparative cartilage and normal cartilage. GAG concentrations in cartilage biopsy specimens were measured by using high-performance liquid chromatography. To evaluate delayed gadolinium-enhanced MR imaging of cartilage for assessment of GAG concentration, the authors defined the relative R1(pre), relative R1(post), and relative DeltaR1 (ie, R1(pre), R1(post), or DeltaR1, respectively, in reparative cartilage divided by that in normal cartilage) and the relative GAG concentration (ie, GAG concentration in reparative cartilage divided by that in normal cartilage). They then examined the relationships between relative R1(pre), relative R1(post), relative DeltaR1, and relative GAG by using correlation analysis. RESULTS: A significant correlation between relative DeltaR1 and relative GAG concentration (r = 0.818, P < .05) was observed. However, no significant correlation between relative R1(pre) and relative GAG concentration (r = 0.010, P = .983) or between relative R1(post) and relative GAG concentration (r = 0.660, P = .106) was observed. CONCLUSION: Study results indicate that pre- and postcontrast imaging is necessary for delayed gadolinium-enhanced MR imaging evaluation of reparative cartilage after ACI.

Optimizing T2-weighted magnetic resonance sequences for surface coil microimaging of the eye with regard to lid, eyeball and head moving artifacts.

PURPOSE: To acquire high-resolution magnetic resonance (MR) images, we developed a new blinking artifact reduced pulse (BARP) sequence with a surface coil specialized for microscopic imaging (47 mm in diameter). MATERIALS AND METHODS: To reduce eye movement, we ascertained that the subjects' eyes were kept open and fixated to the target in the 1.5-T MR gantry. To reduce motion artifacts from blinking, we inserted rest periods for blinking (1.5 s within every 5 s) during MR scanning (T2-weighted fast spin echo; repetition time, 5 s; echo time, 100 ms; echo train, 11; matrix, 256 x 128; field of view, 5 cm; 1-mm thickness x 30 slices). Three scans (100 s x 3) were performed for each normal subject, and they were added together after automatic adjustment for location to reduce quality loss caused by head motion. RESULTS: T2-weighted MR images were acquired with a high resolution and a high signal-to-noise ratio. Motion artifacts were reduced with BARP, as compared with those with random blinking. Intraocular structures such as the iris and ciliary muscles were clearly visualized. Because the whole eye can be covered with a 1-mm thickness by this method, three-dimensional maps can easily be generated from the obtained images. CONCLUSION: The application of BARP with a surface coil of the human eye might become a useful and widely adopted procedure for MR microimaging.

Time course evaluation of reparative cartilage with MR imaging after autologous chondrocyte implantation.

The aim of this study was to evaluate the qualitative change in reparative cartilage after autologous chondrocyte implantation (ACI). Ten knees of 10 patients were studied. The signal intensities of reparative and normal cartilage were evaluated by fat-suppressed three-dimensional spoiled-gradient recalled (FS 3D-SPGR) MR imaging. The signal intensity (SI) index (signal intensity of reparative cartilage divided by that of normal cartilage) was defined and the change in SI index was investigated. Histological and biochemical evaluation was done at the second look arthroscopy. The SI index was at its lowest level immediately after ACI and increased with time to 9 months thereafter. After 9-12 months, the SI index settled to almost level and was maintained at that value for at least 2-3 years postoperatively. The average of the SI indexes after 12 months to the last examination was 74.2 +/- 4.6 (range 64.2-82.8), which means signal intensity of reparative cartilage was maintained at a value lower than that of normal cartilage. The total ICRS score was 11.6 +/- 2.3 points (mean +/- SD). The GAG concentration was 107.9 +/- 17.0 microg/mg (mean +/- SD) in normal cartilage and 65.9 +/- 9.4 microg/mg in reparative cartilage. The quality of reparative cartilage as hyaline cartilage was inferior to that of normal cartilage. In the present study, the time course change in the SI index indicates that the major maturation process of implanted chondrocytes neared completion in 9-12 months. Minor changes, such as matrix remodeling with reorganization of the collagen fibers in reparative cartilage, may continue, but an almost identical condition seemed to be maintained during the first 2-3 years of follow-up. SI index does not always reflect all properties of reparative cartilage but may be a useful parameter for noninvasive evaluation.

Development of a dielectric equivalent gel for better impedance matching for human skin.

It would be useful to develop a tissue equivalent gel to improve the uniformity of the electromagnetic field in the human body, and for making a tissue equivalent dielectric human phantom. In this study, solid type, water based gelatin-honey gels were developed which have the electrical characteristics of skin tissue. It was demonstrated that a stable and homogeneous gel, with a relative dielectric constant epsilon ' chosen from desired ranges found in skin, can be made for 200-400 MHz.