Oral formulation of bendamustine hydrochloride for patients with advanced solid tumors; a phase 1 study.

To determine the maximum tolerated dose (MTD) and recommended dose (RD) of orally-administered bendamustine in Japanese patients with advanced solid tumors. The optimal dosing schedule, safety, pharmacokinetics, and preliminary antitumor effects were also evaluated. A multicenter, open-label trial with a standard 3 + 3 design and dose escalation by dose-limiting toxicity (DLT) was conducted. The treatment schedules were once daily for 7, 14, and 21 days every 3 weeks as one cycle. The total dose per cycle was increased from 175 to 840 mg/m2. Eighteen patients were enrolled in this study. DLT occurred in one of six patients at 75 mg/m2/day × 7 days, and one of three patients at 37.5 mg/m2/day × 14 days and 25 mg/m2/day × 21 days. However, the delayed recovery from a decrease in neutrophil or platelet count hampered the start of subsequent treatment cycles, and the trend was more prominent at 37.5 mg/m2/day × 14 days and 25 mg/m2/day × 21 days than in 75 mg/m2/day × 7 days. MTD was determined as 75 mg/m2/day × 7 days to allow acceptable hematologic recovery. The pharmacokinetics of orally-administered bendamustine were generally dose-dependent; however, the inter-individual variability is relatively large. The major adverse events were hematologic toxicities; gastrointestinal disorders were generally mild. Adverse drug reactions did not lead to the discontinuation of the drug. A partial response was observed in two of six patients (prostatic small cell carcinoma and thymic carcinoma) at 75 mg/m2/day × 7 days. The RD and optimal dosing schedule of orally-administered bendamustine was 75 mg/m2 once daily for 7 days every 3 weeks for the treatment of advanced solid tumors. (Trial registration number ClinicalTrials.gov NCT03604679. Registration date July 27, 2018).

Neural basis of visual perception and reasoning ability in Alzheimer's disease: correlation between Raven's Colored Progressive Matrices test and 123 I-IMP SPECT imaging results.

OBJECTIVE: Impairment of visual perception frequently occurs in Alzheimer's disease (AD) and can cause severe constraints in daily activities. The nonverbal Raven's Colored Progressive Matrices (RCPM) test consists of sets A, AB, and B and is easily performed in a short time to evaluate both visual perception and reasoning ability. The purpose of this study was to evaluate the neural basis of visual perception and reasoning ability in patients with AD using RCPM and single-photon emission computed tomography (SPECT). METHODS: Fifty patients who fulfilled the National Institute on Aging/Alzheimer's Association criteria for probable AD dementia were examined with RCPM and SPECT. All SPECTs were performed using N-isopropyl-p-[123 I]-iodoamphetamine. A multiple regression model was used to perform multivariate analyses of the relationships between regional cerebral blood flow (rCBF) and RCPM scores. RESULTS: There was a significant positive correlation between RCPM total score and rCBF in the inferior parietal lobes bilaterally, the right inferior temporal gyrus, and the right middle frontal gyrus. Set A was positively correlated with rCBF in the right temporal and right parietal lobes. Set AB was positively correlated with rCBF in the right temporal, right parietal, and right frontal lobes. Set B was positively correlated with rCBF in the right parietal and right frontal lobes. CONCLUSION: Our findings suggest that deteriorations of specific brain regions are associated with dysfunction of visual perception and reasoning ability in AD. RCPM is another informative assessment scale of cognition for use in patients with AD. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluation of serial changes on computed tomography and magnetic resonance imaging after implantation of carmustine wafers in patients with malignant gliomas for differential diagnosis of tumor recurrence.

Carmustine wafers are approved for localized treatment of malignant glioma. In this study, overall changes in computed tomography (CT) and magnetic resonance (MR) images of malignant glioma patients treated with carmustine wafer implantation were evaluated. The subjects were 25 patients undergoing craniotomy for malignant glioma resection and carmustine wafer implantation. Changes in the appearance of wafers, the resection cavity, and the adjacent parenchyma on CT and MR imaging were evaluated retrospectively. On CT, the wafers changed from an initially high-dense to an iso-dense appearance. All MR studies showed a low-intense wafer within 2 days. The wafers changed to a high- or iso-intense appearance on fluid attenuated inversion recovery and T1-weighted imaging, whereas they changed to an iso- to low-intense appearance on T2-weighted imaging. Gas in the cavity increased gradually after surgery, achieved a peak at 1 week postoperatively, and then disappeared in 1-3 months. Increased volume of the resection cavity was observed in 48% of patients. Regarding changes in the adjacent parenchyma, obvious contrast enhancement at the wall of the resection cavity was seen in 91% of cases at 1 month, but this disappeared gradually. Edema around the resection cavity was increased in 7 patients (28%), of whom only two experienced symptoms due to edema. We conclude that these radiological changes after carmustine wafer implantation should be carefully followed up, because these changes can easily be mistaken for infectious disease or recurrent tumors.

Radiological features of cerebellar glioblastoma.

BACKGROUND AND PROPOSE: Glioblastoma (GBM) is the most common type of malignant primary central nervous system tumor in adults; however, the prevalence of GBM arising in the cerebellum is extremely low. This study aimed to demonstrate the radiological features of cerebellar GBMs, including computed tomography (CT), magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and (18)F-fluorodeoxyglucose (FDG)- and (11)C methionine (MET)-positron emission tomography (PET) findings. MATERIALS AND METHODS: We retrospectively reviewed seven patients with cerebellar GBM (six men and one woman: mean age: 56 years, range: 18-73 years). We reviewed medical records and radiological data, including preoperative CT, MRI and PET. All patients underwent CT and MRI. DWI data were acquired in four patients. Three patients underwent FDG- and MET-PET examinations. All patients underwent total or subtotal tumor resection and received pathological diagnoses. RESULTS: Four patients had imaging findings consistent with GBM and received preoperative cerebellar GBM diagnoses. Two patients exhibited homogeneous patchy and nodular enhancement without necrosis on MRI, which resembled malignant lymphoma and metastasis. One case exhibited Lhermitte-Duclos disease-like parallel linear striations (i.e.,"tiger-striped" appearance). Although the imaging findings of these three patients were inconsistent with GBM, pathological diagnosis confirmed cerebellar GMB. CONCLUSIONS: Some evaluated cases of cerebellar GBM did not exhibit the common CT, MRI, and PET findings of supratentrial GBM, leading to considerable difficulty with preoperative differential diagnosis.

Relationship between regional cerebral blood flow and neuropsychiatric symptoms in dementia with Lewy bodies.

OBJECTIVE: This aim of this study was to examine the mechanisms underlying the neuropsychiatric symptoms in dementia with Lewy bodies by investigating regional cerebral blood flow. METHODS: Participants were 27 patients who fulfilled the diagnostic criteria for probable dementia with Lewy bodies. All subjects underwent single-photon emission computed tomography scans using technetium-99 m hexamethylpropyleneamine oxime. Neuropsychiatric symptoms were evaluated by neuropsychiatric inventory. Multiple regression analyses using neuropsychiatric inventory and voxel-based analyses of covariance of the regional cerebral blood flow images between subjects with or without each neuropsychiatric symptom were performed. Additionally, similar voxel-based analyses of covariance between subjects with each neuropsychiatric symptom and normal subjects were performed. RESULTS: There were no significant correlations in any psychiatric symptoms in multiple regression analyses. All subjects had hallucination but none had euphoria. We analyzed eight neuropsychiatric symptom scores with the exception of hallucination and euphoria using voxel-based analyses of covariance. Significant differences of regional cerebral blood flow were shown in groups with agitation, disinhibition, and irritability. Subjects with agitation showed hypoperfusion in the parietal lobule, the precuneus, and the angular gyrus, and hyperperfusion in the fusiform gyrus, the lingual gyrus, and the thalamus. Subjects with disinhibition showed hypoperfusion in the left frontal gyrus. Subjects with irritability showed hyperperfusion in the right frontal gyrus. There were no significant differences in regional cerebral blood flow between subjects with any neuropsychiatric symptoms and normal subjects. CONCLUSION: This study reveals that dysfunction of specific brain regions is associated with various neuropsychiatric symptoms in dementia with Lewy bodies.

Surgical results of tumor resection using tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials for preservation of motor function in patients with glioblastomas near the pyramidal tracts.

The current optimal surgery for glioblastomas (GBMs) near the pyramidal tract (PT) is to remove as much tumor as possible and to preserve motor function. The purpose of this study is to investigate the usefulness of tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials (MEPs) for preserving postoperative motor function after GBM surgery. We retrospectively examined 49 patients who underwent resection for GBM near the PT. Diffusion tensor (DT) imaging-based tractography of the PT was performed preoperatively and integrated into the navigation system. When possible, silicon catheters were used as "fence-posts" and were inserted along the tumor boundaries, avoiding the PT, before tumor removal using the navigation system (fence-post catheter techniques). Cortical and subcortical MEPs were also monitored during resection of the tumor. Fence-post catheter techniques using a tractography-integrated navigation system were used in 45 of 49 patients. This technique enabled placement of the catheters, avoided the motor pathways, and allowed easier resection of the tumors. Tumors near the PT were resected using subcortical and cortical MEPs. The amplitudes of cortical MEPs after tumor removal were maintained at over 33 % of those obtained before resection. Thirty-six patients showed obvious responses of subcortical MEPs at ≤20 mA. The degree of resection was gross total in 21 patients, subtotal in 21, and partial in seven. One month after surgery, only one patient showed worsened motor function. Therefore, fence-post catheter techniques using a tractography-integrated navigation system and MEPs may contribute to preserving motor function after surgery for GBMs that are near the PT.

Diagnosis of unruptured intracranial aneurysms: 3T MR angiography versus 64-channel multi-detector row CT angiography.

BACKGROUND AND PURPOSE: We compared 3-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) using a 3-tesla (T) MR unit with 64-channel multi-detector row computed tomographic angiography (64-MDCTA) for detection and characterization of angiographically proven unruptured intracranial aneurysms. METHODS: Thirty-eight patients with 47 aneurysms and 8 patients without aneurysms underwent 3T, 3D TOF MRA; 64-MDCTA; and intra-arterial angiography. As a first study, 3 radiologists blinded to pertinent clinical information independently reviewed MRA and CTA images. We evaluated diagnostic accuracy using an alternative free-response receiver operating characteristic (AFROC) analysis and evaluated the sensitivity and specificity of each technique. Next, 2 radiologists used volume-rendering images generated from MRA or CTA data to evaluate the morphology of the 47 aneurysms detected, and MRA and CTA results were compared. Three-dimensional digital angiography (DA) images were used as the standard of reference. RESULTS: On the AFROC analysis, the value of the mean area under the AFROC curve (A(1)) was 0.91 for both modalities. Mean sensitivity of 89% and specificity of 76% for MRA were not significantly different from sensitivity of 87% and specificity of 79% for CTA. Therefore, when used to evaluate aneurysmal morphology, both modalities appear satisfactory for determining these vascular anomalies. CONCLUSION: Three-tesla, 3D TOF MRA and 64-MDCTA are excellent modalities with high diagnostic accuracy for evaluating unruptured intracranial aneurysms and no significant difference between them in diagnostic performance.

Evaluation of tumor blood flow in musculoskeletal lesions: dynamic contrast-enhanced MR imaging and its possibility when monitoring the response to preoperative chemotherapy-work in progress.

PURPOSE: The objective of this study was to calculate tumor blood flow (TBF) in musculoskeletal lesions and to evaluate the usefulness of this parameter in differentiating malignant from benign lesions and monitoring the treatment response to preoperative chemotherapy. MATERIALS AND METHODS: Altogether, 33 patients with musculoskeletal lesions underwent a total of 50 dynamic magnetic resonance imaging (MRI) examinations, including 28 on 9 patients undergoing preoperative chemotherapy. TBF was calculated using deconvolution analysis. Steepest slope (SS) was determined from the time-intensity curve during the first pass of contrast medium. RESULTS: TBF ranged from 2.7 to 178.6 mL/100 mL/min in benign lesions and from 15.4 to 296.3 mL/100 mL/min in malignant lesions. SS ranged from 0.5%/s to 31.8%/s for benign lesions and from 3.1%/s to 64.8%/sec for malignant lesions. TBF and SS did not differ significantly between benign and malignant lesions. Among the nine patients who underwent preoperative chemotherapy, TBF after chemotherapy was lower in good responders (11.7, 11.0, 7.9 mL/100 mL/min) (n = 3, tumor necrosis > or =90%) than in poor responders (23.4-141.5 mL/100 mL/min) (n = 6, tumor necrosis <90%). CONCLUSION: TBF and SS cannot reliably differentiate malignant from benign lesions. However, they have potential utility in evaluating the preoperative treatment response in patients with malignant musculoskeletal tumors.

Comparison of breast cancer detection by diffusion-weighted magnetic resonance imaging and mammography.

PURPOSE: Breast cancer-detecting ability of diffusion-weighted magnetic resonance imaging (DW-MRI) was investigated by comparing the breast cancer detection rates of DW-MRI and mammography (MMG). MATERIALS AND METHODS: The subjects were 48 women who had breast cancer (53 cancer lesions) who underwent DW-MRI before surgery. Altogether, 41 lesions were invasive ductal carcinoma (IDC), 7 were noninvasive ductal carcinoma (NIDC) and 5 were "others." RESULTS: The breast cancer detection rates by MMG and DW-MRI were 84.9% and 94.3% (P < 0.001), respectively. In each classification of histology and size, the detection rate by DW-MRI was higher than that by MMG. In relation to the mammary gland density, the detection rates of fatty, scattered, heterogeneously dense, and extremely dense mammary glands were 100%, 100%, 92.0%, and 83.3%, respectively. The mean apparent diffusion coefficient values of the histologic types were 1.07 +/- 0.17 x 10(-3), 1.50 +/- 0.24 x 10(-3), 1.12 +/- 0.25 x 10(-3), and 2.01 +/- 0.29 x 10(-3) mm(2)/s for IDC, NIDC, others, and normal breast, respectively, showing that the values of IDC and NIDC were significantly different from that of the normal breast (P < 0.001 each). A significant difference was also noted between IDC and NIDC (P < 0.001). CONCLUSION: DW-MRI may be useful for detecting breast cancer in a wide age group of women, including young women with dense mammary glands.

Sensitivity of an eight-element phased array coil in 3 Tesla MR imaging: a basic analysis.

PURPOSE: To evaluate the performance advantages of an 8-element phased array head coil (8 ch coil) over a conventional quadrature-type birdcage head coil (QD coil) with regard to the signal-to-noise ratio (SNR) and image uniformity in 3 Tesla magnetic resonance (MR) imaging. MATERIALS AND METHODS: We scanned a phantom filled with silicon oil using an 8 ch coil and a QD coil in a 3T MR imaging system and compared the SNR and image uniformity obtained from T(1)-weighted spin echo (SE) images and T(2)-weighted fast SE images between the 2 coils. We also visually evaluated images from 4 healthy volunteers. RESULTS: The SNR with the 8 ch coil was approximately twice that with the QD coil in the region of interest (ROI), which was set as 75% of the area in the center of the phantom images. With regard to the spatial variation of sensitivity, the SNR with the 8 ch coil was lower at the center of the images than at the periphery, whereas the SNR with the QD coil exhibited an inverse pattern. At the center of the images with the 8 ch coil, the SNR was somewhat lower, and that distribution was relatively flat compared to that in the periphery. Image uniformity varied less with the 8 ch coil than with the QD coil on both imaging sequences. CONCLUSION: The 8 ch phased array coil was useful for obtaining high quality 3T images because of its higher SNR and improved image uniformity than those obtained with conventional quadrature-type birdcage head coil.

[Magnetic resonance imaging could predict delayed encephalopathy after acute carbon monoxide intoxication].

OBJECTIVES: Some patients with acute carbon monoxide (CO) intoxication relapse into severe neuropsychiatric symptomes several weeks after the lucid interval. This serious neurological sequelae, delayed encephalopathy, is difficult to anticipate. Although magnetic resonance imaging (MRI) was reported to show characteristic findings, there has been few information on MRI during the lucid interval. We retrospectively reviewed MR images obtained within 15 days after the exposure, and analyzed whether MRI could predict delayed encephalopathy. DESIGN: Retrospective, single-center study. PATIENTS: Sixteen serial patients with severe CO intoxication, who were found unconscious and underwent hyperbaric oxygen therapy, and in whom MR-imagings were performed at least once within 15 days after the exposure. MEASUREMENTS AND MAIN RESULTS: Although all 16 patients recovered consciouness, six of them (37.5 %) went into delayed encephalopathy (DE group) while the others did not (non-DE group). FLAIR images of all patients in DE group showed bilateral diffuse high intensity in white matter of centrum semiovale after the relapse of neuropsychiatric symptomes. In 4 of them, the identical findings were recognized earlier during the lucid interval. In contrast, no MR images of patients in non-DE group showed white matter hyperintensity (4/6 vs 0/10, p < 0.01). T2-hyperintensities in basal ganglia were seen not only in DE group (3 of 6 patients) but also in non-DE group (2 of 10). Diffusion-weighted images (DWI) were obtained in 10 patients (5 in each group). Although white matter hyperintensities in DWI were positive in 4 patients in DE group (none in non-DE group), 3 of them showed negative findings during the lucid interval. CONCLUSIONS: Bilateral symmetric white matter hyperintensity in MRI (T2WI/FLAIR) could be a good predictor of delayed encephalopathy after acute CO intoxication.

Time related changes in reversible MRI findings after prolonged hypoglycemia.

Diffusion weighted magnetic resonance images (DWI) in hypoglycemic coma show more definite and earlier findings than do T1-weighted images, or even fluid-attenuated inversion recovery (FLAIR). However, there has been limited information on the time related changes of such MRI images. We report here the time related changes of MRI findings after prolonged hypoglycemia in a diabetic 62-year-old man without hypoxia. We found in the patient that hyperintensities in DWI, T2-weighted and FLAIR images disappeared on the 14th day along with normalization of the apparent diffusion coefficient (ADC). Single photon emission computed tomography (SPECT) showed no low perfusion findings throughout the course. Since the day when the hyperintensities disappeared, the patient became to open his eyes in response to verbal command. This paper demonstrates serial alterations in reversible DWI findings after prolonged hypoglycemia and we need to define its mechanisms in the future.

Extraskeletal osteosarcoma in the thigh: a case report.

Extraskeletal osteosarcoma is a rare malignant soft-tissue tumor. There are few reports describing the radiological findings of this tumor, especially concerning its MRI and scintigraphic appearance. We report a 58-year-old man with extraskeletal osteosarcoma in the thigh. Radiographs showed small foci of mineralization in the mass. The tumor showed low intensity on T1-weighted images and predominantly high intensity on T2-weighted images, and the tumor was heterogeneously well enhanced on Gd-DTPA-enhanced T1-weighted images. Bone scintigraphy showed extraskeletal uptake in the tumor, and thallium-201 scintigraphy revealed marked inhomogeneous accumulation.

Usefulness of turbo-fluid-attenuated inversion-reovery (tFLAIR) sequence in diagnosing meningioma.

PURPOSE: We evaluated qualitatively and quantitatively the usefulness of turbo-FLAIR (tFLAIR) in diagnosing meningioma in comparison with the T2-weighted turbo spin echo (T2W-TSE) sequence. MATERIALS AND METHODS: Forty-eight patients diagnosed with meningioma were studied. In the qualitative study, we evaluated tumor delineation, contrast (Co) of tumor-to-CSF (cerebrospinal fluid), Co of tumor-to-brain parenchyma, Co of peripheral edema-to-brain parenchyma, and detectability of tumor margin. In quantitative study-1, using signal intensity (SI), we measured SI and calculated Co-SI of tumor-to-gray matter, Co-SI of tumor-to-white matter, Co-SI of peripheral edema-to-white matter, and Co-SI of tumor-to-CSF. In quantitative study-2, using film density, we measured density (De) on hard-copy film images and calculated Co-De for the same items as in quantitative study-1. RESULTS: In the qualitative study, tFLAIR was superior to T2W-TSE in tumor delineation, Co of tumor-to-CSF, Co of tumor-to-brain parenchyma, and Co of peripheral edema-to-brain parenchyma. In quantitative study-1, tFLAIR was superior to T2W-TSE in Co-SI of tumor-to-CSF, however, T2W-TSE was superior to tFLAIR in Co-SI of tumor-to-white matter. In quantitative study-2, tFLAIR was superior to T2W-TSE in all Co-De. CONCLUSION: tFLAIR was superior to T2W-TSE in the depiction of meningioma.

Remitting seronegative symmetric synovitis with pitting edema: scintigraphic and magnetic resonance imaging findings.

Remitting seronegative symmetric synovitis with pitting edema (RS3PE) was first reported by McCarty et al in 1985 and refers to a rheumatologic set of symptoms with acute onset, with no erosive bone lesions, with seronegative findings, affecting the elderly more frequently, and showing an excellent prognosis with low-dose steroid therapy. Although these characteristics make it possible to differentiate it from rheumatoid arthritis and rheumatic polymyalgia, there have been very few reports on the imaging findings. The authors present scintigraphic and magnetic resonance images in a case of RS3PE.

Evaluation of the tumor-brain interface of intracranial meningiomas on MR imaging including FLAIR images.

PURPOSE: The usefulness of fluid-attenuated inversion recovery (FLAIR) imaging for the evaluation of brain diseases has been reported. The purpose of this study was to evaluate the brain-meningioma interface with MRI including FLAIR imaging. MATERIALS AND METHODS: This study involved 48 patients with 50 intracranial meningiomas. We retrospectively evaluated the brain-meningioma interface by various imaging method including FLAIR. If a thin layer with a signal intensity different from that of the tumor and brain was observed in the areas of the tumor-brain interface in T(1)-weighted IR (T(1)WIR) and T(2)-weighted turbo SE (T(2)WTSE) images, we defined this structure as the rim. The presence or absence of the rim and the signal intensity were evaluated, and the length and the signal intensity of the rim observed with FLAIR and contrast-enhanced T(1)WIR (CE-T(1)WIR) images were evaluated. RESULTS: In 35 of the 50 lesions (70.0%), the rim was observed in the tumor-brain interface as a layer of low signal intensity in T(1)WIR images and high signal intensity in T(2)WTSE images. In 13 lesions (26.0%), no rim was detected. Flow voids were observed at the tumor-brain interface in 20 of the 50 lesions (40.0%). No rim showed a low signal intensity of the tumor-brain interface in both T(1)WIR and T(2)WTSE images. The rim exhibited an iso-to-high signal intensity compared to the tumor parenchyma in FLAIR images and an enhanced signal intensity in CE-T(1)WIR images. In contrast to T(1)WIR images, the rim in FLAIR images tended to be identified across the entire circumference. CONCLUSION: The rim at the brain-meningioma interface revealed as low signal intensity in T(1)WIR images and high signal intensity in T(2)WTSE images, which was conventionally considered to be the CSF cleft, was often revealed in FLAIR images as high signal intensity compared to the tumor parenchyma, and an enhanced signal intensity in CE-T(1)WIR images. Therefore, the presence of CSF in such rims is unlikely, and the rims might reflect the capsule structure of the tumor surface.

Prediction of tumor-brain adhesion in intracranial meningiomas by MR imaging and DSA.

OBJECTIVES: The purpose of this study was to evaluate the usefulness of MRI (magnetic resonance imaging) and DSA (digital subtraction angiography) by using preoperative MRI and DSA findings in the examination of meningiomas before excision. In particular, we focused on their usefulness in predicting tumor-brain adhesion during surgery. MATERIALS AND METHODS: The subjects were 36 patients with intracranial meningioma who underwent tumor excision at which time neurosurgeons examined the tumor-brain adhesion. Two neurosurgeons evaluated the degree of tumor-brain adhesion from operation records and videotapes recorded during surgery. Two neuroradiologists retrospectively evaluated the preoperative MRI findings including tumor diameter, signal intensity of the tumor parenchyma obtained with T(2)-weighted imaging (T(2)WI), characteristics of the tumor-brain interface, and degree of peritumoral brain edema. The vascular supply was also evaluated from the preoperative DSA findings. The relationship between these MRI and DSA findings and the degree of tumor-brain adhesion during surgery as classified by the neurosurgeons was statistically analyzed. RESULTS: The degree of peritumoral brain edema and the shapes and characteristics of the tumor-brain interface, including the findings of FLAIR (fluid-attenuated inversion recovery) imaging and vascular supply observed by DSA, were significantly correlated with tumor-brain adhesion. In particular, the shapes and characteristics of the tumor-brain interface as observed by T(1)-weighted imaging (T(1)WI), T(2)WI, and FLAIR, respectively, as well as the vascular supply observed by DSA, were closely correlated with the degree of tumor-brain adhesion encountered during surgery. According to these results, we developed a method of predicting tumor-brain adhesion that considers the shape of the tumor-brain interface revealed by MRI and the vascular supply revealed by DSA. CONCLUSIONS: We retrospectively examined the findings of MRI and DSA performed before excision of meningioma and clarified the relationship between the findings and tumor-brain adhesion. We speculated that tumor-brain adhesion can be accurately and simply predicted before surgery with a new method that considers the shape of the tumor-brain interface observed by MRI and vascular supply observed by DSA.

Optimization of scan parameters for T1-FLAIR imaging at 1.5 and 3T using computer simulation.

PURPOSE: We attempted to optimize scan parameters for T1-weighted fluid-attenuated inversion recovery (T1-FLAIR) sequence at 3 and 1.5 tesla (T) using computer simulation. METHODS: We measured the T1 and T2 relaxation time values (T1v and T2v) of gray (GM) and white matter (WM) at 3 and 1.5T, generated computer-simulated T1-FLAIR (CS-T1-FLAIR) images using those values, and compared the simulated and actual T1-FLAIR images to verify the contrast reliability of our computer simulation. We mathematically and visually evaluated CS-T1-FLAIR images at various repetition times (TR) and echo times (TE). RESULTS: At 3T, the measured relaxation values for GM were T1v, 1524 ms, and T2v, 85 ms, and for WM, T1v, 750 ms, and T2v, 65 ms. At 1.5T, the measured relaxation values for GM were T1v, 1251 ms, and T2v, 99 ms, and for WM, T1v, 623 ms, and T2v, 75 ms. Contrast of CS-T1-FLAIR and actual T1-FLAIR images was identical. An optimal TR of 3140 ms was determined for T1-FLAIR at 3T and 2440 ms at 1.5T based on mathematical evaluation. The optimal TR ranges were 2400 to 3900 ms at 3T and 1800 to 3200 ms at 1.5T based on visual assessment of CS-T1-FLAIR. A shorter TE provided better T1 contrast. CONCLUSION: We optimized T1-FLAIR by focusing on its most important scan parameters using computer simulations and determined that a longer TR was suitable at 3T than at 1.5T. Our computer simulation was useful for determining the optimal scan parameters.

Whole-body magnetic resonance angiography for presurgical planning of free-flap head and neck reconstruction.

OBJECTIVES: Aim of the study was to evaluate if a whole-body magnetic resonance angiography (MRA) protocol meets the requirements to evaluate the donor and host site target vessels for planning of microvascular head and neck reconstructions. PATIENTS AND METHODS: In 20 patients, scheduled for reconstruction of the mandible with fibular free flaps, contrast-enhanced whole-body MRA was performed prior to surgery. 32-Channel 1.5-T MR angiograms were acquired using a 2-step contrast (gadobutrol) injection scheme to visualize the arterial vasculature from head to feet. Maximum intensity projection and multiplanar reconstruction technique was employed to visualize MRA data. For image evaluation the arterial tree was divided into 51 segments. The presence of artefacts impairing diagnostic quality was noted. Evaluable segments were assessed regarding the presence of stenoses >50% diameter reduction, occlusions or aneurysms. RESULTS: No adverse reactions or complications occurred. Of 1020 vessel segments 1003 (98.3%) were evaluable. 36 stenoses >50%, 50 occlusions and one aneurysm were observed. In 21 of 40 lower limbs relevant atherosclerotic changes were depicted. CONCLUSION: Whole-body MRA proved to be a suitable three-dimensional, noninvasive, nonionising modality for preoperative evaluation of the entire arterial vasculature.

Accuracy of diffusion tensor magnetic resonance imaging-based tractography for surgery of gliomas near the pyramidal tract: a significant correlation between subcortical electrical stimulation and postoperative tractography.

BACKGROUND: Diffusion tensor (DT) imaging-based fiber tracking is a noninvasive magnetic resonance technique that can delineate the course of white matter fibers. OBJECTIVE: To evaluate the accuracy and usefulness of this DT imaging-based fiber tracking for surgery in patients with gliomas near the pyramidal tract (PT). METHODS: Subjects comprised 32 patients with gliomas near the PT. DT imaging-based fiber tracks of the PT were generated before and within 3 days after surgery in all patients. A tractography-integrated navigation system was used during the operation. Cortical and subcortical motor-evoked potentials (MEPs) were also monitored during resection to maximize the preservation of motor function. The threshold intensity for subcortical MEPs was examined by searching the stimulus points and changing the stimulus intensity. Minimum distance between the resection border and the illustrated PT was measured on postoperative tractography. RESULTS: In all subjects, DT imaging-based tractography of the PT was successfully performed, preoperatively demonstrating the relationship between tumors and the PT. With the use of the tractography-integrated navigation system and intraoperative MEPs, motor function was preserved postoperatively in all patients. A significant correlation was seen between threshold intensity for subcortical MEPs and the distance between the resection border and PT on postoperative DT imaging. CONCLUSION: DT imaging-based fiber tracking is a reliable and accurate method for mapping the course of subcortical PTs. Fiber tracking and intraoperative MEPs were useful for preserving motor function in patients with gliomas near the PT.