[Usefulness of Voxel-Based Quantification (VBQ) Smoothing in Relaxation Time Mapping].

Purpose: Voxel-based quantification (VBQ) smoothing is a technique used to smooth quantitative parametric maps in the Montreal Neurological Institute standard space. Although VBQ smoothing could suppress changes in quantitative values at tissue boundaries, its effectiveness on relaxation time (T and T values and proton density PD) maps has not been investigated. The purpose of this study was to clarify the usefulness of VBQ smoothing in relaxation time mapping.

[Evaluation of the Accuracy of Relaxation Time Measurements Using 3D-QALAS at 3.0 T MRI and Comparison with 2D-MDME].

Purpose: Three-dimensional (3D) quantification using an interleaved Look-Locker acquisition sequence with a T preparation pulse (QALAS) is a quantitative sequence used to measure relaxation times. The accuracy of the relaxation time measurement of 3D-QALAS at 3.0 T and the bias of 3D-QALAS have not yet been assessed.

A Preliminary Pathological Evaluation of Extracellular Volume Fraction with Contrast-enhanced Computed Tomography as a Novel Quantitative Parameter of Pancreatic Fibrosis.

Objective The extracellular volume (ECV) calculated based on contrast-enhanced computed tomography (CT) has been reported as a novel imaging parameter reflecting the morphological change of fibrosis in several parenchymal organs. Our retrospective study assessed the validity of the ECV fraction for diagnosing pancreatic fibrosis and the appropriate imaging condition as the "equilibrium phase". Methods In 27 patients undergoing multiphasic CT and subsequent pancreaticoduodenectomy, we investigated pathological fibrotic changes related to the ECV fraction and conducted analyses using the value obtained by subtracting the equilibrium CT value of the portal vein from that of the abdominal aorta (Ao-PV) to estimate eligibility of the equilibrium phase.

Novel Mathematical Diagnostic Analysis of Malignant Biliary Stenosis Using Magnetic Resonance Cholangiography in Patients Undergoing Pancreaticoduodenectomy.

Background/aim: A novel mathematical diagnostic analysis using Fourier transform (FT) algorithm of the extrahepatic bile duct (BD) using magnetic resonance-cholangiography (MRC) was performed to evaluate irregularities of the bile duct lumen indicating BD cancer (BDC) extension compared to pancreatic head malignancies controls.

Patients And Methods: BD lumen was automatically traced, and a 2D-diagram cross-section was measured and a FT-based integrated-power-spectral-density-function value (FTV) of both diameter and area (mm  and mm /Hz) was calculated for cancerous and non-cancerous parts utilizing a computer workstation.

Results: FT analysis that was achieved in 59 patients consisted of BDC in 31, pancreatic cancer with biliary stenosis (PC) in 10 and pancreatic neoplasm without stenosis (PN) in 18.

[Prediction of the Incomplete Region of Fat Suppression Using the Banding Artifact of the Balanced Steady-state Free Precession Sequence].

When the fat-suppression technique was used in the MRI examinations of neck and extremities, incomplete regions of fat suppression were depicted frequently. These incomplete regions were caused by the non-uniform static magnetic field (B). On the other hand, a non-uniform B caused banding artifacts using a balanced steady-state free precession (bSSFP) sequence.

A 3D Quantitative MRC Modeling Images Detected Case of Intrahepatic Biliary Stricture Diseases.

In the future, the application of quantitative imaging and computational analysis will reduce the burden on radiologists. We herein report 8 pilot cases both with and without intrahepatic biliary stricture (IHBS) diseases which have been analyzed with the novel analytical system MRCP+ (Perspectum Ltd., Oxford, UK).

Novel analysis using magnetic resonance cholangiography for patients with pancreaticobiliary maljunction.

Purpose: We used a novel diagnostic Fourier transform (FT) algorithm of the entire extrahepatic bile duct (EHBD) measured by magnetic resonance cholangiography (MRC) to evaluate subtle deformation of bile duct lumen, indicating the malignant potential of EHBD, in patients with pancreaticobiliary maljunction (PBMJ) and in a comparative group of controls without PBMJ.

Methods: From the workstation, the EHBD lumen was traced automatically and a 2D diagram cross section was measured at 0.5 mm-longitudinal intervals.

Low putamen activity associated with poor reward sensitivity in childhood chronic fatigue syndrome.

Motivational signals influence a wide variety of cognitive processes and components of behavioral performance. Cognitive dysfunction in patients with childhood chronic fatigue syndrome (CCFS) may be closely associated with a low motivation to learn induced by impaired neural reward processing. However, the extent to which reward processing is impaired in CCFS patients is unclear.

Intracranial dural arteriovenous fistulas: evaluation with 3-T four-dimensional MR angiography using arterial spin labeling.

Purpose: To evaluate whether 3-T four-dimensional (4D) arterial spin-labeling (ASL)-based magnetic resonance (MR) angiography is useful for the evaluation of shunt lesions in patients with intracranial dural arteriovenous fistulas (AVFs).

Materials And Methods: Institutional review board approval and prior written informed consent from all patients were obtained. Nine patients with intracranial dural AVF (seven men, two women; age range, 52-77 years; mean age, 63 years) underwent 4D ASL MR angiography at 3 T and digital subtraction angiography (DSA).

Osmotic release oral system-methylphenidate improves neural activity during low reward processing in children and adolescents with attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is neurobehavioral disorder characterized by inattention, hyperactivity/impulsivity and impaired reward system function, such as delay aversion and low reward sensitivity. The pharmacological treatment for ADHD includes methylphenidate (MPH), or osmotic release oral system-MPH (OROS-MPH), which increases extrasynaptic dopamine and noradrenaline levels by blocking their reuptake. Although previous functional magnetic resonance imaging (fMRI) studies revealed that acute treatment with MPH alters activation of the nucleus accumbens during delay aversion in children and adolescents with ADHD, the effects a relatively long period of OROS-MPH treatment on delay aversion as well as reward sensitivity remain unclear.

[Abbreviations of special terms for presentation/paper titles in magnetic resonance study].

Purpose: A large number of abbreviations have been created for various special terms, and used in magnetic resonance (MR) study. However, the use of these abbreviations in the paper title has been restricted by the majority of societies and journals. In this study, we investigated the use of various abbreviations for special terms in MR study in order to clarify which abbreviation could be used in the paper title without spelling.

Comparison of 3D phase-sensitive inversion-recovery and 2D inversion-recovery MRI at 3.0 T for the assessment of late gadolinium enhancement in patients with hypertrophic cardiomyopathy.

Rationale And Objectives: To compare free-breathing three-dimensional (3D) phase-sensitive inversion recovery (PSIR) with breath-holding two-dimensional (2D) IR sequences to determine which is better for detecting and characterizing myocardial late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients.

Materials And Methods: Thirty HCM patients clinically underwent 3.0 T cardiac magnetic resonance imaging that included 3D-PSIR and 2D-IR.

[Development of the computerized scheme for reconstructing three dimensional ultrasonography from the conventional two dimensional dynamic images].

In this study, a computerized scheme for reconstructing three dimension (3D)-ultrasonography (US) of a breast mass using off-line B-mode two dimension (2D) dynamic US images obtained by conventional 2D equipment was developed. Two off-line 2D dynamic US images were obtained with two orthogonal directions for each mass. The z axis of reconstructed 3D-US of a breast mass was estimated by using a length of the mass on the orthogonal image.

Signal intensity of lanthanum carbonate on magnetic resonance images: phantom study.

Purpose: Lanthanum carbonate (LC) is used to treat hyperphosphatemia. The purpose of this study was to investigate the signal intensity (SI) of LC on magnetic resonance imaging (MRI) scans of phantoms.

Materials And Methods: LC tablets were thoroughly ground and mixed with distilled water or edible agar (0.

Enhancement effects of hepatic dynamic MR imaging at 3.0 T and 1.5 T using gadoxetic acid in a phantom study: comparison with gadopentetate dimeglumine.

To identify the optimum sequence at gadoxetic acid enhanced hepatic dynamic magnetic resonance imaging in the arterial phase, we studied phantoms that contained gadoxetic acid or gadopentetate dimeglumine diluted in human blood. We obtained magnetic resonance images at 3.0 T and 1.

[Investigation of T2* map measurement sequence in the liver at 3.0T MR].

T2* value measurement of the liver parenchyma with a 3.0T MR scanner may be useful for evaluating focal liver function. Currently, there are 2 sequences for measurement of T2* value of the liver: multi-echo fast field echo (mFFE), and multi-echo planar imaging (EPI).

Detection of hemorrhagic hypointense foci in the brain on susceptibility-weighted imaging clinical and phantom studies.

Rationale And Objectives: To determine the sensitivity of susceptibility-weighted imaging (SWI) for depicting hemorrhagic hypointense foci of the brain in comparison with gradient-recalled echo (GRE)- and GRE-type single-shot echo-planar imaging (GREI, GRE-EPI), and to assess the basic characteristics of the susceptibility effect by using a phantom.

Materials And Methods: We prospectively examined 16 patients (9 males, 7 females, aged 10-74 years, mean 43 years) with hypointense foci using SWI, GREI, and GRE-EPI at a 1.5-T magnetic resonance (MR) unit.

Pulmonary nodules at chest CT: effect of computer-aided diagnosis on radiologists' detection performance.

Purpose: To evaluate the effect of computer-aided diagnosis (CAD) on radiologists' detection of pulmonary nodules.

Materials And Methods: Fifty chest computed tomographic (CT) examination cases were used. The mean nodule size was 0.

[Dosimetry study using an anthropomorphic head phantom for stereotactic radiosurgery].

A dosimetry study using an anthropomorphic head phantom (Radiosurgery Verification Phantom (RSVP)) and a micro-ionization chamber for stereotactic radiosurgery was performed. To study the characteristics of the micro-ionization chamber, tissue maximum ratios (TMRs), off-axis ratios (OARs) and output factors were measured and compared, using a Si semiconductor detector and the film method. The directional difference in sensitivity and the effect of the polarity of the micro-ionization chamber were measured.