Usefulness of pituitary high-resolution 3D MRI with deep-learning-based reconstruction for perioperative evaluation of pituitary adenomas.

Purpose: To evaluate the diagnostic value of T1-weighted 3D fast spin-echo sequence (CUBE) with deep learning-based reconstruction (DLR) for depiction of pituitary adenoma and parasellar regions on contrast-enhanced MRI.

Methods: We evaluated 24 patients with pituitary adenoma or residual tumor using CUBE with and without DLR, 1-mm slice thickness 2D T1WI (1-mm 2D T1WI) with DLR, and 3D spoiled gradient echo sequence (SPGR) as contrast-enhanced MRI. Depiction scores of pituitary adenoma and parasellar regions were assigned by two neuroradiologists, and contrast-to-noise ratio (CNR) was calculated.

Comparisons of Hepatobiliary Phase Imaging Using Combinations of Parallel Imaging and Variable Degrees of Compressed Sensing With Use of Parallel Imaging Alone.

Objective: This study aimed to compare the image quality in the hepatobiliary phase images of gadoxetic acid-enhanced liver magnetic resonance imaging using parallel imaging (PI) and compressed sensing (CS) reconstruction, using variable CS factors with the standard method using the PI technique.

Methods: In this study, 64 patients who underwent gadoxetic acid-enhanced liver magnetic resonance imaging at 3.0 T were enrolled.

Reliability of respiratory-gated real-time two-dimensional cine incorporating deep learning reconstruction for the assessment of ventricular function in an adult population.

This study aimed to assess the image quality and accuracy of respiratory-gated real-time two-dimensional (2D) cine incorporating deep learning reconstruction (DLR) for the quantification of biventricular volumes and function compared with those of the standard reference, that is, breath-hold 2D balanced steady-state free precession (bSSFP) cine, in an adult population. Twenty-four patients (15 men, mean age 50.7 ± 16.

Technical Background for 4D Flow MR Imaging.

Recently, the hemodynamic assessments with 3D cine phase-contrast (PC) MRI (4D flow MRI) have attracted considerable attention from clinicians. Unlike 2D cine PC MRI, the technique allows for cardiac phase-resolved data acquisitions of flow velocity vectors within the entire FOV during a clinically viable period. Thus, the method has enabled retrospective flowmetry in the spatial and temporal axes, which are essential to derive hemodynamic parameters related to vascular homeostasis and those to the progression of the pathologies.

Reconstruction of cardiovascular black-blood T2-weighted image by deep learning algorithm: A comparison with intensity filter.

Background: Deep learning-based methods have been used to denoise magnetic resonance imaging.

Purpose: The purpose of this study was to evaluate a deep learning reconstruction (DL Recon) in cardiovascular black-blood T2-weighted images and compare with intensity filtered images.

Material And Methods: Forty-five DL Recon images were compared with intensity filtered and the original images.

Amide proton transfer imaging in differentiation of type II and type I endometrial carcinoma: a pilot study.

Purpose: This study aimed at evaluating the efficacy of amide proton transfer (APT) imaging in differentiation of type II and type I uterine endometrial carcinoma.

Materials And Methods: Thirty-three patients diagnosed with uterine endometrial carcinoma, including 24 with type I and 9 with type II carcinomas, underwent APT imaging. Two readers evaluated the magnetization transfer ratio at 3.

Reliability of respiratory-triggered two-dimensional cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling for the assessment of biventricular volume and function in patients with repaired tetralogy of Fallot.

Objective: To compare left ventricular (LV) and right ventricular (RV) volume, function, and image quality of a respiratory-triggered two-dimensional (2D)-cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling (2D kat-ARC) with those of the standard reference, namely, breath-hold 2D balanced steady-state free precession (2D SSFP), in patients with repaired tetralogy of Fallot (TOF).

Methods: 30 patients (14 males, mean age 32.2 ± 13.

Abnormal Flow Dynamics Result in Low Wall Shear Stress and High Oscillatory Shear Index in Abdominal Aortic Dilatation: Initial in vivo Assessment with 4D-flow MRI.

Purpose: To characterize the non-laminar flow dynamics and resultant decreased wall shear stress (WSS) and high oscillatory shear index (OSI) of the infrarenal abdominal aortic dilatation, cardiac phase-resolved 3D phase-contrast MRI (4D-flow MRI) was performed.

Methods: The prospective single-arm study was approved by the Institutional Review Board and included 18 subjects (median 67.5 years) with the dilated infrarenal aorta (median diameter 35 mm).

Optimal Plane Selection for Measuring Post-prandial Blood Flow Increase within the Superior Mesenteric Artery: Analysis Using 4D Flow and Computational Fluid Dynamics.

Purpose: 2D cine phase contrast (PC)-MRI is a standard velocimetry for the superior mesenteric artery (SMA); however, the optimal localization of the measurement plane has never been fully discussed previously. The purpose of this Institutional Review Board approved prospective and single arm study is to test whether flow velocimetry of the SMA with combined use of 2D cine PC-MRI and meal challenge is dependent on the localizations of the measurement planes and to seek optimal section for velocimetry.

Methods: Seven healthy volunteers underwent cardiac phase resolved ECG gated 2D cine PC-MRI pre- and 30 min post-meal challenge at three measurement planes: proximal, curved mid section and distal straight section of the SMA at 3T.

Comparison of Silent Navigator Waveform Generation Methods.

The silent navigator technique utilizes a non-selective excitation and an appropriate respiratory waveform generation method is necessary for an accurate motion detection. We compared three methods for silent navigator waveform generation. The profile generation method with coil selection (prof-selection) resulted in a high cross correlation with bellows signals and a large respiration amplitude.

Myocardial T1 values in healthy volunteers measured with saturation method using adaptive recovery times for T1 mapping (SMART1Map) at 1.5 T and 3 T.

Myocardial T1 mapping is clinically valuable for assessing the myocardium, and modified look-locker inversion-recovery (MOLLI) approaches have been commonly used for measuring myocardial T1 values. To date, several other sequences have been developed for measuring myocardial T1 values, and saturation-recovery-based sequences have been shown to be less dependent on various factors, such as T2 times and magnetization transfer, than inversion-recovery techniques. Systematic differences in T1 values between different sequences have been reported; therefore, definition of the normal range of native T1 values is required before clinical usage can begin.

Correction to: Ultrashort time-to-echo quantitative magnetic resonance imaging of the triangular fibrocartilage: differences in position.

The original version of this article, published on 03 September 2018, unfortunately contained a mistake.

Ultrashort time-to-echo quantitative magnetic resonance imaging of the triangular fibrocartilage: differences in position.

Purpose: To compare T2* values of the triangular fibrocartilage (TFC) obtained by ultrashort time-to-echo (UTE) techniques at the neutral position, ulnar flexion of the wrist, and pronation of the forearm.

Materials And Methods: MR imaging was performed in ten healthy volunteers with a 3-T MR system by using an eight-channel knee coil. Coronal wrist T2* maps from three-dimensional cone UTE pulse sequences were obtained at the neutral, ulnar flexion, and pronation positions (TR: 19 ms, TE: 0.

Quantitative estimation of progression of chronic liver disease using gadoxetate disodium-enhanced magnetic resonance imaging.

Aim: The purpose of this study was to determine whether the liver stiffness (LS) measured on magnetic resonance (MR) elastography can be estimated by a combination of gadoxetate disodium-enhanced MR imaging (EOB-MRI) and ordinary blood tests.

Methods: We evaluated 33 consecutive patients with suspected liver disease who underwent EOB-MRI using a Differential Subsampling with Cartesian Ordering MR sequence and MR elastography using a 1.5-T MR system in this prospective study.

Silent navigator-triggered silent MRI of the abdomen.

Purpose: To develop and demonstrate the feasibility of a silent respiratory navigator technique for prospective triggering, which was incorporated into a three-dimensional radial zero-echo-time sequence for respiratory navigated silent abdominal imaging.

Methods: A nonselective hard excitation radiofrequency pulse was used for the navigator sequence with a derated readout gradient, to avoid generation of high levels of acoustic noise. The acquired navigator signals were processed in real time and used for prospective triggering of the zero-echo-time sequence.

Utility of real-time prospective motion correction (PROMO) for segmentation of cerebral cortex on 3D T1-weighted imaging: Voxel-based morphometry analysis for uncooperative patients.

Objective: To assess the utility of the motion correction method with prospective motion correction (PROMO) in a voxel-based morphometry (VBM) analysis for 'uncooperative' patient populations.

Methods: High-resolution 3D T1-weighted imaging both with and without PROMO were performed in 33 uncooperative patients with Parkinson's disease (n = 11) or dementia (n = 22). We compared the grey matter (GM) volumes and cortical thickness between the scans with and without PROMO.

Utility of real-time prospective motion correction (PROMO) on 3D T1-weighted imaging in automated brain structure measurements.

PROspective MOtion correction (PROMO) can prevent motion artefacts. The aim of this study was to determine whether brain structure measurements of motion-corrected images with PROMO were reliable and equivalent to conventional images without motion artefacts. The following T1-weighted images were obtained in healthy subjects: (A) resting scans with and without PROMO and (B) two types of motion scans ("side-to-side" and "nodding" motions) with and without PROMO.

Three-dimensional cardiac cine imaging using the kat ARC acceleration: Initial experience in clinical adult patients at 3T.

Objective: Three-dimensional cardiac cine imaging has demonstrated promising clinical 1.5-Tesla results; however, its application to 3T scanners has been limited because of the higher sensitivity to off-resonance artifacts. The aim of this study was to apply 3D cardiac cine imaging during a single breath hold in clinical patients on a 3T scanner using the kat ARC (k- and adaptive-t auto-calibrating reconstruction for Cartesian sampling) technique and to evaluate the interchangeability between 2D and 3D cine imaging for cardiac functional analysis and detection of abnormalities in regional wall motion.

Multiple-animal MR imaging using a 3T clinical scanner and multi-channel coil for volumetric analysis in a mouse tumor model.

Purpose: Multiple small-animal magnetic resonance (MR) imaging to measure tumor volume may increase the throughput of preclinical cancer research assessing tumor response to novel therapies. We used a clinical scanner and multi-channel coil to evaluate the usefulness of this imaging to assess experimental tumor volume in mice.

Methods: We performed a phantom study to assess 2-dimensional (2D) geometric distortion using 9-cm spherical and 32-cell (8×4 one-cm(2) grids) phantoms using a 3-tesla clinical MR scanner and dedicated multi-channel coil composed of 16 5-cm circular coils.

[Comparison of 3 Tesla whole heart coronary MRA (WHCA) with 1.5 Tesla].

Whole heart coronary MRA (WHCA) is a noninvasive method used to image all coronary arteries with cardiac and real-time respiratory gating. We compared the coronary depiction ability of 3T WHCA with that of 1.5T using healthy volunteers.

Isotropic diffusion-weighted MR imaging with tetrahedral gradients in the upper abdomen.

A tetrahedral gradient diffusion sequence for body imaging for a 1.5T scanner was implemented, and we compared the quality of images acquired with the new technique and with the conventional orthogonal technique. Image quality was better using the tetrahedral technique in terms of signal homogeneity in the right liver lobe and signal loss artifact in the left lobe, and the technique was considered useful for magnetic resonance imaging in the upper abdomen.

Contrast-enhanced three-dimensional MR angiography with an elliptical centric view for the evaluation of intracranial aneurysms.

The purpose of this study was to assess the feasibility of high spatial resolution, selective arterial phase, 3D contrast-enhanced (CE) MR angiography with first pass bolus, software-trigger, elliptical centric view ordering in the detection of intracranial aneurysms. Our study included nine consecutive patients with ten intracranial aneurysms. 3D TOF MR angiography and 3D CE MR angiography were carried out with a 1.

Magnetic resonance cholangiopancreatography: comparison of respiratory-triggered three-dimensional fast-recovery fast spin-echo with parallel imaging technique and breath-hold half-Fourier two-dimensional single-shot fast spin-echo technique.

Purpose: The aim of this study was to compare magnetic resonance cholangiopancreatography (MRCP) using respiratory-triggered (resp) three-dimensional Fourier transformation (3D) fast-recovery fast spin echo (FR-FSE) sequence with array spatial sensitivity technique (ASSET) for visualization of the pancreatobiliary system with breath-hold single thick-section and multiple thin-section MRCP using 2D single shot FSE (SSFSE) sequences.

Materials And Methods: Forty patients underwent MRCP for evaluation of pancreatobiliary abnormalities in a 1.5-T magnet.