Publications by authors named "Kuninori Kobayashi"

Purpose: Polarity-corrected inversion time preparation (PCTIP), a myocardial T1 mapping technique, is expected to reduce measurement underestimation in the modified Look-Locker inversion recover method. However, measurement precision is reduced, especially for heart rate variability. We devised an analysis using a recurrence formula to overcome this problem and showed that it improved the measurement accuracy, especially at high heart rates.

View Article and Find Full Text PDF

Purpose: As the lenticulostriate arteries (LSAs) perfuse neurologically important areas, it is necessary to accurately assess the origin and number of the LSAs before surgery. Although three-dimensional time-of-flight MR angiography (3D-TOF MRA) is a non-invasive procedure, it requires high-resolution (HR) images to depict the LSAs with a small diameter. Therefore, we performed 3D-TOF MRA with the maximum HR (HR-MRA) using a 3 T scanner to examine whether a good depiction of the LSAs, equivalent to that of digital subtraction angiography (DSA), could be obtained.

View Article and Find Full Text PDF

We analyzed modified Look-Locker inversion recovery (MOLLI) T1 measurements by applying a dictionary matching strategy and aimed to acquire T1 measurements more accurately than those acquired by the conventional three-parameter matching analysis. We particularly clarified the robustness of this method for measuring heart rate (HR) variability. A phantom experiment using a 3T MRI system was performed for various HRs.

View Article and Find Full Text PDF

With the recent spread of three tesla (3 T) magnetic resonance imaging (MRI), time-spatial labeling inversion pulse (Time-SLIP) technique at high magnetic field can be used. The purpose of this study was to determine appropriate renal artery imaging parameters and to compare with the 1.5 T MRI image quality of a renal artery using the Time-SLIP technique.

View Article and Find Full Text PDF

Background: The total kidney volume (TKV) and total liver volume (TLV) increase and renal function decreases progressively in patients with autosomal dominant polycystic kidney disease (ADPKD). Somatostatin analogues, such as octreotide, reduce these increases in TKV and TLV. The aim of this study was to examine the safety of the short-term administration of octreotide long-acting release (octreotide-LAR) in a small number of cases.

View Article and Find Full Text PDF

Background: The clinical effects of increased water intake on autosomal dominant polycystic kidney disease (ADPKD) progression are unknown.

Methods: ADPKD patients with creatinine clearance ≧ 50 mL/min/1.73 m(2) were divided into high (H-, n = 18) and free (F-, n = 16) water-intake groups, mainly according to their preference.

View Article and Find Full Text PDF

Purpose: To assess the feasibility of a new MR angiography (MRA) technique named hybrid of opposite-contrast MRA (HOP MRA) that combined the time-of-flight (TOF) MRA with a flow-sensitive black-blood (FSBB) sequence in the diagnosis of major trunk stenoocclusive diseases.

Materials And Methods: On a 1.5 Tesla imager using a dual-echo three-dimensional (3D)-gradient-echo sequence, we obtained the first echo for TOF MRA followed by the second echo for FSBB.

View Article and Find Full Text PDF

Unlabelled: The effects of imaging conditions and measures for their improvement were examined with regard to recognition of the effects of contrast on images when T1-weighted imaging with selective fat suppression was applied.

Method: Luminance at the target region was examined before and after contrast imaging using phantoms assuming pre- and post-imaging conditions. A clinical examination was performed on tumors revealed by breast examination, including those surrounded by mammary gland and by fat tissue.

View Article and Find Full Text PDF