Use of landiolol hydrochloride, a new beta-blocker, in coronary computed tomography angiography.

We investigated the usefulness of landiolol hydrochloride, an ultrashort-acting beta(1)-selective agent, for coronary computed tomography angiography (CTA). Intravenous landiolol was administered to 133 patients before coronary CTA. Hemodynamic changes, adverse effects, image quality, and diagnostic accuracy for detection of coronary stenoses were evaluated. HR was significantly reduced during injection, but quickly recovered after cessation of landiolol. Neither significant changes in BP nor adverse effects were seen. The sensitivity, specificity, and positive and negative predictive values of coronary CTA for detection of significant stenoses were excellent, compared with invasive angiography. Therefore, our results show that intravenous landiolol administration gives a favorable image quality and facilitates diagnostic accuracy without causing adverse effects, indicating that landiolol is a useful premedication for coronary CTA.

Optimal starting time of acquisition and feasibility of complementary administration of nitroglycerin with intravenous beta-blocker in multislice computed tomography.

OBJECTIVES: We determined the optimal starting time of acquisition after sublingual nitroglycerin (NTG) administration and evaluated the effects on multislice computed tomographic (MSCT) images of a complementary administration of sublingual NTG with beta-blocker. METHODS: Sixty patients who underwent MSCT coronary angiography (CA) were randomly divided into 2 groups as follows: 30 patients given an intravenous administration of beta-blocker (landiolol hydrochloride, mean dose of 0.032 mg/kg per minute; group B); and 30 patients given a coadministration of intravenous beta-blocker and sublingual NTG (0.3 mg; group N). Blood pressure and heart rate were recorded every 1 minute after NTG administration. In addition, the maximum diameters of the proximal and distal lesions in each coronary artery were measured, and the number of assessable segments was calculated. RESULTS: Blood pressure significantly decreased and heart rate significantly increased 4 minutes after NTG administration. The number of assessable segments was significantly greater in group N than in group B. The maximum diameters of the distal lesions of the left anterior descending and left circumflex arteries and both proximal and distal lesions of the right coronary artery were significantly larger in group N than in group B. CONCLUSIONS: It is advisable to obtain MSCT images after sublingual NTG administration because nitrates are always given during conventional CA and may prevent beta-blocker-induced coronary spasm. The optimal starting time for MSCT CA is approximately 3 minutes after sublingual NTG administration.

Feasibility of intravenous administration of landiolol hydrochloride for multislice computed tomography coronary angiography: initial experience.

BACKGROUND: The feasibility of using landiolol hydrochloride in multislice computed tomography (MSCT) coronary angiography (CAG) was investigated in the present study. METHODS AND RESULTS: Landiolol hydrochloride was continuously administered intravenously to 145 patients before starting MSCT CAG. Hemodynamic changes [blood pressure (BP), heart rate (HR)], adverse effects, image quality using a 5-point scale, and accuracy of detecting significant stenoses (>or=50% reduction in lumen diameter) were evaluated. HR was significantly reduced during injection, and quickly recovered after cessation of administration, of landiolol hydrochloride. Neither significant changes in BP nor adverse effects occurred. Among visible segments, 1,869 (94%) displayed an excellent (83%) or good (11%) image quality. Diagnostic accuracy was evaluated in 39 of 145 patients who underwent invasive CAG within 3 weeks after MSCT. The sensitivity, specificity, positive predictive value, and negative predictive value of MSCT CAG for detection of significant stenoses in assessable segments were excellent (per artery: 94%, 98%, 92%, and 100%; per segment: 92%, 98%, 94%, and 96%, respectively). CONCLUSIONS: Intravenous administration of landiolol hydrochloride reduces HR without a significant reduction in BP, which enables favorable image quality and diagnostic accuracy without adverse effects, making this agent feasible as a premedication for MSCT CAG.

Diffusion-weighted imaging of the liver: technical challenges and prospects for the future.

Diffusion-weighted imaging (DWI) has recently been attempted in the abdominal region. We review diffusion-weighted images of the liver, especially from the technical point of view. We discuss selection of pulse sequence parameters, effects of anti-breathing motion technique, tips for measuring apparent diffusion coefficient (ADC), and utility of superparamagnetic iron oxide (SPIO), showing clinical cases, including those at 3T. Our current trial of new pulse sequencing, such as SPIO-mediated breath-holding black-blood fluid-attenuated inversion recovery (BH-BB-FLAIR), imaging is shown. Some prospects for the future in DWI of the liver are also stated.

Intravenous urography-virtual cystoscopy is a better preliminary examination than air virtual cystoscopy.

OBJECTIVE: To describe a new technique of virtual cystoscopy (VC, used previously but with catheterization to drain residual urine and insufflation with air or carbon dioxide) with no invasive catheterization, used in parallel with intravenous urography (IVU), as conventional cystoscopy is an invasive but essential examination, and VC with multislice computed tomography (CT) was introduced to make preliminary examinations noninvasive. PATIENTS AND METHODS: Using multislice CT and a device with 16 rows of detectors, we examined five patients using VC that previously involved catheterization, termed 'air VC' and 16 using VC with the new technique, termed 'IVU VC'. We assessed the new technique by evaluating the tumour detection rate, and merits and demerits of both types of VC. RESULTS: The detection rate of bladder tumours by IVU VC was similar to that from air VC; moreover, IVU VC overcame two significant disadvantages of air VC, i.e. the appearance of the water surface and the need for catheterization. CONCLUSION: Conventional cystoscopy is still an essential examination but this new method of IVU VC may be ideal for preliminary examination of the bladder.

Pseudostenosis of the internal carotid artery in 3D time-of-flight MR angiography: effects of a magnetization transfer contrast pulse and metallic material.

Pseudostenosis or pseudoocclusion of the internal carotid artery in 3D time-of-flight MR angiography has been reported to be caused by susceptibility artifacts due to the presence of a metallic foreign body in the subject's neck. We experimentally demonstrate that the use of a non-slice-selective magnetization transfer contrast (MTC) pulse increases the degree of pseudostenosis, whereas slice-selective MTC does not. Selective MR angiography demonstrating this phenomenon was also performed. We then report a case that exhibited this phenomenon. We conclude that the magnetic field inhomogeneity induced by metallic material causes the non-slice-selective MTC pulse to act as a local presaturation pulse. Selective MR angiography using this phenomenon can be applied on varieties of MR scanners from different vendors.

Regional ADC values of the normal brain: differences due to age, gender, and laterality.

The purpose of this study was to evaluate the stability of measurement for apparent diffusion coefficient (ADC) values in normal brain, to clarify the effect of aging on ADC values, to compare ADC values between men and women, and to compare ADC values between right and left sides of the brain. To evaluate the stability of measurements, five normal volunteers (four men and one woman) were examined five times on different days. Then, 294 subjects with normal MR imaging (147 men and 147 women; age range 20-89 years) were measured. The ADC measurement in normal volunteers was stable. The ADC values stayed within the 5% deviation of average values in all volunteers (mean+/-standard deviation 2.3+/-1.2%). The ADC values gradually increased by aging in all regions. In thalamus, no significant difference was seen between right and left in the subjects under 60 years; however, right side showed higher values in the subjects over 60 years (p<0.01). In the subjects under 60 years, women showed higher values in right frontal, bilateral thalamus, and temporal (p<0.01); however, in the subjects over 60 years, no region showed difference between men and women. The knowledge obtained in this study may be helpful to understand the developmental and aging mechanisms of normal brain and may be useful for the future quantitative study as a reference.