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R Y Shifrin

Publications and source records attributed to R Y Shifrin.

8 recordsLinked to original sources
PubMed2000

Three-dimensional cardiac cine magnetic resonance imaging with an ultrasmall superparamagnetic iron oxide blood pool agent (NC100150).

The purpose of this study was to assess image quality of three-dimensional (3D) cardiac cine magnetic resonance (MR) imaging before and after administration of a T1-shortening ultrasmall superparamagnetic iron oxide blood pool agent (NC100150). 3D cardiac cine MR imaging was performed in 13 volunteers using a radiofrequency-spoiled cardiac-gated 3D cine gradient-echo sequence with short repetition and echo times. Compared with precontrast images, postcontrast images showed no enhancement in fat and skeletal muscle, moderate enhancement in myocardium, and significant enhancement in ventricular cavity. After contrast injection, the signal ratio of the ventricular chamber to the myocardium significantly increased, and dramatic improvements were seen in the quality of the cineangiographic images and the depiction of cardiac valves. This quantitative study has shown that 3D cardiac cine MR imaging using a blood pool agent provided MR ventriculography and cineangiography with excellent image quality.

Adult↗
PubMed1999

Fast 3D cardiac cine MR imaging.

We describe a technique for three-dimensional cine MR imaging. By using short repetition times (TR) and interleaved slice encoding, volumetric cine data can be acquired throughout the cardiac cycle with a temporal resolution of approximately 80 msec. A T1-shortening agent is used to produce contrast between blood and myocardium. A comparison between the acquisition times of this and several other two-dimensional techniques is presented.

Contrast Media↗
PubMed1996

Aspiration in patients in critical care units.

Pulmonary aspiration is a serious cause of morbidity and mortality in patients with a depressed sensorium, patients with neuromuscular discoordination, or patients having a structural disorder of the upper aerodigestive tract. This problem is relatively frequent in patients in critical care units and other areas where anesthesia is used. The most common manifestations of pulmonary aspiration are chemical pneumonitis, pleuropulmonary infection, and acute airway obstruction. The clinical and radiographic manifestations of pulmonary aspiration are nonspecific and diagnosis depends on a consistent constellation of clinical and radiographic criteria.

Airway Obstruction↗
PubMed1995

The CT nephrogram: implications for evaluation of urinary tract disease.

The urographic nephrogram is an important indicator of underlying functional and structural renal disease. With expansions in use of cross-sectional imaging, the computed tomographic (CT) nephrogram (ie, contrast material enhancement within the renal parenchyma) has assumed a greater role in the evaluation of urinary tract disorders. Both quantitative and qualitative nephrographic abnormalities are well demonstrated by CT, including global or segmental absence or persistence of the nephrogram, slowed temporal progression, striated pattern, and rim pattern. Global absence is nearly always unilateral and is most often seen with blunt abdominal trauma with renal pedicle injury. Segmental absence is attributable to focal renal infarction, most likely due to arterial emboli. Global persistence, which is much more common than segmental persistence, may be unilateral (caused by renal artery stenosis, renal vein thrombosis, or urinary tract obstruction) or bilateral (due to systemic hypotension, intratubular obstruction, or abnormalities in tubular function). Striated nephrograms may be unilateral or bilateral and are caused by ureteric obstruction, acute pyelonephritis, contusion, renal vein thrombosis, tubular obstruction, hypotension, and autosomal recessive polycystic kidney disease. The rim pattern is most often associated with renal infarction and occasionally with acute tubular necrosis and renal vein thrombosis. Careful evaluation of the CT nephrogram is an integral part of the abdominal CT examination.

Contrast Media↗
PubMedDate not supplied

Ultrafast contrast-enhanced three-dimensional MR angiography: state of the art.

Ultrafast breath-hold contrast material-enhanced magnetic resonance (MR) angiography can be performed with a flexible imaging sequence. With the current generation of high-speed imaging gradients, it is possible to achieve sequence repetition times of 4 msec or less. These repetition times make it possible to obtain high-resolution (512 x 512 x 64) images in under 30 seconds. Applications of this versatile technique include imaging of aortic dissection, thoracic and abdominal aortic aneurysm, pulmonary embolus, carotid stenosis, and peripheral vascular disease. The administration of contrast material must be tailored to the vascular anatomy under examination to avoid venous enhancement. The rapid data acquisition times can be used to image multiple temporal phases or multiple locations. With this technique and administration of a T1-shortening contrast agent, high-quality MR angiography can be routinely performed in a variety of vascular regions (eg, thoracic and abdominal aorta, pulmonary arteries, carotid arteries, lower extremities).

Aortic Aneurysm↗
PubMedDate not supplied

Contrast-enhanced three-dimensional fast spoiled gradient-echo renal MR imaging: evaluation of vascular and nonvascular disease.

Breath-hold contrast material enhanced three-dimensional (3D) fast spoiled gradient-echo (FSPGR) sequences are valuable techniques for evaluation of renal arteries and veins and diagnosis of significant renal arterial stenosis at magnetic resonance (MR) imaging. The excellent spatial and contrast resolution with these techniques, combined with the ability to perform studies in multiple vascular phases, also make them attractive for the diagnosis of a wide range of nonvascular processes that affect the kidneys, including renal infections, renal parenchymal diseases, and renal trauma. Particularly when combined with T1- and T2-weighted MR imaging, the contrast-enhanced techniques are highly effective for characterization of renal masses owing to the ability to portray dynamic contrast enhancement. The ability to display venous structures with contrast-enhanced 3D FSPGR techniques helps staging of renal cell carcinoma. This article presents examples of the wide range of vascular and nonvascular renal diseases that may be effectively imaged with contrast material enhanced 3D FSPGR techniques and illustrates the usefulness of the techniques for renal MR imaging.

Diagnosis, Differential↗