Search PubMed⌕ Search

Biomedical subjects

J M Rubin

Publications and source records attributed to J M Rubin.

At least 163 records · Page 9Linked to original sources
PubMed1983

Appearance of the gallbladder and biliary tree by CT cholangiography.

The computed tomographic (CT) cholangiographic appearance of the gallbladder and bile ducts was retrospectively analyzed in 121 patients undergoing routine abdominal CT. The entire course of the common duct was visualized in 106 cases (88%). From this group, 100 (94%) patients had ducts that coursed in a parasagittal or oblique plane, and six patients (4%) had ducts with a horizontal course. Opacification of the gallbladder was observed in 102 patients (83%), with the majority (80 patients) demonstrating a homogeneous appearance. Different patterns of inhomogeneous opacification are described. Signs of cholelithiasis or cholecystitis include: a filing defect in an opacified gallbladder, a focal density in a faintly opacified gallbladder, or the indirect sign of a nonopacified gallbladder with an opacified bile duct.

Aged↗
PubMed1983

Work in progress: intraoperative ultrasonography of the spine.

We demonstrate the application of intraoperative real-time ultrasound sector scanning in two patients who had spinal tumors. The scans were obtained through a 4- to 5-cm deep, saline-filled operative field. Ultrasonography imaged the tumors, the relationships of the lesions to the spinal cords, and the normal internal structures of the cords themselves. The technique could prove useful in certain forms of spinal surgery.

Aged↗
PubMed1983

Intraoperative neurosurgical ultrasound in the localization and characterization of intracranial masses.

Seventy-two lesions were demonstrated in 70 patients who were examined using intraoperative real-time ultrasonography. Fifty-five lesions were supratentorial and 17 were infratentorial. The neurosurgeon used ultrasonography to evaluate his operative field before, during, and after resection. Nineteen lesions contained cystic components. In eight cases, ultrasonography added information not provided by CT including definitive characterization of cystic components and loculations or localization of solid masses within the cysts. Biopsy of 13 lesions was performed under ultrasonic guidance. In all cases, the biopsy probe could be seen passing through the lesions leaving an echogenic trail, possibly blood filled, after the probe had been removed. Three lesions with diameters of less than 1 cm were localized and successfully removed under ultrasonic guidance. Intraoperative real-time ultrasonography is a safe and reliable technique, and it can be a valuable aid to the neurosurgeon.

Brain Diseases↗
PubMed1983

A cannula for use in ultrasonically guided biopsies of the brain. Technical note.

The authors describe a cannula that has been modified to improve its visibility during ultrasonically guided biopsies of the brain. To enhance the echogenicity of the tip of the cannula, six parallel rings, 0.25 to 0.30 mm deep and 0.40 to 0.50 mm apart, were etched into the tip of the cannula. The cannula was also lengthened to approximately 19 cm to permit its unencumbered passage through any biopsy guidance device that may be employed. Detailing the precise location of the tip of the biopsy cannula is most important. The tip of this modified probe is much more echogenic and hence more easily seen ultrasonically than it would be otherwise, both in vivo and in vitro. This modified cannula is useful in any ultrasonically guided intracranial biopsy procedure.

Biopsy↗
PubMed1982

Intrauterine growth retardation risk detection for fetuses of unknown gestational age.

A method of plotting growth rate of the biparietal diameter against the concurrent size of the biparietal diameter was used to assess risk of intrauterine growth retardation. The technique does not require knowledge of gestational age of the fetus. Therefore, it is uniquely useful for patients with unknown or uncertain menstrual dates who present relatively late in pregnancy when a reliable estimate of gestational age cannot be sonographically obtained. One hundred twenty-one patients were studied. Ninety-seven percent of the fetuses who demonstrated a normal rate of growth were either appropriate or large for gestational age by weight. Thirty-five percent of the fetuses who had a subnormal rate of growth of the biparietal diameter were intrauterine growth retarded by weight. The data presented support the use of this technique for assessing the risk for intrauterine growth retardation, when an accurate estimate of gestational age account be made.

Age Determination by Skeleton↗
PubMed1982

Color vision and image intensities: when are changes material?

The difficulty in understanding a biological system or its components without some idea of its goals has been emphasized by Marr. In this paper, a preliminary goal for color vision is proposed and analyzed. That goal is to determine where changes of material occur in a scene (using only spectral information). The goal is challenging because the effects of many processes (shadowing, shading from surface orientation changes, highlights, variations in pigment density) are confounded with the effects of material changes in the available image intensities. We show there is a minimal and unique condition, the spectral crosspoint that rejects instances of these confounding processes. (If plots are made of image intensity versus wavelength from two image regions, and the plots intersect, we say that there is a spectral crosspoint.) An operator is designed to detect crosspoints; it turns out to resemble double-opponent cells described in primate visual cortex.

Color Perception↗
PubMed1982

Intraoperative ultrasound imaging of the spinal cord: syringomyelia, cysts, and tumors--a preliminary report.

Dynamic intraoperative imaging of the spinal cord was done using a real-time ultrasound scanner. Prior to opening the dura mater the neurosurgeon is able to "explore" the intradural space and with a 7.5 MHz transducer visualize the normal spinal cord, including the central canal and the dentate ligaments. Anterior and posterior spinal arteries may be seen in certain patients. In syringomyelia the fluid-filled cavities may be visualized with ultrasound and drained or shunted with intraoperative ultrasound guidance. Spinal cord cysts or cystic components of tumors can be precisely identified and drained using ultrasound. Intramedullary tumors can be demonstrated sonographically, as can the location and extent of intradural extramedullary tumors and tumors that have both extradural and intradural components. Experience to date with intraoperative imaging of the spinal cord and with the real-time ultrasound scanner is very encouraging, and in the future it should allow for a more precise characterization of and operative approach to lesions of the spinal cord.

Cysts↗
PubMed1982

Use of ultrasonically guided probes and catheters in neurosurgery.

The utility of two-dimensional, real-time intraoperative ultrasound sector scanning for purposes of tumor localization, tumor biopsy, cyst drainage, and placement of ventricular shunt catheters in 13 patients is demonstrated. The technique allows the neurosurgeon to assess the progress of the procedure as it happens. The surgeon can observe biopsy probes entering tumors, thus confirming the location of the tissue sample. Shunt catheters can be easily guided into optimal positions for drainage. The technique is simple and safe, and could become a valuable aid in certain types of neurosurgical operations.

Astrocytoma↗
PubMed1982

Equation counting and the interpretation of sensory data.

Many problems in biological information processing require the solution to a complex system of equations in many unknown variables. An equation-counting procedure is described for determining whether such a system of equations will indeed have a unique solution, and under what conditions the solution should be interpreted as 'correct'. Three examples of the procedure are given for illustration, one from auditory signal processing and two from vision.

Animals↗
PubMed1982

Isolated internal iliac artery aneurysms.

A case of bilateral isolated internal iliac artery aneurysms in a patient with sciatic symptoms is presented. Iliac artery aneurysms are rare in the absence of aortic aneurysms; they are usually atherosclerotic in nature and present most commonly with gastrointestinal, genitourinary, or neurologic symptoms.

Aged↗
PubMed1982

Computed-tomographic cholangiography: a new technique for evaluating the head of the pancreas and distal biliary tree.

Computed-tomography cholangiography was used to evaluate the abdomen of 97 patients. The gallbladder and/or biliary tree was visualized well in 84 patients (87%); the distal common bile duct (CBD) was visualized well in 68 patients (70%). For 26 patients (30%) from the latter group, visualization of the opacified CBD was essential in order to differentiate the pancreatic head from the duodenum. Measurements of the distal CBD showed a significant difference between patients with gallbladders (mean, 4.7 +/- 1.2 mm) and those without gallbladders (mean, 6.8 +/- 1.1 mm). By visualizing the CBD and the superior mesenteric vein, exact dimensions of the uncinate process can be obtained. Also, the pancreatic head can be assessed more accurately, and the distal biliary tree can be evaluated.

Cholangiography↗