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Biomedical subjects

C L Partain

Publications and source records attributed to C L Partain.

12 recordsLinked to original sources
PubMed1992

Clinical impact of picture archiving and communication systems: evaluation of a prototype system.

Opinion surveys were gathered before and 6 months after installation of a prototype picture archiving and communication system (PACS) (PACS/1, Siemens Medical Systems, Iselin, NJ). Median turnaround times and the percent of delayed or missing reports were calculated for 1,026 baseline and 8,438 follow-up studies at 6 months. Neuroradiological (neuro) computed tomography (CT) used PACS, while neuro magnetic resonance (MR), body CT, and body MR served as controls. The opinion surveys showed improved service in all categories, including those not directly affected by PACS. PACS images favorably impressed 86% of respondents, but most considered the system too slow, unreliable, and the storage capacity too low. A majority of 81% recommended against purchase of PACS now. There was an overall increase in the median report turnaround time for both neuro CT and the controls. Neuro CT showed a 41% decrease in delayed or missing reports, but controls also showed similar decreases. The effects of this prototype PACS on turnaround time or on report delivery could not be distinguished from section-wide changes in CT and MR services. Future improvements in PACS should vigorously address increased speed, reliability, and storage capacity.

Attitude of Health Personnel↗
PubMed1992

Magnetic resonance angiography techniques.

After a radio frequency pulse, the decay of the magnetic resonance (MR) signal is described by two relaxation processes, T1 and T2. T1 describes the rate at which the magnetization realigns itself along the external magnetic field direction (ML), and T2 describes the rate of decay of the magnetization component along the transverse axis (MT). Magnetic resonance angiography (MRA) sequences have been developed that encode flow as changes in the apparent T1 or T2 of the moving blood relative to stationary tissues. MRA sequences typically use either time-of-flight (TOF) techniques to encode T1 or phase-contrast techniques to encode T2. TOF techniques encode flow as an apparent T1 shortening through the wash-in of fully relaxed blood from outside the image volume. The shorter T1 produces an enhancement of vascular structures relative to stationary tissues. TOF methods may use either sequential two-dimensional, three-dimensional, or multi-slab three-dimensional imaging sequences to produce a three-dimensional MRA data set. Phase-contrast methods use additional magnetic field gradients to encode flow as shifts in the phase of MT. Both TOF and phase-contrast methods use maximum intensity projection (MIP) images displayed in a cine format to aid in the visualization of three-dimensional vascular structures.

Animals↗
PubMed1992

Quantitative imaging of renal blood flow and function.

Noninvasive renal blood flow quantitation has been historically difficult, although radionuclide imaging methods for measuring related parameters of renal function such as glomerular filtration rate and effective renal plasma flow have been successful. Radionuclide methods have long played an important role in the evaluation of renal function, but recent advances in other modalities such as positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging (MRI) have the potential to provide information not available with nuclear medicine techniques. The high spatial resolution provided by these modalities, coupled with dynamic imaging of contrast agents or radioactive tracers, potentially could allow detailed clinical evaluation of regional renal function and blood flow. A specialized MR technique, diffusion-weighted imaging, also shows promise for providing information not otherwise available concerning the renal microcirculation. This report provides a brief review of the available clinical techniques for the evaluation of renal blood flow and function as well as new methods under investigation.

Animals↗
PubMed1979

Multiple imaging modalities for the study of pancreatic disease.

Gray scale ultrasonography (US) and computed tomography (CT) have enhanced the role of various imaging modalities in the evaluation of patients with suspected pancreatic disease. When these anatomical studies are normal or equivocal, a functional, radionuclide pancreas scan may be useful. Pancreatic imaging can be achieved using ultrasound, transmission CT, single photon radionuclide imaging, and positron emission CT. A diagnostic imaging decision chart for the evaluation of patients with possible pancreatic disease is useful in choosing the correct imaging modality in a specific situation. Such a chart and its theoretic basis are described in this review. The need to optimize the pancreatic work-up with respect to cost-benefit decisions and diagnostic accuracy, sensitivity, and specificity are of particular concern to the physician. Of all the potential areas for disease, the pancreas has been and remains a particularly difficult diagnostic problem.

Humans↗
PubMed1979

Placenta praevia: significance in the second trimester.

A prospective study was performed on 98 patients to determine the risk of a second trimester placenta praevia remaining until term. The presence and degree of anterior or posterior praevia were scored for each patient. Follow-up data were obtained at delivery on 58 patients. A greater fraction (63.8%) of second trimester praevia was implanted posteriorly. The overall incidence of a second trimester praevia persisting until term was 8.8%.

Female↗
PubMed1979

Cerebral venous angioma: correlation of radionuclide brain scan, transmission computed tomography, and angiography.

Three cases of intracerebral venous angioma, a rare vascular malformation, were studied by radionuclide brain scan, transmission computed tomography (TCT) and angiography. In each case, the radionuclide flow study demonstrated a typical area of abnormal increase in activity during the venous phase; in two of the cases the arterial phase was also abnormal. Each contrast angiogram demonstrated a normal arterial distribution and a characteristic network of abnormal veins that converged to a large transcerebral draining vein. The TCT scans showed enhancing, curvilinear densities; while not specific, this finding should suggest the possibility of venous angioma in the brain.

Adult↗
PubMed1979

The value of the bone scan in idiopathic regional migratory osteoporosis.

Idiopathic regional migratory osteoporosis is a self-limited entity of unknown origin, which has received little attention in the nuclear medicine literature. It is characterized by severe joint pain, typically in a hip, with normal laboratory and normal early radiographic findings. Spontaneous recovery occurs, but recurrence is frequent in another joint, often the opposite hip. Recurrence in the same joint has never been reported. The bone scan is shown to be positive with first symptoms and is important in the diagnosis and management of this entity. Three cases are presented.

Adipose Tissue↗
PubMed1978

Quantitative multiregional CSF kinetics using serial, metrizamide enhanced computed tomography.

Two rhesus monkeys studied by serial metrizamide (Amipaque) enhanced computer tomography (CT) imaging were used to quantitatively analyze cerebrospinal fluid (CSF) kinetics in multiple anatomical regions. Time--density curves were generated for the cisterna magna, suprasellar cistern, quadrigeminal cistern, and sylvian fissure, If clinical, biochemical, and routine static CT scanning indicate a profile suggesting normal pressure hydrocephalus, then CSF kinetics may be quantitatively and dynamically studied by CT imaging with metrizamide enhancement. This multiregional approach may be applied in an attempt to accurately distinguish normal pressure hydrocephalus from cerebral atrophy as a means of predicting which patients will likely profit from surgical diversionary shunting.

Animals↗
PubMed1978

Claw hammer technique for extraction of knives.

A knife deeply imbedded in a patient's shoulder could not be pulled out easily before post-withdrawal angiographic study. The claw of a hammer was placed beneath the hilt of the knife for additional leverage, and the weapon was thereupon successfully removed. The advantage of a post-withdrawal angiogram to assess the degree of extravasation is stressed.

Adult↗
PubMed1978

A multiregional kinetics model for cerebrospinal fluid.

A mathematical model was developed to describe the multiregional flow of intrathecal indium-111 DTPA, and hence indirectly the flow of cerebrospinal fluid, in sequential spinal and cerebral CSF images. The model provides for an arbitrary input function, transport delay between appropriate compartments, transmeningeal and transependymal transport, and for bidirectional flow between most compartments. Two- and eight-compartment models were evaluated. The set of eight nonlinear differential equations was solved using numerical techniques. This model provides a quantitative basis for the interpretation of CSF kinetics.

Adult↗