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R N Rankin

Publications and source records attributed to R N Rankin.

At least 37 records · Page 2Linked to original sources
PubMed1994

Physicians Innovation Awareness Program: helping radiologists learn about innovations.

The Physicians Innovation Awareness Program (PIAP) was designed to study the strategies of Canadian radiologists implementing innovations into their practices and to use the information to design an educational program to help radiologists learn about innovations. Canadian radiologists were asked, by means of a mail survey, for information about innovations in practice adopted in the previous 2 years and planned for the next 2 years. Surveys were sent to the 1077 practising radiologists registered in the Canadian Association of Radiologists (CAR) as of Sept. 30, 1991; 325 (30.2%) responded. Most (281) of the responding radiologists were practising in communities with a population of 50,000 or more; 103 of the 188 respondents for whom faculty status was known were affiliated with a university. Most of the respondents reported that they spent up to 25% of their working time in at least one subspecialty pursuit. From the information in the surveys, an educational strategy was designed to help radiologists in learning about innovations. This program involved special sessions on six selected topics presented at two annual meetings of the CAR, as well as publications, mailings and other lectures. The authors conclude that a specialty society can obtain adequate information from its members to design an educational program to help practitioners in adopting innovations.

Canada↗
PubMed1994

Adoption of innovations by Canadian radiologists.

The purpose of this study was to determine the factors that help or hinder the adoption of new procedures and practices by Canadian radiologists. Canadian radiologists were asked, by means of a mail survey, for information about innovations in practice adopted during the previous 2 years or planned for the next 2 years. Surveys were sent to the 1077 practising radiologists registered in the Canadian Association of Radiologists as of Sept. 30, 1991; 325 responded (30.2%). The responses were correlated with demographic information obtained in the same survey and through the Maintenance of Competence Program of the Royal College of Physicians and Surgeons of Canada. Magnetic resonance imaging (MRI) was more likely to be adopted in larger communities (those with a population of more than 500,000), computed tomography in medium-sized and larger communities (more than 100,000), mammography in medium-sized and smaller communities (500,000 or less) and ultrasonography (US) in smaller communities (100,000 or less). Radiologists with a faculty appointment at a university were more likely to adopt MRI and digital imaging, whereas those with no faculty status were more likely to adopt US and structural changes to a practice. The authors conclude that the size of the community in which a practice is located and the practitioner's faculty status both play a role in the adoption of innovations.

Canada↗
PubMed1994

Lost gallstones during laparoscopic cholecystectomy: are they really benign?

The long-term effect of stones spilled into the peritoneal cavity during laparoscopic cholecystectomy is unknown. The course of a 58-year-old man who had recurrent right subphrenic abscesses and a right empyema secondary to spilled gallstones during laparoscopic cholecystectomy is described. The authors outline techniques for minimizing the spillage of stones during laparoscopic cholecystectomy: the application of hemoclips, endoloops and sutures, and placement of the necrotic, friable gallbladder in an endoscopic bag immediately upon completion of the dissection, before extraction of the gallbladder. They conclude that spillage of stones during laparoscopic cholecystectomy may lead to serious infection and should be recorded in the operative notes so that stones may be suspected when a patient presents with abdominal infection after laparoscopic cholecystectomy.

Cholecystectomy, Laparoscopic↗
PubMed1993

Three-dimensional colour Doppler imaging.

We have developed a system to acquire in vivo three-dimensional (3D) colour velocity images of peripheral vasculature. A clinical ultrasound system was modified by mounting the transducer on a motor-driven translation stage, allowing planar ultrasound images to be acquired along a 37 mm long stroke. A 3D velocity image is acquired by digitizing, in synchrony with the cardiac cycle, successive video images as the transducer is moved over the skin surface. 3D images require about 1 min to acquire and 10 min to reconstruct before being viewed interactively. Image acquisition at several points in the cardiac cycle permits a cine-type reconstructed image. Geometrical, temporal and velocity accuracy of the acquisition and reconstruction have been quantified and found not to degrade the image.

Adult↗
PubMed1993

Stability studies on chemoembolization mixtures. Dialysis studies of doxorubicin and lipiodol with Avitene, Gelfoam, and Angiostat.

RATIONALE AND OBJECTIVES: Chemoembolization, using a combination of embolic and chemotherapeutic agents, appears to be an effective treatment for hepatocellular carcinoma. Although the postulated mechanism of effectiveness hinges on a prolonged drug delivery, increasing evidence suggests that embolization mixtures are not stable. The objective of this study was to investigate examples of these mixtures. METHODS: Dialysis techniques have been used to examine the pharmacokinetic properties of chemoembolization mixtures that contain doxorubicin, Lipiodol (Guerbet Products, Montreal, Quebec), and the embolizing agents Avitene (Alcon Laboratories Inc., Fort Worth, Texas), Gelfoam (Upjohn, Kalamazoo, MI), and Angiostat (Regional Therapeutic Inc., Pacific Palisades, CA). RESULTS: Lipiodol, Gelfoam, and Avitene, when combined with doxorubicin, had only a small effect on the diffusion of the drug when compared with the diffusion curve of doxorubicin alone. Gelfoam or Avitene produced a thrombus-like consistency when added to a doxorubicin/Lipiodol combination, and an additional decrease in the doxorubicin appearance rate was observed. However, after 6 hours, doxorubicin levels for these mixtures reached control values observed in 3 hours. Angiostat without Lipiodol produced a profound concentration-dependent decrease in the diffusion of doxorubicin. After 9 hours, only 23% of the doxorubicin had been released. CONCLUSION: The strong complexing ability of the embolic agent Angiostat may enable it to be a carrier for doxorubicin and surpass other mixtures currently employed for transcatheter chemoembolization.

Antineoplastic Agents↗
PubMed1993

Intracavitary aspergilloma: transthoracic percutaneous injection of amphotericin gelatin solution.

For aspergillomas in patients with fibrocavitary lung disease, surgery is often not recommended. Injection or lavage of the cavities with solutions of potassium iodide or antifungal agents has had varying success and requires repeated sessions because of nonretention of the therapeutic agent within the cavity. In three patients with four aspergillomas, the authors used fluoroscopic or computed tomographic (CT) guidance to inject amphotericin in gelatin as a liquid that solidifies within the cavity at body temperature. The patients were followed up with serial chest radiography or CT. The mixture was successfully instilled in every case. Three of the four aspergillomas completely resolved within 3 months or less, with no evidence of recurrence at follow-up of 6-18 months. The remaining aspergilloma decreased in size, but the patient needed pneumonectomy because of recurrent hemoptysis within 6 months of amphotericin injection. Transthoracic instillation of a liquid mixture of amphotericin and gelatin that solidifies rapidly at body temperature may be useful as a one-step treatment for aspergillomas.

Adult↗
PubMed1993

Safety of outpatient peripheral angioplasty.

PURPOSE: The safety of performing peripheral percutaneous angioplasty on an outpatient basis was studied. MATERIALS AND METHODS: A retrospective cohort study was conducted of all peripheral angioplastic procedures performed at one institution during a 4-year period. The 350 procedures in 235 patients included 84 inpatient cases, 141 outpatient cases, and 125 1-day-care cases (ie, procedures performed in patients transferred from other hospitals). RESULTS: The rates of major complications were 8.3% +/- 3.0 (mean +/- standard error) (n = 7) for inpatients. 5.0% +/- 1.8 (n = 7) for outpatients, and 5.6% +/- 2.1 (n = 7) for 1-day-care patients. Furthermore, 95% confidence intervals for the difference between complication rates were -10.3% and 3.5% for outpatient versus inpatient cases and -9.9% and 4.4% for 1-day-care versus inpatient cases. CONCLUSION: The risk of a major complication resulting from peripheral angioplasty in appropriately selected outpatients is no greater than it is for patients admitted for overnight observation.

Adult↗
PubMed1993

Three-dimensional sonographic reconstruction: techniques and diagnostic applications.

In this review, we summarize the techniques of obtaining and reconstructing three-dimensional (3D) sonograms in a number of anatomic areas, catalog the clinical efforts at 3D sonography so far, and introduce more recent work in this area that takes advantage of the unique features of sonography. Although it is an active area of 3D imaging research, cardiac 3D imaging is not discussed because it has unique requirements stemming from the heart's anatomic inaccessibility and motion. Image analysis and display also are not covered, as no clear consensus has been reached about the usefulness of the large number of available methods.

Female↗
PubMed1993

Doppler ultrasonography after renal transplantation: value of reversed diastolic flow in diagnosing renal vein obstruction.

The observation of reversed diastolic flow during Doppler ultrasonography (US) of renal transplants has been described as sensitive but not specific in the diagnosis of renal vein thrombosis. To determine the diagnostic accuracy of reversed diastolic flow for renal vein obstruction in patients who underwent renal transplantation at a tertiary-care teaching hospital over a 3-year period, the authors identified all patients in whom reversed diastolic flow was observed during Doppler US (17 patients) and those in whom complete renal vein obstruction occurred, necessitating nephrectomy (16 patients). Three types of reversed diastolic flow were found; the wave-forms of two of these had a large reversed component. One of these two types was present in nine of the patients in whom complete venous obstruction occurred. The sensitivity, specificity and positive predictive value of reversed diastolic flow were 82%, 99% and 75% respectively. The authors conclude that a US finding of reversed diastolic flow with a large reversed component is a sensitive and specific sign of renal vein obstruction, usually renal vein thrombosis.

Diastole↗
PubMed1993

Excimer-laser-assisted angioplasty in chronic femoropopliteal occlusion: the significance of an intimal flap in predicting reocclusion.

Angioplasty assisted by excimer laser was performed on 27 chronic femoropopliteal occlusions, ranging from 2 to 30 cm in length, in 26 patients. Twenty-one (78%) of the procedures were successful initially. Of these, 12 (57% [44% of the total]) remained patent at follow-up 3 months later. In seven of the nine cases of reocclusion observed after 3 months (78%) a large intimal flap resulting from the angioplasty-induced dissection could be identified in the postprocedure angiogram. The authors stress the possible importance of such an intimal flap in limiting the success of laser-assisted angioplasty of long femoropopliteal occlusions.

Adult↗
PubMed1991

Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.

BACKGROUND: Without strong evidence of benefit, the use of carotid endarterectomy for prophylaxis against stroke rose dramatically until the mid-1980s, then declined. Our investigation sought to determine whether carotid endarterectomy reduces the risk of stroke among patients with a recent adverse cerebrovascular event and ipsilateral carotid stenosis. METHODS: We conducted a randomized trial at 50 clinical centers throughout the United States and Canada, in patients in two predetermined strata based on the severity of carotid stenosis--30 to 69 percent and 70 to 99 percent. We report here the results in the 659 patients in the latter stratum, who had had a hemispheric or retinal transient ischemic attack or a nondisabling stroke within the 120 days before entry and had stenosis of 70 to 99 percent in the symptomatic carotid artery. All patients received optimal medical care, including antiplatelet therapy. Those assigned to surgical treatment underwent carotid endarterectomy performed by neurosurgeons or vascular surgeons. All patients were examined by neurologists 1, 3, 6, 9, and 12 months after entry and then every 4 months. End points were assessed by blinded, independent case review. No patient was lost to follow-up. RESULTS: Life-table estimates of the cumulative risk of any ipsilateral stroke at two years were 26 percent in the 331 medical patients and 9 percent in the 328 surgical patients--an absolute risk reduction (+/- SE) 17 +/- 3.5 percent (P less than 0.001). For a major or fatal ipsilateral stroke, the corresponding estimates were 13.1 percent and 2.5 percent--an absolute risk reduction of 10.6 +/- 2.6 percent (P less than 0.001). Carotid endarterectomy was still found to be beneficial when all strokes and deaths were included in the analysis (P less than 0.001). CONCLUSIONS: Carotid endarterectomy is highly beneficial to patients with recent hemispheric and retinal transient ischemic attacks or nondisabling strokes and ipsilateral high-grade stenosis (70 to 99 percent) of the internal carotid artery.

Aged↗
PubMed1991

Portobiliary fistula: occurrence and treatment.

Portobiliary fistula is a rare complication of percutaneous biliary drainage. The authors report its occurrence in four patients who had multiple percutaneous biliary procedures. One patient was treated by simple tamponade over several days, the other three by temporary balloon tamponade and permanent coil occlusion.

Aged↗
PubMed1991

Biliary-jejunal drainage for failed biliary-duodenal drainage.

Percutaneous biliary drainage, as palliation for malignant biliary obstruction, is subject to complications, particularly blockage of the drainage tube. Blockage may occur because of duodenal tumour involvement. In nine patients with blockage of the biliary-duodenal drainage tube, conversion to biliary-jejunal drainage allowed continued internal drainage of bile.

Aged↗
PubMed1989

Carotid transluminal angioplasty with evidence of distal embolization. Case report.

A 57-year-old woman presented with symptomatic triple tandem stenosis of the left carotid artery. Transluminal angioplasty of an atherosclerotic stenosis at the origin of the common carotid artery was performed retrogradely through a distal arteriotomy after endarterectomy. The postangioplasty effluent was collected and analyzed. Cholesterol crystals and amorphous plaque debris were identified, indicating a source for distal embolization. The clinical significance of this small amount of debris embolizing to the intracranial circulation is uncertain, but should be of concern when considering angioplasty of the cerebral circulation.

Angioplasty, Balloon↗
PubMed1989

Digital teleradiology: Seaforth--London network.

A total digital teleradiology system using a prototype DuPont laser beam scanner (DTR 2000) and a Bell Canada digital transmission network was evaluated. A total of 489 radiographic and ultrasonographic examinations were transmitted for interpretation from a 41-bed rural community hospital in Seaforth to the University Hospital in London, Ontario, 80 km away. There was concurrence in 98% of these examinations, i.e. the laser-sensitive facsimile film clearly duplicated the original film findings and allowed a confident interpretation to be made. We conclude that this system could readily serve the needs of family physicians in rural communities for radiologic consultation, diagnosis, management, and triage of patients 24 hours per day.

Evaluation Studies as Topic↗