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Biomedical subjects

S T Cochran

Publications and source records attributed to S T Cochran.

At least 37 records · Page 2Linked to original sources
PubMed1989

Incidental fibromuscular dysplasia in potential renal donors: long-term clinical follow-up.

The clinical natural history of renal arterial fibromuscular dysplasia (FMD) in patients with normal blood pressure is unknown, to the authors' knowledge. The authors reviewed the results of 1,862 renal angiograms obtained in potential renal donors. FMD was present in 71 patients (3.8%). The average age at which FMD was discovered was 50.8 years. Seventy-five percent of the patients with FMD were female. Of 30 patients who did not undergo nephrectomy, eight (26.6%) developed hypertension over a mean followup interval of 7.5 years. Of 19 patients who underwent nephrectomy, despite the presence of FMD, five (26.3%) developed hypertension over a mean follow-up interval of 4.4 years. In comparison, three subjects (6.1%) (from a randomized control group of 49 age- and sex-matched healthy individuals) developed hypertension over a mean follow-up period of 7.1 years. The authors conclude that asymptomatic middle-aged individuals with renal FMD develop hypertension at a rate greater than that of age-matched control subjects with normal blood pressure.

Adult↗
PubMed1989

Wilms tumor (nephroblastoma) in the adult patient: clinical and radiologic manifestations.

Wilms tumor (nephroblastoma), a primary renal neoplasm containing primitive blastema and embryonic glomerulotubular structures, is seen rarely in adults. To identify clinical and radiologic criteria for preoperative diagnosis of adult Wilms tumor, we studied 29 cases reported in the literature from 1975 to 1987 (all patients were 15 years old or older) and four newly diagnosed cases. The mean age of patients was 30 years; 80% were less than 35 years old. Each patient presented with a large, rapidly growing, abdominal mass (average duration of symptoms, less than 2 months), had no constitutional symptoms (e.g., weight loss, fever), and otherwise were healthy (80%). Twenty-six patients had IV or retrograde pyelograms. Twenty-three showed a nonspecific mass effect. In seven (78%) of nine patients, abdominal CT scans showed a large, inhomogeneous mass with large areas of low density and increased enhancement of the compressed remaining normal renal parenchyma, which resembled a pseudocapsule. In five (63%) of eight patients, sonograms showed a complex mass with large cystic components. In 18 (82%) of 22 patients, arteriograms showed a hypovascular mass with fine wavy or zigzag (creeping-vine) neovascularity. We conclude that a rapidly growing renal mass in a young patient (less than 35 years old) that is shown to be complex and cystic by CT or sonography and that is hypovascular with fine, wavy neovascularity on arteriography is suggestive of adult Wilms tumor (75-80%). An awareness of this constellation of findings may be helpful in diagnosing this unusual tumor before surgery.

Adolescent↗
PubMed1989

Genitourinary imaging and procedures by the emergency physician.

Optimal imaging of the urinary tract in the Emergency Department does not require sophisticated or rare equipment. The supervising physician must review each ExU, cystogram, or RUG film as it becomes available and decide upon the proper course of action. Indications for contrast studies in injured patients continue to evolve, with a trend away from investigation of stable patients with microscopic hematuria on the first urine. Urethral catheterization and suprapubic cystostomy are complementary options for bladder drainage. Careful attention to details of anatomy and technique allow for success in the majority of patients. There are substantial pitfalls in the diagnosis and treatment of male genital emergencies. The acute treatment of priapism is rapidly changing as understanding of penile physiology becomes more complete. Acute scrotal pathology can be difficult to categorize without surgical exploration. Urologic consultation, therefore, is mandatory in these conditions.

Cystostomy↗
PubMed1988

Extracorporeal shock wave lithotripsy: clinical results.

The uroradiological experience with extracorporeal shock wave lithotripsy (ESWL) treatment of over 1,500 urinary calculi is summarized. Percutaneous nephrostomies were needed in 5-50% of ESWL patients depending upon the size and location of stone being treated. Over 25% of percutaneous nephrostomy tracts were subsequently used for other procedures. When staghorn calculi were treated by ESWL, the collaborative efforts of uroradiologists and urologists is mandatory.

Humans↗
PubMed1988

Percutaneous nephrostomy in conjunction with ESWL in treatment of nephrolithiasis.

The use of percutaneous nephrostomies (PCNs) in 1456 patients (1660 kidneys) treated with extracorporeal shock-wave lithotripsy (ESWL) was evaluated. In this group, 138 PCNs (130 patients) were performed in 133 kidneys. Forty-seven percent of PCNs were placed in patients with staghorn calculi; 24% were for stones in the renal pelvis, and 20% for ureteral stones. The most common indication for PCN was fever and obstruction (57%). In 15%, the indications were failure to decompress an obstructed system from a retrograde direction, clogged double-J ureteral stents, and perforation of the ureter. Prophylactic PCN placement in the treatment of staghorn calculi and large stones in the renal pelvis accounted for 12%. Five percent were placed for miscellaneous other reasons, and for 11% there was no documentation of the indication because they were placed before the patients came to our center. Localization of the collecting system for optimal placement of PCN is unique in ESWL patients because the residual stone fragments provide natural contrast. This eliminates the need for administration of contrast material in 50% of the patients. Twenty-six percent of PCN tracts were subsequently used for other procedures (e.g., percutaneous nephrolithotomy, fragment irrigation, ureteral stone manipulation). Bleeding complications from PCN occurred in 7%. Other minor complications occurred in 12% of cases. PCN is a useful adjuvant to ESWL treatment of kidney stones. Although its major use is to relieve urinary tract obstruction, it is also used as a preliminary step in planning other percutaneous interventional procedures. This is particularly the case in the treatment of large bulky stones in the renal pelvis and staghorn calculi.

Adolescent↗
PubMed1988

Evaluation of lopamidol and diatrizoate in excretory urography: a double-blind clinical study.

Image opacification, patients' tolerance, and clinical and laboratory findings were evaluated in patients having excretory urography at three centers. In a double-blind, parallel study, iopamidol was compared with diatrizoate (50-ml dose), and in an open-label trial, the administration of a 100-ml dose of iopamidol was evaluated. In the double-blind study, a total of 84 patients received 50 ml of either iopamidol or diatrizoate. In the open-label study, another 42 patients received a 100-ml dose of iopamidol. Image opacification scores after the administration of the 50-ml doses showed better opacification with iopamidol than with diatrizoate in the renal calices (p less than .05) and in the composite kidney (p less than .05). Opacification scores were higher for 100-ml doses of iopamidol than for 50-ml doses in all anatomic regions as well as in the composite kidney (p = .0001). Patients' tolerance to iopamidol was significantly better than their tolerance to diatrizoate (p less than .025). Investigators observed adverse drug reactions in a total of 10 patients. In the double-blind study, one of 43 patients had transient bradycardia after the administration of iopamidol. In the same study, four of 41 patients who received diatrizoate had five minor adverse drug reactions. With 100-ml doses of iopamidol, five of 42 patients had adverse reactions. No adverse side effects required therapy in either study. There were no significant changes in vital signs or laboratory values after drug administration. The results of this study show that iopamidol is a suitable agent for excretory urography at doses of 50 and 100 ml. Patients report fewer unpleasant side effects with iopamidol than with diatrizoate. Overall image quality was better with iopamidol than with diatrizoate. Overall evaluation of drug performance was better with iopamidol than with diatrizoate.

Adolescent↗
PubMed1987

Radiation dose enhancement therapy with iodine in rabbit VX-2 brain tumors.

Loading tissue with iodine enhances the radiation dose absorbed from low energy X-rays. In order to test whether this is a useful procedure for treating brain tumors, we infused radiographic contrast media into rabbits carrying VX-2 brain tumors and delivered 15 Gy of 120 kVp X-rays in 3 fractions to the tumor. From CT scans we estimated that the dose enhancement was approximately 30%. The median survival times, after tumor detection on CT, of untreated rabbits, treated with radiation alone, and treated with radiation plus contrast media were 3, 25.5, 38.5 days, respectively. The repeated infusion of contrast media, 3.5 g of iodine per kg of body weight, did not affect kidney function as measured by serum creatinine levels. This method of enhancing radiation dose in brain tumors therefore appears promising.

Animals↗
PubMed1987

Extracorporeal shock wave lithotripsy: impact on the radiology department of a stone treatment center.

Extracorporeal shock wave lithotripsy (ESWL) was performed on 925 patients (1,222 treatments) for 446 calyceal, 345 pelvic, 172 ureteral, and 108 staghorn calculi. ESWL necessitated 6.3 KUB and 1.2 renal ultrasound studies per treatment session. Intravenous urography was required in 6% of patients after ESWL. Percutaneous nephrostomy tube placement was performed by the radiologists in 10% of patients. Procedures related to nephrostomy tube placement included percutaneous nephrolithotripsy, tube changes, nephrostography, and stone fragment irrigations and retrievals. Staghorn calculi treatment with ESWL required the most procedures by radiologists (34% for partial staghorn and 56% for complete staghorn) compared with 3%, 8%, and 11% for calyceal, pelvic, and ureteral stones, respectively. In all, 8,478 radiologic examinations and procedures were performed pertaining to ESWL. This is approximately 35 studies per day. While this number may be high because it represents the early experience of the authors with ESWL, the impact on the radiology department can be substantial.

Adolescent↗
PubMed1985

Development of rabbit brain tumor model for radiologic research.

A rabbit brain tumor model using transplanted VX-2 carcinoma had an 85% rate of successful implantation. Rabbits lived 8.5 +/- 1.3 days. The tumor doubling time was 0.5 to 2.6 days. Some tumors were shown as early as four days after implantation and all tumors were seen by ten days after implantation. Two of three rabbits receiving radiation therapy to the tumor had significant extension of life. This model is a useful radiologic research tool.

Animals↗
PubMed1984

Renal infarction: CT diagnosis and correlation between CT findings and etiologies.

The CT scans and the clinical records of 12 patients who had renal infarction were reviewed. The renal infarcts were classified as either focal or global. The CT findings were correlated with the etiologies of renal infarction. Embolism was the most common cause of renal infarcts that were multifocal with involvement of both kidneys. Trauma caused a unilateral global type of infarct. A case of sickle cell anemia presented with multiple "slit-like" focal infarcts and enlarged kidneys. Forty-seven per cent of infarcts demonstrated the cortical rim sign, 11% were associated with mass effect, 21% had a subcapsular fluid collection, and 6% had an abnormally thickened renal fascia.

Diagnosis, Differential↗
PubMed1984

Hyperdense renal masses: a CT manifestation of hemorrhagic renal cysts.

Eleven patients with sharply circumscribed round to ovoid renal cysts measuring 70-90 H on CT are reported. The cysts were hyperdense on unenhanced scans, measuring 30-60 H greater than the adjacent parenchyma, and either hypodense, isodense, or hyperdense on enhanced scans. Four patients had polycystic kidney disease; of the other 7 patients, the cysts were cortical in 6 and parapelvic in 1. Eight patients had a solitary cyst and 3 had multiple cysts. Sonography demonstrated internal echoes and/or lack of increased through-transmission in 6 patients. Pathological analysis was available in 6 cases and indicated a benign, hemorrhagic renal cyst. This hyperdense CT appearance is characteristic of some hemorrhagic renal cysts, though differentiation between benign and malignant cysts requires cyst puncture and/or surgery.

Adult↗
PubMed1983

Predicting angiography-induced acute renal function impairment: clinical risk model.

Two hundred sixty-six patients were evaluated for development of acute renal function impairment after renal angiography. Forty-five (16.9%) had a significant increase in serum level of creatinine (sCr), six developed oliguria or anuria, and one required permanent dialysis. Age, proteinuria, abnormal baseline sCr, use of Renografin 76, and preexisting renal disease were the five independent risk factors in the series. An odds-ratio analysis establishes the relative risk (i.e., likelihood) of developing acute renal insufficiency when a given risk factor is present. For example, patients with underlying renal disease were 6.6 times more likely to develop a transient increase in sCr than those with no renal disease. A clinical test model was devised to predict the likelihood that a given individual would develop acute renal insufficiency after renal angiography on the basis of the number of risk factors present. An increasing relation was demonstrated; the more factors present, the more likely it becomes that a patient will develop acute renal insufficiency.

Acute Kidney Injury↗
PubMed1982

Radiographic grading system for renal cell carcinoma with clinical and pathological correlation.

Clinical records, pathological specimens, and radiographs of 106 patients with renal cell carcinoma were reviewed and coded for computer analysis. Twenty radiographic features of the tumor were examined for their possible prognostic significance. Three angiographic signs were associated with an unfavorable prognosis: tumor size greater than 10 cm, poor definition of tumor margins, and parasitic circulation. A new radiological grading system was developed based on these signs. Upon comparison with existing clinical staging and pathological grading systems, the new system predicted prognosis equally well. In addition, it has the advantages of predicting prognosis preoperatively and being simple for clinical use.

Adenocarcinoma↗
PubMed1981

Physical pain and the goal of aversively stimulated aggression.

Several studies have indicated that anger arousal elicits instigation to inflict injury, but there is good evidence to date that noninsulting aversive events also create a desire to hurt someone. The verbal hostility or physical aggression displayed in previous investigations of the effects of such aversive stimuli might be expressions of an instigation to hit, but not necessarily to hurt, the available target. Two experiments were designed to demonstrate that painful environmental conditions evoke aggressive inclinations directed toward doing harm even when the available target is not responsible for the suffering. In both studies university women kept one hand in a tank of water that was either painfully cold or much warmer while they delivered rewards and punishments to another woman supposedly in the course of supervising her work. Half of the subjects in each condition were informed that their punishments might hurt their partner, whereas the others were told that these punishments probably would be helpful. In the first experiment the two variables interacted to affect the subjects' behavior only during the first work period. Experiment 2 yielded interaction in both periods for the reward measure. In general, the women exposed to the warmer water tended to deliver the greatest number of rewards when they had been told punishment would hurt, whereas those in the cold-water condition were least rewarding if they had been informed punishment would injure their partner. Citing evidence that a lower number of rewards was somewhat punitive, we conclude that the aversive stimulation had evoked an instigation to do harm, and that the information about the possibility of hurting the partner served as a goal cue facilitating the overt expression of the instigation. Factor analyses of the subjects' feelings in the second study suggested that the women's feelings were organized differently the first and second times they had their hand in the water.

Aggression↗
PubMed1981

Female urethral diverticula: double-balloon catheter study.

A double-balloon catheter was used to evaluate the female urethra in 51 patients. Six different radiographic appearances were identified. Three of the categories are considered variants of normal. One of the categories consisted of eight patients with urethral diverticula. All showed large rounded or lobulated collections of contrast material which were adjacent to the urethra and which persisted on postvoid films. Other abnormalities should be closely correlated with the clinical findings to determine their significance. The diagnosis of urethral diverticulum may be missed, as physical examination and endoscopy can be negative. Therefore, the optimal method for identifying its presence and extent includes both a double-balloon catheter study and a voiding cystourethrogram.

Adult↗
PubMed1981

The reliability of the "hypernephroma halo".

The excretory urograms and renal arteriograms of 68 patients with renal adenocarcinoma and 84 patients with renal masses other than renal adenocarcinoma were reviewed. The radiographs were examined for the presence or absence of the "hypernephroma halo." The sensitivity of this sign was observed to be only 6% and 35% on excretory urography and arteriography, respectively. The specificity was 92% and 77%. However, the overall accuracy of this sign was only 54% and 59%. The relation between the halo and its postulated structural correlate, the tumor capsule, was also examined. There was no significant association demonstrable. It was concluded that the hypernephroma halo is not a reliable sign for diagnosing renal adenocarcinoma and that it probably does not represent the tumor capsule.

Adenocarcinoma↗
PubMed1980

Radiographic evaluation of an artificial urinary sphincter (AMS 742).

The American Medical Systems' inflatable anti-incontinence device is a relatively new prosthesis. Its design, function, and proper method of radiographic evaluation in the pre- and postoperative patient are discussed. Complications peculiar to this device are demonstrated.

Humans↗