Quality-oriented mass mammography screening.

PURPOSE: To demonstrate the ability of a mass mammography screening program to provide consistently high-quality mammography screening, while at the same time sustain a large volume of patients to keep the cost of mammography low. MATERIALS AND METHODS: A public-funded, mass mammography screening program, begun in 1988, is currently being conducted in five Canadian provinces. For the Screening Mammography Program of British Columbia, complete follow-up data are available for the first 57 months of operation. During that time, the program expanded from one center with five radiologist screeners to 14 centers with 30 radiologist screeners. There were 201,937 examinations performed on 128,325 women, 35% of whom were younger than 50 years. RESULTS: There were 802 cancers detected at an overall rate of 6.2 per 1,000 women (2.8 per 1,000 in women younger than 50 years and 8.1 per 1,000 in women older than 50 years). In the women younger than 50 years, 90 (72%) of the cancers were stage 0 or stage I, and the axillary lymph nodes were involved in 14 (11%). In the women 50 years or older, 496 (73%) of the cancers were stage 0 or stage 1, and the axillary lymph nodes were involved in 97 (14%). CONCLUSION: If quality is carefully controlled, the results of a mass screening program can be either maintained or improved. For both age groups, the prognostic characteristics are similar.

Interval breast cancers in the Screening Mammography Program of British Columbia: analysis and classification.

OBJECTIVE: Interval cancers in an annual mammography screening program are defined as cancers detected within 12 months after a mammographic screening in which findings are considered normal. Our objective was to analyze interval cancers for histologic type, tumor size, staging, and histologic grade. A classification for interval cancers is presented. Detection of interval cancers is an integral part of quality control and is required for the establishment of sensitivity rates for screening mammography, a necessary part of implementing the recommendations for breast cancer screening. MATERIALS AND METHODS: A total of 47,583 mammographic screening examinations of 38,219 women were available for review for the period of July 1988 to March 1991. Linkage with the provincial population-based cancer registry provided identification of all interval cancers of the breast. Histologic analysis of breast cancers was provided by an internationally recognized breast cancer pathologist who interpreted the specimens twice. RESULTS: A total of 207 breast cancers were detected at mammographic screening (true-positive cancers) during the first 33 months of the program, and 37 interval cancers were identified during the 33 months of screening plus a 12-month interval. Blinded review by three radiologists experienced in screening mammography resulted in classification of 21 of 37 cases as true interval cancers and 16 cases as misses. No interval cancers were missed because of poor mammographic technique. The sensitivity of screening mammography was 85%, 63% for patients less than 50 years old and 89% for patients more than 50 years old. The specificity was 93% for all patients (both younger and older than 50 years). CONCLUSION: The availability of a population-based cancer registry in the province of British Columbia makes an accurate determination of interval cancers and sensitivity rates possible. These data are essential for quality analysis, program planning, and education of radiologists in screening mammography. There were more true interval cancers than misses, and histologic analysis demonstrated that the majority of interval cancers were in stages I and II.

Benign mucous membrane pemphigoid: treatment of esophageal stricture.

The authors describe a 35-year-old man who has had benign mucous membrane pemphigoid from the age of 12 years. Upper esophageal stricture, a rare complication of the syndrome, developed when he was 24 years old. This recurrent condition has been followed for 11 years. It was treated initially, for 6 years, with esophagoscopy and bougie dilatation. Balloon dilatation under fluoroscopic guidance was then substituted for bougienage; this procedure has been performed successfully 10 times over the last 5 years and remains the patient's preferred treatment. The mean period for recurrence of symptoms has been 5 months. Several previous reports of this condition describe treatment with esophagoscopy and bougie dilatation, but there has been no previous report of interventional radiology with balloon dilatation.

The Canadian National Breast Screening Study: a Canadian critique.

The Canadian National Breast Screening Study (CNBSS) was the first study designed to determine the efficacy of screening for breast carcinoma in women 40-49 years old. Women were randomized to undergo either annual mammography and physical examination or usual care after an initial physical examination [1]. Women 50-59 years old were randomized to undergo either annual mammography and physical examination or annual physical examination only [2]. This study, published by epidemiologists on the efficacy of a radiologic examination, therefore, invites evaluation by radiologists.

Percutaneous transluminal biopsy of the biliary tract.

Percutaneous transluminal biopsy performed under fluoroscopic control uses interventional access routes and allows direct sampling of biliary tract lesions. The authors report their experience with this technique in 20 patients. The biopsy site was the gallbladder in 9 patients and the intrahepatic or extrahepatic bile ducts in 11. A suspected malignant lesion was the indication for biopsy in 17 patients; 3 patients underwent biopsy of the gallbladder mucosa during ablation therapy. The procedure was performed with the forceps (for 17 patients), brush (for 2) or "scrape" (for 1) technique; diagnostic material was obtained in all but one case. The sensitivity, specificity and overall accuracy of diagnosis in the patients with a suspected malignant lesion were 71%, 100% and 88% respectively. There were no false-positive results. In this series one major complication, hemobilia necessitating transarterial embolization, occurred after the scrape biopsy, and minor, self-limiting gallbladder hemorrhage occurred in one patient. This study shows that percutaneous transluminal biopsy is a reliable technique for examining a variety of biliary tract lesions and can lead to an accurate pathological diagnosis.

Colorectal cancer. Can we lower the death rate in the 1990s?

Colorectal cancer is second only to lung cancer in the number of lives it claims annually, yet it is a curable cancer. Early detection is possible in high-risk individuals. The risk for colorectal cancer almost doubles every 7 years in patients older than 50. The authors review the epidemiology and site distribution of colorectal cancer, compare available diagnostic techniques, and consider the cost effectiveness of screening. Barium enema and endoscopy are recommended diagnostic tests, but expensive colonoscopy does not appear to be justified for screening.

Are there predictors for future academic radiologists? A Canadian survey.

In 1990 the authors surveyed all members of the Canadian Association of Radiologists and all graduates of the radiology residency program at the University of British Columbia in the previous 10 years. They compared radiologists with and those without a university affiliation to determine the influences on career choice. The factors considered included teaching, research and publication experience, as well as educational background. Most respondents had decided on a career path during the second half of the residency or later. The authors found certain predictors and influences associated with a greater probability that a radiologist would pursue an academic career. For example, academic radiologists were more likely to have performed research, published and presented the results of their research activities, and taught before undertaking the residency program in radiology than their counterparts who were not affiliated with a university or a residency program. However, class standing in medical school and prior educational experience were similar for academic and nonacademic radiologists. The influences most often cited as leading toward an academic career were a desire to teach, the inspiration of a role model and an interest in research. Job satisfaction was higher among nonacademic radiologists, as indicated by the number that would consider a career change. Most of the respondents disapproved of a special residency curriculum for academic radiologists.

The value of sonography in determining cystic duct patency.

A prospective blinded comparison of ultrasonography (US) and oral cholecystography (OCG) was performed in 100 patients with symptomatic gall-stones to determine whether US would enable an accurate assessment of cystic duct patency to be made. Patency of the cystic duct was defined as gall-bladder opacification on OCG or a greater than 20% decrease in gall-bladder volume by US post-fatty meal. The ellipsoid method of volume measurement was used. Any patient who had a non-opacified gall-bladder on OCG but a greater than 20% volume decrease on US had cholescintigraphy performed (DISIDA). Oral cholecystography demonstrated cystic duct patency in 88 patients (88%), and fatty-meal gall-bladder US met the specified study criteria for patency in 86 patients (86%). False negative results were identified in four of the OCG and in six of the US examinations. The results of this study indicate that gall-bladder sonography with a post-fatty meal contraction of greater than 20% is a very accurate predictor of cystic duct patency. A contraction of less than 20%, however, cannot be considered a reliable predictor of cystic duct occlusion.

Extracorporeal shockwave lithotripsy for a giant calcified gallbladder stone. Case report.

Extracorporeal shockwave lithotripsy to gallstones is an alternative treatment to surgery in the high-risk patient with acute cholecystitis. We describe the successful fragmentation of a giant gallbladder stone and the subsequent removal of fragments through a cholecystostomy tract. Even though the treatment required 22 days in hospital and multiple procedures, these were all considered low risk in this patient with severe chronic obstructive airway disease.

Silicone drain mimicking a surgical sponge.

Because the appearances of a retained surgical sponge and the radiopaque portion of an in situ Snyder Hemovac flat silicone drain are similar at radiographic evaluation, confirmation should be obtained that a patient in whom a retained surgical sponge is suspected does not have this type of drain in place. The difference between the two items is especially difficult to discern in large patients or in patients with overlying dressings or a gas-distended abdomen.

Cholelithiasis and the interventional radiologist.

The Interventional Radiologist plays an important part in the team with Surgeons and Gastroenterologists for the treatment of stone disease in the Gallbladder and Bile ducts. He must be familiar with the natural history, the clinical picture, the treatment variety, and the technical details of radiologic intervention under fluoroscopic control in order to assume his proper place in the therapy of cholelithiasis. This is especially true for the patient with a high surgical risk factor.

Extracorporeal shockwave lithotripsy of pancreatic duct stones.

Encouraging results with extracorporeal shockwave lithotripsy (ESWL) for pancreatic duct stones have been reported from Europe. We present our experience with the first two North American patients, treated with excellent results in one and limited clinical improvement in the other patient at 1 year follow-up. Targeting of pancreatic duct stones was achieved with either fluoroscopy or ultrasound.

The British Columbia Mammography Screening Program: evaluation of the first 15 months.

We report our experiences in the first 15 months of a government-funded pilot project begun in 1988 to study the feasibility of rapid throughput, low-cost screening mammography in British Columbia. The primary goals of the project were (1) to determine the unit cost of screening mammography within the context of the program; (2) to design and put into operation a centralized system of data collection, analysis, and quality control to enable calculations of cancer detection rates, biopsy rates, biopsy yield ratios, staging, and other specific cancer characteristics; and (3) to study compliance in the community where the program was offered. A total of 11,824 women had mammography at a unit cost of U.S. $32.66. Computerized analysis revealed that (1) 11% of women had known primary risk factors; (2) findings on mammograms were interpreted as abnormal in 9% of screening examinations; (3) breast cancers were confirmed in 47 (22%) of 211 patients who had biopsies, and 87% of these were stage 0-1. The overall cancer detection rate was four per 1000, with five per 1000 for women who had not had mammography in the preceding 2 years and one per 1000 for women who had had mammography in the past 2 years. The results show that screening mammography can be conducted at low cost. Data collection and analysis and compliance were sufficiently convincing to initiate province-wide expansion.

Effectiveness of transcutaneous electrical nerve stimulation (TENS) for analgesia during biliary lithotripsy.

The effectiveness of transcutaneous electrical nerve stimulation (TENS) in controlling pain during biliary extracorporeal shockwave lithotripsy (BESWL) was assessed in 100 patients with symptomatic gallbladder calculi. Patients were divided into four groups: TENS electrodes were placed on the back at cutaneous anesthesia sites and on the right leg and the gallbladder acupuncture site in groups A and B. Electrodes were "turned on" only in group A. In groups C and D, electrodes were placed only on the back at cutaneous dermatomes. Electrodes were "turned on" in group C only. The TENS unit was stimulated at the pulse rate of 60 to 100 microseconds and frequency of 80 to 125 Hz. Lithotripsy was performed with the Lithostar Plus overhead module. The differences in the amount of analgesic used and the pain experiences by the patients in all groups were not statistically significant. The proportion of patients requiring intravenous analgesia in each group was also not significantly different (72%, 80%, 68%, 76% in groups A to D, respectively). Thus, TENS did not help in reducing the amount of intravenous analgesia required or the average pain perceived by the patient during lithotripsy treatment.

Gallbladder contractility: variation in normal subjects.

Gallbladder contractility can be quantified radiologically, but it is not known whether the degree of contraction exhibited by a person's gallbladder varies from day to day. Thirty healthy volunteers were studied with sonography on three separate occasions to determine the variation of individual gallbladder contractility. Using the ellipsoid method, we measured gallbladder volume after an overnight fast (fasting gallbladder volume) and between 45 and 60 min after a standard fatty meal (residual gallbladder volume). Percentage gallbladder contraction was calculated by dividing the difference between the fasting and residual gallbladder volumes by the fasting gallbladder volume and multiplying by 100. The 90 studies in 30 subjects exhibited a wide range of values: fasting gallbladder volume from 1.9 to 45.5 ml, residual gallbladder volume from 0.1 to 21.0 ml, and percentage gallbladder contraction from -10% to 99%. Within each subject, fasting gallbladder volume measurements varied from 1.5 to 26.2 ml (mean +/- two standard deviations, 10.3 +/- 5.1 ml) and residual gallbladder volume from 0.3 to 15.4 ml (5.1 +/- 3.8 ml). Percentage gallbladder contraction varied from 6% to 87% (28% +/- 18%). In 60% of the subjects, percentage gallbladder contraction values varied by more than 20%, and in 20% of the subjects it varied by more than 40%. These data show that a wide variation exists within a normal person in the degree of gallbladder contraction exhibited from one day to another, and a single test for gallbladder contraction can be misleading.

Altered gallbladder contractility after extracorporeal shock-wave cholecystolithotripsy.

Change in gallbladder contractility after biliary extracorporeal shock-wave lithotripsy (ESWL) may significantly influence the clearance of fragments after successful gallstone fragmentation. We assessed changes in gallbladder contractility in response to an oral fatty meal in 50 patients 1 month after biliary ESWL (all fragments were smaller than 3 mm) and also in a separate group of 10 patients 3 months after complete clearance of fragments. The prevalence of persistent lumen-obliterating contraction of the gallbladder after biliary ESWL also was analyzed in 325 patients. Gallbladder contractility remained unchanged in 30, increased in nine, and decreased in 11 of the 50 patients. The average reduction in the fasting gallbladder volume after lithotripsy was 28% (p less than .001). Gallbladder contractility remained unchanged 3 months after complete clearance of fragments in six of 10 patients studied separately. A decrease (n = 2) or increase (n = 2) in contractility was seen in the remaining patients. No significant difference occurred in the average ejection fraction of the gallbladder before lithotripsy and after complete clearance of the fragments. Thirty-four of the 325 patients who have so far undergone biliary ESWL had a completely contracted gallbladder with no lumen visible on sonography. The gallbladder returned to a relaxed state in half of these patients within 1-9 months. Thus, biliary ESWL did not significantly alter gallbladder contractility in 60% of patients. A significant reduction in the volume of the fasting gallbladder occurred after lithotripsy. Successful clearance of fragments did not improve the contractility of stonebearing gallbladders in the majority of patients.