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Biomedical subjects

W F Bennett

Publications and source records attributed to W F Bennett.

At least 19 recordsLinked to original sources
PubMed2002

PACS monitors: an evolution of radiologist's viewing techniques.

When initially evaluating picture archiving communication systems (PACS) many radiologists try to duplicate the film environment and believe that multiple monitors are required to maintain the productivity of the radiologist. The authors were under the same impression initially but found that they underwent a paradigm shift over a period of time. This report documents the evolution that the radiologists underwent. The author's department consists of 28 diagnostic radiologists and 21 residents who actively read cases on a PACS. The department has been filmless for 6 months, although they have been reading soft copy films for 2 years. All modalities except mammography are included. The authors conducted interviews with both attending radiologists and residents to evaluate the change in methodology from the preconceptions to initial use to current use. The number and kind of monitors preferred for plain films, ultrasound scan, computed tomography (CT), and magnetic resonance imaging (MRI) were recorded. Additionally, viewing methods of different modalities were discussed. The authors found that there was a decrease in the number of monitors from preconceptions to actual use. Furthermore, to a lesser degree, there is a reduction of monitors used initially to that which is currently being used. The style of viewing cross-sectional images has changed. There has been a decrease in the number of images displayed on each monitor. The use of the roller ball on the mouse has affected this viewing style. Changing from a film-based reading environment to PACS environment not only brings about change in the overall technology in image delivery but also in the viewing techniques by radiologists. At our institution we have evolved from initially expecting to use 4 monitors all the time to actually preferring 2 monitors and occasionally 1 monitor to view images. Presentation software and viewing aids such as the roller ball on a mouse for viewing CTs in stack mode are key contributions to this paradigm shift. The decrease in monitors makes PACS more affordable and will allow further penetration of filmless radiology. The authors have found that after using PACS, radiologists prefer using 2 monitors. The style of reading films has changed with experience. Hospitals that plan to purchase PACS should consider this and ensure that the vendor has presentation software that optimizes the 2 monitor system.

Computer Terminals↗
PubMed2002

Delivering images to the operating room: a web-based solution.

As radiology departments become filmless, they are discovering that some areas are particularly difficult to deliver images. Many departments have found that the operating room is one such area. There are space constraints and difficulty in manipulating the images by a sterile surgeon. This report describes one method to overcome this obstacle. The author's institution has been using picture archiving and communication system (PACS) for approximately 3 years, and it has been a filmless department for 1 year. The PACS transfers images to a webserver for distribution throughout the hospital. It is accessed by Internet Explorer without any additional software. The authors recently started a pilot program in which they installed dual panel flat screen monitors in 6 operating rooms. The computers are connected to the hospital backbone by ethernet. Graphic cards installed in the computers allow the use of dual monitors. Because the surgeons were experienced in viewing cases on the enterprise web system, they had little difficulty in adapting to the operating room (OR) system. Initial reception of the system is positive. The use of the web system was found to be superior by the surgeons because of the flexibility and manipulation of the images compared with film. Images can be magnified to facilitate viewing from across the room. The ultimate goal of electronic radiology is to replace hardcopy film in all aspects. One area that PACS has difficulty in accomplishing this goal is in the operating room. Most institutions have continued to print film for the OR. The authors have initiated a project that may allow web viewing in the OR. Because of limited space in the OR, an additional computer was undesirable. The CPU tower, keyboard, and mouse were mounted on a frame on the wall. The images were displayed on 2 flat screen monitors, which simulated the viewboxes traditionally used by the surgeons. Interviews with the surgeons have found both positive and negative aspects of the system. Overall impression is good, but the timeliness of the intraoperative films needs to be improved. The author's pilot project of installing a web-based display system in the operating room still is being evaluated. Their initial results have been positive, and if there are no major problems that arise the project will be expanded. These results show that it is possible to provide image delivery to the OR over the intranet that is acceptable to the surgeons.

Computer Systems↗
PubMed2002

MR cholangiopancreatography in patients with primary sclerosing cholangitis: interobserver variability and comparison with endoscopic retrograde cholangiopancreatography.

OBJECTIVE: The purpose of our study was to determine the degree of interobserver variability and correlation between MR cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP) for the presence of bile duct strictures in patients with primary sclerosing cholangitis. MATERIALS AND METHODS: For this retrospective study involving 26 patients with primary sclerosing cholangitis, 31 MR cholangiopancreatograms were compared with 30 endoscopic retrograde cholangiopancreatograms. The MR cholangiopancreatograms were independently interpreted by two abdominal radiologists in a blinded, randomized manner for overall image quality, extent of ductal visualization, and the presence and location of bile duct strictures. Unweighted multirater kappa coefficient values were estimated for each comparison. RESULTS: Visualization of more than 50% of the expected ductal length was possible in the extrahepatic, central intrahepatic, and peripheral intrahepatic bile ducts in 99%, 88%, and 69% of the MR cholangiopancreatograms and 100%, 86%, and 52% of the endoscopic retrograde cholangiopancreatograms, respectively. Strictures were detected in the extrahepatic, central, and peripheral ducts in 53%, 68%, and 87% of the MR cholangiopancreatograms and 73%, 67%, and 63% of the endoscopic retrograde cholangiopancreatograms, respectively. The interobserver agreement for stricture detection was 61% for MR cholangiopancreatography and 76% for ERCP. MR cholangiopancreatographic findings were consistent with ERCP findings for the presence of strictures in 69% of the cases. CONCLUSION: In patients with primary sclerosing cholangitis, MR cholangiopancreatography better shows the bile ducts and can depict more strictures, especially of the peripheral intrahepatic ducts, than ERCP. MR cholangiopancreatography can be used to noninvasively diagnose and follow up patients with primary sclerosing cholangitis.

Adult↗
PubMed2001

Survival after conservative (palliative) management of pleural malignant mesothelioma.

BACKGROUND AND OBJECTIVES: Malignant mesothelioma is a lethal disease. Aggressive multimodality treatment protocols are reportedly associated with improved survival, but the apparent survival benefits may simply reflect patient selection and the variable natural history of this malignancy. Before embarking on our own protocol of experimental treatment for mesothelioma, we sought to identify important prognostic factors and document the survival of patients treated conservatively (with palliative intent only) in our region. METHODS: We performed a retrospective review of all patients with a diagnosis of malignant mesothelioma seen at our center between 1987 and 1999. Since curative intent treatment had not been given, we assumed that measured survival would largely reflect the natural history of the malignancy. RESULTS: There were 101 patients (80 males and 21 females). Mean age was 65 +/- 9.2 years. Symptoms of disease were present for a median time of 5 months before the diagnosis was established. The most common presenting symptoms were dyspnea (46 patients), chest pain (30 patients), and weight loss (22 patients). Sixty-eight patients (68%) had a history of asbestos exposure. Mesothelioma subtypes included epithelial (43 patients), sarcomatous (26 patients), mixed (19 patients), desmoplastic (4 patients), and unspecified (9 patients). All 101 patients were treated with palliative intent. Talc pleurodesis was performed in 70 patients. At the time of analysis, 90 patients had died and 11 remained alive. Median survival was 213 (95% CI 137-289) days. Survival for the three major histological subtypes was significantly different (log rank, P = 0.0016). Histological subtype (epithelial favorable) was the only significant independent prognostic factor (Cox proportional hazard regression, P = 0.0009). CONCLUSIONS: Patients with epithelial mesothelioma survive longer than those with other histological subtypes. Conservatively managed patients with pleural malignant mesothelioma have a median survival of approximately 7 months. These data from conservatively treated patients can serve as baseline information for future studies of experimental treatments.

Adult↗
PubMed2001

A meta-analysis of randomized controlled trials of route of reconstruction after esophagectomy for cancer.

BACKGROUND: A gastric conduit is usually used to reconstruct the foregut after esophagectomy for cancer. It can be transposed through a posterior or anterior mediastinal route. The choice of route is often debated but there is little evidence to support the use of one route over the other. We performed a meta-analysis of randomized controlled trials (RCTs) to determine the effect of route of reconstruction on patient outcomes. METHODS: Medline and manual searches were done (completed independently and in duplicate) to identify all published RCTs that addressed the issue of route of gastric conduit reconstruction after esophagectomy for cancer. The selection process was inclusive; no trials were excluded. Trial validity assessment was done and a trial quality score was assigned. Major outcomes for quantitative data synthesis included operative mortality, anastomotic leaks, cardiac morbidity, and pulmonary morbidity. A random-effects model was used and relative risk was the principal measure of effect. Systematic qualitative review was used for other outcomes such as duration of ventilation, length of hospital stay, operative blood loss, duration of surgery, anastomotic strictures, dysphagia, gastric emptying, and quality of life. Data on cancer survival were not available in the RCTs. RESULTS: Six RCTs were selected with quality scores ranging from 1 to 4 (5-point Jadad scale). Selection and validity agreement was strong. Relative risk (95% confidence interval; P value), expressed as posterior versus anterior mediastinal route (treatment versus control), was 0.56 (0.17, 1.82; P = 0.34) for mortality, 1.01 (0.35, 2.94; P = 0.98) for leaks, 0.43 (0.17, 1.12; P = 0.08) for cardiac complications, and 0.67 (0.34, 1.33; P = 0.26) for pulmonary complications. Systematic qualitative review did not suggest any difference in other perioperative outcomes or conduit function for the two routes of reconstruction. CONCLUSIONS: Data synthesized from existing RCTs show that posterior and anterior mediastinal routes of reconstruction are associated with similar outcomes after esophagectomy for cancer. However, a difference in outcomes for the two reconstructive routes remains possible. Further trials with larger numbers of patients are needed.

Esophageal Neoplasms↗
PubMed2001

Duration of knowledge in general thoracic surgery.

BACKGROUND: Medical knowledge changes rapidly, so current medical education approaches emphasize the development of life-long learning skills ("teaching the learner to learn") as opposed to the simple acquisition of contemporary medical knowledge. Because there are no data on the rapidity of change of general thoracic surgical knowledge, we do not know whether this trend in medical education is appropriate for thoracic surgical trainees. We undertook a study to assess the duration of knowledge in general thoracic surgery. METHODS: The first general thoracic surgery article from each issue of The Annals of Thoracic Surgery between 1965 and 1997 was abstracted into a summary statement. A form, made up of 360 summary statements in random order, was assessed by 6 general thoracic surgeons. They assessed statement validity on a 5-point scale (1 = statement false; 5 = statement true). Average statement validity scores for 30 time intervals were calculated. The relationship between time of publication and statement validity was analyzed. RESULTS: Average validity scores ranged from 2.24 (represents 1965 to 1966) to 4.32 (represents 1969 to 1970). Validity scores increased with time (y = 3.46 + 0.017x, where y is validity score and x is time), and this was significant (r = 0.40; p = 0.027). However, the absolute change in average validity scores over the 33-year study period was only 0.52 or 13.1% of the "modern" era scores. CONCLUSIONS: The assumption that medical knowledge changes quickly may not be true in general thoracic surgery. Although life-long learning skills are important, general thoracic surgery training programs should continue to emphasize fundamental knowledge in the specialty.

Clinical Competence↗
PubMed2001

Self-inflicted pneumothoraces.

Self-inflicted pneumothoraces are rare manifestations of psychiatric illness. Two patients with self-inflicted pneumothoraces are reported, and the typical clinical features of factitious disorders are described. If thoracic surgeons are aware of these conditions, inappropriate surgery- and poor outcomes-can be avoided.

Adult↗
PubMed2001

Open lung biopsy as an outpatient procedure.

BACKGROUND: Lung biopsies are frequently needed to diagnose diffuse interstitial lung diseases. Both limited thoracotomy (open lung biopsy) and thoracoscopy can be used for lung biopsies, but both procedures have traditionally required hospital admission. We report a series of patients that underwent outpatient open lung biopsy to show the safety and effectiveness of this practice. METHODS: We reviewed records of ambulatory, nonoxygen dependent patients with a clinical diagnosis of diffuse interstitial lung disease that underwent outpatient open lung biopsy between January 1997 and December 1999. All procedures were done by a senior surgeon using single lumen endotracheal anesthesia, a small anterolateral thoracotomy without rib spreading, stapled wedge resection, and no chest tube. Patients were discharged the same day. RESULTS: Thirty-two patients with a clinical diagnosis of diffuse interstitial lung disease underwent outpatient open lung biopsy. Mean age was 58 years (range, 21 to 74 years). Preoperative forced expiratory volume in 1 second was 74.3%+/-7.0% of predicted. A pathologic diagnosis was established in all patients: usual interstitial pneumonia, 26 patients; sarcoidosis, 2; metastatic carcinoma, 2; desquamative interstitial pneumonia, 1; and mixed dust pneumoconiosis, 1 patient. No patient required a chest tube, overnight observation, or hospital admission. No complications occurred. CONCLUSIONS: Selected patients with a clinical diagnosis of diffuse interstitial lung disease can safely and effectively undergo diagnostic outpatient open lung biopsy. However, careful patient selection and attention to operative detail are essential.

Adult↗
PubMed2001

Handsewn or stapled esophagogastric anastomoses after esophagectomy for cancer: meta-analysis of randomized controlled trials.

Gastric transposition with esophagogastric anastomosis is a common method of reconstruction after esophagectomy for cancer. The anastomosis can be fashioned using a handsewn or stapled technique. The choice of anastomotic technique is often debated but there is little evidence to support the use of one method over the other. We performed a meta-analysis of randomized controlled trials (RCTs) to determine the effect of esophagogastric anastomotic method (handsewn or circular stapled) on patient outcomes. Medline and manual searches were done (completed independently and in duplicate) to identify all published RCTs that addressed the issue of handsewn or stapled esophagogastric anastomosis after esophagectomy for cancer. The selection process was inclusive; no trials were excluded. Trial validity assessment was done and a trial quality score was assigned. Major outcomes for quantitative data synthesis included operative mortality, anastomotic leaks, anastomotic strictures, cardiac morbidity, and pulmonary morbidity. A random-effects model was used and relative risk was the principal measure of effect. Systematic qualitative review was used for other outcomes such as duration of operation and time to complete the anastomosis. Data on cancer survival were not available in the RCTs. Five RCTs were selected with quality scores ranging from 2 to 3 (5-point Jadad scale). Selection and validity agreement was strong. Relative risk (95% confidence interval, CI; P-value), expressed as handsewn vs. stapled (treatment vs. control), was 0.45 (0.20, 1.00; P=0.05) for operative mortality, 0.79 (0.44, 1.42; P=0.43) for anastomotic leaks, 0.60 (0.27, 1.33; P=0.21) for anastomotic strictures, 0.99 (0.55, 1.77; P=0.97) for cardiac morbidity, and 0.93 (0.63, 1.37; P=0.72) for pulmonary morbidity. Data synthesized from existing RCTs show that handsewn and circular stapled esophagogastric anastomotic techniques give similar results for anastomotic outcomes, such as leaks and strictures. The stapled anastomotic method appears to increase operative mortality (P=0.05). Although it is difficult to explain this finding, it should not be dismissed. Several hypotheses are discussed.

Aged↗
PubMed2001

Visualization of the anatomy of the rotator interval and bicipital sheath.

A systematic evaluation of the glenohumeral joint should be routinely performed with all shoulder arthroscopy and include all anatomic areas. However, to date, less attention has been given to the insertion of the subscapularis tendon, superior glenohumeral ligament (SGHL), and medial head of the coracohumeral ligament (MCHL). This article outlines arthroscopic techniques that may aid in the evaluation of the anatomy of the rotator interval and bicipital sheath. In this apical region, the CHL contributes fibers to the SGHL (forming the internal reflection of the bicipital groove-SGHL/CHL complex), the subscapularis tendon, and the joint capsule. The CHL is more anterior to the SGHL. There is a distinct anatomic difference between the SGHL/CHL insertion complex and the subscapularis insertion. The normal insertion of the subscapularis tendon is into a small trough on the lesser tuberosity. Together, these structures make up the medial wall of the superior biceps pulley. With the arthroscope advanced to the anterior portion of the joint, the shoulder is elevated from 60 degrees to 90 degrees and a neuroprobe is advanced through the anterior cannula. By internally rotating the arm, the subscapularis tendon insertion and SGHL/CHL complex slacken. A neuroprobe can be placed under the insertion of the subscapularis tendon and SGHL/CHL complex. A 70 degrees arthroscope can aid in visualization with less shoulder elevation. These techniques allow for a thorough visualization of the structures of the rotator interval and medial bicipital sheath.

Arthroscopy↗
PubMed2001

Subscapularis, medial, and lateral head coracohumeral ligament insertion anatomy. Arthroscopic appearance and incidence of "hidden" rotator interval lesions.

PURPOSE: The purpose of this study was to document the incidence of lesions of the rotator interval, illustrate the arthroscopic appearance of subtle differences in these lesions, and discuss how various lesions may affect biceps tendon stability in the bicipital groove. TYPE OF STUDY: A Data Registry has been used in my office since 1995 (Microsoft Office Access). This study reports on the results of a retrospective database "query" of the prospectively entered data from 1995 to 1998. Thus, by default, the format of this study is a consecutive sample. Only patients with a disruption of rotator cuff tendons, labrum and/or gleno-coracohumeral ligaments are included by study design. METHODS: This study has identified and reports on 46 arthroscopically identified subscapularis tears, 25 "hidden" rotator interval lesions (SGHL/MCHL complex) and 6 SGHL/CHL complex plastic deformation lesions in 165 patients undergoing shoulder arthroscopy for conditions ranging from anterior instability to rotator cuff tears. Arthroscopically identified lesions include partial or complete disruptions of the subscapularis tendon, disruptions of the superior glenohumeral/medial head coracohumeral ligament complex (SGHL/MCHL), disruptions of the lateral head coracohumeral ligament (LCHL), and various combinations of the above. RESULTS: The incidence rate of subscapularis tendon involvement in 165 arthroscopically treated shoulder patients was 27%. The incidence rate of subscapularis tendon disruptions with rotator cuff pathology was 35%. The incidence rate of SGHL/MCHL lesions (tear or stretch) in 165 arthroscopically treated shoulder patients was 18%. The incidence rate of SGHL/MCHL tears in 165 arthroscopically treated shoulder patients was 15%. Forty-seven percent of all subscapularis tears involved the SGHL/CHL complex. Ten percent of all rotator cuff tears involving the supraspinatus tendon involved the LCHL. CONCLUSIONS: This study has recorded the incidence of lesions of the subscapularis, SGHL/MCHL complex and/or the LCHL, and combinations thereof in degenerative cuff and instability patients. Primary lesions of the rotator interval can occur and regardless of the associated pathology, and if these lesions are not repaired, biceps tendon subluxation may exist.

Arthroscopy↗
PubMed2001

Antitumor activity of the growth hormone receptor antagonist pegvisomant against human meningiomas in nude mice.

OBJECT: The authors have previously demonstrated that modulation of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis can significantly affect meningioma growth in vitro. These studies were performed to evaluate the efficacy of GH receptor blockade in vivo. METHODS: Primary cultures from 15 meningioma tumors obtained in humans were xenografted into athymic mice. Approximately 1.5 million cells from each of the 15 tumors were implanted into the flanks of two female mice, one pair for each tumor. One animal from each of the 15 pairs was then treated with the GH receptor antagonist pegvisomant and the other with vehicle alone for 8 weeks. The tumor volume was measured using digital calipers three times per week. The mean tumor volume at the initiation of injections was 284 +/- 18.8 mm3 in the vehicle group and 291.1 +/- 20 mm3 in the pegvisomant group. After 8 weeks of treatment, the mean volume of tumors in the pegvisomant group was 198.3 +/- 18.9 mm3 compared with 350.1 +/- 23.5 mm3 for the vehicle group (p < 0.001). The serum IGF-I concentration in the vehicle group was 319 +/- 12.9 microg/L compared with 257 +/- 9.7 in the pegvisomant group (p < 0.02). A small but significant decrease was observed in circulating IGF binding protein (IGFBP)-3 levels, whereas slight increases occurred with respect to serum IGFBP-1 and IGFBP-4 levels. In the placebo group the tumor weight was 0.092 +/- 0.01 g compared with 0.057 +/- 0.01 g in the pegvisomant group (p < 0.02). The IGF-I and IGF-II concentrations were measured in the tumors by using a tissue extraction method. These human-specific immunoassays demonstrated that there was no autocrine production of IGF-I in any of the tumors, either in the pegvisomant or vehicle group. The IGF-I levels were highly variable (0-38.2 ng/g tissue) and did not differ significantly between treatment groups. CONCLUSIONS: In an in vivo tumor model, downregulation of the GH/IGF-I axis significantly reduces meningioma growth and, in some instances, causes tumor regression. Because the concentrations of IGF-II in tumor did not vary with pegvisomant treatment and there was no autocrine IGF-I production by the tumors, the mechanism of the antitumor effect is most likely a decrease of IGF-I in the circulation and/or surrounding host tissues. Because the authors have previously demonstrated that the GH receptor is ubiquitously expressed in meningiomas, direct blockade of the GH receptor on the tumors may also be contributing to inhibitory actions.

Adult↗
PubMed2001

Prophylactic intracavitary (pneumonectomy space) antibiotic instillation: a comparative study.

BACKGROUND AND OBJECTIVES: Postpneumonectomy empyema is a dreaded complication of pneumonectomy. The effectiveness of prophylactic intracavitary antibiotic instillation is not known. We conducted a retrospective review to assess the effect of pneumonectomy space antibiotic instillation on septic complications (empyema and bronchial fistula) of pneumonectomy. METHODS: Ninety-three consecutive patients underwent pneumonectomy at our institution over a three-year period. Their charts were reviewed retrospectively and data was collected on age, gender, diagnosis, intravenous antibiotics, intracavitary (pneumonectomy space) antibiotics, empyemas, bronchial fistulas, length of hospital stay, and operative mortality. RESULTS: All 93 patients received 3 perioperative doses of prophylactic intravenous antibiotics. One group (n=47) of patients also received intraoperative intracavitary instillation of an antibiotic solution (penicillin G: 5 million units, bacitracin: 50,000 units, gentamicin: 60 mg, in 1 litre of saline) while the other group (n=46) did not. Age, gender, diagnosis, and length of stay were not significantly different in the two groups. There were no empyemas or bronchial fistulas in the intracavitary antibiotic group. Postpneumonectomy empyemas occurred in 6 (13%) patients (empyema with bronchial fistula: 5, empyema alone: 1) that had not received intracavitary antibiotics (p=0.012). There were 4 deaths (9%) in each group (p=0.63). CONCLUSIONS: Prophylactic intraoperative intracavitary antibiotic instillation may reduce the incidence of empyemas after pneumonectomy. However, a randomized trial would be needed to prove the effectiveness of this form of prophylactic antibiotic strategy.

Aged↗
PubMed2001

Anastomotic leaks after esophagectomy for esophageal cancer: a comparison of thoracic and cervical anastomoses.

BACKGROUND AND OBJECTIVES: Esophagogastric anastomotic leaks remain a significant problem after esophagectomy for esophageal cancer. Many investigators have reported that leaks are more frequent after cervical, as opposed to thoracic, esophagogastric anastomoses. We conducted a retrospective review to assess the effect of anastomotic location (thoracic or cervical) on anastomotic leak incidence and severity. METHODS: Seventy-four consecutive patients with esophageal cancer underwent esophagectomy and esophagogastric anastomoses at our institution over a four-year period. Their charts were reviewed retrospectively and data was collected on age, gender, histology, stage, resection margin status, adjuvant therapy, cancer survival, anastomotic location, anastomotic leaks, and operative mortality. RESULTS: Cervical anastomoses were done in 19 patients and thoracic anastomoses were done in the other 55 patients. The two groups were similar with respect to age, gender, histology, stage, adjuvant therapy, and overall survival. Operative mortality for the entire group of 74 patients was 4% (3 patients). Resection margins were positive for residual tumor in 2 of 19 (11%) patients with cervical anastomoses and 9 of 55 (16%) patients with thoracic anastomoses (p=0.42). Leaks complicated 1 of 19 (5%) cervical and 9 of 55 (16%) thoracic esophagogastric anastomoses (p=0.21). Positive resection margins and anastomotic leaks were not significantly related (p=0.54). One of 9 (11%) leaks in the thoracic group proved fatal. CONCLUSIONS: In our experience cervical esophagogastric anastomoses do not have a higher incidence of leaks than thoracic anastomoses.

Aged↗
PubMed2000

Treatment of acromegaly with the growth hormone-receptor antagonist pegvisomant.

BACKGROUND: Patients with acromegaly are currently treated with surgery, radiation therapy, and drugs to reduce hypersecretion of growth hormone, but the treatments may be ineffective and have adverse effects. Pegvisomant is a genetically engineered growth hormone-receptor antagonist that blocks the action of growth hormone. METHODS: We conducted a 12-week, randomized, double-blind study of three daily doses of pegvisomant (10 mg, 15 mg, and 20 mg) and placebo, given subcutaneously, in 112 patients with acromegaly. RESULTS: The mean (+/-SD) serum concentration of insulin-like growth factor I (IGF-I) decreased from base line by 4.0+/-16.8 percent in the placebo group, 26.7+/-27.9 percent in the group that received 10 mg of pegvisomant per day, 50.1+/-26.7 percent in the group that received 15 mg of pegvisomant per day, and 62.5+/-21.3 percent in the group that received 20 mg of pegvisomant per day (P<0.001 for the comparison of each pegvisomant group with placebo), and the concentrations became normal in 10 percent, 54 percent, 81 percent, and 89 percent of patients, respectively (P<0.001 for each comparison with placebo). Among patients treated with 15 mg or 20 mg of pegvisomant per day, there were significant decreases in ring size, soft-tissue swelling, the degree of excessive perspiration, and fatigue. The score fortotal symptoms and signs of acromegaly decreased significantly in all groups receiving pegvisomant (P< or =0.05). The incidence of adverse effects was similar in all groups. CONCLUSIONS: On the basis of these preliminary results, treatment of patients who have acromegaly with a growth hormone-receptor antagonist results in a reduction in serum IGF-I concentrations and in clinical improvement.

Acromegaly↗
PubMed2000

Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging.

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 micromol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease.

Adult↗
PubMed2000

Cable modem access to picture archiving and communication system images using a web browser over the Internet.

This presentation describes our experiences using a web-based viewing software and a browser to view our picture archiving and communication system (PACS) images at a remote site with cable modem-internet communications. Our testing shows that using a cable modem to access our radiology webserver produces acceptable transmission speeds to remote sites. The average time-to-display (TTD) for 16 computed tomography (CT) images on the web-based intranet system in our hospital was 7 to 8 seconds. Using a cable modem and comparable equipment at a remote site, the average TTD is 16 seconds over the internet. The TTD does not significantly change during various hours of the day. Security for our hospital-based PACS is provided by a firewall. Access through the firewall is accomplished using virtual private network (VPN) software, a secure ID, and encryption. We have found that this is a viable method for after-hours subspecialty radiology consultation.

Academic Medical Centers↗