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Biomedical subjects

P N Cascade

Publications and source records attributed to P N Cascade.

At least 37 records · Page 2Linked to original sources
PubMed1995

Implications of unsuspected pulmonary embolism detected by computed tomography.

OBJECTIVE: To describe the computed tomography (CT) findings and clinical implications of pulmonary thromboembolism noted incidentally on CT. PATIENTS AND METHODS: The authors reviewed the CT studies and medical records for nine patients in whom CT had shown clinically unsuspected pulmonary thromboembolism. The study group consisted of seven men and two women ranging in age from 51 to 75 years, who were referred for CT over a 5-year period for a variety of indications. The location of the emboli and the presence and location of parenchymal and pleural abnormalities were determined. Subsequent changes in patient care were analysed. RESULTS: The locations of the thromboemboli were described according to pulmonary zone. One case involved zone 1 (main pulmonary artery to a lung), all involved zone 2 (first-order branches), and four involved extension into zone 3 (second-order branches). No emboli were distinguished in zone 4 (beyond the segmental arteries). Four patients had pleural-based opacities characteristic of infarcts, and three had pleural effusions. Eight patients underwent confirmatory testing. A vena cava filter was placed in three patients, one of whom also received anticoagulation therapy. The other six patients were treated by anticoagulation alone. All of the patients survived and were discharged. CONCLUSION: Radiologists should watch carefully for occult pulmonary thromboembolism when interpreting CT studies of the thorax. Establishing this diagnosis can result in immediate changes to treatment and possibly a reduction in the substantial morbidity and mortality associated with untreated pulmonary emboli.

Aged↗
PubMed1995

Helical computed tomography for the evaluation of tracheal stenosis.

BACKGROUND: Helical computed tomography with multiplanar reconstruction (CT/MPR) was used to study proximal airway stenosis. METHODS: Twenty-eight helical CT/MPR studies were obtained in 25 patients with known or suspected stenosis of the trachea or main bronchi. Computed tomographic results were compared with planar tomograms and bronchoscopic evaluation of the airway. RESULTS: CT/MPR accurately demonstrated the site and degree of tracheal and main bronchial stenoses with a sensitivity of 93%, a specificity of 100%, and an accuracy of 94%. There was one false negative study in a patient with tracheomalacia. In a second patient, a tracheal web was only apparent on nonstandard viewing windows. CONCLUSIONS: CT/MPR provides good anatomic detail and is an increasingly available technique. Potential drawbacks include the need for a longer breath-hold (15 to 45 seconds) and increased complexity of data compared with conventional tomograms. Helical CT/MPR is useful in the preoperative evaluation of these patients and, as experience accumulates, may replace the use of conventional tomograms.

Bronchial Diseases↗
PubMed1994

High-resolution CT detection of lacerations in the transplanted lung after transbronchial biopsy.

Relatively large tissue samples may be obtained from the lung with the "Alligator" biopsy forceps. We report the radiographic and high-resolution computed tomography (HRCT) appearances of six pulmonary lacerations in the transplanted lungs of three asymptomatic patients after transbronchial biopsy with this large caliber biopsy forceps. All patients had undergone transbronchial biopsy from 4 to 10 days before HRCT that was performed as part of routine surveillance after transplantation. The site and histopathologic findings of lung biopsies and negative microbiologic studies on bronchoalveolar washings correlated accurately with each pulmonary lesion seen. Laceration size varied from 9 to 20 mm (mean 14 mm) on HRCT. A thickened wall or surrounding alveolar reaction related to bronchoalveolar lavage or biopsy-induced hemorrhage was seen in five lesions. These simulated the appearance of lung abscess or invasive fungal disease. Only nonspecific alveolar opacities were noted on chest radiographs. The Alligator biopsy forceps may cause pulmonary lacerations in transplanted lungs that are detectable on HRCT but not on chest radiographs. Differentiation from opportunistic infection by CT criteria alone is difficult in these immunocompromised patients. CT studies in this population should be performed prior to transbronchial biopsy whenever possible.

Adult↗
PubMed1994

Transvenous and subcutaneous implantable cardioverter defibrillators: radiographic assessment.

PURPOSE: To assess chest radiograph configurations in 102 patients following total or partial transvenous and subcutaneous insertion of a non-thoracotomy lead implantable cardioverter defibrillator (NTL-ICD) device. MATERIALS AND METHODS: The four overlapping system types reviewed were the Endotak (49 patients), PCD (32 patients), Res-Q (10 patients), and hybrid combinations of NTL-ICD and surgically inserted pericardial and epicardial automatic implantable cardioverter defibrillator (AICD) devices (15 patients). RESULTS: Abnormalities were detected on radiographs both at the time of implantation and at early follow-up. NTL-ICD electrodes partially replaced or augmented AICD systems in 11 patients (10.7%) because of sensing lead or defibrillation failure or infection. Defibrillation failure necessitated augmentation of NTL-ICD systems with AICD pericardial patches in four patients (3.9%). Catheter displacement, lead fracture, or pneumothorax was detected in eight patients (7.8%). CONCLUSION: Complex radiographic appearances may be seen and important abnormalities may be detected after insertion of these devices.

Defibrillators, Implantable↗
PubMed1994

Sarcoidosis: recurrence of primary disease in transplanted lungs.

PURPOSE: To assess findings of recurrent disease on thin-section computed tomographic (CT) studies and results of bronchoalveolar lavage and transbronchial biopsy (BAL-TBB) procedures performed in adult lung transplant recipients. MATERIALS AND METHODS: Between 1990 and 1993, 32 single-lung, 14 double-lung, and three heart-lung transplantation procedures were performed in 47 patients; 176 thin-section CT scans were reviewed, with a mean follow-up of 18.9 months after transplantation. RESULTS: Sarcoidosis was diagnosed after BAL-TBB of the lung allografts 3 and 15 months after transplantation in both patients without symptoms who received transplants for treatment of sarcoidosis. In one patient, diffuse miliary nodules seen on chest radiographs and thin-section CT scans disappeared after administration of an increased dose of corticosteroids; in the other patient, no radiologic finding of sarcoidosis was present. No recurrence was seen in patients who received transplants for treatment of other diseases. CONCLUSION: Recurrence of primary disease should be considered whenever abnormalities are seen on chest radiographs or thin-section CT scans. Sarcoidosis may recur with or without radiologic findings after transplantation.

Adolescent↗
PubMed1994

Solarization in clinical imaging.

X-ray exposure levels at which solarization occurs were determined for a new screen-film system and its predecessor, both from the same manufacturer and both with a speed class of 400. Solarization (contrast reversal [lead markers imaged as black on a lighter back-ground]) was clearly evident with the new system at a cassette exposure level of 132 mR (3.4 x 10(-5) C/kg). No solarization was exhibited by the old system even at five times this exposure. In rare cases, solarization can obscure bone and soft-tissue detail, thereby degrading the diagnostic accuracy of the radiograph.

Humans↗
PubMed1994

Quality assessment and improvement: what radiologists do and think.

OBJECTIVE: The main objectives of the study were as follows: first to study the nature and extent of radiologists' involvement in and their attitudes toward quality assessment (QA) and continuous quality improvement (CQI)/total quality management (TQM) in hospitals and in offices; and second, to ascertain whether differences in size, type, and location among hospitals and nonhospital radiology offices affect the QA and CQI/TQM activities of radiologists. We analyzed data from a national survey conducted by the American College of Radiology (ACR) in 1993. MATERIALS AND METHODS: Questionnaires about QA and CQI/TQM activities and attitudes were mailed to 216 hospital-affiliated diagnostic radiology group practices using a sample selected from the ACR master list of radiology practices in the United States. The response rate was 90%. A stratified random sample ensured representation of different geographic regions, various group sizes, and both academic and nonacademic groups. Responses were weighted so that our data show what answers about hospitals would have been if (i) the survey had been answered by all hospital radiology departments in the United States (except for those few staffed by solo practitioners or nonradiologists) and (ii) our questions about nonhospital offices had been answered by all radiology groups in the United States (except those few having no hospital activity). RESULTS: The majority (86%) of hospital radiology departments report having a program to monitor and evaluate physicians' performances. Fifty-one percent collect incorrect diagnoses by specific radiologist. Twenty-eight percent collect some of their QA data through computerized information systems. We found some statistically significant differences by hospital size and location, with larger hospitals and urban hospitals being more likely to engage in some QA activities. Multivariate analyses, once controlled for hospital size and location, found no significant differences in QA activity between university and community hospitals or between hospitals with and without a residency program. QA and CQI programs were less common in offices than in hospitals. With the exception of mammographic interpretations, most practices did not monitor and evaluate physicians' performances in the office setting. Respondents representing 58% of hospital radiology departments thought that QA and CQI contributed to improvement in patient care. Only 19% of radiology practices answered that CQI has been of cost benefit to their organization. CONCLUSION: Most radiology practices engage in a variety of QA and CQI activities in hospitals. However, this is less true in offices, in which radiologists have more discretion, and radiologists remain skeptical about the usefulness of CQI.

Attitude of Health Personnel↗
PubMed1994

Aspects of chest imaging in the intensive care unit.

Timely performance and accurate interpretation of portable chest radiographs in the ICU setting are fundamental components of quality care. Teamwork between intensive care clinicians and radiologists is necessary to assure that the appropriate studies, of high technical quality, are obtained. By working together to integrate available clinical information with systematic comprehensive analysis of images, accurate diagnoses can be made, optimal treatment instituted, and successful outcomes optimized.

Cardiovascular Diseases↗
PubMed1994

Pulmonary function in single lung transplantation for chronic obstructive pulmonary disease.

The primary determinants of pulmonary function after heart-lung or double lung transplantation are the volume and compliance of the recipient's thoracic cage. This study evaluated the influence of recipient chest wall factors on static and dynamic lung volumes after single lung transplantation for chronic obstructive pulmonary disease. Fourteen patients with chronic obstructive pulmonary disease received 15 single lung transplants (one retransplant). Posttransplantation follow-up data at 3 and 6 months, in the absence of infection or rejection, were available in nine patients. Overall pulmonary function at 6 months improved from preoperative levels to 55% to 65% of predicted values (forced vital capacity 38% to 55%, forced expiratory volume at 1 second 18% to 55%, maximum voluntary ventilation 21% to 65%), and allograft-specific pulmonary function improved to nearly normal predicted single-lung values (forced vital capacity 89%, forced expiratory volume at 1 second 90%, maximum voluntary ventilation 105%). Postoperative pulmonary function in these patients correlated significantly with preoperative thoracic volume measured by planimetry of chest radiographs. No correlation between postoperative pulmonary function was demonstrated with either the estimated volume of donated lung tissue or relative donor-to-recipient size matching. These findings support the concept that recipient chest wall factors determine postoperative pulmonary function in patients undergoing single lung transplantation for chronic obstructive pulmonary disease. Furthermore, the allograft lung functions at a normal level for the recipient and does not appear to be constrained by hyperinflation of the contralateral lung.

Adult↗
PubMed1993

Portable chest imaging: comparison of storage phosphor digital, asymmetric screen-film, and conventional screen-film systems.

The quality of chest images obtained with portable radiography was evaluated for a conventional screen-film system, a new asymmetric screen-film chest system, and computed radiography (CR). Sixty chest images were obtained in 20 patients in an intensive care unit. The CR system was ranked by all three evaluating radiologists as substantially better in overall diagnostic quality, interpretability of the lungs, and musculoskeletal detail and by two of the three observers as better for the visibility of catheters and lines. In the upper abdomen and mediastinum, there was not a clear preference. Standard deviations of film density were +/- 0.12, +/- 0.41, and +/- 0.39 for the CR, conventional, and asymmetric systems, respectively. For the same systems, phantom results indicated the relative lung contrast values were 1.2, 1.0, and 0.89, respectively. Similarly, the limiting resolution values in the lung were 2.0, 4.2, and 6.3 line pairs per millimeter. The CR system had twice the root-mean-square noise of the screen-film systems. Overall, the preferred system for portable chest imaging was the CR system.

Electricity↗
PubMed1993

Negative-pressure pulmonary edema after endotracheal intubation.

A review of complications occurring in conjunction with general anesthesia identified eight patients with laryngospasm-induced negative-pressure pulmonary edema after endotracheal intubation. Six male and two female patients (mean age, 31.9 years) developed pulmonary edema immediately or up to 25 minutes after extubation. Radiographs obtained 15-165 minutes after symptoms developed revealed alveolar edema and predominating interstitial edema in four patients each. Seven of eight had bilateral centralized patterns, and one had unilateral pulmonary edema. The mean vascular pedicle width was 67 mm +/- 12, a value 40% higher than the normal mean of 48 mm. The mean cardiothoracic ratio was 0.54 +/- .07 (normal mean, 0.53). There were no radiologic abnormalities of the trachea. Negative-pressure pulmonary edema should be suspected in young patients with findings of bilateral centralized pulmonary edema, a wide vascular pedicle, and a normal cardiothoracic ratio in the immediate postoperative period.

Adult↗
PubMed1993

Role of femoral vessel catheterization and altered hemostasis in the development of extraperitoneal hematomas: CT study in 44 patients.

OBJECTIVE: To ascertain the role of femoral vessel catheterization and altered hemostasis in the development of extraperitoneal hematomas, we evaluated CT scans to study the locations of extraperitoneal hematomas in three distinct clinical settings: (1) after femoral vessel catheterization with concurrent altered hemostasis due to anticoagulant, thrombolytic, and/or antiplatelet therapy (catheterized-altered hemostasis group); (2) after femoral vessel catheterization without altered hemostasis (catheterized group); and (3) with no history of femoral vessel catheterization, with or without altered hemostasis caused by a bleeding diathesis or pharmacotherapy (uncatheterized group). MATERIALS AND METHODS: Forty-four patients were identified who had CT evidence of extraperitoneal hematomas. Twenty-four were in the catheterized-altered hemostasis group, one was in the catheterized group, and 19 were in the uncatheterized group. CT scans were evaluated for anatomic subspace involvement by hemorrhage and for the presence or absence of contiguity between the hematoma and the femoral vessels. RESULTS: Bilateral hematomas were present in six of 24 patients in the catheterized-altered hemostasis group and in four of 19 patients in the uncatheterized group. We found no significant difference between the catheterized-altered hemostasis and the uncatheterized groups regarding the proportion of cases involved at any individual retroperitoneal site (p > .05). The mean number of hematoma sites in the catheterized-altered hemostasis group (4.3) was not significantly different from the mean number in the uncatheterized group (3.7) (p > .05). Contiguity between the sites of hematoma and the punctured femoral vessels was present in 75% of the patients in the catheterized-altered hemostasis group; contiguity between the hematoma and a groin was seen in 58% in the uncatheterized group. Twenty-two of 24 patients in the catheterized-altered hemostasis group had CT findings of subcutaneous fat infiltration in the groin; however, six of 19 patients in the uncatheterized group also had this finding, indicating that its presence does not always represent changes caused by catheterization. CONCLUSION: Retroperitoneal hematomas in patients with altered hemostasis and femoral vessel catheterization do not show a unique distribution attributable solely to contiguous spread of blood from the vessel puncture site. Many of these hematomas probably arise at sites distant from the femoral vessel puncture. When the hematoma is not contiguous with the punctured femoral vessels, altered hemostasis is most likely the cause of the hemorrhage.

Catheterization, Peripheral↗
PubMed1993

Nonthoracotomy lead implantable cardioverter defibrillators: normal radiographic appearance.

Recently, cardioverter defibrillators with leads and patches that can be implanted via a combination of transvenous and subcutaneous routes rather than via thoracotomy have been developed. Early experience in patients subject to serious ventricular arrhythmias suggests that, as with surgically implanted defibrillators, these nonthoracotomy defibrillators can reduce the risk of sudden death due to cardiac arrest [1]. Moreover, high perioperative complication rates associated with thoracotomy-inserted cardioverter defibrillators are avoided [2]. Four models are currently undergoing clinical trials in the United States. We have used three of these models: PCD (Medtronic, Minneapolis, MN), ENDOTAK (Cardiac Pacemakers Inc., St. Paul, MN), and RES-Q (Intermedics, Freeport, TX). This essay illustrates the normal radiographic appearance of these devices.

Defibrillators, Implantable↗
PubMed1991

Percutaneous biopsy of left adrenal masses: prevalence of pancreatitis after anterior approach.

Acute pancreatitis is an unusual but recognized complication of percutaneous aspiration biopsy of the pancreas. As the pancreatic tail is located anterior to the left adrenal gland, percutaneous biopsy of a left adrenal mass via the anterior approach may result in needle passage through the tail of the pancreas with subsequent potential development of pancreatitis. To evaluate this risk, we retrospectively reviewed 48 CT-directed percutaneous aspiration biopsies of left adrenal masses done between 1984 and 1989 at two institutions. Positioning of the patient, the course of the needle, the number of needle passes, and the size of the needle were analyzed. Thirty-three (69%) of 48 biopsies of a left adrenal mass were performed by using the anterior approach. The pancreas was traversed by one or more needles in 32 of 33 cases. Biopsies were performed with 20- to 22-gauge needles, and the number of needle passes varied widely. The medical records of the 33 patients in whom the anterior approach was used also were reviewed for complications. Acute pancreatitis, which required 11-13 days of hospitalization, developed in two patients (6%). None of the other 31 patients suffered a complication. We conclude that the pancreatic tail is routinely traversed by the biopsy needle when biopsy of a left adrenal mass is done via the anterior approach and that severe acute pancreatitis can occur as a result.

Acute Disease↗
PubMed1990

Rib compression of the coronary arteries.

This report describes the finding of coronary artery narrowing caused by compression by an overlying rib in two patients with cardiomegaly. There is probably no clinical significance to this finding. The primary differential diagnostic entity is myocardial bridging.

Aged↗
PubMed1990

Monitoring and evaluating the quality and appropriateness of angiographic/interventional radiologic procedures.

The safety and efficacy of invasive radiologic procedures should be monitored in all departments that include such activities. Assessing the data arising from such monitoring and taking the actions needed to improve quality and appropriateness of care are additional steps that must be taken to meet the expectations of the JCAHO. The SCVIR has distributed to its membership for comment a proposal for a model program for monitoring and evaluating angiographic/interventional procedures that, if adopted by a department, would help meet external accrediting reviews. The SCVIR also has under study a proposal to develop a national data base that would act as a repository of information on invasive radiologic procedures. By voluntarily participating in the program, departments would receive feedback that periodically documents performance and compares it with national norms established by all participants in the program. If the data base is sufficiently detailed, distinct advantages of collaborative research could result. Data related to comparative technology assessment, cost-benefit analyses, and other derived information could then be made available to other physicians, the public, payers, and government agencies. The discipline of radiology would have a vehicle to influence and create national recommendations for health care policy decisions.

Angiography↗