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P Costello

Publications and source records attributed to P Costello.

At least 55 records · Page 3Linked to original sources
PubMed1995

In vivo three-dimensional evaluation of the tracheobronchial tree.

Traditionally computed axial tomography has had limitations in evaluating diseases that affect the tracheobronchial tree because of respiratory-induced artifacts, with the likelihood of missing lesions as a result of misregistration. Spiral computed tomography (CT) differs from conventional CT in that the entire thorax can be rapidly imaged in the axial plane after a single breath-hold. Five patients underwent non-contrast-enhanced volumetric CT, with emphasis on three-dimensional reconstruction, and endoscopic evaluation with pathologic confirmation. In all cases, there was complete corroboration between volumetric CT and endoscopic evaluation. The use of selective thresholds allowed the air within the tracheobronchial tree to be used as a negative contrast agent. Thus with the integration of selective windowing, detailed three-dimensional tracheobronchial anatomy may be elucidated. The absence of respiratory registration artifact due to the single breath-hold technique raises the confidence that three-dimensional and multiplanar images generated from such studies are accurate representations of the pathologic conditions at hand. By the integration of volumetric CT techniques and rapid three-dimensional display of tracheobronchial structures, volumetric CT bronchography becomes practical.

Aged↗
PubMed1994

Spiral CT of the thorax.

Spiral CT represents a major advance in CT technology. While the patient is advanced through the scanner gantry, continuous data acquisition occurs during suspended respiration eliminating many of the limitations associated with conventional thoracic CT. By eliminating respiratory misregistration and by offering the ability to reconstruct overlapping images at small intervals, spiral CT is advantageous for pulmonary nodule detection. Airway pathology and lesions adjacent to the diaphragm are better visualized with spiral CT and can be displayed in multiplanar or three-dimensional formats. Vascular imaging, including pulmonary embolus detection, is improved by spiral CT because scanning occurs rapidly at the peak of vascular enhancement.

Adult↗
PubMed1994

Comparison of rapid detection methods for influenza A virus and their value in health-care management of institutionalized geriatric patients.

Respiratory specimens from 160 geriatric patients with suspected influenza illness were used to evaluate the abilities of two enzyme immunoassays (EIAs; Directigen FLU-A [Becton Dickinson Microbiology Systems, Cockeysville, Md.] and Prima EIA [Baxter/Bartels Diagnostics, Inc., Issaquah, Wash.]) and direct immunofluorescence testing (immunofluorescence assay [IFA]) to identify influenza A virus. In comparison with culture isolation, the sensitivities and specificities of the IFA, Directigen FLU-A, and Prima EIA were 92.5 and 97.2%, 86.8 and 99.1%, and 92.5 and 98.1%, respectively. In contrast to EIA, IFA was labor intensive and required a high degree of technical expertise, and the results of IFA were difficult to interpret. These factors may preclude the use of IFA for testing large numbers of specimens. A retrospective epidemiologic survey of influenza infection was done in six geriatric institutions which had used either rapid and culture testing or culture alone. Preventable cases of influenza A virus infection ranged from 9 to 38% of all cases in facilities which used culture testing only and which had not instituted amantadine prophylaxis. The use of direct specimen testing is recommended as an adjunct to culture isolation for the identification of influenza A virus. Use of a combination of these methods permits the timely administration of appropriate antiviral therapy and infection control measures, while it also permits the antigenic surveillance of circulating influenza strains, which is necessary for present vaccine efficacy evaluations and the creation of future effective vaccine formulations.

Aged↗
PubMed1994

Thoracic helical CT.

Helical CT depicts small pulmonary nodules not seen at conventional CT by elimination of respiratory misregistration and thorough analysis of a contiguous data volume. Pulmonary lesions can be analyzed in detail with use of retrospective reconstruction of the data volume. Multiplanar and three-dimensional images of lung masses and arteriovenous malformations are free of motion artifacts. The airways are clearly depicted by helical CT, a capability that enhances the radiologic evaluation of patients with hemoptysis, bronchial strictures, tumors, and recent lung transplantation. In comparison to conventional CT, helical CT provides a more consistent level of vascular enhancement because of the shortened acquisition time. Clinical applications include the detection of central pulmonary thromboemboli and the assessment of aortic aneurysms and dissections.

Angiography↗
PubMed1994

Cost-effective use of low-osmolality contrast media for CT of the liver: evaluation of liver enhancement provided by various doses of iohexol.

OBJECTIVE: Because of pending efforts to reform health care in the United States, judicious use of low-osmolality contrast media is important. We studied the effects of using various concentrations and volumes of iohexol, compared with the conventional dose and concentration of diatrizoate meglumine used for CT, to determine if a more cost-effective dose results in diagnostically efficacious liver enhancement. SUBJECTS AND METHODS: A total of 902 patients received one of nine different doses of IV contrast media. Eight doses of iohexol were used: 125 ml of iohexol 350 (350 mg l/ml, 44 g l/dose), 100 ml of iohexol 350 (35 g l/dose), 150 ml of iohexol 300 (300 mg l/ml, 45 g l/dose), 120 ml of iohexol 300 (36 g l/dose), 100 ml of iohexol 300 (30 g l/dose), 175 ml of iohexol 240 (240 mg l/ml, 42 g l/dose), 150 ml of iohexol 240 (36 g l/dose), and 125 ml of iohexol 240 (30 g l/dose). A single dose (150 ml) of diatrizoate meglumine 60% (w/v) was used (42 g l/dose). Contrast material was injected at a rate of 2 ml/sec. Scanning began 35-45 sec after injection. Quantitative analysis of enhancement was performed by obtaining region-of-interest measurements through the liver on scans obtained before and after injection of contrast material. Mean and maximum changes in hepatic density and mean time to maximum enhancement were measured. Mean time-density curves were subsequently derived for each dose of contrast material. Qualitative analysis of enhancement was performed by using subjective, previously defined criteria. All studies were interpreted in a double-blind fashion. RESULTS: Mean hepatic enhancement was greater with 125 ml of iohexol 350 and 150 ml of iohexol 300 than with other doses of contrast material (p < .05). Both 125 ml of iohexol 350 and 150 ml of iohexol 300 produced actual hepatic enhancement of more than 50 H for over 60 sec. The greatest maximum increase in hepatic density occurred with 125 ml of iohexol 350. When analyzed qualitatively, 150 ml of iohexol 300 resulted in the highest percentage of optimum enhancement. CONCLUSION: According to quantitative analysis, 125 ml of iohexol 350 administered at a rate of 2 ml/sec produces the best enhancement, whereas according to qualitative analysis, 150 ml of iohexol 300 produces the best enhancement. All doses of iohexol 240 provide poor enhancement compared with a conventional dose of contrast material of 150 ml of diatrizoate meglumine 60% or 150 ml of iohexol 300. A moderate cost savings can be achieved by using 125 ml of iohexol 350 for dynamic sequential CT.

Cost-Benefit Analysis↗
PubMed1993

Clinical assessment of an interventional CT table.

A computed tomographic (CT) system was modified to enable fluoroscopy during interventional CT procedures. Five patients with infradiaphragmatic abscesses underwent drainage by means of fluoroscopic CT guidance with a mean procedural time of 12 minutes. The addition of fluoroscopy facilitates avoidance of the diaphragm and injection of contrast material, makes catheter exchange easy, and minimizes procedural time.

Abdomen↗
PubMed1992

Evaluation of three immunoassays for detection of Chlamydia trachomatis in urine specimens from asymptomatic males.

The performances of three commercially available immunoassays (Chlamydiazyme/Antibody Blocking Assay [Abbott Diagnostics, Abbott Park, Ill.], IDEIA [Analytab Products, Plainview, N.Y.], and Microtrak EIA [Syva Co. Palo Alto, Calif.]) were evaluated for the detection of Chlamydia trachomatis in urine specimens from asymptomatic males. Assay results were compared with direct specimen immunofluorescence (DFA) analysis of urine sediment (Syva Microtrak; Syva Co.), which was chosen as the study confirmation assay. An overall Chlamydia prevalence of 7% (24 of 340) was found in our study population, with peak incidences occurring in the adolescent (8 of 93 specimens) and young adult (11 of 146 specimens) age groups. Sensitivity and specificity data among the Chlamydiazyme, IDEIA, and Microtrak enzyme immunoassays (EIAs) were determined to be 79.1 and 99%, 91.7 and 98%, and 95.8 and 99%, respectively. The Microtrak EIA and IDEIA products demonstrated sensitivities and specificities equal to or greater than those claimed for urine specimens. The diagnostic accuracies of these assays on asymptomatic subjects, along with the ease of this collection method, suggest a role for these products as screening tools. The sensitivity of the Chlamydiazyme assay was lower than that claimed previously in symptomatic patients, with 5 of 24 positive specimens demonstrating false-negative results. In those cases, centrifugation of the original immunoassay aliquot material and then DFA examination confirmed specimen positivity. Urine immunoassay screening in combination with DFA confirmation (which was chosen because it has antibody epitopic specificity different from that of the primary assay) provides a high degree of diagnostic precision. The use of noninvasive collection methods could result in greater testing compliance among asymptomatic males and, subsequently, could reduce the incidences of both symptomatic and silent chlamydial infections.

Adolescent↗
PubMed1992

Spiral CT in evaluation of head and neck lesions: work in progress.

Spiral computed tomography (CT) was used in the evaluation of 21 patients with head and neck lesions. Scanning time ranged from 24 to 36 seconds, and high-quality diagnostic scans with excellent anatomic resolution and minimal motion artifact were produced. Vascular opacification was optimized with substantially less contrast medium than used in conventional studies. These preliminary results show spiral CT to be at least comparable with conventional CT in the evaluation of the head and neck.

Female↗
PubMed1992

Spiral CT of the thorax with reduced volume of contrast material: a comparative study.

The effectiveness of spiral computed tomography (CT) of the thorax performed with 60 mL of 60% contrast material was compared with that of conventional dynamic incremental CT performed with 120 mL of 60% contrast material. Fifty patients in whom contrast material-enhanced thoracic CT examination was necessary were assigned to undergo either spiral CT or dynamic incremental CT. Vascular opacification and mediastinal-lung image quality were graded independently by two observers. Vascular opacification and lung image quality were better with spiral CT than with conventional CT. Results of this pilot study encourage the use of spiral CT to decrease the volume of contrast medium used in patients undergoing thoracic CT.

Adult↗
PubMed1992

Spiral CT of the pancreas.

Computed tomography (CT) is the modality of choice for evaluation of pancreatic disease. In this prospective study, images obtained with spiral CT, which enables examination of a region of the body in a single breath-hold, were compared with those obtained by means of dynamic CT with automatic table incrementation in two groups of 30 patients referred for suspected disease of the pancreas. In both groups, vascular opacification and anatomic detail were analyzed with a grading system (1 = poor, 2 = good, 3 = excellent). Vascular opacification received mean grades of 2.78 and 2.33 in the spiral CT and control groups, respectively. Anatomic detail received mean grades of 2.63 and 2.42 in the spiral CT and control groups, respectively. Respiratory motion artifact was absent in all spiral CT examinations but was present in 17 of 30 control CT examinations. Images obtained with spiral CT showed superior vascular opacification and reduced respiratory artifact with smaller amounts of contrast agent (90 mL vs 120 mL) compared with those obtained with dynamic CT.

Adult↗
PubMed1992

Assessment of the thoracic aorta by spiral CT.

A recently developed technique, spiral CT, allows rapid data acquisition through an entire anatomic region during a single breath-hold. High-quality spiral CT scans of the thoracic region have been obtained with volumes of contrast material that are small relative to those used with conventional CT. This essay illustrates the diseases of the aorta as seen on spiral CT performed with low volumes of contrast material.

Aged↗
PubMed1992

Noninvasive liver imaging: new techniques and practical strategies.

The goals and expectations of liver imaging have expanded as the treatment options for a range of liver diseases have advanced. Unfortunately, no single modality can yet achieve all the goals that an ideal imaging modality should satisfy. Currently available liver imaging techniques should be considered complementary rather than competitive in their roles, and appropriate utilization of the expanding technical capabilities of cross-sectional imaging depends on many considerations, including patient factors, referring physician expectations and biases, experience and bias of the radiologist, and the availability of state-of-the-art technical capabilities for each modality. This article reviews the advantages, limitations, and roles of fast CT and fast MR liver imaging techniques as well as the complimentary role of ultrasound, and the future of new imaging considerations including the role of contrast agents.

Humans↗
PubMed1992

Cross-sectional imaging of liver transplantation.

Orthotopic liver transplantation is commonly performed at many institutions around the world. The care of these critically ill patients has heavily relied upon cross-sectional imaging. CT, MRI, and ultrasound help enormously in the preoperative assessment of these patients and in the postoperative management of the various complications. This article reviews the role of these cross-sectional modalities and their respective strengths and weaknesses in the adult transplant candidate and recipient.

Humans↗