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Assessment criteria for diagnostic imaging technologies.

Expensive diagnostic imaging technologies need to be assessed. Assessment is most difficult with new technologies. Rapid technical change creates pressure for widespread provision because of apparently self-evident advantages. For the health care provider, technology assessment is of central importance. Timing is crucial; economic and clinical studies have to be carried out simultaneously; and studies must be broadly based. Assessment should be carried out only on properly selected technologies. Apart from picture archiving and communication systems, existing expensive diagnostic imaging technologies are now so mature that assessment is concerned mainly with costs and benefits. To be provided, a technology needs to be effective, economic, appropriate and needed. The history of computed tomography illustrates technology assessment from innovation to routine application. Technology assessment also provides essential guidance for equipment selection. Different regulations and controls, explicit or implicit, exist in different countries. There are special requirements for technology assessment in each country according to overall health requirements and policies. The main contemporary challenges are the correct selection of equipment for assessment, and the development of predictive methods of assessment.

Diagnostic Imaging↗

Diagnostic imaging in small hospitals.

Diagnostic imaging in small hospitals is discussed. Four key questions are answered: (1) Are diagnostic imaging technologies necessary at this level? (2) Which technologies should be chosen and why? (3) How can they be most rationally and cost effectively used? (4) How can their total impact on health care be assessed? The paper concludes that small hospitals should have diagnostic imaging facilities and that the modalities of choice are diagnostic radiology and ultrasonography. A detailed description is given of the WHO Basic Radiological System and General Purpose Ultrasonographic equipment together with WHO recommendations for the rational use of diagnostic imaging.

Diagnostic Imaging↗

Image compression techniques for medical diagnostic imaging systems.

As a result of recent technological advances, a significant (and increasing) number of the images in a typical radiology department are represented in digital form. This includes images that have been captured using digital imaging modalities such as computed tomography and magnetic resonance imaging as well as images that have been digitally converted from film originals as in computed radiography. To provide economical storage of such images and to allow for their efficient transmission over various networks, it becomes necessary to consider digital image compression techniques. In this article, the fundamental concepts of several popular reversible and nonreversible image compression schemes are reviewed. In addition, the performance of the schemes in terms of compression ratio and reconstructed image quality as applied to medical diagnostic images is investigated.

Diagnostic Imaging↗

The use of Imagent BP in diagnostic imaging research and 19F magnetic resonance for PO2 measurements.

Imagent BP (90% w/v perflubron emulsion) is radiopaque and serves as an X-ray contrast medium. Quantitative X-ray Computed Tomography, provides the means to non-invasively estimate tissue perflubron concentration providing three unique capabilities: 1) The use of the same animal for biodistribution and elimination analysis; 2) The precise geographic distribution of the agent to more accurately quantitate localized accumulations; and 3) The ability to gather physiologic data by monitoring the time dependent distribution of perflubron. It is known that the T1(-1) of 19F of perfluorochemicals is linearly related to the dissolved oxygen which allows the quantitation of PO2 in-vivo. We showed using perflubron in phanta that not only was T1(-1) linearly related to PO2 but also T2(-1) and both were insensitive to perflubron concentration. Since flow interferes with signal, the first in-vivo experiments have focused on stationary perflubron located within phagocytes. T1(-1) measured from this environment suggested a PO2 of 15-25 Torr. T1(-1) increased by nearly 50% when the FIO2 was increased from 20 to 100% reflecting an increase in intracellular PO2 on the order of 25 Torr.

Animals↗

Trends in diagnostic imaging for low back pain: has MR imaging been a substitute or add-on?

PURPOSE: To assess whether magnetic resonance (MR) imaging has replaced other diagnostic imaging modalities in the evaluation of persistent low back pain. MATERIALS AND METHODS: Data on diagnostic imaging use in 2,374 adult patients with persistent low back pain in 1987-1990 were analyzed. Multiple logistic regression was used to estimate the annual adjusted odds of lumbosacral spine radiography, MR imaging, unenhanced computed tomography (CT), or CT myelography use. The national cost of diagnostic imaging for persistent low back pain in 1990 relative to 1987 was estimated. RESULTS: The adjusted odds of performing MR imaging in 1990 relative to 1987 was 3.44 (95% confidence interval, 2.63, 4.51), which reflects an estimated increase from 22 studies per 100 enrollees in 1987 to 75 studies per 100 enrollees in 1990. Use of MR imaging in combination with radiography, unenhanced CT, or CT myelography increased. The additional national cost of diagnostic imaging for persistent low back pain in 1990 relative to 1987 was estimated at $70-$176 million. CONCLUSION: MR imaging was used primarily as an add-on rather than a substitute for other imaging modalities in the evaluation of persistent low back pain. Thus, the volume and cost of diagnostic imaging for persistent low back pain have increased.

Adult↗

[The benefits of diagnostic imaging in general practice].

INTRODUCTION: Diagnostic imaging provides great benefits to general practitioners in the diagnosis of a number of diseases. However, their employment involves a large use of resources and exposure to radiation. We estimate the value of the diagnostic imaging examinations most frequently used by general practitioners and seek to evaluate their role in the primary health care system. MATERIALS AND METHODS: All patient files in a single-doctor general practice were retrospectively reviewed in regard to the results of electronically accessible diagnostic imaging examinations. 396 cases were characterised by indication, diagnosis and clinical consequences of the examination. RESULTS: The examinations were divided into five groups of specific examinations and one group of miscellaneous examinations. 7.5% of 93 radiographic examinations of the thorax resulted in clinical intervention. The equivalent figures for radiographic examinations of the thoracic and lumbar spine were 26.7% of 45, of the knees 30.8% of 39, of the hips 3.2% of 31 and of abdominal ultrasound scan 20.4% of 49, respectively. CONCLUSION: We discuss the value of the most common diagnostic imaging examinations used in the primary health care system. We conclude that patients in our practice are given radiographic examinations of the thorax and hips relatively infrequently, while radiographic examinations of the thoracic and lumbar spine and abdominal ultrasound scans are done more frequently and more often result in clinical intervention.

Denmark↗

Advanced diagnostic imaging techniques in ophthalmology.

Diagnostic imaging techniques continue to gain tremendous importance in the evaluation of ocular and orbital disease as technical developments and refinements are made. This article presents key diagnostic imaging methods, with special focus directed toward the advanced modalities important in evaluation of the traumatized eye and orbit. The text has been prepared specifically for the clinical ophthalmologist. Each of the diagnostic modalities discussed is presented in terms of its basic biophysical mechanism, indications, and advantages and disadvantages. The techniques described include simple plain film roentgenography (and its contrast-related applications: dacryocystography, orbital venography, and angiography), axial hypocycloidal tomography, computed tomography, ultrasonography, and magnetic resonance imaging.

Diagnostic Imaging↗

[Radiology of the temporomandibular joint. Diagnostic imaging of the temporomandibular joint].

Diagnostic imaging plays an important role in the diagnosis of disorders of the masticatory system. The most frequent disorders are osteoarthrosis and internal derangements. The clinical diagnosis of these disorders may be confirmed by diagnostic imaging. In addition, diagnostic imaging contributes to the staging of the degenerative changes. Techniques for examination of the temporomandibular joint, including conventional (panoramic, transpharyngeal, transcranial) as well as more sophisticated techniques (tomography, fluoroscopy, arthrography, computed tomography, scintigraphy and magnetic resonance imaging) are briefly described. The interpretation of the radiological image of the joint in health and when affected by osteoarthrosis and internal derangement is presented.

Humans↗

Cost-effectiveness of magnetic resonance imaging and enteroclysis in the diagnostic imaging of Crohn's disease.

OBJECTIVES: To compare the cost-effectiveness of magnetic resonance imaging (MRI) and enteroclysis in patients with Crohn's disease (CD). METHODS: A decision analytic model was performed considering the correct diagnoses of CD and complications such as fistulas and abscesses as effects. Costs were estimated in Euro([symbol: see text]) using German fee schedules. RESULTS: MRI was more effective and more costly compared with enteroclysis. Incremental cost-effectiveness of MRI versus enteroclysis was [symbol: see text]1,595 per additional correctly diagnosed patient. CONCLUSIONS: The use of MRI in the work-up of patients with CD cannot be generally recommended from an economical perspective, but results of sensitivity analysis suggest that in patients with high prevalence of complications, MRI becomes as cost-effective as enteroclysis, which is accepted standard diagnostic imaging.

Abdominal Abscess↗

Diagnostic imaging costs: are they driving up the costs of hospital care?

PURPOSE: To retrospectively determine how changes in utilization of computed tomography (CT), magnetic resonance (MR) imaging, and other imaging technologies between 1996 and 2002 influenced costs of inpatient hospital care at one large academic medical center. MATERIALS AND METHODS: Institutional review board did not require its approval or patient informed consent for studies with use of billing data. Patient anonymity was protected by removal of potentially identifying information. Data on hospital costs for 17 139 patients admitted to Massachusetts General Hospital, Boston, Mass, between 1996 and 2002 were downloaded from hospital cost-accounting system; sample was restricted to inpatients with diagnoses in diagnosis-related groups 014-015 (Stroke and TIA [transient ischemic attack]), 164-167 (Appendectomy), 082 (Lung Cancer), 182-183 (Upper Gastrointestinal Conditions), 148-149 (Colon Cancer), and 243 (Back Problems). For each patient, data on demographics, all products and services used, and costs associated with each product or service were obtained. By using institutional codes, we calculated costs of CT, MR imaging, and total imaging relative to total hospital costs. Statistical analyses were performed with Student t test and multiple linear regression analysis. RESULTS: Between 1996 and 2002, number of inpatient CT and MR images obtained at the hospital more than doubled. In 2002, hospital costs were 155% those of 1996 levels; inpatient imaging costs were 151% those of 1996 levels. Total costs increased an average of 7.8% per year; imaging costs increased 8.3% per year. Although highly variable over the study period, as a percentage of total imaging costs, CT and MR imaging costs appeared to remain stable relative to costs of other imaging modalities. CONCLUSION: Despite substantial increases in utilization of inpatient CT, MR imaging, and other imaging technologies, diagnostic imaging costs increased at approximately same rate as did total costs for inpatients with several diagnoses. CT and MR imaging do not appear to be driving the cost increases seen between 1996 and 2002.

Costs and Cost Analysis↗

[Diagnostic imaging in constipation].

Diagnostic imaging modalities play a key role in the definition of the possible causes of constipation. Barium Enema (BE), Defecography (DG), Intestinal Transit Time (ITT), Computed Axial Tomography (CT) and Magnetic Resonance (MR) are necessary diagnostic tools for the identification either of the possible organic causes of the disease or of the functional disorders. The ITT evaluation is the main investigation to look for functional colic constipation; this method is in fact able to distinguish between the hypertonic type (in which the fecal progression is slowed down to such an extent that radiopaque markers accumulate in the most proximal part of the colon) and the atonic one (characterized by a global slowing down with the markers distributed along the whole colon). DG gives very accurate dynamic documentation of the pathologic alteration of the rectum-anal conduit, as well as of the disease of the supporting and anchoring system and of the levator complex; this type of investigation allows the definition (characterisation) of the different types of the functional rectum-anal constipation. Even in this case TAC and RM can greatly contribute to the definition of the whole picture of the constipation.

Constipation↗

Developmental cystic renal neoplasms in children. Diagnostic imaging characteristics.

We report diagnostic imaging and histopathologic findings in four children with different cystic renal neoplasms. The features discerned with computed tomography (CT), as well as ultrasound, correlated well with gross histologic findings, although a definitive diagnosis could not be made on the basis of CT and ultrasound alone. Because the most malignant variants of these lesions cannot be excluded preoperatively, we advocate complete diagnostic imaging studies, followed by nephrectomy, for all cases of cystic renal neoplasms in infants and children.

Child, Preschool↗

Intraarticular lesions in traumatic anterior shoulder instability: a study based on the results of diagnostic imaging.

BACKGROUND: Diagnostics of intraarticular lesions is important in the treatment of traumatic anterior shoulder instability. PATIENTS AND METHODS: We studied 30 patients: 26 men and 4 women. For all patients preoperative examinations involved arthrography, CT arthrography, MR arthrography, and 3D-CT. RESULTS: The articular capsule adhered to the margin of the glenoid in only 3 cases. In the remaining 27 patients, the joint capsule was detached, showing medial translation. Hill-Sachs lesions were present in 24 cases. Bankart lesions were detected in all cases, and they extended over 2-5 h. Osseous Bankart lesions were detected in 13 cases. MR arthrography revealed the articular labrum in all cases, but AIGHL in only 16 cases. Bankart lesions were found in all cases. When the patients were divided according to the frequency of dislocation, there was a correlation between both distance of the detached joint capsule and visualization of AIGHL and the frequency of dislocation. INTERPRETATION: From this study, the frequency of dislocation was higher in the patients with severe detachment of the joint capsule, in whom AIGHL could not be visualized by MR arthrography.

Adolescent↗