Impact of the Publication of Appropriate Use Criteria on Utilization Rates of Myocardial Perfusion Imaging Studies in Ontario, Canada: A Population-Based Study.

BACKGROUND: Concern regarding overutilization of cardiac imaging has led to the development of appropriate use criteria (AUC). Myocardial perfusion imaging (MPI) is one of the most commonly used cardiac imaging modalities worldwide. Despite multiple iterations of AUC, there is currently no evidence regarding their real-world impact on population-based utilization rates of MPI. Our goal was to assess the impact of the AUC on rates of MPI in Ontario, Canada. We hypothesized that publication of the AUC would be associated with a significant reduction in MPI rates. METHODS AND RESULTS: We conducted a retrospective cohort study of the adult population of Ontario from January 1, 2000, to December 31, 2015. Age- and sex-standardized rates were compared from 4 different periods intersected by 3 published iterations of the AUC. Overall, 3 072 611 MPI scans were performed in Ontario during our study period. The mean monthly rate increased from 14.1/10 000 in the period from January 2000 to October 2005 to 18.2/10 000 between November 2005 and June 2009. After this point in time, there was a reduction in rates, falling to a mean monthly rate of 17.1/10 000 between March 2014 and December 2015. Time series analysis revealed that publication of the 2009 AUC was associated with a significant reduction in MPI rates (P<0.001). This translated into ≈88 849 fewer MPI scans at a cost savings of ≈72 million Canadian dollars. CONCLUSIONS: Our results reflect a potential real-world impact of the 2009 MPI AUC by demonstrating evidence of a significant effect on population-based rates of MPI.

When the value of gold is zero.

This manuscript presents the concerns around the increasingly common problem of not having readily available or useful "gold standard" measurements. This issue is particularly important in critical care where many measurements used in decision making are surrogates of what we would truly wish to use. However, the question is broad, important and applicable in many other areas.In particular, a gold standard measurement often exists, but is not clinically (or ethically in some cases) feasible. The question is how does one even begin to develop new measurements or surrogates if one has no gold standard to compare with?We raise this issue concisely with a specific example from mechanical ventilation, a core bread and butter therapy in critical care that is also a leading cause of length of stay and cost of care. Our proposed solution centers around a hierarchical validation approach that we believe would ameliorate ethics issues around radiation exposure that make current gold standard measures clinically infeasible, and thus provide a pathway to create a (new) gold standard.

Invited review--Off-site PET imaging programs: challenges and opportunities.

Veterinarians are gaining interest in and access to Position Emission Tomography (PET and PET/CT) imaging for both clinical and research applications. This manuscript provides an overview of how veterinarians may approach the use of off-site PET and PET/CT scanners already in use for human medical imaging in order to gain access to this technology without direct investment in costly equipment and infrastructure. An overview of general procedures, animal transport, and radiation safety considerations is offered along with references to key regulatory statutes that may apply to the operation of PET imaging facilities in individual states.

[ECONOMIC EFFICIENCY TECHNOLOGIES DIAGNOSIS OF ISCHEMIC HEART DISEASE BY MAHNITOTOKARDIOHRAFIYI].

The article is devoted to clinical--economic analysis of modern diagnostic technology--magnetocardiography by analyzing the "cost-effectiveness". Economic effectiveness of diagnosis of coronary artery disease using magnetocardiography in terms of cost/effectivness is shown. The economicaly optimal sequence of several noninvasive methods for diagnosis of coronary artery disease is defined.

CT clinical perspective: challenges and the impact of future technology developments.

Computed tomography is not the most frequent radiologic imaging procedure, but is arguably the most important in terms of clinical impact. CT is used extensively for emergencies, cardiovascular, pulmonary, gastrointestinal, endocrine, neurological, orthopedic and other applications -often as the first and only imaging procedure needed for diagnosis. The chances are very high that a patient will have a CT scan in the emergency department, as an outpatient or as an inpatient for a multitude of indications - pain, trauma, suspected infection or malignancy, and frequently to investigate symptoms such as pain, or to answer a question raised by another abnormal test, such as an EKG abnormality or ultrasound finding. Despite the universality of CT in hospitals and clinics as well as free-standing imaging centers, the technology continues to evolve with greater coverage, faster acquisition and multienergy sources or detectors. The most demanding imaging applications are cardiovascular, where complex motion and small morphologic features coexist, so imaging methods that are very satisfactory elsewhere in the body may not be successful. Clinical CT scanning consists of administering toxic materials, e.g., contrast media, often monitoring the EKG and illuminating the body with high brightness x-rays. Larger area detectors and higher acquisition rates are welcome improvements, but don't solve all of the problems encountered with scan variability due to respiratory, random body, and cardiac motion, especially in a spectrum of patients from infant to massively obese adult sizes (< 1 kg to 250 kg or more). The challenges and pitfalls in CT will be delineated and evaluated relative to current and future technology.

Recent payment and utilization trends in radionuclide myocardial perfusion imaging: comparison between self-referral and referral to radiologists.

PURPOSE: The aim of this study was to examine the effects of self-referral by comparing recent trends in payments and utilization rates for radionuclide myocardial perfusion imaging (MPI) among radiologists and cardiologists between 1998 and 2006. MATERIALS AND METHODS: Nationwide Medicare Part B claims databases for 1998 through 2006 were used. The 4 primary MPI codes were selected. Using Medicare's physician specialty codes, physician providers were identified as radiologists, cardiologists, or other physicians. Payments for MPI to the 3 groups were tracked over the study period. Trends in utilization rates in both hospital and private office settings were also compared among the 3 groups. In addition, utilization trends were studied for related procedures, such as stress echocardiography (SE) and invasive diagnostic coronary angiography (CA). RESULTS: Between 1998 and 2006, Medicare Part B payments to radiologists for MPI increased from $72.6 million to $84.0 million (+16%), while among cardiologists, payments increased from $242.6 million to $972.0 million (+301%). Private office utilization rates per 1,000 Medicare beneficiaries increased by 215% among cardiologists, compared with 32% among radiologists. In hospital settings, the rate changes were much more modest. Hospital utilization rates were consistently higher among radiologists than cardiologists; in hospital settings in 2006, the rate was 15.3 per 1,000 among radiologists, compared with 11.8 per 1,000 among cardiologists. Between 1998 and 2006, the utilization rate for SE among cardiologists increased by 20%, and the rate for diagnostic CA among cardiologists also increased by 20%. CONCLUSION: In recent years, there have been very sharp increases in the costs and utilization of MPI among cardiologists compared with radiologists. Most of the growth occurred in cardiologists' private offices. In hospital settings, radiologists still do more MPI examinations than cardiologists. Because MPI is a highly reimbursed procedure and there is no evidence that coronary disease is increasing in frequency in the Medicare population, this trend raises a concern about inappropriate self-referral. This is particularly true in view of the facts that the utilization of a competing procedure such as SE also continues to increase among cardiologists and that MPI is not substituting for an invasive procedure such as diagnostic CA.

Significance of radiation dose in medical imaging.

Publicized cases of errant high radiation exposure delivered to patients undergoing diagnostic imaging have led to heightened awareness and scrutiny of the costs and benefits of imaging by physicians, the public, and policymakers.The statistical risks associated with the ever-increasing utilization of modalities employing damaging ionizing radiation across the population are compounded by the development of the latest generation of devices, which are capable of delivering greater radiation doses than their predecessors for comparable diagnostic applications.This article reviews the fundamental concepts and risks of medical radiation exposure, trends in imaging utilization, and the role of radiologists and their physician colleagues in managing and appropriately utilizing imaging for patient diagnosis.

Structural neuroimaging in psychosis: a systematic review and economic evaluation.

OBJECTIVES: To establish the clinical effectiveness and cost-effectiveness of structural neuroimaging [structural magnetic resonance imaging (MRI) or computed tomography (CT) scanning] for all patients with psychosis, particularly a first episode of psychosis, relative to the current UK practice of selective screening only where it is clinically indicated. DATA SOURCES: Major electronic databases were searched from inception to November 2006. REVIEW METHODS: A systematic review of studies reporting the additional diagnostic benefit of structural MRI, CT or combinations of these in patients with psychosis was conducted. The economic assessment consisted of a systematic review of economic evaluations and the development of a threshold analysis to predict the gain in quality-adjusted life-years (QALYs) required to make neuroimaging cost-effective at commonly accepted threshold levels (20,000 pounds and 30,000 pounds per QALY). Sensitivity analyses of several parameters including prevalence of psychosis were performed. RESULTS: The systematic review included 24 studies of a diagnostic before-after type of design evaluating the clinical benefit of CT, structural MRI or combinations in treatment-naive, first-episode or unspecified psychotic patients, including one in schizophrenia patients resistant to treatment. Also included was a review of published case reports of misidentification syndromes. Almost all evidence was in patients aged less than 65 years. In most studies, structural neuroimaging identified very little that would influence patient management that was not suspected based on a medical history and/or physical examination and there were more incidental findings. In the four MRI studies, approximately 5% of patients had findings that would influence clinical management, whereas in the CT studies, approximately 0.5% of patients had these findings. The review of misidentification syndromes found that 25% of CT scans affected clinical management, but this may have been a selected and therefore unrepresentative sample. A threshold analysis with a 1-year time horizon was undertaken. This combined the incremental cost of routine scanning with a threshold cost per QALY value of 20,000 pounds and 30,000 pounds to predict the QoL gain required to meet these threshold values. Routine scanning versus selective scanning appears to produce different results for MRI and CT. With MRI scanning the incremental cost is positive, ranging from 37 pounds to 150 pounds; however, when scanning routinely using CT, the result is cost saving, ranging from 7 pounds to 108 pounds with the assumption of a 1% prevalence rate of tumours/cysts or other organic causes amenable to treatment. This means that for the intervention to be viewed as cost-effective, the QALY gain necessary for MRI scanning is 0.002-0.007 and with CT scanning the QALY loss that can be tolerated is between 0.0003 and 0.0054 using a 20,000 pounds threshold value. These estimates were subjected to sensitivity analysis. With a 3-month time delay, MRI remains cost-incurring with a small gain in QoL required for the intervention to be cost-effective; routine scanning with CT remains cost-saving. When the sensitivity of CT is varied to 50%, routine scanning is both cost-incurring or cost-saving depending on the scenario. Finally, the results have been shown to be sensitive to the assumed prevalence rate of brain tumours in a psychotic population. CONCLUSIONS: The evidence to date suggests that if screening with structural neuroimaging was implemented in all patients presenting with psychotic symptoms, little would be found to affect clinical management in addition to that suspected by a full clinical history and neurological examination. From an economic perspective, the outcome is not clear. The strategy of neuroimaging for all is either cost-incurring or cost-saving (dependent upon whether MRI or CT is used) if the prevalence of organic causes is around 1%. However, these values are nested within a number of assumptions, and so have to be interpreted with caution. The main research priorities are to monitor the current use of structural neuroimaging in psychosis in the NHS to identify clinical triggers to its current use and subsequent outcomes; to undertake well-conducted diagnostic before-and-after studies on representative populations to determine the clinical utility of structural neuroimaging in this patient group, and to determine whether the most appropriate structural imaging modality in psychosis should be CT or MRI.

Recommendations for optimal use of imaging studies to clinically stage mediastinal lymph nodes in non-small-cell lung cancer patients.

Appropriate clinical staging of mediastinal lymph nodes in non-small-cell lung cancer (NSCLC) patients has important therapeutic and prognostic implications. Because of the wide variations in practice patterns among community and academic physicians, we reviewed the literature so that we could provide evidence-based recommendations on the use of imaging studies in the pretreatment clinical staging of NSCLC patients. We concluded that the most sensitive and accurate method of noninvasive mediastinal nodal staging is a positron emission tomography/computed tomography fusion scan; we believe this tool should be a component of clinical staging of all NSCLC patients. Given insufficient sensitivity with currently available imaging studies, mediastinal nodal staging should also include histologic evaluation.

Clinical value, cost-effectiveness, and safety of myocardial perfusion scintigraphy: a position statement.

Mortality rates due to coronary artery disease (CAD) have declined in recent years as result of improved prevention, diagnosis, and management. Nonetheless, CAD remains the leading cause of death worldwide with most casualties expected to occur in developing nations. Myocardial perfusion scintigraphy (MPS) provides a highly cost-effective tool for the early detection of obstructive CAD in symptomatic individuals and contributes substantially to stratification of patients according to their risk of cardiac death or nonfatal myocardial infarction. MPS also provides valuable information that assists clinical decision-making with regard to medical treatment and intervention. A large body of evidence supports the current applications of MPS, which has become integral to several guidelines for clinical practice.

The role of imaging in Graves' disease: a cost-effectiveness analysis.

According to many guidelines, scintigraphy remains the first suggested diagnostic procedure in hyperthyroid patients in spite of the widespread availability of ultrasounds. The aim of this study was to evaluate the cost-effectiveness of sonography versus scintigraphy in the management of Graves's disease, and to assess ultrasound features suggesting cancer in detecting thyroid nodules. Among 1470 hyperthyroid patients evaluated in our department from 2002 to 2005, 426 (29%) had Graves' disease: echographic and scintigraphic features were not suggestive of GD in 20/426 (4.8%) and 11/426 (2.6%) patients, respectively (p=0.763), even if one of the two procedures was almost always diagnostic. Ultrasound identified 68/426 (16%) patients with a concomitant solid lesion, while scintigraphy detected only 9/426 (2.1%) "cold" nodules (p<0.001). Thyroid cancer was diagnosed in 30/68 (47.7%) patients. Malignancy presented at ultrasound investigation blurred margins (26.7% versus 15.8%), microcalcifications (33.3% versus 28.9%) and an anteroposterior and transverse diameter ratio>or=1 (73.3% versus 71.1%); more frequently than benign nodules, but this was not statistically significant. The total cost to obtain a diagnosis by ultrasound was euro14645.34 (euro13312.5 for echography+euro1332.84 for scintigraphy in the 29 patients "negative" at echographic evaluation for GD) versus euro19922.71 by scintigraphy (euro19578.96 for scan+euro343.75 for ultrasounds in the 11 patients "negative" at scintigraphy). Our data show no difference in terms of diagnosis between sonography and scintigraphy. Indeed, scintigraphy was less sensitive in detecting nodules (often of malignant nature) than ultrasound, and, moreover, with a consequent increase of the direct cost of nodule management when scintigraphy is the first line procedure. In conclusion, according to our results, we suggest that ultrasounds with color-Doppler evaluation should be performed as first step in all hyperthyroid patients, and that scintigraphic examination should be limited only to the uncommon cases, where physician's observation, laboratory assays and/or ultrasounds are not diagnostic.

Valor clínico y pronóstico de la corrección de atenuación con rayos X en la SPECT de perfusión miocárdica post-estrés / Valor clínico y pronóstico de la corrección de atenuación con rayos X en la SPECT de perfusión miocárdica post-estrés

Objetivo. El propósito del estudio fue validar la técnica de corrección de atenuación con rayos X, aplicada a la tomografía por emisión de fotón único (SPECT) de perfusión miocárdica post-estrés. Material y métodos. Se estudiaron 56 pacientes con sospecha clínica de cardiopatía isquémica y sin antecedentes de infarto de miocardio ni de revascularización coronaria. A todos se les realizó una tomografía por emisión de fotón único (SPECT) de perfusión miocárdica post-estrés ergométrico (38) o farmacológico (18). El tiempo medio de seguimiento clínico fue de 18,6 meses. Se valoraron los estudios tras su reconstrucción mediante la técnica de retroproyección filtrada, y después de aplicar la técnica de corrección de atenuación con rayos X. Los resultados obtenidos se relacionaron con el diagnóstico clínico final. Resultados. Once estudios no corregidos fueron normales y 45 mostraron defectos de perfusión. Tras la corrección de atenuación, se observó la ausencia de defectos significativos de perfusión en 24 casos (42,9 % del total) y finalmente se descartó cardiopatía isquémica en 22. Se observó una mayor frecuencia de normalización del estudio en hombres (p = 0,048; odds ratio = 2.923), pero este hecho no mostró correlación significativa con las siguientes variables: probabilidad pre-test de cardiopatía isquémica, índice de masa corporal superior a 30, presencia o ausencia de factores de riesgo cardiovascular y edad del paciente. Conclusiones. La aplicación de la técnica de corrección de atenuación con rayos X hubiera permitido obviar la realización de un estudio de perfusión de reposo en el 42,9 % de los pacientes, sin modificarse aparentemente la seguridad diagnóstica del test. Este hecho se observó con mayor frecuencia en hombres. El método parece ser seguro, así como tiempo y coste-efectivo

Materials and methods. Fifty-six patients with clinically suspected ischemic heart disease and no history of myocardial infarction or coronary revascularization were studied. All patients underwent a myocardial perfusion SPECT after exercise (38) or pharmacological stress (18). Mean clinical follow-up time was 18.6 months. Studies were assessed after reconstruction using the filtered back projection technique and after application of the X-ray-based attenuation correction technique, and the results obtained were related to the final clinical diagnosis. Results. Eleven uncorrected studies were normal, while 45 studies showed perfusion defects. After attenuation correction, absence of significant perfusion defects was observed in 24 cases (42.9 % of all cases), and ischemic heart disease was finally ruled out in 22 cases. A greater study normalization rate was seen in men (p = 0.048; odds ratio = 2,923), but this fact was not shown to be significantly correlated to the following variables: pre-test probability of ischemic heart disease, body mass index greater than 30, presence of cardiovascular risk factors or otherwise, and age. Conclusions. Application of the X-ray-based attenuation correction technique would have allowed for obviating the conduct of a resting perfusion study in 42.9 % of patients without apparently changing the diagnostic safety of the test. This fact was seen more frequently in men. This method seems to be both safe and time- and cost-effective

The roles of PET and PET/CT in the diagnosis and management of prostate cancer.

2-(18)F-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) imaging in prostate cancer is challenging because glucose utilization in well-differentiated prostate cancer is often lower than in other tumor types. Nonetheless, FDG-PET has a high positive predictive value for untreated metastases in viscera, but not lymph nodes. A positive FDG-PET can provide useful information to aid the clinician's decision on future management in selected patients who have low prostate-specific antigen levels and visceral changes as a result of metastases. On the other hand, FDG-PET is limited in the identification of prostate tumors, as normal urinary excretion of radioisotope can mask pathological uptake. Moreover, there is an overlap in the degree of uptake between prostate cancer, benign prostatic hyperplasia and inflammation. The tracer choice is also important. (11)C-choline has the advantage of reduced urinary excretion, and thus (11)C-choline PET may provide more accurate information on the localization of main primary prostate cancer lesions than MRI or MR spectroscopy. (11)C-choline PET is sensitive and accurate in the preoperative staging of pelvic lymph nodes in prostate cancer. A few studies are available but there were no PET or PET/CT studies with a large number of patients for tissue confirmation of prostate cancer; further investigations are required.

Acquiring new technology and surviving environmental pressures.

CONTEXT: The U.S. health care system faces increased pressures to expand coverage to the elderly, the uninsured and the poor, while maintaining costs and quality of care. Because of the federal budget deficit and continued fiscal uncertainties, resource allocation will become even more scrutinized. OBJECTIVE: How does a health care system allocate limited funds and still provide quality care using innovative technology? METHOD: This article reviews the literature on the acquisition of new technologies from a theoretical perspective, using positron emission tomography (PET) as an example. A unified model, including concepts from the resource dependency theory (RDT) supplemented with organizational survival concepts from the ecological theory, was used to analyze resource acquisition for technological innovation and organizational survival. An attempt was made to evaluate a hospital's profit maximization, recognition as a center of clinical excellence and role as a technological leader of the community with respect to acquisition of PET equipment. CONCLUSION: Organizations acquire new technology for a variety of reasons that can be explained by RDT and ecological theory concepts. In terms of the profit maximization motive, hospitals purchase PET equipment to enhance revenue generation. From the clinical excellence perspective, organizations seek the best available technology to meet the needs of their patients. Finally, hospitals adopt new technology to enhance their image as a technological leader.

Oncologic PET/CT: current status and controversies.

The introduction of integrated PET/CT has dramatically increased the worldwide rate of growth for PET, predominantly for oncologic imaging with the glucose analog 18F-fluorodeoxyglucose (FDG). A rapidly expanding body of literature demonstrates that the use of FDG-PET/CT and the resultant ability to interpret coregistered and fused PET and CT images lead to improved observer confidence and improved diagnostic performance by comparison with PET alone, CT alone, and visually correlated PET and CT. The value of PET/CT is likely to be even greater with new PET radiopharmaceuticals under development, many of which produce PET images with even fewer anatomical landmarks than FDG images. PET/CT is also likely to lead to the resurrection of 18F-fluoride as a principal agent for radionuclide bone imaging. There are a number of controversies related to PET/CT, including minimum training and experience requirements for interpreting physicians and defining new models for technical and professional reimbursement.