Biomedical subjects

Leon Lenchik

Publications and source records attributed to Leon Lenchik.

8 recordsLinked to original sources

PubMed2003

Position Development Conference.

In a series of three published articles, the International Society for Clinical Densitometry has recorded the findings reached by an expert panel at the ISCD Position Development Conference held in July 2001. The key elements of those papers have been reviewed in this executive summary. It should be emphasized that the ISCD recommendations are not meant to serve as rigid guidelines or to replace clinical judgment. The recommendations will be reviewed and updated periodically as more data become available. A second Position Development Conference will be held in July 2003 in Cincinnati, OH. For information, visit the ISCD web site: http://www.iscd.org/.

Absorptiometry, Photon↗

PubMed2002

Executive summary International Society for Clinical Densitometry position development conference Denver, Colorado July 20-22, 2001.

Bone densitometry is routinely used to assess the skeleton in patients who have diseases or conditions that can cause low bone mass. However, there are some areas of controversy related to the interpretation of bone densitometry results. To address these issues, the International Society for Clinical Densitometry (ISCD) convened a Position Development Conference in Denver, Colorado, July 20-22, 2001. The ISCD is a not-for-profit multidisciplinary society whose main mission is to promote quality in the performance and interpretation of bone densitometry examinations.

Bone Density↗

PubMed2002

Position statements of the International Society for Clinical Densitometry: methodology.

Given the need for authoritative positions in areas of controversy in the field of bone densitometry, the International Society for Clinical Densitometry (ISCD) convened a Position Development Conference in Denver, CO, USA, in July 2001. Four general areas were selected on the basis of clinical importance and likelihood of reaching agreement. These areas were discussed at length prior to the conference by the Scientific Advisory Committee of the ISCD and presented to a panel of experts at the conference. The four areas included discussions of (1). the regions of interest of central dual X-ray densitometry (DXA), (2). the criteria by which a densitometric diagnosis of osteoporosis can be made in men and non-Caucasian women, (3). the role of serial BMD measurements in patient management, and (4). the standards by which bone mass measurements at peripheral sites should be used in the diagnosis of osteoporosis. Details of the methodology used at the conference are discussed. The following papers explain the results of the discussions and describe the official ISCD positions.

Bone Density↗

PubMed2002

Which central dual X-ray absorptiometry skeletal sites and regions of interest should be used to determine the diagnosis of osteoporosis?

Although central measurement of bone mass by dual X-ray absorptiometry (DXA) is viewed by many as the "gold standard" for the diagnosis of osteoporosis in patients without previous fragility fracture, controversy remains on how best to use central DXA as a tool for diagnosis. Questions concerning the measurement of bone mass of the central skeleton were addressed at the International Society for Clinical Densitometry Position Development Conference. An expert panel agreed on the following positions: First, the diagnosis of osteoporosis should be based on the lowest T-score of either the PA spine or hip. Second, both the PA spine and hip should be measured. Third, whenever possible, bone mineral density (BMD) of the first four lumbar vertebrae should be measured. Fourth, DXA manufacturers should use L1-L4 as the default region of interest for their printouts. Fifth, BMD of either hip may be measured. Sixth, the lowest T-score of the three sites total hip, femoral neck, or trochanter should be considered. Seventh, Ward's area should not be used for diagnostic purposes; DXA manufacturers should not include this region in the default printout. Eighth, BMD of the forearm should be measured if the hip or spine cannot be accurately measured. Finally, lateral spine BMD should not be used to diagnose osteoporosis.

Absorptiometry, Photon↗

PubMed2002

What are the criteria by which a densitometric diagnosis of osteoporosis can be made in males and non-Caucasians?

Osteoporotic fractures are not rare in men or non-Caucasian women. However, for these groups, there is no consensus densitometric definition of osteoporosis. As is the case in Caucasian women, low bone mineral density (BMD) is associated with increased fracture risk among men and non-Caucasian women; thus, a densitometric definition of osteoporosis seems feasible. Reaching agreement on criteria for diagnosing osteoporosis in men and non-Caucasians was among the goals of the International Society for Clinical Densitometry Position Development Conference held in July 2001. To this end, the conference recommendation for males is that osteoporosis be defined as a BMD T-score of -2.5 or below the young normal mean for men. Since the relationship between BMD and fracture risk may differ between men and women, it is recommended that T scores in men continue to be derived using a male normative database. Similarly, for non-Caucasians, the recommendation is to diagnose osteoporosis at or below a T-score of -2.5. However, given the difficulty in defining race or ethnic groups, a dearth of data, and their conflicting nature correlating BMD with fracture risk in different ethnicities, it is recommended that a uniform normative database (not adjusted for race) be utilized in the United States for T-score derivation in non-Caucasians. Note that these are current clinical recommendations, which may change as additional data accumulate. Furthermore, there was agreement that the following individuals should have their bone density measured: anyone (male or female, regardless of race) with prior fragility fractures or with conditions widely recognized to increase the risk of bone loss and fracture (such as hypogonadism, corticosteroid treatment, hyperparathyroidism, alcohol abuse, anticonvulsant use, and prior gastrectomy); women on long-term hormone replacement therapy; and in the absence of these conditions, women age 65 and older (regardless of race) and men age 70 and older.

Absorptiometry, Photon↗

PubMed2002

What is the role of serial bone mineral density measurements in patient management?

The ability of dual X-ray absorptiometry (DXA) to monitor bone mineral density (BMD) has been well documented in epidemiologic and pharmaceutical trials. However, its application to monitoring of patients in clinical practice has been subject to recent controversies. Despite these controversies, most clinical centers rely on DXA for monitoring of patients, and therefore guidance is needed. In this article, we report the positions developed by an expert panel of the International Society for Clinical Densitometry on the use of densitometry for the serial measurement of bone mass for monitoring change in BMD. The panel found DXA to be a precise method of measuring change in BMD if used with an appropriate level of least significant change (LSC), at anatomic sites with good precision and response to therapy, and at 1- to 2-yr time intervals. Monitoring is acceptable for determining when therapy is indicated, and if an agent is not therapeutically effective (i.e., when bone loss occurs despite treatment). Each densitometry center should perform an in vivo precision study on individuals similar to the patient population at the center and determine LSC at a 95% confidence level. If such a precision study cannot be performed, benchmark precision might be used, although there was no agreement on what values should be used. The PA spine is the preferred anatomic site for monitoring. The total hip can be used when the spine study is technically invalid. We conclude with recommendations for further research.

Absorptiometry, Photon↗

PubMed2002

What are the standards by which bone mass measurement at peripheral skeletal sites should be used in the diagnosis of osteoporosis?

Measurement of bone mineral density (BMD) at central skeletal sites with dual X-ray absorptiometry is the "gold standard" both for the diagnosis of osteoporosis using the criteria of the World Health Organization (WHO) and for monitoring individuals receiving antiresorptive treatment for osteoporosis. Measurement of BMD at peripheral sites (peripheral BMD) can be used to assess fracture risk, but application of the WHO criteria gives different prevalence values for "osteoporosis" with peripheral devices, and different risks for fracture at the same cut points. The International Society for Clinical Densitometry Position Development Conference panelists reached the following conclusions about peripheral BMD testing: First, WHO T-score criteria should not be used with peripheral devices. Second, for the identification of a level for peripheral BMD measurements above which osteoporosis is unlikely, device-specific cut points for peripheral BMD should be identified that have 90% sensitivity for identifying patients who have osteoporosis (T-score of -2.5 or below) based on measurements of the spine and hip. If central BMD testing is available, patients who have peripheral BMD below the 90% sensitivity level should have a central BMD measurement. If central BMD testing is not available, peripheral BMD might be used for identification of patients who are likely to have osteoporosis. Risk-based cut points were preferred to prevalence based cut points, and, again, device-specific cut points are needed. For patients tested only with a peripheral BMD device whose result is intermediate, clinical judgment would be needed. Third, peripheral BMD testing should not be used for monitoring patients who are taking antiresorptive therapy for osteoporosis. Fourth, peripheral BMD testing performs best when used for postmenopausal women. Further research on all these issues is needed.

Absorptiometry, Photon↗

PubMed2002

Nontraumatic avulsions of the pelvis.

OBJECTIVE: The purpose of this report is to describe the imaging findings of nontraumatic avulsions of the pelvis. CONCLUSION: A diagnosis of avulsion fracture of the pelvis in an adult without appropriate history of substantial trauma must raise the suspicion of an underlying malignancy. If a patient has not been diagnosed as having a primary neoplasm, additional imaging evaluation is recommended. Also, biopsy may be considered in the proper clinical setting.

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