Using Portable Force Plates to Assess Vertical Jump Performance: A Metrological Appraisal.

The purpose of this study was to verify the metrological properties of portable force plates that are used to assess countermovement jump performance. While 88 participants (38 males, 50 females) were included in the agreement analyses, 84 participants (37 males and 47 females) completed the reliability part of the study. This randomized crossover design suggests that portable force plates could be used interchangeably with a reference system. Indeed, the differences between both devices were all considered trivial (effect size (ES) < 0.20), and the mean bias was never greater than 3.41% in comparison to the reference system. In addition, the absolute and relative reliability parameters were found to be acceptable for clinical use, even when used on different floor surfaces. However, it was found that the ratio between flight time and contraction time (FTCT) showed questionable reliability when tests were conducted on different surfaces (intraclass correlation coefficient = 0.49; coefficient of variation = 26.72%). Therefore, practitioners should be careful when installing the portable device on different floor surfaces in order to optimize the reliability and the ability to detect real change in the context of a countermovement jump monitoring process.

Selectively false-positive radionuclide scan in a patient with sarcoidosis and papillary thyroid cancer: a case report and review of the literature.

BACKGROUND: Radioiodine and Tc-99 m pertechnetate scans are routinely relied upon to detect metastasis in papillary thyroid cancer; false-positive scans are relatively rare. To our knowledge, no published reports exist of sarcoidosis causing such selectively false-positive scans. METHODS: We present a case of a 41-year-old woman with known metastatic papillary thyroid cancer (T1bN1aMx) in whom sarcoidosis-affected cervical and mediastinal lymph nodes demonstrated uptake of thyroid-targeting radionuclides. Only the minority of these nodes demonstrated radionuclide uptake, raising the suspicion of adjacent or coexisting sarcoid and metastatic involvement. Selective uptake of thyroid-targeted radionuclides by isolated sarcoidosis is, to our knowledge, a previously undocumented occurrence. RESULTS: Biopsies of uptake-negative mediastinal nodes revealed sarcoidosis. Pathology from a subsequent neck dissection excising uptake-positive cervical nodes also showed sarcoidosis, with no coinciding malignancy. CONCLUSIONS: We document a case of sarcoidosis causing a selectively false-positive thyroid scintigraphy scan. It is useful for clinicians to be aware of potential false-positives and deceptive patterns on radionuclide scans when managing patients with both well-differentiated thyroid cancer and a co-existing disease affecting the nodal basins draining the thyroid gland.

Bone scintigraphy in femoroacetabular impingement: a preliminary report.

Femoroacetabular impingement (FAI) has recently been recognized as a cause of hip pain, labral tears, and cartilage damage in young adults. We determined the sensitivity and specificity of bone scans in diagnosing FAI and describe its findings on nuclear imaging. We prospectively followed 25 patients with hip pain (four bilateral) of greater than 6 months' duration and a positive impingement sign (IS). All patients had plain radiographs and a three-phase bone scan followed by single-photon emission computed topographic (SPECT) images of both hips. We presumed patients had FAI if they had all three of the following findings: hip pain, positive IS, and diagnostic radiographs. Forty-six of the 50 hips had bony abnormalities on radiographs and 26 hips were diagnosed with FAI according to our criteria. Twenty-two of these 26 hips showed an increased uptake on SPECT representing true-positives. There were four false-positives, nine false-negatives, and 15 true-negatives. Sensitivity of bone SPECT was 84.7%, specificity 62.5%, positive predictive value 71%, and negative predictive value 78.9%. Focal uptake was localized to the superolateral acetabular rim and/or anterolateral femoral head-neck junction consistent with the reported intra-articular cartilage hip damage seen in FAI.

The bedside investigation of pulmonary embolism diagnosis study: a double-blind randomized controlled trial comparing combinations of 3 bedside tests vs ventilation-perfusion scan for the initial investigation of suspected pulmonary embolism.

BACKGROUND: We sought to determine whether using combinations of 3 bedside tests (7-variable clinical model, non-enzyme-linked immunosorbent assay D-dimer test, and alveolar dead-space fraction) to exclude pulmonary embolism (PE) before diagnostic imaging was as safe as a standard strategy of starting with ventilation-perfusion (V/Q) scan. METHODS: In this double-blind, randomized, controlled equivalency trial, patients were randomized to initial bedside tests or to initial V/Q scan without bedside tests. Patients assigned to the bedside test group had a sham V/Q scan performed if at least 2 of 3 bedside test results were negative; otherwise, they underwent an actual V/Q scan. Further diagnostic management was determined by a blinded physician after V/Q scan. The primary outcome measure was recurrent venous thromboembolic events during 3 months among patients who were not taking anticoagulant agents after the initial investigations were completed. RESULTS: Four hundred fifty-eight consecutive adults with suspected PE were eligible for the study; 398 of 399 consenting and randomized patients completed the study. The follow-up venous thromboembolic event rate was 2.4% in the bedside test group vs 3.0% in the V/Q scan group (P = .76). Pulmonary embolism was excluded in 34% (67/199) of the bedside test group patients with at least 2 negative results on 3 bedside tests vs 18% (35/199) excluded using only the 7-variable clinical model and the D-dimer test. CONCLUSION: Excluding PE with at least 2 negative results on 3 bedside tests safely eliminates the need for diagnostic imaging in 34% of patients with suspected PE.