Idiopathic nasal bone osteitis: A preliminary report on a recently recognized entity.

Osteitis of the nasal bones is a rare disease; when it occurs, it usually has a known etiology. To the best of our knowledge, idiopathic nasal bone osteitis (NBO) has not been described before. We conducted a study to analyze the behavior of idiopathic NBO and its outcome and to determine a cutoff level for diagnosis using technetium-99m-methylene-diphosphonate (Tc-MDP) bone scanning.

The predictive value of ventilation-perfusion scanning for the diagnosis of pulmonary embolism in patients with impaired renal function.

Background: Computed tomography pulmonary angiography (CTPA) is considered the method of choice for diagnosing pulmonary embolism (PE). In most patients with impaired renal function, ventilation-perfusion (V/Q) scanning is the preferred modality.

Objectives: To evaluate the predictive value of V/Q scanning in patients with impaired renal function.

The "bladder sign"--an important early marker of retroperitoneal hemorrhage.

Retroperitoneal hemorrhage remains one of the major complications of cardiac and peripheral vascular catheterization. Its high associated morbidity and mortality require vigilance and early intervention. We report six cases of retroperitoneal hemorrhage featuring a "bladder sign.

Combined assessment of coronary anatomy and myocardial perfusion using multidetector computed tomography for the evaluation of coronary artery disease.

Multidetector computed tomography (MDCT) is increasingly used as an alternative to invasive coronary angiography. Although computed tomographic coronary angiography (CTCA) has been validated against invasive coronary angiography and nuclear myocardial perfusion imaging, the potential of MDCT to evaluate perfusion has not been fully explored. We sought to (1) develop a new technique for quantitative assessment of myocardial enhancement based on analysis of MDCT images acquired for CTCA, (2) identify the underlying causes of myocardial hypoenhancement detected by MDCT, and (3) determine the added diagnostic value of the MDCT perfusion index when combined with CTCA.

Value of multidetector computed tomography evaluation of myocardial perfusion in the assessment of ischemic heart disease: comparison with nuclear perfusion imaging.

MDCT-derived myocardial perfusion has not yet been validated against accepted standards. We developed a technique for quantification of myocardial perfusion from MDCT images and studied its diagnostic value against SPECT myocardial perfusion imaging (MPI). Ninety-eight patients were studied.

Reevaluation of routine invasive strategy versus noninvasive testing following uncomplicated ST-elevation myocardial infarction.

Background And Aims: While current guidelines recommend a selective invasive approach after low-risk ST-elevation myocardial infarction (STEMI) treated by thrombolysis, based on noninvasive identification of patients with residual or inducible myocardial ischemia, in many instances physicians employ a strategy of routine angiography. The present study was undertaken to reexamine the correlation between noninvasive testing and coronary angiography in patients recovering from uncomplicated STEMI with regard to detection and management of residual infarct artery stenosis and to identify patients with multivessel (MVD) or high-risk coronary disease.

Methods: We prospectively performed predischarge exercise testing (ETT) and myocardial perfusion scintigraphy (MPS) prior to routine predischarge coronary angiography in 83/276 consecutive STEMI patients, who after treatment with initial and early thrombolysis, were defined as low risk by ACC/AHA risk classification.

Myocardial stunning demonstrated with rest and post-stress measurements of left ventricular function using dual-isotope gated myocardial perfusion SPECT.

Objectives: We have evaluated left ventricular ejection fraction (LVEF) at rest (REF) and after stress (SEF) with dual-isotope gated myocardial perfusion SPECT (GMPS) with 201Tl injected at rest and 99mTc sestamibi (99mTc-MIBI) injected at peak stress, to assess the occurrence of post-stress stunning.

Methods: Two hundred and thirty-six consecutive patients had GMPS at rest and post-stress. The summed stress and rest scores and the summed difference score (SDS) were calculated using a 17-segment model analysis of GMPS.

The added value of spiral computed tomographic angiography after lung scintigraphy for the diagnosis of pulmonary embolism.

Objectives: The objectives of this study were to evaluate the added clinical value of spiral computed tomographic angiography (CTA) after ventilation-perfusion lung scintigraphy (V/Q) for the management of patients with suspected pulmonary embolism (PE).

Methods: Of 987 patients who had V/Q during 2001, 64 patients (6%) had CTA performed for further evaluation. V/Q and CTA findings were retrospectively analyzed by 2 clinicians who were blinded to the patients' outcome.

Myocardial perfusion abnormalities early (12-24 h) after coronary stenting or balloon angioplasty: implications regarding pathophysiology and late clinical outcome.

Objective: We prospectively examined the prevalence of reversible perfusion defects on very early (12-24 h) thallium-201 single photon emission computed tomography (SPECT) scintigraphy after angiographically successful percutaneous coronary intervention (PCI) by stenting and/or stand-alone balloon angioplasty and the predictive value of these defects for late target lesion revascularization (TLR).

Patients And Methods: 83 consecutive patients undergoing PCI for 88 lesions (38 balloon angioplasties, 50 stents) underwent very early (12-24 h) SPECT thallium-201 scintigraphy at rest and following administration of 0.7 mg/kg intravenous dipyridamole after PCI.

Prediction of bone loss in patients with primary hyperparathyroidism using quantitative bone SPECT.

Unlabelled: Bone loss is a major complication of primary hyperparathyroidism (PHPT), and it has significant implications in the treatment of this disease. Bone turnover was measured in patients with PHPT, using quantitative bone SPECT (QBS), to determine if the rate of bone loss could be predicted before a significant decrease in bone mass occurs.

Methods: Forty-six patients were included in the study.

17beta-estradiol inhibits apoptosis of endothelial cells.

Endothelial cells provide an antithrombotic and anti-inflammatory barrier for the normal vessel wall. Dysfunction of endothelial cells has been shown to promote atherosclerosis, and normalization of previously dysfunctional endothelial cells can inhibit the genesis of atheroma. In normal arteries, endothelial cells are remarkably quiescent.

Observer variation in the interpretation of bone scintigraphy.

To assess the reliability of bone scintigraphy, a random sample of 100 bone scans was reviewed twice by each of two physicians. Observer variation in the description and interpretation of bone scintigrams varied by diagnosis. Good to excellent k values were obtained for inter- and intraobserver variation in relation to metastasis or normal scans.

Importance of immediate and very early postprocedural angiographic and thallium-201 single photon emission computed tomographic perfusion measurements in predicting late results after coronary intervention.

We examined prospectively the hypothesis that the adequacy of initial dilatation may be a major determinant of the late result of coronary angioplasty and that a better assessment of initial dilatation can be made from a combined angiographic and perfusion study than from angiography alone. Angiographic and perfusion (thallium-201 single-photon-emission computed tomography) measurements were made very early (18 to 24 hours) after coronary angioplasty in 59 patients (67 lesions) and also immediately (37 +/- 16 minutes) after the procedures in 19 of them (23 lesions). The early measurements, singly, in combination, and as a restenosis index (restenosis index = thallium-201 ischemic score (units) - minimal luminal area (squared millimeters) were examined as predictors of the late angiographic result.

Bone loss in patients with chronic renal disease: prediction with quantitative bone scintigraphy with SPECT.

Purpose: To determine whether quantitative bone scintigraphy (QBS) with single-energy photon emission computed tomography (SPECT) can help predict which patients with chronic renal disease will show bone mineral density (BMD) loss.

Materials And Methods: In 18 patients, the percentage of injected dose of technetium-99m methylene diphosphonate per cubic centimeter of bone was measured with QBS SPECT in the lumbar vertebrae and femoral neck. The differences in BMD over an average of 20 months were measured and compared with SPECT measurements.

Bone turnover in cortical and trabecular bone in normal women and in women with osteoporosis.

Unlabelled: This study is based on the assumption that is bone turnover, shown by the uptake of 99mTc-MDP, indicates a high rate of bone loss in patients with osteoporosis, it could potentially predict bone loss in patients at risk before significant bone loss has occurred.

Methods: Quantitative bone SPECT (QBS) using 99mTc-MDP, expressed as the %ID/cc x 10(-3), was performed in 71 women who had osteoporosis in the lumbar vertebrae, the femoral neck or both, and in 54 age-matched normal female controls. Of the women with osteoporosis, 42 had postmenopausal osteoporosis and 29 had primary hyperparathyroidism (HPT) and osteoporosis.

Growth factor receptors, phospholipases, phospholipid kinases and actin reorganization.

Upon binding to their ligand, several growth factor receptors that contain a tyrosine kinase within their cytoplasmic domain [receptor tyrosine kinases (RTKs)] induce a substantial reorganization of the actin cytoskeleton. This change in actin superstructure is necessary to produce multiple motile responses within the target cells. RTKs catalyse the clustering of effector proteins within functional units underneath the plasma membrane.

Semiquantitative skull planar and SPECT bone scintigraphy in diabetic patients: differentiation of necrotizing (malignant) external otitis from severe external otitis.

Unlabelled: Early diagnosis of necrotizing external otitis (NEO) includes the use of bone scintigraphy since clinical assessment alone cannot differentiate the necrotizing type of otitis from the severe type of external otitis in which there is no extension to the adjacent bone. Four-hour planar bone scintigraphy may reflect soft-tissue infection, and therefore may not be useful in distinguishing NEO from severe external otitis (SEO). Twenty-four-hour bone scintigraphy using planar or SPECT imaging may better reflect bone uptake and increase the accuracy of the test.

The yield of bone scintigraphy in cancer and non-cancer patients: its association with indication and clarity of the referral question.

The yield of bone scintigraphy was assessed in a general hospital. A random 1:2 sample of the bone studies performed within a year was evaluated. The referral forms were judged to show absent, ambiguous or clear diagnostic questions.

Effect of blockade of the ATP-sensitive potassium channel on metabolic coronary vasodilation in the dog.

The hypothesis that the ATP-sensitive potassium channel provides the link between change in coronary blood flow and myocardial oxygen demand was tested in 9 dogs instrumented to measure coronary flow and regional wall thickening in the basal state and at a high level of myocardial oxygen consumption produced by systemic infusion of phenylephrine and simultaneous atrial pacing at an elevated heart rate. Measurements were recorded before and after blockade of ATP-sensitive potassium channels with intracoronary glibenclamide (2 mumol/min). While glibenclamide reduced the absolute level of coronary flow in the basal state, the increase in flow due to increased metabolic demand was unchanged compared with control.

Spectrum of scintigraphic appearance of liver hemangiomas.

Two hundred and twenty five liver hemangiomas in 166 patients were studied with Tc-99m labeled RBC and are the basis for this atlas. All hemangiomas showed various presentations of the perfusion blood pool mismatch, which is the basis for diagnosis. The size of the hemangiomas was the factor that determined the mixing of the Tc-99m RBC with the blood and, hence, the sequence of visualization of the lesion.

Imaging patterns of vascular lesions of the head and neck demonstrated by Tc-99m labeled red blood cells.

The authors report on three patients with head and neck masses who demonstrated different imaging patterns on Tc-99m RBC scintigraphy, suggesting different vascular pathology of the lesions. Defining these patterns can be helpful in the diagnosis and decision making concerning the appropriate treatment of these patients.