Left ventricular function in response to dipyridamole stress: head-to-head comparison between Rubidium PET and Tc-sestamibi SPECT ECG-gated myocardial perfusion imaging.

Purpose: Myocardial perfusion imaging (MPI) with Tc-sestamibi (sestamibi) SPECT and rubidium-82 (Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose.

Materials And Methods: A group of 221 consecutive patients (65.

In vitro evaluation of the effect of different polishing techniques on the surface roughness of composite resins submitted to at-home and in-office bleaching procedures.

Objective: Bleaching agents may affect the properties of dental materials. The aim of this study was to evaluate the effect of different polishing techniques on the surface roughness of composite resins submitted to the at-home and in-office bleaching treatment.

Materials And Methods: Disc-shaped specimens were carried out of nanofilled and microhybrid composites (n = 10).

Adhesive Restorations as An Esthetic Solution in Dentinogenesis Imperfecta.

Loss of tooth structure is the main sequela of dentinogenesis imperfecta (DI). Due to severe enamel attrition, patients with DI often present with esthetic, occlusal, endodontic, and speech complications. Therefore, an interdisciplinary approach, divided into separate clinical steps, should be developed to provide comprehensive dental rehabilitation.

Influence of Water Storage and Bonding Material on Bond Strength of Metallic Brackets to Ceramic.

This study investigated the influence of water storage (24 h and 6 months), and Transbond XT and Fuji Ortho LC bonding materials on the bond strength of metallic brackets bonded to feldspathic ceramic. Four cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 60 s. Each cylinder received two layers of silane.

Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block.

Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease.

Objective: We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block.

Recurrent angina caused by coronary subclavian steal syndrome confirmed by positron emission tomography.

Coronary subclavian steal syndrome is a rare cause of recurrent angina after coronary artery bypass grafting. Identification of the myocardial ischemic region is crucial because it guides revascularization interventions to improve symptoms and myocardial ischemia. Positron emission computed tomography (PET) with rubidium might be a helpful tool because it identifies ischemia, localizes more precisely the ischemic region, and evaluates coronary flow reserve.

Influence of successive light-activation on degree of conversion and Knoop hardness of the first layered composite increment.

Purpose: To evaluate the influence of light-activation of second, third and fourth increments on degree of conversion (DC) and microhardness (KHN) of the top (T) and bottom (B) surface of the first increment.

Materials And Methods: Forty samples (n = 5) were prepared. In groups 1-4, after each increment light-activation (multiple irradiation), T and B of the first increment were measured in DC and KHN.

Influence of the arm position in myocardial perfusion imaging acquisition.

Objective: despite the technologic advances in myocardial perfusion imaging, we keep using an uncomfortable and sometimes impracticable patient position - supine with arms raised above the head (U). The purpose of this study was to investigate whether perfusion and functional cardiac gated SPECT scan results of acquisition U are equivalent to another position modality: supine with arms down at the sides of the trunk (D).

Methods And Results: we performed U acquisition and in sequence D acquisition in 120 patients (pts) using a one-day MPI (rest-gated/stress), with 99mTc-sestamibi (370 MBq and 1110 MBq).

Early postnatal rat ventricle resection leads to long-term preserved cardiac function despite tissue hypoperfusion.

One-day-old mice display a brief capacity for heart regeneration after apex resection. We sought to examine this response in a different model and to determine the impact of this early process on long-term tissue perfusion and overall cardiac function in response to stress. Apical resection of postnatal rats at day 1 (P1) and 7 (P7) rendered 18 ± 1.

Influence of light-activation protocol on methacrylate resin-composite evaluated by dynamic mechanical analysis and degree of conversion.

The aim of this study was to evaluate the degree of conversion (DC) and to identify the viscoelastic properties: storage modulus (E'), loss modulus (E"), tangent delta (tan δ), and glass transition temperature (T g ) of a microhybrid resin-composite light-activated by three different protocols. A Filtek Z250 (3 M ESPE) shade A3 was inserted in a Teflon mold (21 mm × 5 mm × 1 mm for viscoelastic properties; and 5 mm × 1 mm for DC) and light-activated according to the following light-activation protocols: (S) 1,000 mW/cm(2) × 19 s, (HP) 1,400 mW/cm(2) × 14 s, and (PE) 3,200 mW/cm(2) × 6 s, all set up to deliver 19 J/cm(2). Viscoelastic properties was assessed by dynamic mechanical analysis (DMA) (n = 3), performed in single cantilever clamped mode.

Effect of different monomer-based composites and acid etching pre-treatment of enamel on the microleakage using self-etch adhesives systems.

Objective: To evaluate quantitatively the marginal microleakage of restorations carried out with self-etching adhesives with or without prior phosphoric enamel acid etching of silorane or methacrylate resin-based composite restorations subjected to thermal cycling.

Materials And Methods: Forty cavities were prepared at the proximal surface of bovine incisors and randomly divided according to the etching of the enamel and restorative system used. The groups were restored with methacrylate [Adper SE Plus adhesive (3M ESPE) + Filtek Z250 (3M ESPE)] or silorane [Filtek LS adhesive (3M ESPE) + Filtek LS composite (3M ESPE)] restorative systems, light-cured using a LED unit (Bluephase 16i, Vivadent).

Effect of energy density and delay time on the degree of conversion and Knoop microhardness of a dual resin cement.

Aim: In the present study, we evaluated the influence of the photo-curing delay time and energy density on the degree of conversion and the Knoop microhardness of a resin cement.

Methods: Seventy-eight samples were assigned to 13 groups (n = 6), one of which received no light curing (control). The samples were made of a dual-cured resin cement (RelyX ARC) with the aid of a Teflon matrix, submitted to one of the following energy densities (J/cm²): 7, 14, 20, and 28.

Low-carbohydrate diet versus euglycemic hyperinsulinemic clamp for the assessment of myocardial viability with 18F-fluorodeoxyglucose-PET: a pilot study.

Positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) is considered the gold standard for myocardial viability. A pilot study was undertaken to compare FDG-PET using euglycemic hyperinsulinemic clamp before (18)F-fluorodeoxyglucose ((18)F-FDG) administration (PET-CLAMP) with a new proposed technique consisting of a 24-h low-carbohydrate diet before (18)F-FDG injection (PET-DIET), for the assessment of hypoperfused but viable myocardium (hibernating myocardium). Thirty patients with previous myocardial infarction were subjected to rest (99m)Tc-sestamibi-SPECT and two (18)F-FDG studies (PET-CLAMP and PET-DIET).

Left cardiac sympathetic denervation for treatment of symptomatic systolic heart failure patients: a pilot study.

Aims: To evaluate the feasibility, safety, and potential beneficial effects of left cardiac sympathetic denervation (LCSD) in systolic heart failure (HF) patients.

Methods And Results: In this prospective, randomized pilot study, inclusion criteria were New York Heart Association (NYHA) functional class II or III, left ventricular ejection fraction (LVEF) ≤40%, sinus rhythm, and resting heart rate >65 b.p.

Does an additional UV LED improve the degree of conversion and Knoop Hardness of light-shade composite resins?

Objective: The purpose of this study was to evaluate the degree of conversion (DC) using FT-Raman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5.

Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces.

Cardiac MRI for detection of unrecognized myocardial infarction in patients with end-stage renal disease: comparison with ECG and scintigraphy.

Objective: The purposes of this study were to use the myocardial delayed enhancement technique of cardiac MRI to investigate the frequency of unrecognized myocardial infarction (MI) in patients with end-stage renal disease, to compare the findings with those of ECG and SPECT, and to examine factors that may influence the utility of these methods in the detection of MI.

Subjects And Methods: We prospectively performed cardiac MRI, ECG, and SPECT to detect unrecognized MI in 72 patients with end-stage renal disease at high risk of coronary artery disease but without a clinical history of MI.

Results: Fifty-six patients (78%) were men (mean age, 56.

Cardiac resynchronization therapy evaluated by myocardial scintigraphy with 99mTc-MIBI: changes in left ventricular uptake, dyssynchrony, and function.

Purpose: (99m)Tc-MIBI gated myocardial scintigraphy (GMS) evaluates myocyte integrity and perfusion, left ventricular (LV) dyssynchrony and function. Cardiac resynchronization therapy (CRT) may improve the clinical symptoms of heart failure (HF), but its benefits for LV function are less pronounced. We assessed whether changes in myocardial (99m)Tc-MIBI uptake after CRT are related to improvement in clinical symptoms, LV synchrony and performance, and whether GMS adds information for patient selection for CRT.

Cardiac resynchronization therapy improves the uptake of MIBI-99mTc and cardiac function.

This case shows the improvement promoted by cardiac resynchronization therapy (CRT) on myocardial perfusion and left ventricular (LV) performance assessed by gated myocardial perfusion scintigraphy. The patient had idiopathic dilated cardiomyopathy, left bundle branch block and severe heart failure despite optimized medical treatment. After CRT, clinical improvement, QRS reduction and improvement of previously hypoperfused anterior and septal walls were observed.

Cardiac sympathetic activity pre and post resynchronization therapy evaluated by 123I-MIBG myocardial scintigraphy.

Background: Imaging with (123)I-metaiodobenzylguanidine (MIBG) is used for the assessment of cardiac sympathetic activity (CSA). We analyzed CSA before and after cardiac resynchronization therapy (CRT), and correlated these data with CRT response.

Methods And Results: Thirty patients with chronic heart failure and classic indications for CRT were prospectively studied before and at least 3 months after CRT.

Role of 18F-fluorodeoxyglucose positron emission tomography in preoperative assessment of cytologically indeterminate thyroid nodules.

Objective: The objective of the study was to determine the diagnostic accuracy of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) in the preoperative diagnosis of thyroid nodules with indeterminate fine-needle aspiration biopsy results.

Methods: Forty-two consecutive patients with thyroid nodules with indeterminate cytological results participated in this study. Abnormal (18)F-FDG PET uptake was assessed visually and by measuring the maximum standardized uptake value (SUVmax) in thyroid topography.

Ventricular synchrony in patients with dilated cardiomyopathy and normal individuals: assessment by radionuclide ventriculography.

Objective: To establish the parameters of intra- and interventricular synchrony in normal individuals and to compare them with patients with dilated cardiomyopathy with and without conduction disorders shown in the electrocardiogram (ECG) examination.

Methods: Three groups of patients were included in this study: 18 individuals (G1) with no cardiomyopathy and with a normal ECG (52+/-12 years, 29% male); 50 patients with dilated cardiomyopathy and severe left ventricular dysfunction, with 20 patients (G2) presenting QRS <120 ms (51+/-10 years, 75% male) and 30 patients (G3) with QRS >120 ms (57+/-12 years, 60% male). All patients underwent RV.

Gender differences in ventricular volumes and left ventricle ejection fraction estimated by myocardial perfusion imaging: comparison of Quantitative Gated SPECT (QGS) and Segami software programs.

Objectives: To test for gender differences in the measurements obtained by Segami and Quantitative Gated SPECT (QGS) software programs.

Methods: 181 asymptomatic individuals without heart disease were submitted to myocardial perfusion imaging. End-diastolic volumes (EDV), end-systolic volumes (ESV) and left ventricular ejection fraction (LVEF) were measured by QGS and Segami software programs to evaluate the influence of gender, age, weight, height, heart rate, systolic blood pressure, diastolic blood pressure, body mass index and body surface area.

Myocardial perfusion scintigraphy to predict outcomes after coronary stenting.

The value of myocardial perfusion scintigraphy (MPS) in predicting the occurrence of restenosis or new coronary lesions after stent implantation is debatable. A total of 47 patients treated with successful bare stent implantation underwent stress gated SPECT MPS at three time-points: pre-procedure, early pos-procedure, and 6-month follow-up. Follow-up angiographic re-study was obtained at 6 months.