Edge-preserving adaptive autoregressive model for Poisson noise reduction.

Autoregressive models in image processing are linear prediction models that split an image into a predicted (i.e. filtered) image and a prediction error image, which extracts data on the image edges.

Does bone scintigraphy show Modic changes associated with increased bone turnover?

Purpose: Our purpose was to evaluate whether Modic changes (MC) revealed in lumbar MRI are associated with increased tracer uptake shown in bone scintigraphy. To our knowledge, this has not previously been studied.

Methods: We included patients with MC shown in lumbar MRI and bone scintigraphy performed within six months before or after MRI.

Adaptive Autoregressive Model for Reduction of Noise in SPECT.

This paper presents improved autoregressive modelling (AR) to reduce noise in SPECT images. An AR filter was applied to prefilter projection images and postfilter ordered subset expectation maximisation (OSEM) reconstruction images (AR-OSEM-AR method). The performance of this method was compared with filtered back projection (FBP) preceded by Butterworth filtering (BW-FBP method) and the OSEM reconstruction method followed by Butterworth filtering (OSEM-BW method).

Safety and biodistribution study of bone marrow-derived mesenchymal stromal cells and mononuclear cells and the impact of the administration route in an intact porcine model.

Background Aims: Bone marrow mononuclear cells (BM-MNCs) and bone marrow-derived mesenchymal stem stromal cells (BM-MSCs) could have therapeutic potential for numerous conditions, including ischemia-related injury. Cells transplanted intravascularly may become entrapped in the lungs, which potentially decreases their therapeutic effect and increases the risk for embolism.

Methods: Twelve pigs were divided into groups of 3 and received (99m)Tc- hydroxymethyl-propylene-amine-oxime-labeled autologous BM-MNCs or allogeneic BM-MSCs by either intravenous (IV) or intra-arterial (IA) transplantation.

Transient proteolytic modification of mesenchymal stromal cells increases lung clearance rate and targeting to injured tissue.

Systemic infusion of therapeutic cells would be the most practical and least invasive method of administration in many cellular therapies. One of the main obstacles especially in intravenous delivery of cells is a massive cell retention in the lungs, which impairs homing to the target tissue and may decrease the therapeutic outcome. In this study we showed that an alternative cell detachment of mesenchymal stromal/stem cells (MSCs) with pronase instead of trypsin significantly accelerated the lung clearance of the cells and, importantly, increased their targeting to an area of injury.

Followup of a solid solitary pulmonary nodule with low metabolic activity.

An incidentally found solid solitary pulmonary nodule (SPN) was studied using FDG PET/CT. The SPN (at that time 11mm) showed only minimal FDG uptake, with a maximum standardized uptake value of 1.7 (max SUV).

Intra-arterial bone marrow mononuclear cell distribution in experimental global brain ischaemia.

Objectives: Bone marrow mononuclear cells (BM-MNCs) can ameliorate focal ischaemic brain injury. A global ischaemic brain injury, which can occur after cardiac or thoracic surgery, could be an essential target for BM-MNCs. No studies using BM-MNCs for this indication have been conducted.

Cell surface structures influence lung clearance rate of systemically infused mesenchymal stromal cells.

The promising clinical effects of mesenchymal stromal/stem cells (MSCs) rely especially on paracrine and nonimmunogenic mechanisms. Delivery routes are essential for the efficacy of cell therapy and systemic delivery by infusion is the obvious goal for many forms of MSC therapy. Lung adhesion of MSCs might, however, be a major obstacle yet to overcome.

Adaptive autoregressive model for reduction of poisson noise in scintigraphic images.

Unlabelled: In the present paper, a 2-dimensional adaptive autoregressive filter is proposed for noise reduction in images degraded with Poisson noise. In autoregressive models, each value of an image is regressed on its neighborhood pixel values, called the prediction region. The autoregressive models are linear prediction models that split an image into 2 additive components, a predictable image and a prediction error image.

Acute homing of bone marrow-derived mononuclear cells in intramyocardial vs. intracoronary transplantation.

Objectives: Cell homing optimisation after transplantation is critical in myocardial infarction (MI) cell therapy.

Design: Eight pigs were randomized to receiving autologous purified (111)indium-labeled bone marrow mononuclear cells (BMMCs) (10(8) cells/2 ml) by intramyocardial (IM) (n=4) or by intracoronary (IC) (n=4) transplantation after 90 minutes occlusion of the CX-coronary artery. Dual isotope SPECT imaging was performed 2 and 24 hours postoperatively.

Repeatability of successive measurements with a portable nitric oxide analyser in patients with suggested or diagnosed asthma.

The objective of our study was to determine the repeatability of successive measurements of exhaled nitric oxide (NO) with a portable device (NIOX MINO). We assembled a sample of 332 pairs of repeated NO measurements acquired in the same session. The mean of the two successive measurements varied from 4.

Three-phase bone scintigraphy in chronic epicondylitis.

Objective: To assess the utility of 3-phase bone scintigraphy as a complementary diagnostic method in chronic epicondylitis.

Design: A cross-sectional study.

Setting: Hospital outpatient clinic admitting patients with musculoskeletal disorders.

Tutorial on multivariate autoregressive modelling.

In the present paper, the theoretical background of multivariate autoregressive modelling (MAR) is explained. The motivation for MAR modelling is the need to study the linear relationships between signals. In biomedical engineering, MAR modelling is used especially in the analysis of cardiovascular dynamics and electroencephalographic signals, because it allows determination of physiologically relevant connections between the measured signals.

Bone oedema predicts erosive progression on wrist MRI in early RA--a 2-yr observational MRI and NC scintigraphy study.

Objectives: To investigate if disease assessment by contrast-enhanced dynamic and static magnetic resonance imaging (MRI) and quantitative nanocolloid (NC) scintigraphy gives useful additional information in early rheumatoid arthritis (RA).

Methods: Twenty-seven patients with early RA (disease duration < or =12 months) were followed up for 1 yr and 24 of them for 2 yrs with contrast-enhanced MRI and NC scintigraphy of the wrist joint. Synovial inflammation was assessed by measuring time-dependent enhancement rates (E-rate) from dynamic MRI scans and technetium(99m)-labelled nanocolloid ((99m)Tc-NC) uptake from scintigraphy scans.

Tutorial on univariate autoregressive spectral analysis.

In the present paper, the theoretical basis of autoregressive (AR) modelling in spectral analysis is explained in simple terms. Spectral analysis gives information about the frequency content and sources of variation in a time series. The AR method is an alternative to discrete Fourier transform, and the method of choice for high-resolution spectral estimation of a short time series.

Inhibition of carnitine-acyl transferase I by oxfenicine studied in vivo with [11C]-labeled fatty acids.

Methods: Anesthetized pigs were studied with [(11)C]-labeled fatty acids (FAs) with carbon chain length ranging from 8 to 16 carbon atoms, during control conditions and during inhibition of carnitine-palmitoyl transferase I (CPT I) with oxfenicine. The myocardial uptake of [(11)C]-FAs from blood was measured together with the relative distribution of [(11)C]-acyl-CoA between rapid mitochondrial oxidation and incorporation into slow turnover lipid pools in the heart.

Results: During baseline conditions, the fractional oxidative utilization of palmitate was almost as high as that of carnitine-independent short-chain FAs, unless the carnitine shuttle was inhibited by high levels of lactate.