A pilot study of respiratory rate derived from a wearable biosensor compared with capnography in emergency department patients.

Respiratory rate is assessed less frequently than other vital signs, and documented respiratory rates are often erroneous. This pilot study compared respiratory rates derived from a wearable biosensor to those derived from capnography. Emergency department patients with respiratory complaints were enrolled and had capnography via nasal cannula and a wireless, wearable biosensor from Philips applied for approximately one hour.

Stability and trapping of magnetic resonance imaging contrast agents during high-intensity focused ultrasound ablation therapy.

Objectives: The purpose of this study was to investigate the use of Gd-DTPA shortly before magnetic resonance guided high-intensity focused ultrasound MR-HIFU thermal ablation therapy with respect to dissociation, trapping, and long-term deposition of gadolinium (Gd) in the body.

Materials And Methods: Magnetic resonance-HIFU ablation treatment was conducted in vivo on both rat muscle and subcutaneous tumor (9L glioma) using a clinical 3T MR-HIFU system equipped with a small-animal coil setup. A human equivalent dose of gadopentetate dimeglumine (Gd-DTPA) (0.

SPECT/CT imaging of temperature-sensitive liposomes for MR-image guided drug delivery with high intensity focused ultrasound.

The goal of this study was to investigate the blood kinetics and biodistribution of temperature-sensitive liposomes (TSLs) for MR image-guided drug delivery. The co-encapsulated doxorubicin and [Gd(HPDO3A)(H₂O)] as well as the ¹¹¹In-labeled liposomal carrier were quantified in blood and organs of tumor bearing rats. After TSL injection, mild hyperthermia (T=42 °C) was induced in the tumor using high intensity focused ultrasound under MR image-guidance (MR-HIFU).

Magnetic resonance guided high-intensity focused ultrasound mediated hyperthermia improves the intratumoral distribution of temperature-sensitive liposomal doxorubicin.

Objectives: The aim of this study was to investigate the intratumoral distribution of a temperature-sensitive liposomal carrier and its encapsulated compounds, doxorubicin, and a magnetic resonance (MR) imaging contrast agent after high-intensity focused ultrasound (HIFU)-mediated hyperthermia-induced local drug release.

Materials And Methods: (111)In-labeled temperature-sensitive liposomes encapsulating doxorubicin and [Gd(HPDO3A) (H(2)O)] were injected intravenously in the tail vein of rats (n = 12) bearing a subcutaneous rhabdomyosarcoma tumor on the hind leg. Immediately after the injection, local tumor hyperthermia (2 × 15 minutes) was applied using a clinical 3 T MR-HIFU system.

The magnetic susceptibility effect of gadolinium-based contrast agents on PRFS-based MR thermometry during thermal interventions.

Background: Proton resonance frequency shift (PRFS) magnetic resonance (MR) thermometry exploits the local magnetic field changes induced by the temperature dependence of the electron screening constant of water protons. Any other local magnetic field changes will therefore translate into incorrect temperature readings and need to be considered accordingly. Here, we investigated the susceptibility changes induced by the inflow and presence of a paramagnetic MR contrast agent and their implications on PRFS thermometry.

Dual-isotope 111In/177Lu SPECT imaging as a tool in molecular imaging tracer design.

The synthesis, design and subsequent pre-clinical testing of new molecular imaging tracers are topic of extensive research in healthcare. Quantitative dual-isotope SPECT imaging is proposed here as a tool in the design and validation of such tracers, as it can be used to quantify and compare the biodistribution of a specific ligand and its nonspecific control ligand, labeled with two different radionuclides, in the same animal. Since the biodistribution results are not blurred by experimental or physiological inter-animal variations, this approach allows determination of the ligand's net targeting effect.

Tumour hyperthermia and ablation in rats using a clinical MR-HIFU system equipped with a dedicated small animal set-up.

Purpose: We report on the design, performance, and specifications of a dedicated set-up for the treatment of rats on a clinical magnetic resonance high intensity focused ultrasound (MR-HIFU) system.

Materials And Methods: The small animal HIFU-compatible 4-channel MR receiver volume coil and animal support were designed as add-on to a clinical 3T Philips Sonalleve MR-HIFU system. Prolonged hyperthermia (T ≈ 42°C, 15 min) and thermal ablation (T = 65°C) was performed in vivo on subcutaneous rat tumours using 1.

Synthesis and in vivo evaluation of 201Tl(III)-DOTA complexes for applications in SPECT imaging.

Introduction: The aim of this study was to assess the use of (201)thallium(3+) ((201)Tl(3+)) as a radiolabel for nuclear imaging tracers. Methods for labeling of 1,4,7,10-tetraazacyclododecane-N,N',N″,N'″ tetraacetic acid (DOTA) and diethylenetriaminepentaacetic acid (DTPA) chelators with (201)Tl(3+) were investigated, and the levels of stability of these chelates were tested in vitro and in vivo.

Methods: (201)Tl(I)Cl was treated with hydrochloric acid and ozone to form (201)Tl(III)Cl(3).

Magnetic resonance imaging of high intensity focused ultrasound mediated drug delivery from temperature-sensitive liposomes: an in vivo proof-of-concept study.

Temperature-sensitive liposomes (TSLs) co-encapsulating doxorubicin and 250 mM [Gd(HPDO3A)(H₂O)] were evaluated for HIFU-mediated drug delivery under MR image guidance. In vitro studies showed simultaneous and quantitative release of the drug and the MRI contrast agent from the lumen of the TSLs at 42°C, while no leakage was observed over 1 h at 37°C. In a proof-of-concept study, local hyperthermia has been applied for 30 min in 9L rat tumors using a clinical MR-HIFU system.