Search results for "Radio"
showing 10 items of 8895 documents
Value of serial magnetic resonance imaging in the assessment of brain metastases volume control during stereotactic radiosurgery
2016
AIM To evaluate brain metastases volume control capabilities of stereotactic radiosurgery (SRS) through serial magnetic resonance (MR) imaging follow-up. METHODS MR examinations of 54 brain metastases in 31 patients before and after SRS were reviewed. Patients were included in this study if they had a pre-treatment MR examination and serial follow-up MR examinations at 6 wk, 9 wk, 12 wk, and 12 mo after SRS. The metastasis volume change was categorized at each follow-up as increased (> 20% of the initial volume), stable (± 20% of the initial volume) or decreased (< 20% of the initial volume). RESULTS A local tumor control with a significant (P < 0.05) volume decrease was observed in 25 meta…
Radiation exposure in CT-guided interventions.
2013
To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction.We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series.Eighty-five percent of the total radiation dose was applied during the pre- and post-interv…
Adverse effects of iodine thyroid blocking: a systematic review
2011
(131)I, when released in a radiological or nuclear accident as happened recently in Fukushima, Japan, may cause thyroid cancer as a long-term consequence. Iodine thyroid blocking (ITB) is known to reduce the risk of developing thyroid cancer. Potential adverse effects of ITB have not been systematically investigated so far. This article summarises the results of a review on adverse effects of ITB based on a systematic literature search in scientific medical databases. A meta-analysis was not performed as identified studies displayed major heterogeneity. The search resulted in 14 articles relevant to the topic, reporting mostly on surveys, ecological and intervention studies. Only one study …
Assessment of pulmonary hypertension by CT and MR imaging.
2003
In the recent World Health Organization (WHO) classification the group of pulmonary arterial hypertension (PH) comprises the classic primary pulmonary hypertension and several conditions with definite or very high risk factors to develop pulmonary arterial hypertension. Therapeutic advances drive the need for a comprehensive pre-therapeutic evaluation for optimal treatment. Furthermore, follow-up examinations need to be performed to monitor changes in disease status and response to therapy. Up to now, the diagnostic imaging work-up of PH comprises mainly echocardiography, invasive right heart catheterization and ventilation/perfusion scintigraphy. Due to technical advances helical computed …
Kontrastmittelverstärkte dreidimensionale MR-Angiographie der Lungenarterien bei Patienten mit chronisch-rezidivierender Lungenembolie - Vergleich mi…
2000
Purpose: This study compares contrast-enhanced 3D-MR angiography (MRA) of the pulmonary arteries with selective intraarterial DSA in patients with chronic thromboembolic pulmonary hypertension. Materials and Methods: 20 patients preoperatively underwent a contrast-enhanced 3D-MRA of the pulmonary arteries at 1.5T using the phased-array body coil. For MRA, we used a 3D-Flash-sequence after bolus timing. 2 radiologists analyzed the acquired image material in consensus with respect to the detection of central thromboembolic material and the visualization of the pulmonary arterial tree. Finally, the MR angiograms were compared with selective DSA images using surgical findings as the definitive …
Die dynamische 31-Phosphor-Magnetresonanz-Spektroskopie des M. quadriceps: Einfluß von Geschlecht und Alter auf spektroskopische Parameter
1999
PURPOSE 31P-MRS is used to assess the influence of sex und age on quadriceps muscle metabolism before and after exercise. MATERIALS AND METHODS 32 healthy volunteers (15 women, 17 men, mean age: 38 +/- 17 yrs.) were examined by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric und an isotonic form of exercise until exhaustion, respectively. RESULTS Resting conditions: With increasing subjects' age, the ratio beta-adenosine triphosphate/total phosphate decreased (r = -0.37; p = 0.02). With increasing subjects' age, the ratios inorganic phosphate/phosphocreatine (r = 0.79; p = 5 x 10(-8), phosphomonoester/beta-…
Failure mode and effects analysis of skin electronic brachytherapy using Esteya® unit
2016
Purpose: Esteya® (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden) is an electronic brachytherapy device used for skin cancer lesion treatment. In order to establish an adequate level of quality of treatment, a risk analysis of the Esteya treatment process has been done, following the methodology proposed by the TG-100 guidelines of the American Association of Physicists in Medicine (AAPM). Material and methods: A multidisciplinary team familiar with the treatment process was formed. This team developed a process map (PM) outlining the stages, through which a patient passed when subjected to the Esteya treatment. They identified potential failure modes (FM) and each individual FM…
Radiologists' leading position in image-guided therapy
2013
Image-guided diagnostic and therapeutic procedures are related to, or performed under, some kind of imaging. Such imaging may be direct inspection (as in open surgery) or indirect inspection as in endoscopy or laparoscopy. Common to all these techniques is the transformation of optical and visible information to a monitor or the eye of the operator. Image-guided therapy (IGT) differs by using processed imaging data acquired before, during and after a wide range of different imaging techniques. This means that the planning, performing and monitoring, as well as the control of the therapeutic procedure, are based and dependent on the "virtual reality" provided by imaging investigations. Since…
Quality assurance in the treatment of colorectal cancer: the EURECCA initiative
2014
Colorectal cancer is one of the most common cancers in Europe. Over the past few decades, important advances have been made in screening, staging and treatment of colorectal cancer. However, considerable variation between and within European countries remains, which implies that further improvements are possible. The most important remaining question now is: when are we, health care professionals, delivering the best available care to patients with colon or rectal cancer? Currently, quality assurance is a major issue in colorectal cancer care and quality assurance awareness is developing in almost all disciplines involved in the treatment of colorectal cancer patients. Quality assurance has…
Quantitative magnetic resonance imaging for focal liver lesions: bridging the gap between research and clinical practice
2021
Magnetic resonance imaging (MRI) is highly important for the detection, characterization, and follow-up of focal liver lesions. Several quantitative MRI-based methods have been proposed in addition to qualitative imaging interpretation to improve the diagnostic work-up and prognostics in patients with focal liver lesions. This includes DWI with apparent diffusion coefficient measurements, intravoxel incoherent motion, perfusion imaging, MR elastography, and radiomics. Multiple research studies have reported promising results with quantitative MRI methods in various clinical settings. Nevertheless, applications in everyday clinical practice are limited. This review describes the basic princ…