Comparison between microwave ablation and bipolar radiofrequency ablation in benign thyroid nodules: differences in energy transmission, duration of application and applied shots.

Purpose: Comparison between different thermal ablation systems for thyroid nodules regarding their different procedural characteristics such as treatment-time, number of shots and energy transmission in the context of their clinical performance such as complication rate and volume reduction after three months.

Methods: A total of 60 patients with 65 nodules underwent thermal ablation of thyroid nodules with either microwave ablation (MWA) (9 male, 15 female and mean age 57 ± 13 years) or radiofrequency ablation (RFA) (12 male, 24 female and mean age 54 ± 12 years).

Results: Mean initial volume (MWA: 23.

Chondral lesions in the patellofemoral joint in MRI: Intra-individual comparison of short-tau inversion recovery sequence (STIR) with 2D multiple-echo data image combination sequence (MEDIC).

Purpose: To determine the value of the 2D multiple-echo data image combination (MEDIC) sequence relative to the short-tau inversion recovery (STIR) sequence regarding the depiction of chondral lesions in the patellofemoral joint.

Materials And Methods: During a period of 6 month patients with acute pain at the anterior aspect of the knee, joint effusion and suspected chondral lesion defect in the patellofemoral joint underwent MRI including axial MEDIC and STIR imaging. Patients with chondral lesions in the patellofemoral joint on at least one sequence were included.

Impact of an endorectal coil for 1H-magnetic resonance spectroscopy of the prostate at 3.0T in comparison to 1.5T: Do we need an endorectal coil?

Objectives: To evaluate the influence of endorectal coil (ERC) regarding spectral quality and diagnostic suitability and diagnostic performance in 3.0T 1H-magnetic resonance spectroscopy imaging (MRSI) compared to 1.5T MRSI.

Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up.

Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST.

Focal colorectal uptake in (18)FDG-PET/CT: maximum standard uptake value as a trigger in a semi-automated screening setting.

Background: Focal colorectal uptake in (18)FDG-PET/CT may be associated with a malignancy and can be quantified. This provides the basis for an automatic trigger threshold above which cases are flagged for colonoscopic evaluation and below which for individual assessment.

Purpose: To determine the lowest maximum standard uptake (SUVmax) in colorectal cancer that could be used as a threshold to trigger endoscopic evaluation and to evaluate whether the SUVmax needs to be further normalised to a priori known extrinsic factors.

Iterative Reconstruction Leads to Increased Subjective and Objective Image Quality in Cranial CT in Patients With Stroke.

Objective: The purpose of this study was to determine whether iterative reconstruction improves the quality of cranial CT (CCT) images of stroke patients.

Materials And Methods: Fifty-one CCT studies of patients with infarction performed with either a low (260 mAs; n = 21) or standard (340 mAs; n = 30) dose were reconstructed with both filtered back projection (FBP) and sinogram-affirmed iterative reconstruction (SAFIRE) with five strength levels (S1-S5). The resulting six image sets (one FBP and one each for SAFIRE levels S1-S5) were rated separately by two blinded radiologists in terms of conspicuity of infarcted areas on a 5-point scale.

Dose levels and image quality of second-generation 128-slice dual-source coronary CT angiography in clinical routine.

Objectives: To compare radiation exposure and image quality of second-generation 128-slice dual-source CT (DSCT) coronary angiography (cCTA) protocols.

Materials And Methods: We retrospectively analyzed data from four groups with 25 patients, each examined by one of the following DSCT cCTA protocols: prospectively ECG-gated high-pitch (group 1) or sequential (group 2) acquisition, retrospectively ECG-gated acquisition in dual-energy (DECT, group 3) or dual-source (group 4) mode. CT dose index volume, dose length product, estimated radiation dose, contrast-to-noise- and signal-to-noise-ratios were compared.

Gastroenteropancreatic neuroendocrine tumors: standardizing therapy monitoring with 68Ga-DOTATOC PET/CT using the example of somatostatin receptor radionuclide therapy.

The purpose of this study was to standardize therapy monitoring of hepatic metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) during the course of somatostatin receptor radionuclide therapy (SRRT). In 21 consecutive patients with nonresectable hepatic metastases of GEP-NETs, chromogranin A (CgA) and 68Ga-DOTATOC PET/CT were compared before and after the last SRRT. On 68Ga-DOTATOC PET/CT, the maximum standard uptake values (SUVmax) of normal liver and hepatic metastases were calculated.

Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off.

Objective: To determine the performance of FDG-PET/CT in the detection of relevant colorectal neoplasms (adenomas > or =10 mm, with high-grade dysplasia, cancer) in relation to CT dose and contrast administration and to find a PET cut-off.

Methods: 84 patients, who underwent PET/CT and colonoscopy (n = 79)/sigmoidoscopy (n = 5) for (79 x 6 + 5 x 2) = 484 colonic segments, were included in a retrospective study. The accuracy of low-dose PET/CT in detecting mass-positive segments was evaluated by ROC analysis by two blinded independent reviewers relative to contrast-enhanced PET/CT.

Radiopharmaceutical tracking of particles injected into tumors: a model to study clearance kinetics.

Objectives: Success of selective drug therapies depends on the drug's depot time in the target to treat. Depot time is currently being prolonged, using drug-eluting beads or microspheres for selective internal radiation therapy. The purpose of this study was to establish a model for investigating the depot time of particles injected into tumors in relation to tumor vascularization and particle size.

Visualization of somatostatin receptors in prostate cancer and its bone metastases with Ga-68-DOTATOC PET/CT.

Purpose: To assess DOTATOC-affine somatostatin receptor expression in advanced prostate cancer and its bone metastases with regard to DOTATOC-mediated receptor therapies, using a Ga-68-DOTATOC PET/CT.

Procedures: Twenty consecutive patients with advanced prostate cancer underwent bone scintigraphy, followed by Ga-68-DOTATOC PET/CT within 3 weeks. Through side-by-side comparison with bone scintigraphy, the number of visible bone metastases on PET was determined.

Radiosynoviorthesis (RSO): influencing factors and therapy monitoring.

Objective: To evaluate the effectiveness of radiosynoviorthesis (RSO) in relation to joint type and underlying disease by both self-assessment of patients and scintigraphic assessment to determine conditions under which RSO might be preferable to the sole intra-articular corticoid injection.

Methods: Radiosynoviorthesis was performed on 136 patients for 424 joints [242 small, 130 medium-sized, and 52 large joints; 313 with rheumatoid arthritis (RA) and 111 with osteoarthritis (OA)]. The success of RSO was evaluated after 12 months by patients' estimation, and in 35 patients for 157 joints additionally by two-phase bone scintigraphy.

Prostate carcinoma: diffusion-weighted imaging as potential alternative to conventional MR and 11C-choline PET/CT for detection of bone metastases.

In a technical development study approved by the institutional ethics committee, the feasibility of fast diffusion-weighted imaging as a replacement for conventional magnetic resonance (MR) imaging sequences (short inversion time inversion recovery [STIR] and T1-weighted spin echo [SE]) and positron emission tomography (PET)/computed tomography (CT) in the detection of skeletal metastases from prostate cancer was evaluated. MR imaging and carbon 11 ((11)C) choline PET/CT data from 11 consecutive prostate cancer patients with bone metastases were analyzed. Diffusion-weighted imaging appears to be equal, if not superior, to STIR and T1-weighted SE sequences and equally as effective as (11)C-choline PET/CT in detection of bone metastases in these patients.

Peripheral vascular disease: comparison of continuous MR angiography and conventional MR angiography--pilot study.

The aim of this study was to prospectively assess the accuracy of three-dimensional magnetic resonance (MR) angiography for evaluation of stenosis in the peripheral arterial system with a continuous moving table technique, with conventional MR angiography as reference. This study was approved by the local institutional review board; informed consent was obtained. Five healthy male volunteers (mean age, 27 years; range, 24-35 years) and four men and one woman (mean age, 63 years; range, 46-78 years) with peripheral arterial occlusive disease were examined.

Acute pulmonary embolism to the subsegmental level: diagnostic accuracy of three MRI techniques compared with 16-MDCT.

Objective: The purpose of this study was to assess the individual and combined usefulness of MRI techniques in cases of acute pulmonary embolism and to compare the usefulness of these techniques with that of 16-MDCT.

Subjects And Methods: Sixty-two patients with symptoms indicating acute pulmonary embolism underwent an MRI protocol that progressed from real-time MRI through MR perfusion imaging to MR angiography. The results were compared with those of 16-MDCT, which was the reference standard.

Three-dimensional 1H-magnetic resonance spectroscopy of the prostate in clinical practice: technique and results in patients with elevated prostate-specific antigen and negative or no previous prostate biopsies.

To assess the benefit of routinely used three-dimensional 1H-spectroscopy of the prostate combined with magnetic resonance imaging in patients with elevated prostate-specific antigen (PSA) levels and negative or no previous prostate biopsies. Fifty-four patients were examined with our combined imaging protocol, which consisted of transversal, coronal and sagittal T2-weighted fast spin echo sequences. For spectroscopy, we used a three-dimensional chemical shift imaging spin echo (3D-CSI-SE) sequence.

Extracorporeal shock wave therapy in calcific tendinitis of the shoulder.

Objective: To investigate clinical (pain, mobility) and radiological (resolution of calcium deposits) efficacy of different energy levels of extracorporeal shock wave therapy (ESWT) in calcific tendinitis of the shoulder.

Design And Patients: There were 90 study subjects with radiographically verified calcific tendinitis of one shoulder, mean age 52+/-6 years (range 29-65 years; females:males=55:35), all of whom had had symptoms for at least 6 months and substantial restriction of shoulder mobility and pain that required taking anti-inflammatory drugs. Calcium deposits were of type I or type II (clearly circumscribed and dense) and ranged from 1 cm to 3 cm in diameter.

Comparison of volume-rendered and surface-rendered MR colonography.

In the United States and Europe, colorectal cancer is the second leading cause of cancer-related deaths. It is well known that colorectal carcinomas may originate from preexisting adenomas. For the visualization of colorectal cancer and other pathologic changes such as polyps, two 3D methods (volume-rendering (VR) and surface-rendering (SR)) in MR colonography were compared in our study.

Computer-aided diagnosis in contrast-enhanced CT colonography: an approach based on contrast.

Automation in colorectal mass detection is achieved as soon as the voxels representing colorectal masses can be automatically segmented. We tested the Hounsfield (HU) value in intensely contrast enhanced high-resolution CT colonography for automated segmentation of colorectal masses in 18 patients with 35 polyps (28 < 10 mm, 7 > or = 10 mm) and 7 carcinomas. Mean HU values of the colonic wall and masses were determined to deduce a gradient threshold for a segmentation process, which encodes the voxels bordering the colonic lumen with a colour ranging in intensity from 0 to 100% according to the selected gradient threshold range in the volume rendering.

Colonography: current status, research directions and challenges. Update 2002.

With the introduction of multislice CT technology and faster gradients in MRI, CT and MR colonography are increasingly becoming attractive alternatives for colorectal mass screening. In this article we summarise the current status, research directions, and challenges in CT and MR colonography.