Ultrasound confirmation of central venous catheter position via a right supraclavicular fossa view using a microconvex probe: an observational pilot study.

BACKGROUND: Visualisation of a central venous catheter (CVC) with ultrasound is restricted to the internal jugular vein (IJV). CVC tip position is confirmed by chest radiography, intracardiac ECG or transoesophageal/transthoracic echocardiography (TEE/TTE). OBJECTIVE: We explored the feasibility, safety and accuracy of a right supraclavicular view for visualisation of the lower superior vena cava (SVC) and the right pulmonary artery (RPA) as an ultrasound landmark for real-time ultrasound-guided CVC tip positioning via the right IJV. Ultrasound was then compared with chest radiography. DESIGN: An observational pilot study. SETTING: Bonn, University Hospital, Germany. From July to October 2012. PATIENTS: Fifty-one patients scheduled for elective surgery. Reasons for exclusion were emergency procedure, thrombosis or small IJV lumen and mechanical obstacle to guidewire advancement. INTERVENTION: In 48 patients, CVC insertion via the right IJV and progress of the guidewire into the lower SVC were continuously guided by an ultrasound transducer in the right supraclavicular fossa. MAIN OUTCOME MEASURES: CVC tip position in lower SVC and tip-to-carina distance were assessed with chest radiography as a reference method and additionally with TEE in cardiothoracic patients. Insertion depth was compared with intracardiac ECG and body-height formula. RESULTS: The guidewire tip was seen in the SVC of all patients. In four patients, the tip was not visible in proximity of the RPA. Chest radiography and TEE confirmed CVC tip position in the lower SVC (zone A). Bland-Altman analysis revealed an average of difference of 1.6 cm for ultrasound versus ECG (95% limit of agreement -2 to 5 cm) and an average of difference of 1 cm for ultrasound versus body-height formula (95% limit of agreement -2 to 4 cm). CONCLUSION: Ultrasound via a right supraclavicular view is a feasible, well tolerated and accurate approach and should be further explored. Chest radiography confirmed CVC position in the lower SVC.

Strategy for safe performance of extrathoracic magnetic resonance imaging at 1.5 tesla in the presence of cardiac pacemakers in non-pacemaker-dependent patients: a prospective study with 115 examinations.

BACKGROUND: The purpose of the present study was to evaluate a strategy for safe performance of extrathoracic magnetic resonance imaging (MRI) in non-pacemaker-dependent patients with cardiac pacemakers. METHODS AND RESULTS: Inclusion criteria were presence of a cardiac pacemaker and urgent clinical need for an MRI examination. Pacemaker-dependent patients and those requiring examinations of the thoracic region were excluded. The study group consisted of 82 pacemaker patients who underwent a total of 115 MRI examinations at 1.5T. To minimize radiofrequency-related lead heating, the specific absorption rate was limited to 1.5 W/kg. All pacemakers were reprogrammed before MRI: If heart rate was <60 bpm, the asynchronous mode was programmed to avoid magnetic resonance (MR)-induced inhibition; if heart rate was >60 bpm, sense-only mode was used to avoid MR-induced competitive pacing and potential proarrhythmia. Patients were monitored with ECG and pulse oximetry. All pacemakers were interrogated immediately before and after the MRI examination and after 3 months, including measurement of pacing capture threshold (PCT) and serum troponin I levels. All MR examinations were completed safely. Inhibition of pacemaker output or induction of arrhythmias was not observed. PCT increased significantly from pre- to post-MRI (P=0.017). In 2 of 195 leads, an increase in PCT was only detected at follow-up. In 4 of 114 examinations, troponin increased from a normal baseline value to above normal after MRI, and in 1 case (troponin pre-MRI 0.02 ng/mL, post-MRI 0.16 ng/mL), this increase was associated with a significant increase in PCT. CONCLUSIONS: Extrathoracic MRI of non-pacemaker-dependent patients can be performed with an acceptable risk-benefit ratio under controlled conditions and by taking both MR- and pacemaker-related precautions.

Telomerase-pulsed dendritic cells: preclinical results and outcome of a clinical phase I/II trial in patients with metastatic renal cell carcinoma.

OBJECTIVE: Therapeutic vaccination with dendritic cells (DC) showed promising results in first clinical trials in cases of metastatic renal cell carcinoma (RCC). Human telomerase reverse transcriptase (hTERT) could be a potential target because it is detectable in more than 85% of human tumors including RCC. DESIGN: 10 patients with progressive metastatic RCC were enrolled in a clinical phase I/II trial using DC pulsed with hTERT-peptide. Beside toxicity and feasibility aspects, a complex immune monitoring including in vitro data were evaluated. In addition to detection of tumor-specific effector cells we investigated their functionality like IFN-gamma secretion and cytotoxic activity against tumor cells. RESULTS: The vaccine was well tolerated. Two patients showed a mixed response (MR) and one patient a stable disease (SD). Interestingly, responders showed cytotoxic activity already before start of therapy and there was a significant increase in cytotoxic activity of effector cells from all responders (SD and MR patients) after the first vaccination. In contrast non-responders showed no cytotoxic activity before and during treatment. Therefore, cytotoxic activity might be used as a predictive marker in the future. Tetramer staining detected higher amounts of tumor-specific cytotoxic cells in responding patients compared to non-responders. Also, responders possessed increasing amounts of IFN-gamma producing immunological effector cells. CONCLUSION: Telomerase-pulsed DC could enhance a tumor-specific immune response against RCC.

Coronary MR angiography at 3.0 T versus that at 1.5 T: initial results in patients suspected of having coronary artery disease.

PURPOSE: To prospectively evaluate the feasibility, image quality, and accuracy of coronary magnetic resonance (MR) angiography at 3.0 T in patients suspected of having coronary artery disease and to prospectively compare these results with those of coronary MR angiography performed at 1.5 T. MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained from all patients. Eighteen patients (11 men, seven women; mean age, 63 years; age range, 45-76 years) suspected of having coronary artery disease who were scheduled to undergo elective conventional coronary angiography (reference standard) were included. For coronary MR angiography at 3.0 and 1.5 T, a vector electrocardiographically gated three-dimensional segmented k-space gradient-echo imaging sequence was combined with real-time respiratory navigator gating and tracking. Signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), scores of image quality and sensitivity and specificity for the detection of coronary artery stenosis on a segment-by-segment basis were assessed at 3.0 and 1.5 T. Data were analyzed for statistical differences by using the Wilcoxon matched-pairs test and the McNemar test. RESULTS: The average increase in SNR at 3.0 T with respect to that at 1.5 T was 29.5% for the left coronary artery (LCA) and 31.2% for the right coronary artery (RCA) (P < .001), and the average increase in CNR was 21.8% for the LCA and 23.5% for the RCA (P < .001). Scores of image quality (P = .77) and diagnostic accuracy for the detection of coronary artery stenoses (sensitivity and specificity: 82% and 89%, respectively, at 3.0 T vs 82% and 88% at 1.5 T; P > .99) were identical or almost identical at both field strengths. CONCLUSION: Coronary MR angiography at 3.0 T is feasible in patients suspected of having coronary artery disease and yields significant increases in SNR and CNR, although current techniques do not result in significantly improved image quality and diagnostic accuracy compared with the quality and accuracy at 1.5 T. (c) RSNA, 2005.

Breast MR imaging during or soon after radiation therapy.

PURPOSE: To investigate the degree and prevalence of radiation-induced changes on breast magnetic resonance (MR) images in patients who were undergoing radiation therapy at that time or soon after, to assess prospectively whether possible radiation-induced effects impair diagnostic accuracy of imaging, and to investigate the prevalence of residual ipsilateral and synchronous contralateral breast cancer in patients undergoing radiation therapy after resection of a supposedly solitary breast cancer. MATERIALS AND METHODS: A total of 116 dynamic bilateral breast MR studies were performed during and up to 12 months after radiation therapy in 72 patients who had undergone breast-conservation surgery without preoperative MR imaging. Patients were assigned to four groups according to the time span between imaging and radiation therapy. Structural changes, parenchymal enhancement pattern, and prevalence and imaging features of incidental lesions were analyzed and compared with those of the nonirradiated breast. RESULTS: Radiation therapy led to parenchymal edema and a significant (two-tailed paired Student t test) increase in enhancement rates in the irradiated compared with those in the contralateral breasts during and up to 3 months after radiation therapy. Neither during nor at any time after radiation therapy did the mean enhancement rates reach diagnostically relevant rates. Unsuspected residual or recurrent breast cancers were identified in irradiated breasts of five patients and in contralateral breasts of two patients. False-positive MR findings resulted in a biopsy in three patients with irradiated and in one patient with nonirradiated breasts. There was no difference in enhancement kinetics or morphology of benign or malignant lesions in irradiated versus nonirradiated breasts. CONCLUSION: Radiation-induced changes occur at MR imaging during or up to 3 months after radiation therapy but are much less severe than reported. Detection and characterization of lesions were feasible with comparable diagnostic accuracies in irradiated and nonirradiated breasts.