G Kukuk

Proton density fat fraction (PDFF) MRI for differentiation of benign and malignant vertebral lesions

ObjectivesTo investigate whether proton density fat fraction (PDFF) measurements using a six-echo modified Dixon sequence can help to differentiate between benign and malignant vertebral bone marrow lesions.MethodsSixty-six patients were prospectively enrolled in our study. In addition to conventional MRI at 3.0-Tesla including at least sagittal T2-weighted/spectral attenuated inversion recovery and T1-weighted sequences, all patients underwent a sagittal six-echo modified Dixon sequence of the spine. The mean PDFF was calculated using regions of interest and compared between vertebral lesions. A cut-off value of 6.40% in PDFF was determined by receiver operating characteristic curves and used to differentiate between malignant (< 6.40%) and benign (≥ 6.40%) vertebral lesions.ResultsThere were 77 benign and 44 malignant lesions. The PDFF of malignant lesions was statistically significant lower in comparison with benign lesions (p < 0.001) and normal vertebral bone marrow (p < 0.001). The areas under the curves (AUC) were 0.97 for differentiating benign from malignant lesions (p < 0.001) and 0.95 for differentiating acute vertebral fractures from malignant lesions (p < 0.001). This yielded a diagnostic accuracy of 96% in the differentiation of both benign lesions and acute vertebral fractures from malignancy.ConclusionPDFF derived from six-echo modified Dixon allows for differentiation between benign and malignant vertebral lesions with a high diagnostic accuracy.Key Points• Establishing a diagnosis of indeterminate vertebral lesions is a common clinical problem• Benign bone marrow processes may mimic the signal alterations observed in malignancy• PDFF differentiates between benign and malignant lesions with a high diagnostic accuracy• PDFF of non-neoplastic vertebral lesions is significantly higher than that of malignancy• PDFF from six-echo modified Dixon may help avoid potentially harmful bone biopsy

Electrocardiography-controlled central venous catheter tip positioning in patients with atrial fibrillation

Introduction: A significant increase of the p-wave of a real-time intracavitary electrocardiography is a reliable and safe method to confirm the central venous catheter tip position close to the atrium. However, conflicting data about the feasibility of electrocardiography exist in patients with atrial fibrillation. Methods: An observational prospective case–control cohort study was set up to study the feasibility and accuracy of the electrocardiography-controlled central venous catheter tip placement in 13 patients with atrial fibrillation versus 10 patients with sinus rhythm scheduled for elective surgery. Each intervention was crosschecked with ultrasound-guided positioning via right supraclavicular fossa view and chest radiography. Ultrasound-guided supraclavicular venipuncture of the right subclavian vein and guidewire advancement were performed. A B-mode view of the superior vena cava and the right pulmonary artery was obtained to visualize the J-tip of the guidewire. The central venous catheter was advanced over the guidewire and the electrocardiography was derived from the J-tip of the guidewire protruding from the central venous catheter tip. Electrocardiography was read for increased p- and atrial fibrillation waves, respectively, and insertion depth was compared with the ultrasound method. Results: Electrocardiography indicated significantly increasing fibrillation and p-waves, respectively, in all patients and ultrasound-guided central venous catheter positioning confirmed a tip position within the lower third of the superior vena cava. Conclusion: Electrocardiography-guided central venous catheter tip positioning is a feasible real-time method for patients with atrial fibrillation. Combined with ultrasound, the electrocardiography-controlled central venous catheter placement may eliminate the need for postinterventional radiation exposure.

Revised PROPELLER for T2-weighted imaging of the prostate at 3 Tesla: impact on lesion detection and PI-RADS classification

PurposeTo evaluate revised PROPELLER (RevPROP) for T2-weighted imaging (T2WI) of the prostate as a substitute for turbo spin echo (TSE).Materials and methodsThree-Tesla MR images of 50 patients with 55 cancer-suspicious lesions were prospectively evaluated. Findings were correlated with histopathology after MRI-guided biopsy. T2 RevPROP, T2 TSE, diffusion-weighted imaging, dynamic contrast enhancement, and MR-spectroscopy were acquired. RevPROP was compared to TSE concerning PI-RADS scores, lesion size, lesion signal-intensity, lesion contrast, artefacts, and image quality.ResultsThere were 41 carcinomas in 55 cancer-suspicious lesions. RevPROP detected 41 of 41 carcinomas (100%) and 54 of 55 lesions (98.2%). TSE detected 39 of 41 carcinomas (95.1%) and 51 of 55 lesions (92.7%). RevPROP showed fewer artefacts and higher image quality (each pu2009<u20090.001). No differences were observed between single and overall PI-RADS scores based on RevPROP or TSE (pu2009=u20090.106 and pu2009=u20090.107). Lesion size was not different (pu2009=u20090.105). T2-signal intensity of lesions was higher and T2-contrast of lesions was lower on RevPROP (each pu2009<u20090.001).ConclusionFor prostate cancer detection RevPROP is superior to TSE with respect to motion robustness, image quality and detection rates of lesions. Therefore, RevPROP might be used as a substitute for T2WI.Key points• Revised PROPELLER can be used as a substitute for T2-weighted prostate imaging.• Revised PROPELLER detected more carcinomas and more suspicious lesions than TSE.• Revised PROPELLER showed fewer artefacts and better image quality compared to TSE.• There were no significant differences in PI-RADS scores between revised PROPELLER and TSE.• The lower T2-contrast of revised PROPELLER did not impair its diagnostic quality.

Proton density fat fraction (PDFF) MR imaging for differentiation of acute benign and neoplastic compression fractures of the spine

ObjectivesTo evaluate the diagnostic performance of proton density fat fraction (PDFF) magnetic resonance imaging (MRI) to differentiate between acute benign and neoplastic vertebral compression fractures (VCFs).MethodsFifty-seven consecutive patients with 46 acute benign and 41 malignant VCFs were prospectively enrolled in this institutional review board approved study and underwent routine clinical MRI with an additional six-echo modified Dixon sequence of the spine at a clinical 3.0-T scanner. All fractures were categorised as benign or malignant according to either direct bone biopsy or 6-month follow-up MRI. Intravertebral PDFF and PDFFratio (fracture PDFF/normal vertebrae PDFF) for benign and malignant VCFs were calculated using region-of-interest analysis and compared between both groups. Additional receiver operating characteristic and binary logistic regression analyses were performed.ResultsBoth PDFF and PDFFratio of malignant VCFs were significantly lower compared to acute benign VCFs [PDFF, 3.48 ± 3.30% vs 23.99 ± 11.86% (p < 0.001); PDFFratio, 0.09 ± 0.09 vs 0.49 ± 0.24 (p < 0.001)]. The areas under the curve were 0.98 for PDFF and 0.97 for PDFFratio, yielding an accuracy of 96% and 95% for differentiating between acute benign and malignant VCFs. PDFF remained as the only imaging-based variable to independently differentiate between acute benign and malignant VCFs on multivariate analysis (odds ratio, 0.454; p = 0.005).ConclusionsQuantitative assessment of PDFF derived from modified Dixon water-fat MRI has high diagnostic accuracy for the differentiation of acute benign and malignant vertebral compression fractures.Key Points• Chemical-shift-encoding based water-fat MRI can reliably assess vertebral bone marrow PDFF• PDFF is significantly higher in acute benign than in malignant VCFs• PDFF provides high accuracy for differentiating acute benign from malignant VCFs