F Träber

Diffusion-weighted magnetic resonance imaging predicts survival in patients with liver-predominant metastatic colorectal cancer shortly after selective internal radiation therapy

AbstractObjectivesTo investigate whether quantifications of apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) can predict overall survival (OS) in patients with liver-predominant metastatic colorectal cancer (CRC) following selective internal radiation therapy with 90Yttrium-microspheres (SIRT).MethodsForty-four patients underwent DWI 19u2009±u200916xa0days before and 36u2009±u200910xa0days after SIRT. Tumour-size and intratumoral minimal ADC (minADC) values were measured for 132 liver metastases on baseline and follow-up DWI. Optimal functional imaging response to treatment was determined by receiver operating characteristics and defined as ≥22xa0% increase in post-therapeutic minADC. Survival analysis was performed with the Kaplan-Meier method and Cox-regression comparing various variables with potential impact on OS.ResultsMedian OS was 8xa0months. The following parameters were significantly associated with median OS: optimal functional imaging response (18 vs. 5xa0months; pu2009<u20090.001), hepatic tumour burden <50xa0% (8 vs. 5xa0months; pu2009=u20090.018), Eastern Cooperative Oncology Group performance scale <1 (10 vs. 4xa0months; pu2009=u20090.012) and progressive disease according to Response and Evaluation Criteria in Solid Tumours (8 vs. 3xa0months; pu2009=u20090.001). On multivariate analysis, optimal functional imaging response and hepatic tumour burden remained independent predictors of OS.ConclusionFunctional imaging response assessment using minADC changes on DWI may predict survival in CRC shortly after SIRT.Key points• Relative minADC changes may predict survival in liver-predominant metastatic colorectal cancer following SIRTn • Intratumoral minADC changes by ≥22u2009% were best to predict an improved overall survivaln • Functional imaging response assessment is feasible before anatomic tumour-size changes occurn • minADC changes might guide future therapy management in sequential lobar radioembolization approaches

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

Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging

PURPOSEnTo evaluate whether a 3u200aD proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS.nnnMATERIALS AND METHODSn52 patients (26 men, mean age: 41.9u200a±u200a14.5years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40u200a-u200a0.63u200a×u200a0.44u200a-u200a0.89u200a×u200a3mm³) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63u200a×u200a0.68u200a×u200a0.63mm³). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13xa0patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection.nnnRESULTSnThe CR was higher in thexa0ACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (pu200a<u200a0.01 for ACL and PCL; pu200a=u200a0.07 for MEN). Compared to 2u200aD images, the OIQ was rated higher in 3D-PDwFS images (pu200a<u200a0.01) due to fewer artifacts and HFS despite the lower IS (pu200a<u200a0.01). The sensitivity and specificity of lesion detection in 3D- and 2D-PDwFS were similar.nnnCONCLUSIONnCompared to standard multiplanar 2D-PDwFS knee imaging, isotropic high spatial resolution 3D-PDwFS of the knee at 3.0u200aT can be acquired with high image quality in a reasonable scan time. Multiplanar reformations in arbitrary planes may serve as an additional benefit of 3D-PDwFS.nnnKEY POINTSn•u20073D-PDwFS of the knee is acquired with high image quality•u20073D-PDwFS can be achieved in only one measurement with a reasonable scan time•u20073D-PDwFS with the advantage of multiplanar reformation may replace 2D-PD-weighted knee MRI Citation Format: •u2007Homsi R, Gieseke J, Luetkens JA etu200aal. Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging. Fortschr Röntgenstr 2016; 188: 949u200a-u200a956.

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

Frühzeitige Überlebenszeitstratifikation durch Diffusionsbildgebung nach SIRT bei kolorektalen Lebermetastasen

Zielsetzung: Grosenbasierte Verfahren zur Therapieerfolgsmessung lokal interventioneller Therapieverfahren, z.B. RECIST, konnen ein fruhes Therapieansprechen haufig nur unzureichend erfassen. Aktuelle Studienergebnisse weisen darauf hin, dass die MRT-Diffusionsbildgebung (DWI) ein Therapieansprechen bereits vor morphologisch fassbaren Anderungen aufzeigt. Ziel dieser Studie war es daher zu prufen, ob sich die DWI mittels quantitativer Analyse des Diffusionskoeffizienten (ADC) zur fruhen Vorhersage des Gesamtuberlebens (OS) von Patienten mit hepatisch metastasiertem kolorektalem Karzinom nach selektiver interner Radiotherapie (SIRT) eignet. Material und Methodik: 41 Patienten erhielten 19 ± 16 Tage vor und 36 ± 10 Tage nach SIRT mit 90Y-Mikrospharen eine MRT Untersuchung mit DWI (1.5T, Philips Intera). Pra- und posttherapeutische Minimum ADC-Werte (b = 0, 50, 800) wurden in den 3 grosten Lebermetastasen im Behandlungsareal gemessen, gemittelt und verglichen. Mittels Kaplan-Meier-(log-rank-Test) und multivariater Cox-Regressionsanalyse wurde untersucht, ob ein posttherapeutischer ADC-Anstieg prognostische Aussagekraft fur das OS besitzt. Weitere untersuchte Einflussfaktoren auf das OS waren Alter, Geschlecht, Karnofsky-Score, Bilirubin, hepatische Tumorlast und das Vorhandensein extrahepatischer Metastasen. Ergebnisse: Das mediane OS nach Therapie betrug 8 Monate. Patienten mit ADC-Anstieg ≥0% nach SIRT wiesen ein deutlich verlangertes medianes OS als Patienten mit ADC-Reduktion auf (18 vs. 4 Monate; p < 0.001). Weiterhin hatten hepatische Tumorlast ≥50% (6 vs. 8 Monate; p = 0.025) und die applizierte Dosis ≥2 Gy (5 vs. 10 Monate; p = 0.048) einen signifikanten Einfluss auf das OS. In der multivariaten Analyse verblieb das Nichtvorhandensein eines posttherapeutischen ADC-Anstiegs ≥0% als einziger signifikanter und unabhangiger Risikofaktor zur Pradiktion des OS (p < 0.001). Schlussfolgerungen: Die DWI erlaubt eine Einschatzung des Therapieansprechens bereits wenige Wochen nach SIRT und ermoglicht damit eine fruhzeitige Uberlebenszeitstratifikation.