Evaluation of combined Gd-EOB-DTPA and gadobutrol magnetic resonance imaging for the prediction of hepatocellular carcinoma grading.

BACKGROUND: Tumor biopsy is not essential for the diagnosis of hepatocellular carcinoma (HCC); however, grading remains important for the prognosis. PURPOSE: To investigate whether combined Gd-EOB-DTPA and gadobutrol liver magnetic resonance imaging (MRI) can predict HCC grading. MATERIAL AND METHODS: Thirty patients (66.6 ± 7.3 years) with histologically confirmed HCC (grade 1, n = 5; grade 1-2, n = 6; grade 2, n = 13; grade 2-3, n = 2; grade 3, n = 4) underwent two liver MRIs, one with gadobutrol and one with Gd-EOB-DTPA, on consecutive days. Blinded to grading, two radiologists reviewed the gadobutrol and Gd-EOB-DTPA images in consensus with respect to: (i) HCC hyper-/iso-/hypointensity in the arterial, portal-venous/delayed, and Gd-EOB-DTPA hepatocellular phase; and (ii) morphologic tumor features (encapsulated growth, vessel invasion, heterogeneity, liver capsule infiltration, satellite metastases). RESULTS: A significant correlation with grading was not found for either the combined dynamic information of all gadobutrol phases (r = -0.187, P = 0.331) or all the Gd-EOB-DTPA phases (r = 0.052, P = 0.802). No correlation with grading was found for a combination of arterial and hepatocellular phase in Gd-EOB-DTPA MRI (r = 0.209, P = 0.305), a combination of both arterial phases (gadobutrol and Gd-EOB-DTPA) with the Gd-EOB-DTPA hepatocellular phase (r = 0.240, P = 0.248), or a combination of all available gadobutrol and Gd-EOB-DTPA phases (r = 0.086, P = 0.691). For all gadobutrol information (dynamic phases and morphology; r = 0.049, P = 0.801) and for all Gd-EOB-DTPA information (r = 0.040, P = 0.845), no correlation with grading was found. Hepatocellular Gd-EOB-DTPA phase iso-/hyperintensity never occurred in grade 3 HCCs. CONCLUSION: Histological HCC grading cannot be predicted by combined Gd-EOB-DTPA/gadobutrol MRI. However, Gd-EOB-DTPA hepatocellular phase iso-/hyperintensity was never detected in grade 3 HCCs.

Does diffusion-weighted imaging improve therapy response evaluation in patients with hepatocellular carcinoma after radioembolization? comparison of MRI using Gd-EOB-DTPA with and without DWI.

PURPOSE: To investigate whether additional diffusion-weighted imaging (DWI) improves therapy response evaluation by Gd-EOB magnetic resonance imaging (MRI) in hepatocellular carcinoma (HCC) after radioembolization. MATERIALS AND METHODS: Fifty patients with radioembolization for HCC underwent gadobutrol and Gd-EOB MRI with DWI prior to and 30, 90, and 180 days after radioembolization. A combination of gadobutrol MRI, alpha-fetoprotein, and imaging follow-up served as the reference standard. Two radiologists reviewed Gd-EOB alone (Gd-EOB), DWI alone (DWI), and the combination of both (Gd-EOB+DWI) separately and in consensus using a 4-point-scale: 1 = definitely no tumor progression (TP), 2 = probably no TP, 3 = probably TP, 4 = definitely TP. Receiver operating characteristic (ROC) and kappa analysis were performed. RESULTS: Kappa values for Gd-EOB, DWI, and Gd-EOB+DWI ranged between 0.712 and 0.892 (P < 0.001). 30 days after radioembolization three out of 38 patients showed TP, which was missed by DWI in one case. No significant area under the curve (AUC) difference between Gd-EOB (1.0, P = 0.004), DWI (0.881, P = 0.030), and Gd-EOB+DWI (1.0, P = 0.004) was found (P = 0.320). 90 days after radioembolization six out of 28 patients showed TP, which was detected in one patient only by DWI and Gd-EOB+DWI. The AUC did not differ significantly (P = 0.319) between Gd-EOB (0.890, P = 0.004), DWI (1.0, P < 0.001), and Gd-EOB+DWI (1.0, P < 0.001). 180 days after radioembolization five patients showed TP, which in one case was missed by DWI. The AUC did not differ significantly (P1 = 0.322, P2 = 0.369, P3 = 0.350) between Gd-EOB (1.0, P = 0.003), DWI (0.913, P = 0.016), and Gd-EOB+DWI (0.963, P = 0.007). CONCLUSION: Additional DWI does not substantially improve therapy response evaluation by Gd-EOB MRI in HCC after radioembolization but proved helpful in single cases.

Cardiac pathologies in female carriers of Duchenne muscular dystrophy assessed by cardiovascular magnetic resonance imaging.

OBJECTIVES: Duchenne muscular dystrophy (DMD) is the most common and severe dystrophinopathy. DMD carriers rarely present with clinical symptoms, but may suffer from cardiac involvement. Because echocardiographic findings are inconsistent and cardiac magnetic resonance imaging (CMRI) data are limited, this study sought to investigate asymptomatic carriers for cardiac abnormalities using CMRI. METHODS: Fifteen genetically confirmed DMD carriers (age, 32.3 ± 10.2 years) were prospectively examined on a 1.5T MR system. Cine, T2, and late-gadolinium-enhanced (LGE) images were acquired, and were evaluated in consensus by two experienced readers. Left ventricular (LV) parameters were analysed semiautomatically, normalized to BSA. RESULTS: Normalized LV end-diastolic volume was increased in 7% (73.7 ± 16.8 ml/m(2); range, 48-116 ml/m(2)) and normalized LV end-systolic volume in 20% (31.5 ± 13.3 ml/m(2); range, 15-74 ml/m(2)). EF was reduced in 33% (58.4 ± 7.6%; range, 37-69%) and normalized LV myocardial mass in 80% (40.5 ± 6.8 g/m(2); range, 31-55 g/m(2)). In 80%, regional myocardial thinning was detected in more than one segment. In 13% and 40%, apical-lateral accentuation of LV non-compaction was present. LGE was found in 60% (midmyocardial inferolateral accentuation). CONCLUSIONS: Given the high frequency of cardiac pathologies detected by CMRI, regular cardiac risk assessment is advisable for DMD carriers. Besides clinical examination, CMRI is an excellent tool for this purpose. KEY POINTS: • Fifteen Duchenne muscular dystrophy carriers investigated using CMRI all showed cardiac pathologies. • Myocardial mass reduction, regional myocardial thinning, and late gadolinium enhancement were common. • Regular cardiac risk assessment is thus advisable in Duchenne muscular dystrophy carriers. • Besides clinical examination, CMRI is an excellent tool for this purpose.

Therapy response assessment after radioembolization of patients with hepatocellular carcinoma--comparison of MR imaging with gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid and gadobutrol.

PURPOSE: To compare the utility of gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA), a liver-specific magnetic resonance (MR) imaging contrast agent, versus gadobutrol for treatment response evaluation of hepatocellular carcinoma (HCC) after radioembolization. MATERIALS AND METHODS: This prospective study included 50 patients with HCC undergoing radioembolization. All patients underwent contrast-enhanced computed tomography (CT) and MR imaging with gadobutrol and Gd-EOB-DTPA on 2 consecutive days before radioembolization and 30 days, 90 days, 180 days, and 270 days after radioembolization. The standard of reference indicating tumor progression was CT combined with either α-fetoprotein or γ-glutamyltransferase. Gadobutrol-enhanced MR imaging, Gd-EOB-DTPA-enhanced MR imaging without late phase imaging (Gd-EOB-DTPA-), and Gd-EOB-DTPA-enhanced MR imaging with late phase imaging (Gd-EOB-DTPA+) were evaluated by 2 radiologists in consensus using a 4-point scale: 1 = definitely no tumor progression; 2 = probably no tumor progression; 3 = probably tumor progression; 4 = definitely tumor progression. Diagnostic accuracy was assessed with receiver operating characteristic analysis. RESULTS: Tumor progression was detected in 14 of 82 study visits according to the reference standard. Pairwise comparison of the area under the curve showed a tendency toward a larger area under the curve for Gd-EOB-DTPA+ compared with gadobutrol (P = .056). Sensitivity and specificity were higher in Gd-EOB-DTPA+ (0.929 and 0.971) than in Gd-EOB-DTPA- (0.786 and 0.941) or gadobutrol (0.643 and 0.956). In 2 cases, tumor progression was detected by Gd-EOB-DTPA+ and by an increase in α-fetoprotein, but not by CT, gadobutrol, or Gd-EOB-DTPA-. CONCLUSIONS: Gd-EOB-DTPA+ MR imaging was not inferior to gadobutrol-enhanced MR imaging in therapy response evaluation after radioembolization and may allow a more accurate detection of early HCC recurrence in single cases.

Volumetric measurements in patients with corrected tetralogy of Fallot: comparison of short-axis versus axial cardiac MRI and echocardiography.

BACKGROUND: Patients with corrected tetralogy of Fallot (cToF) are prone to develop pulmonary regurgitation and right ventricular enlargement resulting in long-term complications, thus correct right ventricular volumetric monitoring is crucial. However, it remains controversial which cardiovascular magnetic resonance imaging (CMRI) slice orientation is most appropriate in cToF for the analysis of the right ventricular volume. PURPOSE: To investigate which slice orientation is most suited for right ventricular volumetry in cToF we compared short-axis and axial slices, and furthermore we compared right ventricular data between CMRI and echocardiography. MATERIAL AND METHODS: Thirty CMRI examinations of 27 patients with cToF were included retrospectively. Right ventricular end-diastolic (EDV) and end-systolic volume (ESV) were derived from short-axis and axial cine CMRI planes. Furthermore, pulmonary trunk forward flow in phase-contrast CMRI and right ventricular inner diastolic diameter in echocardiography (R VIDdiast) were measured. By Bland-Altman and variance analysis intra- and inter-observer agreement were assessed for cine CMRI data. By Pearson correlation CMRI cine and phase-contrast data and CMRI cine and echocardiographic data were compared. RESULTS: Intra- and inter-observer variability for right ventricular EDV were significantly lower in axial slices (P = 0.016, P = 0.010). For right ventricular ESV a trend towards a lower intra- and inter-observer variability in axial slices was found (P = 0.063, P = 0.138). Right ventricular stroke volume in short-axis (r = 0.872, P < 0.001) and in axial (r = 0.914, P < 0.001) planes correlated highly, respectively very highly with pulmonary trunk forward flow in phase-contrast CMRI. R VIDdiast correlated highly with right ventricular EDV assessed by short-axis and axial CMRI (P < 0.001, P < 0.001). CONCLUSION: Due to lower intra- and inter-observer variability, axial slices are recommended for right ventricular volumetry in cToF.

Diagnostic value of 3D fluid attenuated inversion recovery sequence in multiple sclerosis.

BACKGROUND: Magnetic resonance imaging (MRI) is an indispensable tool in the diagnostic work-up of multiple sclerosis (MS). To date, guidelines suggest MRI protocols containing axial dual-echo, unenhanced and post-contrast T1-weighted sequences. Especially the usage of dual-echo sequences has markedly improved the ability of MRI to detect cortical and infratentorial lesions. Newer 3D FLAIR sequences are supposed to provide even more positive imaging features such as improved detection of white matter lesions and a better resolution due to smaller slice thickness. PURPOSE: To evaluate the diagnostic impact of 3D FLAIR sequences in comparison to conventional T2 and PD sequences. MATERIAL AND METHODS: Examinations of 20 MS patients (10 women, 10 men) were reviewed retrospectively. All patients received MRI standard protocol containing PD and T2 sequences and a mid-sagittal T2 sequence. Additionally an isotropic 3D FLAIR sequence was performed. Whole-brain lesion load and number of lesions in juxtacortical, infratentorial, and midcallosal localizations were assessed by two observers independently and compared. RESULTS: Whole lesion load and the count of detectable lesions at the 3D FLAIR sequence were significantly higher in the juxtacortical and infratentorial regions compared to the PD/T2 sequence. Detection rate of midcallosal lesions did not differ significantly in sagittal T2 and 3D FLAIR sequence. CONCLUSION: 3D FLAIR sequences can improve the detection of brain lesions in patients with MS and are even more sensitive in depicting lesions in cortical and infratentorial locations than current dual-echo sequences. The sequence can replace both PD/T2 sequences and mid-sagittal T2 sequences of the corpus callosum.

Intracranial hemorrhage detection over time using susceptibility-weighted magnetic resonance imaging.

BACKGROUND: The reliable detection of intracranial hemorrhages is important, but just 1 year after the hemorrhage onset it might be missed using T2-weighted spin-echo and gradient-echo sequences. Susceptibility-weighted imaging (SWI) is a new magnetic resonance imaging sequence that is extremely sensitive in hemorrhage detection and that might improve the detection of hemorrhages over time. PURPOSE: To investigate whether the detectability of intracranial blood and its degradation products is independent of the time span after intracranial hemorrhage using SWI. MATERIAL AND METHODS: Sixty-six consecutive patients (28 men, 38 women) with definitely known time point of intracranial hemorrhage and available SWI sequence (1.5 or 3 T) were analyzed retrospectively. Twenty-one patients had a SWI follow-up. All SWI images were assessed by two radiologists in consensus regarding hemorrhage visibility using a 5-point scale. Statistical analysis was performed using Spearman's correlation test. RESULTS: Median time interval between hemorrhage and first available SWI measurement was 819 days (range, 0 days to 13.2 years). Nine of 66 patients had an isolated subarachnoid hemorrhage (iSAH) and were therefore analyzed separately. In eight of these nine patients the hemorrhage could clearly be detected, the remaining one had minor iSAH. Spearman analysis showed no significant correlation between time span and visibility (P = 0.660). In the remaining 57 patients (no iSAH) the hemorrhage was always visible achieving at least 3/5 points on the 5-point scale, and Spearman's analysis revealed only a weak correlation between time span and visibility (r = 0.493, P < 0.001). CONCLUSION: The detectability of blood and its degradation products using SWI is reliably possible over a long period after intracranial hemorrhage.

Hybrid PET/MR imaging of the heart: feasibility and initial results.

PURPOSE: To assess the feasibility of hybrid imaging of the heart with fluorine 18 fluorodeoxyglucose (FDG) on an integrated 3-T positron emission tomography (PET)/magnetic resonance (MR) imaging system. MATERIALS AND METHODS: The present study was approved by the local institutional review board. Written informed consent was obtained from all patients before imaging. Twenty consecutive patients with myocardial infarction (n = 20) underwent cardiac PET/MR imaging examination. Ten patients underwent additional cardiac PET/computed tomography (CT) before PET/MR. Two-dimensional half-Fourier acquisition single-shot turbo spin-echo sequences, balanced steady-state free precession cine sequences, two-dimensional turbo inversion-recovery magnitude T2-weighted sequences, and late gadolinium-enhanced (LGE) segmented two-dimensional inversion-recovery turbo fast low-angle shot sequences were performed. According to the 17-segment model, PET tracer uptake, wall motion, and late gadolinium enhancement were visually assessed for each segment on a binary scale, and categorical intermethod agreement was calculated by using the Cohen κ. The maximum standardized uptake value was measured in corresponding myocardial locations on PET/CT and PET/MR images. RESULTS: Agreement was substantial over all patients and segments between PET and LGE images (κ = 0.76) and between PET and cine images (κ = 0.78). In 306 segments, 97 (32%) were rated as infarcted on PET images, compared with 93 (30%) rated as infarcted on LGE images and with 90 (29%) rated as infarcted on cine images. In a subgroup of patients (n = 10) with an additional PET/CT scan, no significant difference in myocardial tracer uptake between PET/CT and PET/MR images was found (paired t test, P = .95). CONCLUSION: Cardiac PET/MR imaging with FDG is feasible and may add complementary information in patients with ischemic heart disease.

A single-center experience in radioembolization as salvage therapy of hepatic metastases of uveal melanoma.

BACKGROUND: Overall survival (OS) of patients with hepatic metastases of uveal melanoma is strongly linked with hepatic tumor control. Due to the lack of an effective systemic chemotherapy, locoregional therapies like radioembolization should play an increasingly important role. PURPOSE: To report complications and response rates of radioembolization as salvage therapy for hepatic uveal melanoma metastases. MATERIAL AND METHODS: Between October 2006 and January 2014, eight patients (age, 59.1 ± 15.3 years; 5 men) with histologically proven uveal melanoma and hepatic metastases received radioembolization with glass microspheres at a single center. All patients had been heavily pretreated with multiple systemic/locoregional therapies resulting in a long median interval between diagnosis of hepatic metastases and radioembolization (17.1 months; range, 6.4-23.2 months). Follow-up consisted of clinical assessment, laboratory tests and tri-phasic computed tomography (CT) before and 1, 3, 6, 9, and 12 months after radioembolization. Response to therapy was evaluated by CT using RECIST version 1.1 and by survival time. Safety (laboratory and clinical toxicity) was rated according to Common Terminology Criteria for Adverse Events 4.03. Using Kaplan-Meier analysis time to progression of hepatic metastases (hTTP) and OS were calculated. RESULTS: One month after radioembolization 50% of patients presented with stable and 50% with progressive disease. Median hTTP and OS after radioembolization were 4.3 weeks (range, 3.4-28.6 weeks) and 12.3 weeks (range, 3.7-62.6 weeks), respectively. Median OS after diagnosis of hepatic metastases was 19.9 months (range, 7.3-31.4 months). Radioembolization was tolerated well in all patients without toxicity higher than grade 2. CONCLUSION: Radioembolization is a safe salvage therapy even in heavily pretreated hepatic metastases of uveal melanoma.

Integrated 18F-FDG PET/MR imaging in the assessment of cardiac masses: a pilot study.

UNLABELLED: The objective of the present study was to evaluate whether integrated (18)F-FDG PET/MR imaging could improve the diagnostic workup in patients with cardiac masses. METHODS: Twenty patients were prospectively assessed using integrated cardiac (18)F-FDG PET/MR imaging: 16 patients with cardiac masses of unknown identity and 4 patients with cardiac sarcoma after surgical therapy. All scans were obtained on an integrated 3-T PET/MR device. The MR protocol consisted of half Fourier acquisition single-shot turbo spin-echo sequence, cine, and T2-weighted images as well as T1-weighted images before and after injection of gadobutrol. PET data were acquired simultaneously with the MR scan after injection of 199 ± 58 MBq of (18)F-FDG. Patients were prepared with a high-fat, low-carbohydrate diet in a period of 24 h before the examination, and 50 IU/kg of unfractionated heparin were administered intravenously 15 min before (18)F-FDG injection. RESULTS: Cardiac masses were diagnosed as follows: metastases, 3; direct tumor infiltration via pulmonary vein, 1; local relapse of primary sarcoma after surgery, 2; Burkitt lymphoma, 1; scar/patch tissue after surgery of primary sarcoma, 2; myxoma, 4; fibroelastoma, 1; caseous calcification of mitral annulus, 3; and thrombus, 3. The maximum standardized uptake value (SUVmax) in malignant lesions was significantly higher than in nonmalignant cases (13.2 ± 6.2 vs. 2.3 ± 1.2, P = 0.0004). When a threshold of 5.2 or greater was used, SUVmax was found to yield 100% sensitivity and 92% specificity for the differentiation between malignant and nonmalignant cases. T2-weighted hyperintensity and contrast enhancement both yielded 100% sensitivity but a weak specificity of 54% and 46%, respectively. Morphologic tumor features as assessed by cine MR imaging yielded 86% sensitivity and 92% specificity. Consent interpretation using all available MR features yielded 100% sensitivity and 92% specificity. A Boolean 'AND' combination of an SUVmax of 5.2 or greater with consent MR image interpretation improved sensitivity and specificity to 100%. CONCLUSION: In selected patients, (18)F-FDG PET/MR imaging can improve the noninvasive diagnosis and follow-up of cardiac masses.

Selective internal radiation therapy of hepatic tumors: procedural implications of a patent hepatic falciform artery.

Selective internal radiation therapy (SIRT) using 90-yttrium is a local therapy for unresectable liver malignancies. Non-targeted 90-yttrium diversion via a patent hepatic falciform artery (HFA) is seen as risk for periprocedural complications. Therefore, this study aimed to evaluate the impact of a patent HFA on SIRT. 606 patients with SIRT between 2006 and 2012 were evaluated retrospectively. SIRT preparation was performed by digital subtraction angiography including (99m)Tc-HSAM administration and subsequent SPECT/CT. Patients with an angiographically patent HFA were analyzed for procedural consequences and complications. 19 of 606 patients (3%) with an angiographically patent HFA were identified. Only 11 of these 19 patients received 90-yttrium in the hepatic vessel bed containing the HFA. Initial coil embolization of the HFA succeeded only in three of 11 patients. Out of the eight remaining patients four had no abdominal wall (99m)Tc-HSAM accumulation. The other four patients presented with an abdominal wall (99m)Tc-HSAM accumulation, for those a reattempt of HFA embolization was performed or ice packs were administered on the abdominal wall during SIRT. In summary, all patients tolerated SIRT well. A patent HFA should not be considered a SIRT contraindication. In patients with abdominal wall (99m)Tc-HSAM accumulation HFA embolization or ice pack administration seems to prevent complications.

Diagnosis of focal liver lesions suspected of metastases by diffusion-weighted imaging (DWI): systematic comparison favors free-breathing technique.

Two echo planar imaging diffusion-weighted imaging (DWI) techniques [one breath hold (DWI(bh)), repetition time/echo time (TR/TE) 2100/62 ms; one at free breathing (DWI(fb)), TR/TE 2000/65 ms] were compared regarding diagnosis of focal liver lesions (FLLs) in 45 patients with suspected liver metastasis without prior treatment. Apparent diffusion coefficient values of 46 benign and 67 malignant FLLs were analyzed by receiver operating characteristics (ROC) analysis. DWI(fb) detected more malignant lesions than DWI(bh) (P=.002). Lesion size ≤10 mm was associated with FLLs missed by DWI(bh) (P=.018). Area under the ROC curve of DWI(fb) (0.801) was higher compared to that of DWI(bh) (0.669, P<.0113), demonstrating the diagnostic superiority of DWI(fb).

Diffusion weighted imaging of liver lesions suspect for metastases: Apparent diffusion coefficient (ADC) values and lesion contrast are independent from Gd-EOB-DTPA administration.

PURPOSE: Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver MRI is widely used for detection and differentiation of focal liver lesions. Diffusion weighted imaging (DWI) including apparent diffusion coefficient (ADC) measurements is increasingly utilised as a fast and, with limitations, quantitative method for liver lesion detection and characterisation. Herein we investigate whether the administration of Gd-EOB-DTPA affects DWI. MATERIALS AND METHODS: 31 consecutive patients referred to standardised liver MRI (1.5T, Gd-EOB-DTPA, 0.025mmol/kg) were retrospectively reviewed. All underwent a breathhold DWI sequence before and after contrast agent administration (EPI-DWI, TR/TE (effective): 2100/62ms, b-values: 0 and 800s/mm(2)). Patients with previously treated liver lesions were excluded. Signal intensity of lesion, parenchyma and noise on DWI images as well as the ADC value were measured after identification by two observers in consensus using manually placed regions of interest. The reference standard was imaging follow-up determined separately by two radiologists. Data analysis included signal-to-noise (SNR) ratio and contrast-to-noise ratio (CNR) calculations, comparisons were drawn by employing multiple Bonferroni corrected Wilcoxon signed-rank tests. RESULTS: 50 malignant and 39 benign lesions were identified. Neither SNR, CNR nor ADC values showed significant differences between pre- and postcontrast DWI. Both pre- and postcontrast ADC values differed significantly between benign and malignant lesions (P<0.001). CONCLUSION: We did not identify a significant influence of Gd-EOB-DTPA on DWI of liver lesions. This allows for individual tailoring of imaging protocols according to clinical needs.