Motion Artifact Reduction in Contrast-Enhanced Dual-Energy Mammography - A Multireader Study about the Effect of Nonrigid Registration as Motion Correction on Image Quality.

Purpose:  The technically caused delay between low-energy (LE) and high-energy (HE) acquisitions allows motion artifacts in contrast-enhanced dual-energy mammography (CEDEM). In this study the effect of motion correction by nonrigid registration on image quality of the recombined images was investigated.

Materials And Methods:  Retrospectively for 354 recombined CEDEM images an additional recombined image was processed from the raw data of LE and HE images using the motion correction algorithm.

Diagnostic Performance of Simultaneous [F]-FDG PET/MR for Assessing Endoscopically Active Inflammation in Patients with Ulcerative Colitis: A Prospective Study.

To investigate the diagnostic performance of simultaneous F-fluoro-deoxyglucose ([F]-FDG) PET/MR enterography in assessing and grading endoscopically active inflammation in patients with ulcerative colitis. 50 patients underwent PET/MR 24 h before ileocolonoscopy. Inflammatory activities of bowel segments were evaluated with both Mayo endoscopic subscore and Nancy histologic index.

Assessment of Ileocolonic Inflammation in Crohn's Disease: Which Surrogate Marker Is Better-MaRIA, Clermont, or PET/MR Index? Initial Results of a Feasibility Trial.

Our objective was to define an F-FDG PET/MR enterography index as a hybrid surrogate marker for active ileocolonic inflammation in Crohn's disease (CD) and assess its diagnostic performance in comparison to validated MR indices (MR index of activity [MaRIA], Clermont score). Fifty-two CD patients with recurrent symptoms underwent ileocolonoscopy and F-FDG PET/MR enterography. Three hundred three ileocolonic segments were assessed for inflammation using MaRIA and the Clermont score as well as the newly defined PET/MR index.

[F]FDG PET/MR enterography for the assessment of inflammatory activity in Crohn's disease: comparison of different MRI and PET parameters.

Purpose: To evaluate the diagnostic performance of integrated whole-body positron emission tomography (PET)/magnetic resonance (MR) enterography in patients with Crohn's disease (CD).

Methods: Fifty patients with known CD and recurrent symptoms underwent ileocolonoscopy (reference standard) as well as PET/MR enterography. Seven ileocolonic segments were endoscopically analysed using the Simplified Endoscopic Activity Score for Crohn's Disease (SES-CD) and additionally classified into three categories of inflammation (none, mild to moderate and severe ulcerative inflammation).

1.5 versus 3 versus 7 Tesla in abdominal MRI: A comparative study.

Objectives: The aim of this study was to investigate and compare the feasibility as well as potential impact of altered magnetic field properties on image quality and potential artifacts of 1.5 Tesla, 3 Tesla and 7 Tesla non-enhanced abdominal MRI.

Materials And Methods: Magnetic Resonance (MR) imaging of the upper abdomen was performed in 10 healthy volunteers on a 1.

Non-enhanced versus low-dose contrast-enhanced renal magnetic resonance angiography at 7 T: a feasibility study.

Background Considering the currently reported association between a repetitive application and cumulative dosage of Gadolinium (Gd)-based contrast agents and Gd-deposition in brain tissue as well as the risk for the advent of nephrogenic systemic fibrosis (NSF), techniques allowing for a dose reduction become an important key aspect aside from non-enhanced magnetic resonance angiography (MRA) techniques. Thus, this study was focused on the reduction and/or complete omission of contrast agent for renal MRA at 7T. Purpose To evaluate the performance of time-of-flight MRA versus low-dose contrast-enhanced (CE) renal MRA at 7T.

18 F-FDG PET/MR imaging in patients with suspected liver lesions: Value of liver-specific contrast agent Gadobenate dimeglumine.

Objectives: To evaluate the added value of the application of the liver-specific contrast phase of Gadobenate dimeglumine (Gd-BOPTA) for detection and characterization of liver lesions in 18F-FDG PET/MRI.

Methods: 41 patients with histologically confirmed solid tumors and known / suspected liver metastases or not classifiable lesions in 18F-FDG PET/CT were included in this study. All patients underwent a subsequent Gd-BOPTA enhanced 18F-FDG PET/MRI examination.

Evaluation of Ga-DOTATOC PET/MRI for whole-body staging of neuroendocrine tumours in comparison with Ga-DOTATOC PET/CT.

Objectives: To compare the diagnostic performance of Ga-DOTATOC PET/MRI and Ga-DOTATOC PET/CT in the whole-body staging of patients with neuroendocrine tumours (NET).

Methods: Thirty patients with histopathologically confirmed NET underwent PET/CT and PET/MRI in a single-injection protocol. PET/CT and PET/MRI scans were prospectively evaluated with regard to lesion count, localization, nature (NET/non-NET), and conspicuity (four-point scale).

Contrast enhanced renal MR angiography at 7 Tesla: How much gadolinium do we need?

Objectives: To investigate whether a dose reduction of Gadobutrol for renal magnetic resonance angiography (MRA) at 7 Tesla (T) is feasible while preserving diagnostic image quality.

Methods: Ten healthy volunteers were enrolled for a renal MRA on a 7T scanner. Fast low angle shot (FLASH) MRA data sets were obtained utilizing three different doses of Gadobutrol (0.

68Ga-DOTATOC PET/CT in Patients with Iodine- and 18F-FDG-Negative Differentiated Thyroid Carcinoma and Elevated Serum Thyroglobulin.

Unlabelled: This study evaluated the impact of Ga-DOTATOC PET/CT in detecting recurrence or metastases in differentiated thyroid carcinoma (DTC) patients with elevated serum thyroglobulin and both negative radioiodine imaging and negative F-FDG PET/CT.

Methods: Ga-DOTATOC PET/CT (CT without contrast, low-dose) was performed on average 6 wk after negative F-FDG PET/CT (CT contrast-enhanced, full-dose) in 15 consecutive radioiodine-negative DTC patients with elevated and rising thyroglobulin. Visual assessment of Ga-DOTATOC PET/CT images used a 4-point scale for classification of lesions (0, no pathologic findings; 1, benign; 2, equivocal; 3, malignant).

Hybrid imaging of the bowel using PET/MR enterography: Feasibility and first results.

Purpose: To implement a protocol for PET/MR enterography for a multimodal assessment of intestinal pathologies.

Materials And Methods: 19 patients with bowel malignancies, Crohn's disease or fever of unknown origin (male: n=14, female: n=5, age: 57±13years) underwent PET/MR enterography with either [(18)F]FDG (n=10) or [(68)Ga]-DOTATOC (n=9) using an integrated scanner. For small bowel distension a contrast solution (1500 cm(3) of mannitol and locust bean gum) was ingested.

Potential influence of Gadolinium contrast on image segmentation in MR-based attenuation correction with Dixon sequences in whole-body 18F-FDG PET/MR.

Objective: To evaluate the influence of Gadolinium contrast agent on image segmentation in magnetic resonance (MR)-based attenuation correction (AC) with four-segment dual-echo time Dixon-sequences in whole-body [18F]-fluorodeoxyglucose positron emission tomography (PET)/MR imaging, and to analyze the consecutive effect on standardized uptake value (SUV).

Materials And Methods: Hybrid imaging with an integrated PET/MR system was performed in 30 oncological patients. AC was based on MR imaging with a Dixon sequence with subsequent automated image segmentation.

Impact of Point-Spread Function Modeling on PET Image Quality in Integrated PET/MR Hybrid Imaging.

Unlabelled: The aim of this study was to systematically assess the quantitative and qualitative impact of including point-spread function (PSF) modeling into the process of iterative PET image reconstruction in integrated PET/MR imaging.

Methods: All measurements were performed on an integrated whole-body PET/MR system. Three substudies were performed: an (18)F-filled Jaszczak phantom was measured, and the impact of including PSF modeling in ordinary Poisson ordered-subset expectation maximization reconstruction on quantitative accuracy and image noise was evaluated for a range of radial phantom positions, iteration numbers, and postreconstruction smoothing settings; 5 representative datasets from a patient population (total n = 20, all oncologic (18)F-FDG PET/MR) were selected, and the impact of PSF on lesion activity concentration and image noise for various iteration numbers and postsmoothing settings was evaluated; and for all 20 patients, the influence of PSF modeling was investigated on visual image quality and number of detected lesions, both assessed by clinical experts.

Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases.

Background: The aim of this study was to compare the diagnostic accuracy of [18F]FDG-PET/MRI with PET/CT for the detection of liver metastases.

Methods: 32 patients with solid malignancies underwent [18F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence.

Hybrid 18F-labeled Fluoride Positron Emission Tomography/Magnetic Resonance (MR) Imaging of the Sacroiliac Joints and the Spine in Patients with Axial Spondyloarthritis: A Pilot Study Exploring the Link of MR Bone Pathologies and Increased Osteoblastic Activity.

Objective: The biologically active molecule used in positron emission tomography (PET) for depiction of osteoblastic activity is 18F-labeled fluoride (18F-F). We examined whether inflammatory or chronic changes on magnetic resonance imaging (MRI) in the sacroiliac joints (SIJ) and the spines of patients with active ankylosing spondylitis (AS) are linked to osteoblastic activity, assessed by PET/MRI.

Methods: Thirteen patients with AS (mean age 37.

Oncological whole-body staging in integrated (18)F-FDG PET/MR: Value of different MR sequences for simultaneous PET and MR reading.

Objective: To evaluate different magnetic resonance (MR) imaging sequences in integrated positron emission tomography (PET)/MR concerning their ability to detect tumors and allocate increased radionuclide uptake on (18)F-fluorodeoxyglucose ((18)F-FDG) PET in intraindividual comparison with computed tomography (CT) from PET/CT.

Material And Methods: Sixty-one patients (34 female, 27 male, mean age 57.6 y) who were examined with contrast-enhanced PET/CT and subsequent PET/MR (mean delay for PET/MR after injection: 147 ± 43 min) were included.

Diagnostic value of diffusion-weighted imaging in simultaneous 18F-FDG PET/MR imaging for whole-body staging of women with pelvic malignancies.

Unlabelled: The aim of this study was to assess the diagnostic benefit of diffusion-weighted imaging (DWI) in an (18)F-FDG PET/MR imaging protocol for whole-body staging of women with primary or recurrent malignancies of the pelvis.

Methods: Forty-eight patients with a primary pelvic malignancy or suspected recurrence of a pelvic malignancy were included in our study. All patients underwent a whole-body (18)F-FDG PET/MR imaging examination that included DWI.

[(18)F]FDG PET/MRI vs. PET/CT for whole-body staging in patients with recurrent malignancies of the female pelvis: initial results.

Purpose: To evaluate the diagnostic potential of PET/MRI with [(18)F]FDG in recurrent ovarian and cervical cancer in comparison to PET/CT.

Methods: A group of 19 patients with suspected recurrence of pelvic malignancies (ovarian cancer, 11 patients; cervical cancer, 8 patients) scheduled for an [(18)F]FDG PET/CT were subsequently enrolled for a PET/MRI. The scan protocol comprised: (1) a T1-W axial VIBE after contrast agent adminstration, (2) an axial T2-W HASTE, (3) a coronal TIRM, (4) an axial DWI, and dedicated MR sequences of the female pelvis including (5) a T1-W VIBE before contrast agent adminstration, (6) a sagittal T2-W TSE, and (7) a sagittal T1-W dynamic VIBE.

Diagnostic accuracy of whole-body PET/MRI and whole-body PET/CT for TNM staging in oncology.

Purpose: In various tumours PET/CT with [(18)F]FDG is widely accepted as the diagnostic standard of care. The purpose of this study was to compare a dedicated [(18)F]FDG PET/MRI protocol with [(18)F]FDG PET/CT for TNM staging in a cohort of oncological patients.

Methods: A dedicated [(18)F]FDG PET/MRI protocol was performed in 73 consecutive patients (mean age of 59 years, range 21 - 85 years) with different histologically confirmed solid primary malignant tumours after a routine clinical FDG PET/CT scan (60 min after injection of 295 ± 45 MBq [(18)F]FDG).

Clinical applications of PET/MRI: current status and future perspectives.

Fully integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) scanners have been available for a few years. Since then, the number of scanner installations and published studies have been growing. While feasibility of integrated PET/MRI has been demonstrated for many clinical and preclinical imaging applications, now those applications where PET/MRI provides a clear benefit in comparison to the established reference standards need to be identified.

Simultaneous positron emission tomography/magnetic resonance imaging for whole-body staging in patients with recurrent gynecological malignancies of the pelvis: a comparison to whole-body magnetic resonance imaging alone.

Objectives: The objective of this study was to assess the diagnostic value of integrated positron emission tomography/magnetic resonance imaging (PET/MRI) for whole-body staging of patients with recurrent gynecological pelvic malignancies, in comparison to whole-body MRI alone.

Materials And Methods: The study was approved by the local institutional ethics committee. Written informed consent was obtained before each examination.

Whole-body [¹⁸F]FDG PET/MRI vs. PET/CT in the assessment of bone lesions in oncological patients: initial results.

Objectives: To compare [(18)F]FDG PET/MRI with PET/CT for the assessment of bone lesions in oncologic patients.

Methods: This prospective study included 67 patients with solid tumours scheduled for PET/CT with [(18)F]FDG who also underwent a whole-body PET/MRI scan. The datasets (PET/CT, PET/MRI) were rated by two readers regarding lesion conspicuity (four-point scale) and diagnostic confidence (five-point scale).

Non-enhanced T1-weighted liver vessel imaging at 7 Tesla.

Objectives: Aim of the study was to assess the feasibility and to compare three non-enhanced T1-weighted (w) sequences for liver vessel imaging at 7 Tesla (T).

Material And Methods: 12 healthy volunteers were examined on a 7 T whole-body MR-system. The following non-enhanced sequences were acquired: T1w 2D FLASH, T1w 3D FLASH and Time of flight (TOF)-MRA.

Correlation of standardized uptake value and apparent diffusion coefficient in integrated whole-body PET/MRI of primary and recurrent cervical cancer.

Background: To evaluate a potential correlation of the maximum standard uptake value (SUVmax) and the minimum apparent diffusion coefficient (ADCmin) in primary and recurrent cervical cancer based on integrated PET/MRI examinations.

Methods: 19 consecutive patients (mean age 51.6 years; range 30-72 years) with histopathologically confirmed primary cervical cancer (n = 9) or suspected tumor recurrence (n = 10) were prospectively enrolled for an integrated PET/MRI examination.

Depiction and characterization of liver lesions in whole body [¹⁸F]-FDG PET/MRI.

Objectives: To assess the value of PET/MRI with [(18)F]-FDG using a whole body protocol for the depiction and characterization of liver lesions in comparison to PET/CT.

Methods: 70 patients (31 women, 39 men) with solid tumors underwent [(18)F]-FDG PET/CT and followed by an additional PET/MRI using an integrated scanner. Two readers rated the datasets (PET/CT; PET/MRI) regarding conspicuity of hepatic lesions (4-point ordinal scale) and diagnostic confidence (5-point ordinal scale).