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Background 18 F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) has proven to be of substantial benefit in imaging of sarcoma patients. We therefore investigated the feasibility and benefit of combined PET/magnetic resonance imaging (MRI). Methods Twelve patients with sarcoma who underwent FDG PET/MRI for staging and response assessment after chemotherapy were included. Results Based on contrast-enhanced MRI and application of Choi criteria, therapy response was classified as stable disease in 6/12 patients (50%) and as partial remission in 6/12 patients (50%). Conclusion In sarcoma patients, response assessment using Choi criteria based on contrast-enhanced MRI in comparison to FDG PET imaging only demonstrates slight correlation.

OBJECTIVE To compare 2 previously presented algorithms for extracting parameters from intravoxel incoherent motion (IVIM) studies and investigate them in the context of tissue differentiation. METHODS Magnetic resonance imaging (MRI) was performed in 23 patients without histologically proven prostate carcinoma (PCa) and 27 patients with histologically proven PCa. Two methods were used to determine IVIM parameters (f, D, D*). Receiver operating characteristic analysis was performed for IVIM parameters and apparent diffusion coefficient for discrimination of prostate tissue. RESULTS The IVIM parameters showed no significant difference between patients without PCa and normal areas in patients with PCa (r = 0.46-0.99). Results for D were not significantly different for both methods (P = 0.22), whereas f from method 1 was significantly higher than the f from method 2 (P < 0.05). The diffusion parameters D (both methods) and apparent diffusion coefficient could discriminate between tumor and normal areas (receiver operating characteristic analysis, area under the curve, ≥0.90). Additionally, in subgroup analysis, only D was able to discriminate between low- and high-grade PCa. CONCLUSIONS For tumor detection, IVIM diffusion does not yield a clear added value, but the perfusion-free diffusion constant D may hold potential for improved image-based tumor grading.

Objectives To evaluate the Prostate Imaging Reporting and Data System (PIRADS) in multiparametric magnetic resonance imaging (mpMRI) based on single cores and single-core histology. To calculate positive (PPV) and negative predictive values (NPV) of different modalities of mpMRI. Patients and Methods We performed MRI-targeted transrectal ultrasound-guided perineal prostate biopsies on 50 patients (mean age 66 years, mean PSA level of 9.9 ng/mL) with suspicion of prostate cancer. The biopsy trajectories of every core taken were documented in three dimensions (3D) in a 3D-prostate model. Every core was evaluated separately for prostate cancer and the performed biopsy trajectories were projected on mpMRI images. PIRADS scores of 1177 cores were then assessed by a histology ‘blinded’ uro-radiologist in T2-weighted (T2W), dynamic contrast-enhanced (DCE), diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS). Results The PIRADS score was significantly higher in cores positive for cancer than in negative cores. There was a significant correlation between the PIRADS score and histopathology for every modality. Receiver operating characteristic (ROC) analysis showed excellent specificity for T2W (90% peripheral zone/97% transition zone) and DWI (98%/97%) images regardless of the prostate region observed. These numbers decreased for DCE (80%/93%) and MRS (76%/83%). All modalities had NPVs of 99%, if a PIRADS score threshold of 2 (for T2W, DCE, and MRS) or 3 (for DWI) was used. However, PPVs were low. Conclusions Our results show that PIRADS scoring is feasible for clinical routine and allows standardised reporting. PIRADS can be used as a decision-support system for targeting of suspicious lesions. mpMRI has a high NPV for prostate cancer and, thus, might be a valuable tool in the initial diagnostic evaluation.

Computed tomographic angiography is the standard in routine follow-up after endovascular aneurysm repair, causing radiation exposure; thus, dose-saving strategies should be applied. The aim of this study was to evaluate the novel sinogram-affirmed iterative reconstruction (SAFIRE) algorithm in terms of clinical usability and potential reduction of radiation exposure.Forty-six patients underwent computed tomographic angiographic follow-up after endovascular aneurysm repair. Data were acquired using a dual-source computed tomographic scanner running both x-ray tubes at the same voltage (120 kV). Raw data were reconstructed using projections of both tubes with filtered back projection (FBP) and of only one tube with FBP and SAFIRE, corresponding to synthetic acquisition with half the radiation dose of the clinical routine radiation dose. Image sets were objectively compared regarding signal-to-noise ratio and edge sharpness. Two radiologists independently assessed a set of subjective criteria, including diagnostic usability, depiction of contrasted vessels, and image noise.Half-dose (HD) SAFIRE images showed significantly higher signal-to-noise ratios compared to full-dose FBP images (P.001), while having equal edge sharpness (P = .56). Most of the subjectively assessed parameters, such as diagnostic usability and depiction of contrasted vessels, were rated similar for HD SAFIRE and full-dose FBP images. Full-dose FBP images depicted fine anatomic structures more clearly (P.05), while HD SAFIRE data sets showed less noise (P.01). HD FBP images performed worse on all criteria (P.001). Interrater agreement was good (κ = 0.74-0.80).Using the SAFIRE algorithm, the radiation dose of high-contrast abdominal computed tomographic angiography is reducible from routine clinical levels by up to 50% while maintaining good image quality and diagnostic accuracy.

Pulmonary complications are a leading source of mortality in patients treated for hematologic malignancies. After hematopoietic stem cell transplantation, treatment-related noninfectious complications constitute more than half of the pulmonary pathology and represent a particular diagnostic challenge. This review illustrates the high-resolution computed tomography findings of common therapy-related complications and thereby demonstrates a high degree of overlap between the patterns of various toxicities. Clinical background knowledge of the distinct entities is reviewed and highlighted as an indispensable instrument to narrow the differential diagnosis.

To evaluate radiation exposure and image quality in thoracic computed tomography (CT) using a new dose-saving algorithm to protect radiosensitive organs.For dose measurements, an Alderson RANDO phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to the International Commission on Radiologic Protection 103. Exposure was performed on a second-generation dual-source CT. The following parameters for thoracic CT were used: 160 effective mAs, 120 kV, scan range of 30 cm, collimation of 128 × 0.6 mm. For the acquisition, the tube current modulation type XCare was used, which reduces the tube current for anterior tube position to minimize direct exposure to anterior located organs. To compare differences, scans with and without XCare were performed. Objective signal-to-noise measurements were evaluated, and the subjective noise perception was rated in a 3-point scale (1: excellent, 3: affecting diagnostic accuracy) in 30 patients with a standard thoracic examination and a follow-up using XCare.A substantial dose reduction in radiosensitive tissues was evident using the dose-saving algorithm XCare. Specifically, reductions of 35.2% for the female breast and 20.1% for the thyroid gland were measured, resulting in a decreasing effective whole-body dose of 8.0% and 14.3% for males and females, respectively. The objective and subjective evaluation of image quality showed no significant differences between both scan protocols (P0.05). Mean signal-to-noise ratio was 1.3 ± 0.2 and 1.2 ± 0.2 in scan protocols without and with XCare, respectively. The subjective scores at the level of the pulmonary trunk were 1.2 ± 0.4 and 1.4 ± 0.5 in standard chest scan and scans with the dose-saving algorithm XCare, respectively.The XCare technique protects radiosensitive organs like the female breast and the thyroid gland without affecting image quality. Therefore, this dose-saving algorithm may be used in thoracic CT examinations in male and female patients.

Purpose To investigate the feasibility of image fusion of MR-coronary angiography (MRCA) and delayed gadolinium enhancement imaging (LGE) and to assign areas of myocardial infarction to the corresponding supplying coronary arteries. Materials and methods An interactive segmentation of the coronary arteries was performed in MRCA data sets (n = 25). The LGE slices were matched onto the vessel segmentation to perform a fused analysis of coronary artery anatomy and LGE. The results were compared to the segmental model recommended by the American Heart Association (AHA). Standard of reference was the identification of the culprit lesion in the invasive coronary angiography (CA) (n = 20). Results The fused analysis allowed the assignment of MI to the supplying coronary artery in 13/20 patients. The sensitivities/specificities for the assignment of MI to the three main vessels were: LAD 63%/100%, LCX 75%/100%, and RCA 56%/100%, respectively. Using the AHA segmental model the sensitivities/specificities for the correct assignment of MI to the three main vessels were: LAD 88%/58%, LCX 94%/75%, and RCA 77%/73%, respectively. Conclusion Fusion images of MRCA and LGE provides added diagnostic information in the effort to determine the epicardial vessels responsible for the postischemic myocardial injury and therefore might be helpful to establish appropriate future therapeutic steps.

In patients with peritoneal carcinomatosis (PC) accurate preoperative assessment is essential to determine indication and surgical procedure to ensure optimal outcome. Purpose of our study was to assess the diagnostic accuracy (DA) of multiphasic dynamic contrast-enhanced MRI to determine the extent of PC in correlation with surgical and histopathological findings.14 Patients with proven PC were examined on a 1.5T system before peritonectomy and hyperthermic intraperitoneal chemotherapy. Patient preparation included oral application of 2000 mL mannitol solution and 40 mg butylscopolaminiumbromid i.v. Coronal contrast-enhanced multiphasic dynamic T1w 3D gre sequences (T1W DCE) (0.15 mmol Gd-chelate/kg bw) covering the whole abdomen were acquired (TR 2.9 ms, TE 1.1 ms, resolution 2.0 × 2.0 × 1.8 mm, FOV 400 × 400 mm). MRI was assessed by two radiologists and correlated with surgical exploration (SE) and histopathology for each segment based on the peritoneal cancer index proposed by Sugarbaker et al.In total, 182 segments were evaluated. PC was found in 118/121 of 182 segments (reader 1/2) by MRI and in 131 segments by SE. In 4/7 segments MRI was false positive. False negative segments 17/17 in MRI did not result in irresectability. The positive predictive value for PC per segment of MRI was 97%/94%, the negative predictive value 73%/72%, the sensitivity 87%/87% and the specificity 92%/86%. The DA was 88%/87%.T1W DCE is an accurate and clinical valuable tool for the preoperative assessment of peritoneal tumor spread.

Background CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4–13.4 mSv and from 10.1–17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% ± 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% ± 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner.

Objective The objective of this article is to describe MR imaging findings of spinal cord pilocytic astrocytomas at first presentation and following neurosurgery and to discuss briefly some of the most common differential diagnoses. Conclusion MR imaging findings in medullary pilocytic astrocytomas consist generally of focal or diffuse cord-enlarging masses that are irregularly shaped, accompanied by cystic elements and hydromyelia, present different degrees of contrast enhancement, high water diffusivity and a propensity for the thoracic and cervical cord.

To evaluate the feasibility and diagnostic impact of time-resolved MR angiography (TR-MRA) combined with parallel imaging and low contrast dose for the assessment of peripheral high-flow vascular malformations (VM) at 1.5 Tesla (T). Twelve consecutive patients (7 female, 5 male, mean age 24.7 ± 11.1 years) with known or suspected high-flow VM underwent time-resolved MRA. Two readers individually assessed image quality, diagnostic confidence as well as hemodynamic features. Digital subtraction angiography (DSA) correlation was available in 9 patients. TR-MRA provided a comprehensive assessment of all VMs with good quality images, allowing reliable differentiation of the early and main arterial phases and of at least the early venous phase. Based on hemodynamic features VM were classified as predominantly arterial malformations in 5 cases (42%), or arteriovenous malformations in the remaining 7 cases (58%). The high-flow component of a VM was confirmed by DSA in 9/9 (100%) cases during the interventional treatment procedure. TR-MRA of peripheral VMs with temporal interpolation and stochastic spiral trajectories is feasible, allowing the assessment of dynamic inflow and vessel-specific information similar to conventional DSA. Therefore, TR-MRA represents a reasonable alternative imaging technique for the pre-treatment evaluation of high-flow VMs.

To assess the feasibility of a comprehensive MRI protocol using intrabiliary contrast medium (gadolinium-EOB-DTPA) for evaluation of living liver donors. In this prospective study, 30 donor candidates for living-related liver transplantation (17 men; 13 women, mean age 37 ± 10.9 years) underwent MRI including MR-angiography (MRA) as well as a conventional T2-weighted MR-cholangiography (MRC) and a contrast-enhanced sequence for depiction of the biliary structures. MRC and MRA images were evaluated for quality on a four-point-scale (score of 0 indicated poor and a score of 3, excellent image quality). Anatomic variants of the arterial, venous, portal venous, and biliary structures were identified. Image quality was diagnostic in all examinations except for 4 of 30 MRA data sets. Intrahepatic biliary structures, especially with regard to the intrahepatic bile ducts of 2nd and 3rd order could be identified with significantly increased image quality than in conventional T2-weighted MRC sequences (P = 0.005 and P = 0.035). A high percentage rate of anatomic variants regarding the biliary, arterial, venous, and portal venous anatomy was found. This protocol allows the evaluation of liver donors especially with regard to the biliary structures. However, the depiction of the arterial anatomy requires further technical developments.

The objective of our study was to assess the feasibility and diagnostic performance of time-resolved MR angiography (MRA) in the pretreatment evaluation of peripheral vascular malformations at 1.5 T.Twenty-two consecutive patients (15 women and seven men; mean age, 22.1 ± 12.1 years) who were known or suspected to have vascular malformations were studied using time-resolved MRA with interleaved stochastic trajectories and parallel acquisition followed by conventional MRA (n = 12). All studies were performed on a 1.5-T whole-body MR system. Image sets of time-resolved and conventional MRA were independently reviewed by two observers for image quality, level of confidence and presence, location, and classification of vascular malformations. The interobserver agreement was calculated using conventional MRA as the standard of reference.On the basis of time-resolved MRA, nine of the lesions were categorized as high-flow arteriovenous malformations (AVMs), the remaining 13 lesions were categorized as low-flow vascular malformations or hemangiomas. There was no significant difference in the image quality grading scores between the two observers for time-resolved MRA (p = 0.61) and conventional MRA (p = 0.54). The kappa coefficient revealed good agreement (κ = 0.76) between time-resolved MRA and conventional MRA. Both observers visualized fine vascular details with higher confidence in two patients on conventional MRA. The additional functional information regarding feeding artery and flow patterns provided by time-resolved MRA was confirmed by digital subtraction in all nine cases.Time-resolved MRA provided the temporal information needed for the appropriate classification of vascular malformations, enabling visualization of both the arterial feeders and draining veins. Furthermore, time-resolved MRA has the potential to be used as an initial and screening diagnostic tool obviating conventional MRA to categorize these lesions and determine their extent to correctly guide treatment.

Rationale and Objectives The aim of this study was to compare tumor changes in patients with hepatocellular carcinoma receiving sorafenib using evaluation criteria of the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) as opposed to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Materials and Methods Twenty-five patients with inoperable hepatocellular carcinoma receiving oral sorafenib underwent magnetic resonance imaging at baseline and follow-up every 8 weeks (range, 2–19 weeks; mean, 7.6 weeks). Data were evaluated retrospectively. Survey time until progression ranged from 5 to 102 weeks (mean, 25.6 weeks), with a total of 54 target lesions being monitored. Additionally, evaluation of serum α-fetoprotein was performed at follow-up. Results The best response at follow-up using RECIST resulted in rates of 4% objective response (complete remission or partial remission), 24% (progressive disease), and 72% (stable disease). In contrast, AASLD and EASL criteria identified objective responses in 28% and 48%. Twenty percent of all patients classified as having progressive disease by RECIST were identified as having “pseudo”-progression due to extensive necrosis. Eleven percent of patients classified as having stable disease by RECIST were disclosed as essentially progressive. AASLD area and AASLD diameter disclosed 36% and 40% of patients as having partial remission, respectively, whereas EASL criteria discovered only 24%. There was no significant correlation between serum α-fetoprotein progression and AASLD, EASL, or RECIST evaluation criteria. Conclusions Response monitoring via functional criteria such as AASLD or EASL criteria is likely to more accurately reflect vital tumor burden in hepatocellular carcinoma compared to RECIST.

Purpose: To retrospectively determine the potential role of additional computed tomography (CT) attenuation measurements for interim response evaluation in residual masses of patients with Hodgkin disease (HD) and follicular non-Hodgkin lymphoma (NHL). Materials and methods: In this retrospective study, 39 patients with HD and 35 patients with NHL presented with residual masses at mid-treatment CT (after 2–4 cycles of chemotherapy) and were assessed via contrast-enhanced CT at baseline, mid-treatment and post-treatment. Volume was recorded as whole-tumour volume. A tumour attenuation ratio (TAR) was calculated as the quotient of attenuation between tumour and muscle at the respective point in time versus baseline. The standard deviation of attenuation values within the tumour volume was recorded to estimate tumour heterogeneity. Results were correlated with relapse-free survival determined at a minimum of 12 months after end-treatment CT. Results: Tumour volume and TAR at interim versus baseline control were significantly reduced in responders compared with non-responders, even after controlling for age, stage, treatment regimen, and baseline tumour volume. No significant differences with respect to the standard deviation of attenuation values within the tumour volumes (tumour heterogeneity) were observed. The volume and attenuation CT (VACT) criteria yielded the highest sensitivities and specificities for the identification of non-response at a threshold of a >20% increase in volume and an increase in TAR at interim control, i.e. 88% (NHL 80%, HD 100%) and 98% (NHL 97%, HD 100%), respectively. The negative predictive values reached by VACT analysis were ≥97%, according to both parameters. Conclusion: Mid-treatment response assessment of residual masses in patients with HD and NHL using VACT may aid in the risk stratification as an additional surrogate parameter.

Rationale and Objectives To determine whether response to anti-angiogenic therapy in patients with multiple myeloma can be assessed by noncontrast perfusion magnetic resonance imaging (MRI) (ie, arterial-spin-labeling [ASL]), and diffusion-weighted [DWI] MRI. Materials and Methods The study protocol was approved by the local institutional ethic board. Ten consecutive patients (eight men, two women; mean age 60.5 ± 8.5 years) with Stage III multiple myeloma were prospectively included. MRI was performed at baseline, as well as 3 and 8 weeks after onset of antiangiogenic therapy. Functional MRI data were compared with clinical outcome and conventional lesion size and signal-intensity measurements. Differences between baseline and follow-up values for ASL-MRI and DWI-MRI were assessed using a paired Student t -test. Results Nine patients responded well to therapy, whereas one patient was classified a nonresponder. Temporary changes in signal intensity between baseline and follow-up examinations were inconsistent on T1-weighted (w) and T2w images. Likewise, determination of lesion size at follow-up proved unreliable. ASL showed a marked decrease in perfusion from baseline (251 ± 159 mL/(min*100g)) to follow-up at 3 weeks (115 ± 85 mL/(min*100g), P = .01) and 8 weeks (101 ± 90 mL/(min*100g, P = .01), respectively. Relative to the baseline examination, mean diffusion increased from 0.68 ± 0.19 × 10 −3 s/mm 2 at baseline to 0.94 ± 0.24 × 10 −3 s/mm 2 after 3 weeks ( P = .04), and 0.96 ± 0.40 × 10 −3 s/mm 2 after 8 weeks ( P = .049). Both methods were able to correctly classify 9/10 patients as responder or nonresponder. Conclusion ASL perfusion as well as DWI-MRI provide accurate, clinically relevant information regarding tumor viability and can predict response already early after therapy onset, as opposed to classical lesion size and MRI signal-intensity measurements.

Objective: We aimed to estimate the effective dose of 4D-Perfusion-CT proto-cols of the lung, liver, and pelvis for the assessment of tumor vascularity.Materials and Methods: An Alderson-Rando phantom equipped with thermo-luminescent dosimeters was used to determine the effective dose values of 4D-Perfusion-CT. Phantom measurements were performed on a 128-slice single-source scanner in adaptive 4D-spiral-mode with bidirectional table movementand a total scan range of 69 mm over a time period of nearly 120 seconds (26scans). Perfusion measurements were simulated for the lung, liver, and pelvisunder the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs).Results: Depending on gender, the evaluated body region and scan protocol,an effective whole-body dose between 2.9 -12.2 mSv, was determined. The radi-ation exposure administered to gender-specific organs like the female breast tis-sue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in thefemale specific dose by 86% and 100% in perfusion scans of the lung and thepelvis, respectively. Conclusion: Due to a significant radiation dose of 4D-perfusion-CT protocols,the responsible use of this new promising technique is mandatory. Gender- andorgan-specific differences should be considered for indication and planning oftumor perfusion scans. erfusion CT was introduced several years ago as an adjunct to morpho-logical imaging in tumor patients. Considering tumor perfusion as an

To determine if arterial-spin-labelling (ASL) MRI can reliably detect early response to anti-angiogenic therapy in patients with multiple myeloma by comparison with clinical/haematological response.Nineteen consecutive patients (10 men; mean age 63.5 ± 9.1 years) were included in the present study. Inclusion criteria were diagnosis of stage III multiple myeloma and clinical indication for therapeutical administration of bortezomib or lenalidomide. We performed MRI on 3.0T MR in the baseline setting, 3 weeks after onset of therapy and after 8 weeks. Clinical responses were determined on the basis of international uniform response criteria in correlation with haematological parameters and medium-term patient outcome. MRI studies were performed after approval by the local institutional review board.Fifteen patients responded to anti-myeloma therapy; 4/19 patients were non-responders to therapy. Mean tumour perfusion assessed by ASL-MRI in a reference lesion was 220.7 ± 132.5 ml min(-1) 100 g(-1) at baseline, and decreased to 125.7 ± 86.3 (134.5 ± 150.9) ml min(-1) 100 g(-1) 3 (8) weeks after onset of therapy (P 0.02). The mean decrease in paraproteinaemia at week 3 (8) was 52.3 ± 47.7% (58.2 ± 58.7%), whereas β2-microglobulinaemia decreased by 20.3 ± 53.1% (23.3 ± 57.0%). Correlation of ASL perfusion with outcome was significant (P = 0.0037).ASL tumour perfusion measurements are a valuable surrogate parameter for early assessment of response to novel anti-angiogenic therapy.

Objective With the introduction of non-myeloablative hematopoietic cell transplantation, acute graft-versus-host-disease (GvHD) is frequently observed beyond the traditional 100 days cut-off. The aim of this study was to describe and compare CT features of gastrointestinal early and late-onset GvHD and to correlate findings with clinical and pathology grading. Subjects and methods Abdominal CT scans were obtained in 20 patients with early and 15 with late-onset GvHD. Examinations were assessed for intestinal and extraintestinal abnormalities and findings compared between the two subgroups of GvHD. Distinct CT abnormalities as well as a CT-score integrating multiple pathologies were correlated with gut, clinical or pathology grading. Results Frequent intestinal abnormalities included wall thickening, abnormal enhancement, and excessive fluid-filling (94%, 89%, and 94%). 86% of patients showed concomitant small and large bowel involvement. A discontinuous distribution was observed in 54%. Bile tract abnormality was the most common extra-intestinal finding (74%). The distribution of pathologies was equal between subgroups of early or late-onset disease. Wall thickening and mucosal attenuation in non-enhanced scans were significantly related to clinical and pathology scores ( P ≤0.018). Number of abnormal segments, small bowel dilatation, engorgement of the vasa recta, mesenteric fat stranding and ascites were linked to clinical grading ( P ≤0.019). A CT-score integrating multiple abnormalities was correlated to gut, overall clinical and pathology grading ( r =0.64, 0.57, 0.50). Conclusion CT morphology of acute GvHD is independent of its time of onset and, thus, facilitates differential diagnosis of late-onset acute GvHD. Correlation of CT morphology with clinical and pathological grading is important in terms of prognosis and may help guiding the therapeutic approach.

OBJECTIVE. The purpose of this article is to illustrate multitechnique imaging findings in patients with primary and secondary vasculitides involving large and medium-sized vessels and their mimics.CONCLUSION. Large and medium-sized vessels are affected by many primary and secondary inflammatory disorders or mimicking conditions, often presenting similar imaging characteristics. Knowledge of distinctive imaging features such as location, length, and degree of vessel wall enhancement as well as the particular clinical settings will help the clinician in appropriately narrowing down the differential diagnosis.

Rationale and Objectives The long-term prospects for patients with peripheral-arterial-occlusive disease (PAOD) must be considered in the context of coexistent generalized atherosclerosis. We sought to determine the added clinical information of noninvasive magnetic resonance imaging (MRI) for detecting asymptomatic atherosclerotic disease in patients already at high risk. Materials and Methods Eighty-four patients (64 men, mean age 66.2 ± 10.0 years, range 34–84 years) with suspected or known PAOD were examined using a comprehensive cardiovascular MRI protocol. Two experienced observers reviewed all MRIs for the presence of “relevant findings,” which were defined as pathology requiring immediate therapy or mid-term follow-up. Results Assessment of cardiac structures and function in 84 study patients yielded new pathology in 40 (48%) patients, whereas cerebral imaging revealed new findings in 45 (54%) patients. Previously unsuspected vascular findings were evident in 46 (55%) patients. Using the information from the MRIs, in 54 (64%) of patients mid-term follow-up was required, whereas in 7 (8%) patients a change of therapy or immediate treatment was necessary. Conclusion Whole-body cardiovascular MRI is able to detect symptomatic and unsuspected findings in patients with PAOD. This technique was able to detect several vascular abnormalities that necessitated immediate medical attention and intervention in patients already identified as high-risk patients and, therefore, may show an increasing impact to determine individual therapeutic and follow-up concepts.

Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0–1.9 ml and 8.8–11.4%, respectively; right ventricular volumes 1.7–2.1 ml and 9.9–16.9%, respectively). No systematic bias was observed. 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease.

To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease.Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22 +/- 5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure).Myocardial viability imaging showed a high prevalence of known (n = 31) and occult myocardial infarctions (MI) (n = 26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40-55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis.Both reduced EF and the presence of MI influence patients' prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention.

OBJECTIVE. The purpose of this study was to use MRI and physical examination to assess the evolution of disabling musculocutaneous changes induced by chronic graft-versus-host disease in patients receiving immunosuppressive therapy.CONCLUSION. MRI monitoring appears to yield accurate information about the extent and activity of musculocutaneous abnormalities related to chronic graft-versus-host disease during immunosuppressive therapy.

Cardiac MRI is known to be diagnostically valuable in cardiac amyloidosis. Several features are frequently found, including myocardial hypertrophy, diastolic dysfunction, a faster gadolinium blood wash out, pleural and pericardial effusions, and diffuse myocardial delayed enhancement. Cardiac MR facilitates the detection of cardiac amyloidosis and allows longitudinal assessment of myocardial function. This pictorial review focuses on cases with histologically proven systemic amyloidosis and cardiac involvement in order to illustrate typical findings.

For contrast-enhanced imaging techniques relying on strong T1 weighting, 3 T provides increased contrast compared with 1.5 T. The aim of our study was the intraindividual comparison of delayed enhancement MR imaging at 1.5 T and at 3 T. Twenty patients with myocardial infarction were examined at 1.5 T and 3 T. Fifteen minutes after injection of contrast agent (0.1 mmol gadobenate dimeglumine per kg body weight), inversion recovery gradient recalled echo (IR-GRE) sequences were acquired (1.5 T/3 T: TR 11.0/9.9 ms, TE 4.4/4.9 ms, flip 30 degrees /30 degrees , slice thickness 6/6 mm) to assess myocardial viability. Two observers rated image quality (Wilcoxon signed rank test). Quantification of hyperenhanced myocardium and standardized SNR/CNR measurements were performed (Student's t test). There was no significant difference with respect to image quality (1.5 T/3 T: 3.5/3.3, p = 0.34, reader 1; 2.4/2.7, p = 0.12, reader 2) and infarction size (760 +/- 566/828 +/- 677 mm(2) at 1.5 T, 808 +/- 639/826 +/- 726 mm(2) at 3 T, reader 1/reader 2, p0.05). Mean SNR in hyperenhanced/normal myocardium was 19.2/6.2 at 1.5 T and 29.5/8.8 at 3 T (p0.05). Mean CNR was 14.3 at 1.5 T and 26.0 at 3 T (p0.05). Delayed enhancement MR imaging at 3 T is a robust procedure yielding superior tissue contrast at 3 T compared with 1.5 T which is, however, not reflected by increased image quality.

The purpose of this study was to prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography performed at 3 T for assessment of renal artery stenosis (RAS) by using parallel acquisition techniques with high acceleration factors and with digital subtraction angiography (DSA) as the reference standard. The study was institutional review board approved, and written informed consent was obtained from all patients. Twenty-nine patients (18 men, 11 women; mean age, 57.1 years +/- 14.3 [standard deviation]) suspected of having RAS underwent MR angiography. Images were evaluated qualitatively and quantitatively. The interobserver variability, sensitivity, specificity, and positive and negative predictive values of 3-T MR angiography, as compared with DSA (performed in 15 patients), were calculated. All examinations yielded good or excellent image quality. The sensitivity and specificity of MR angiography in grading significant (75%) stenosis were 94% and 96%, respectively. Owing to its high sensitivity, contrast-enhanced 3-T MR angiography can be used reliably to exclude RAS and can serve as a useful screening method in the diagnostic work-up of patients with arterial hypertension.

This study evaluated graft patency and flow at rest/stress in patients with coronary artery bypass grafts using MR flow measurements and MR angiography (MRA). 45 symptomatic patients with 86 grafts (46 arterial, 40 venous) were examined 5.5 years after surgery. MRA was used to assess bypass patency. Flow measurements were performed at rest and after stress induction with dipyridamole. All graft segments were evaluated at MRA for stenosis, and were additionally evaluated by the combination of flow measurements and MRA. Conventional coronary angiography or multidetector computed tomography was regarded as a reference standard. No significant stenosis was observed in 49 grafts (Group A), whereas significant stenosis was observed in 37 grafts (Group B). Sensitivity, specificity, and positive and negative predictive values for stenosis in arterial grafts were 95.2%, 96.8%, 80% and 99.4%, respectively, and in venous grafts were 100%, 97.8%, 87.5% and 100%, respectively. The mean blood flow rate at baseline/stress in Group B was significantly lower than that in Group A (p

PURPOSE: The aim of the present study was to determine the correlation of myocardial perfusion MR imaging (MPMRI) and coronary angiography for the detection of flow-limiting stenosis in symptomatic patients with known coronary artery disease and a history of intervention. MATERIALS AND METHODS: MPMRI was performed in 51 symptomatic patients (44 male, 64.7 ± 9.5 years) with known coronary artery disease and a history of stent implantation (between 5 years and 2 weeks prior to MRI). Malperfused myocardial regions were correlated with findings of coronary angiography. A stenosis of > 70 % was regarded as hemodynamically significant. RESULTS: In MPMRI 37 patients (73 %) showed a stress induced perfusion deficit. In 35 of these patients coronary angiography revealed a stenosis of > 70 %. A total of 38 patients (75 %) showed stenoses of > 70 %. MPMRI yielded a sensitivity of 92 % with a specificity of 85 %. The positive predictive value was 95 % and negative predictive value was 79 %. The assignment of malperfused segments to coronary artery territories was carried out according to the standardized myocardial model of the American Heart Association (sensitivity/specificity was 59/85 % for RCA, 79/81 % for LAD and 54/68 % for LCX). CONCLUSION: MPMRI is a suitable non-invasive method for detecting flow-limiting coronary artery stenoses in patients with a history of stent implantation.

To assess the incremental diagnostic value of time-resolved three-dimensional (3D) magnetic resonance (MR) angiography over single-phase 3D MR angiography and cine MR imaging in juvenile and adult patients with congenital heart disease (CHD).The study was HIPAA compliant and was approved by the institutional review board. Written informed consent was obtained from each patient. Eighty-one consecutive patients (46 male and 35 female patients; mean age, 31.1 years +/- 13.5 [standard deviation]) with CHD were examined with a 1.5-T MR imaging unit. The imaging protocol comprised time-resolved MR angiography (repetition time msec/echo time msec, 2.01/0.81) after injection of 0.03 mmol gadodiamide per kilogram of body weight at 4 mL/sec and single-phase high-spatial-resolution MR angiography (2.87/0.97) after injection of 0.15 mmol/kg gadodiamide at 1.5 mL/sec. After review of the time-resolved and conventional MR angiographic data sets, each of two independent observers listed the additional clinical information gained from time-resolved MR angiographic data. A Wilcoxon signed rank test was used to test for statistical differences between the image quality ratings of the two observers.Time-resolved and single-phase high-spatial-resolution MR angiography yielded diagnostic image data in all patients. Observers 1 and 2 found functional information in time-resolved MR angiographic series in 52 and 51 patients, respectively, that was not seen at high-spatial-resolution MR angiography. Intra- and extracardiac shunts, respectively, were exclusively depicted by time-resolved MR angiography for observer 1 in 18 and two patients and for observer 2 in 15 and two patients. However, both observers reported higher confidence in the assessment of such smaller vascular structures as supraaortic vessels (in 12 patients for observer 1 and 11 patients for observer 2) and major aortopulmonary collateral arteries (in eight patients for observer 1 and 10 patients for observer 2) at high-spatial-resolution MR angiography. No significant difference was evident in image quality scoring between the two observers (P = .32 for time-resolved and P = .47 for conventional MR angiography).Compared with conventional MR angiography, time-resolved MR angiography yields clinically relevant information in a substantial number of patients; hence, the two techniques should be regarded as complementary.

The purpose was to assess 64-slice CT in the analysis of global and regional ventricular function, using a model of acute and subacute myocardial infarction in comparison with cine-MRI. Seven pigs underwent standard MSCT and MRI examination a median 1 and 21 days following creation of reperfused myocardial infarction. Endocardial and epicardial contours were manually defined and ventricular volumes calculated according to Simpson's method. Results were compared by Pearson's correlation coefficient and Blant-Altman analysis. Wall motion was assessed on cine-images and evaluated by kappa statistics. MSCT revealed a strong correlation with cine-MRI regarding quantification of end-diastolic volume (EDV; r = 0.97), end-systolic volume (ESV; r = 0.97), stroke volume (SV; r = 0.94), ejection fraction (EF; r = 0.95) or myocardial mass (MM; r =0.94 ). Minor overestimation was observed for EDV and ESV (bias -1.7 ml; -1.5 ml; P=0.095; 0.025), whilst the mean difference for EF was found to be negligible (bias 0.9%; P = 0.18). Both modalities showed a 96.2% segmental agreement in regional wall motion (weighted-kappa 0.91 for 238 segments). This was true for both acute and subacute infarct phase and MSCT, and thereby enabled accurate intraindividual follow-up of segmental dysfunction. Sixty-four-slice CT allows for reliable analysis of global cardiac function and, moreover, provides accurate evaluation of wall motion in acute and subacute myocardial infarct.

Objective The aim of this study was to assess the accuracy of MSCT in characterizing myocardial infarction (MI) and, thereby, determine the extent of early perfusion defect (ED), microvascular obstruction (MO) and transmural depth of late enhancement (LE) in comparison to MRI and histology. Materials and methods Seven pigs were studied with MSCT (Somatom Sensation 64) and MRI (Magnetom Sonata) a median 1 and 21 days following temporary occlusion of a diagonal branch and creation of small reperfused infarction. For depiction of ED, CT images were acquired in the early arterial phase and following 35 s; LE and MO were evaluated on images obtained at 3, 5, 10 and 15 min. Thereby, a bolus/low-flow contrast injection protocol was used. Triphenyltetrazolium-chloride (TTC) stain and histology were obtained. Volumes of enhancement patterns were assessed as percentage of the ventricle and compared by Bland–Altman analysis. Segmental co-localization and graded transmurality was evaluated with weighted-kappa-test. Results Close spatial agreement was observed for MRI–MO and MSCT–MO (bias = 0.55; CI = −1.49 to 2.60 at 5 min MSCT), TTC and MSCT–LE (bias = −1.28; CI = −3.76 to 1.19) or MRI–LE and MSCT–LE (bias = −0.79; CI = −4.19 to 2.60). There was good segmental co-localization for MO (weighted kappa = 0.93) and high agreement for transmural extent of TTC, MRI–LE and MSCT–LE (weighted kappa = 0.84 TTC versus MSCT; 0.86 MRI versus MSCT). Arterial and 35 s ED significantly underestimated infarct size and showed poor segmental or transmural agreement (weighted kappa = 0.33; 0.44). Conclusions MSCT late-scans not only reliably depict size of MO and LE in acute or subacute infarct phases but, moreover, allow for accurate determination of LE transmurality.

The authors report on a case of arterial embolism caused by bone entrapment of the popliteal artery due to a protrusion of a hydroxyl-apatite wedge. The wedge had been placed 4 years earlier during the course of a valgus osteotomy procedure. Thrombolytic therapy was performed, and the wedge was removed. Because causes for arterial embolism vary, the knowledge of its underlying mechanism is necessary to avoid recurring events. Bone entrapment after knee surgery is a differential diagnosis that should be taken into account, even years after surgery.

Cardiovascular magnetic resonance imaging (MRI) has gained widespread acceptance for the assessment of cardiovascular disease. Cardiac MRI requires fast data acquisition schemes because of constraints imposed by physiological motion of cardiac structures and blood flow, which dictate the suitable window of data acquisition. The ongoing improvement of MRI hardware and the development of tailored imaging techniques have been the cornerstones for rapid progress in cardiac MRI. Cardiac MRI at 3.0 T holds the promise to overcome some of the signal-to-noise (SNR) limitations, especially for techniques with borderline SNR at 1.5 T (eg, myocardial perfusion, assessment of viability, or imaging of coronary arteries). The improved SNR at 3.0 T can be used to increase the spatial resolution and/or reduce imaging time. It was shown that all applications of cardiac imaging at 1.5 T seem feasible also at 3.0 T and predominantly provide similar or improved image quality. Although specific absorption rate limitations and susceptibility effects remain a primary concern, the combination of high-field strength examinations with parallel imaging has increased the performance of techniques such as steady-state free-precession at 3.0 T. Therefore, the signal-to-noise and the contrast-to-noise ratios advantages at 3.0 T and the resulting potential benefit for an improved diagnostic value will constantly fuel further developments in this area and pave the way for novel, promising imaging techniques.

During the past decade, contrast-enhanced magnetic resonance angiography (CE-MRA) has been proven to be a powerful tool to visualize the thoracoabdominal vasculature and, consequently, has become a widely accepted noninvasive imaging modality. With the more recent introduction of high-field whole-body magnetic resonance scanners, a further improvement of diagnostic accuracy can be expected. General considerations for performing high-resolution CE-MRA at higher field strength include the benefits of higher signal-to-noise ratio and an improved contrast between vascular and background tissues. Although there are many positive attributes for performing CE-MRA at 3 T, there are also some tradeoffs, such as static magnetic field inhomogeneity and increase in specific absorption rate. This review describes the main technical innovations of advanced CE-MRA techniques at 3 T, illustrated by characteristic cases.

OBJECTIVE: Contemporary free-breathing non contrast enhanced cardiovascular magnetic resonance angiography (CMRA) was qualitatively and quantitatively evaluated to ascertain the reproducibility of the method for coronary artery luminal dimension measurements. SUBJECTS AND METHODS: Twenty-two healthy volunteers (mean age 32 +/- 7 years, 12 males) without coronary artery disease were imaged at 2 centers (1 each in Europe and North America) using navigator-gated and corrected SSFP CMRA on a commercial whole body 1.5T System. Repeat images of right (RCA, n = 21), left anterior descending (LAD, n = 14) and left circumflex (LCX, n = 14) coronary arteries were obtained in separate sessions using identical scan protocol and imaging parameters. True visible vessel length, signal-to-noise (SNR), contrast-to-noise ratios (CNR) and the average luminal diameter over the first 4 cm of the vessel were measured. Intra-observer, inter-observer and inter-scan reproducibility of coronary artery luminal diameter were determined using Pearson's correlation, Bland-Altman analysis and intraclass correlation coefficients (ICC). RESULTS: CNR, SNR and the mean length of the RCA, LAD and LCX imaged for original and repeat scans were not significantly different (all p > 0.30). There was a high degree of intra-observer, inter-observer and inter-scan agreements for RCA, LAD and LCX luminal diameter respectively on Bland-Altman and ICC analysis (ICC's for RCA: 0.98. 0.98 and 0.86; LAD: 0.89, 0.89 and 0.63; LCX: 0.95, 0.94 and 0.79). CONCLUSION: In a 2-center study, we demonstrate that free-breathing 3D SSFP CMRA can visualize long continuous segments of coronary vessels with highly reproducible measurements of luminal diameter.

With further increase of CT numbers and their dominant contribution to medical exposure, there is a recent quest for more effective dose control. While reintroduction of iterative reconstruction (IR) has proved its potential in many applications, a novel focus is placed on more noise efficient detectors. Our purpose was to assess the potential of IR in combination with an integrated circuit detector (ICD) for aggressive dose reduction in head CT.Non-contrast low-dose head CT [190 mAs; weighted volume CT dose index (CTDIvol), 33.2 mGy] was performed in 50 consecutive patients, using a new noise efficient detector and IR. Images were assessed in terms of quantitative and qualitative image quality and compared with standard dose acquisitions (320 mAs; CTDIvol, 59.7 mGy) using a conventional detector and filtered back projection.By combining ICD and IR in low-dose examinations, the signal to noise was improved by about 13% above the baseline level in the standard-dose control group. Both, contrast-to-noise ratio (2.02 ± 0.6 vs 1.88 ± 0.4; p = 0.18) and objective measurements of image sharpness (695 ± 84 vs 705 ± 151 change in Hounsfield units per pixel; p = 0.79) were fully preserved in the low-dose group. Likewise, there was no significant difference in the grading of several subjective image quality parameters when both noise-reducing strategies were used in low-dose examinations.Combination of noise efficient detector with IR allows for meaningful dose reduction in head CT without compromise of standard image quality.Our study demonstrates the feasibility of almost 50% dose reduction in head CT dose (1.1 mSv per scan) through combination of novel dose-reducing strategies.

OBJECTIVES The purpose of the study was to evaluate and validate diffusion kurtosis imaging (DKI) for detection grading of peripheral zone prostate cancer (PCa) compared with standard diffusion-weighted imaging (DWI) in a cohort of patients with biopsy-proven PCa. MATERIALS AND METHODS In this retrospective, single-institutional study, 55 patients (age, 67.5 ± 6.9 years; range, 52-84 years) who underwent multiparametric magnetic resonance imaging (MRI) before transperineal magnetic resonance/transrectal ultrasound-guided fusion biopsy were included. Suspicious lesions identified in multiparametric MRI underwent image-guided targeted biopsy procedure using a hybrid magnetic resonance/transrectal ultrasound-guided fusion biopsy system. Multiparametric MRI examinations were performed at 3.0 T using a 16-channel phased array coil. Diffusion kurtosis imaging has been acquired with 9 b values (0, 50, 250, 500, 750, 1000, 1250, 1500, and 2000 s/mm). In patients with histologically proven PCa, a representative tumor region was determined as region of interest (ROI) on axial T2-weighted images in consensus by 2 board-certified radiologists. For quantitative evaluation, ROIs located in malignant and contralateral tumor-free regions were transferred to diffusion-weighted images. Diffusion kurtosis imaging parameters (Dapp and Kapp) and apparent diffusion coefficient (ADC) values of the ROIs in tumor and contralateral remote areas were calculated. Estimation of the kurtosis-derived parameters was performed using a voxel-by-voxel fit followed by an ROI-based averaging and a second fit to ROI-averaged signal values. A subgroup analysis was performed to determine the influence of aggressiveness of PCa using ADC, Dapp, and Kapp. The receiver operating characteristic (ROC) curves were calculated for DKI parameters and ADC values. RESULTS In the 55 patients, the average prostate-specific antigen level was 12.4 ± 12.6 ng/mL (range, 2.7–75.0 ng/mL), and the median Gleason score was 7 (range, 6–10). Dapp (units, 10(-3) mm(2)/s) was significantly lower in tumor compared with control regions (1.48 ± 0.35 vs 2.00 ± 0.32, P < 0.05), and Kapp was significantly higher (1.01 ± 0.21 vs 0.76 ± 0.14, P < 0.05). Dapp was significantly higher than standard ADC (units, 10(-3) mm(2)/s) both in tumor regions and in controls (1.48 ± 0.35 vs 1.10 ± 0.25 and 2.00 ± 0.32 vs 1.43 ± 0.25, P < 0.05). Neither the ROI-based calculation of the kurtosis parameters nor the application of the noise correction significantly changed the DKI parameter estimation. There was no significant difference for the applied fitting method for DKI-derived parameters considering the differentiation between tumor and control tissue. Subsequent ROC analyses did not reveal a significant difference between DKI and ADC for detection of PCa. Sensitivities derived by Youden J statistics cutoff values ranged from 69% to 91% for DKI parameters; specificities ranged from 71% to 89%. Subgroup analysis for DKI (Dapp, Kapp) and ADC for assessing aggressiveness of PCa found significant difference (P < 0.05) for discrimination between high- and low-grade findings. However, no significant difference could be obtained between standard DWI- and DKI-derived parameters. CONCLUSIONS The results of this study demonstrated no significant benefit of DKI for detection and grading of PCa as compared with standard ADC in the peripheral zone determined from b values of 0 and 800 s/mm. For clinical routine application, ADC derived from monoexponential fitting of DWI data remains the standard for characterizing peripheral zone cancer of the prostate.

Cardiac MRI has become a clinically useful supplement to ECHO and conventional X-ray angiography in the diagnostic work-up of patients with congenital heart disease (CHD). Three-dimensional (3D) sequences are capable of depicting both intracardiac and extracardiac structures with high accuracy in adults and adolescents. However, diagnostic image quality in infants and young children has not yet been reported. To apply an optimized 3D steady-state free-precession (SSFP) MR sequence in infants and children with CHD. In 20 patients (median age 1.8 years; ten male) with CHD, whole-chest imaging was performed with navigator-gated, isotropic 3D SSFP MRI at 1.5 T. Sequence parameters were adapted to special requirements in infancy. Measurements of intra- and extracardiac structures were performed by two independent observers and compared to spin-echo and cine gradient-recalled-echo sequences. Diagnostic image quality was achieved with the 3D SSFP technique in all patients, allowing the establishment of a diagnosis in all cases. Interobserver comparison of measurements from reformatted 3D SSFP datasets revealed only minor differences with standard deviations ranging from 0.3–1.3 mm for intracardiac and 0.3–0.7 mm for extracardiac anatomy (P = ns). Isotropic 3D SSFP MRI allows reliable and accurate assessment of CHD, even in free-breathing infants and young children.

We sought to assess the feasibility of isotropic 3-dimensional contrast-enhanced magnetic resonance angiography (MRA) covering the supra-aortic and intracranial arteries with a MR sequence using parallel-imaging in phase- and slice-encoding directions.Six volunteers and 5 patients with suspected cerebrovascular disease were examined at 3.0 T using a 16-element head-neck array. Contrast-enhanced 3-dimensional MRA (repetition time 3.2 milliseconds, echo time 1.2 milliseconds, flip angle 30 degrees , bandwidth 390 Hz/pixel) was acquired with integrated generalized autocalibrating partially parallel acquisition (GRAPPA), in both phase- and slice-encoding direction. Images were evaluated independently by 2 radiologists. Signal-to-noise ratio was calculated from phantom measurements.Signal-to-ratio levels of 8.7 +/- 2.2/48.7 +/- 10.2 with and without parallel-imaging (GRAPPA x 6) were measured, respectively. Scoring of image quality by observer 1/observer 2 on a 4-point-scale (range 0-3) yielded 2.5 +/- 1.0/2.4 +/- 1.0 and 2.1 +/- 1.0/2.0 +/- 1.1 for extracranial and intracranial vessel segments in volunteers and 2.8 +/- 0.6/2.7 +/- 0.7 and 2.0 +/- 1.2/2.1 +/- 1.1 in patients, respectively. The interobserver agreement was excellent (k = 0.82).This study shows that contrast-enhanced MRA, applying parallel-imaging in both phase- and slice-encoding direction (iPAT), is feasible at 3.0 T. Coverage of the carotid and vertebro-basilar circulation was achieved.