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Purpose: For reliable DCE MRI parameter estimation, k‐space undersampling is essential to meet resolution, coverage, and signal‐to‐noise requirements. Pseudo‐spiral (PS) sampling achieves this by sampling k‐space on a Cartesian grid following a spiral trajectory. The goal was to optimize PS k‐space sampling patterns for abdomin al DCE MRI. Methods: The optimal PS k‐space sampling pattern was determined using an anthropomorphic digital phantom. Contrast agent inflow was simulated in the liver, spleen, pancreas, and pancreatic ductal adenocarcinoma (PDAC). A total of 704 variable sampling and reconstruction approaches were created using three algorithms using different parametrizations to control sampling density, halfscan and compressed sensing regularization. The sampling patterns were evaluated based on image quality scores and the accuracy and precision of the DCE pharmacokinetic parameters. The best and worst strategies were assessed in vivo in five healthy volunteers without contrast agent administration. The best strategy was tested in a DCE scan of a PDAC patient. Results: The best PS reconstruction was found to be PS‐diffuse based, with quadratic distribution of readouts on a spiral, without random shuffling, halfscan factor of 0.8, and total variation regularization of 0.05 in the spatial and temporal domains. The best scoring strategy showed sharper images with less prominent artifacts in healthy volunteers compared to the worst strategy. Our suggested DCE sampling strategy also showed high quality DCE images in the PDAC patient. Conclusion: Using an anthropomorphic digital phantom, we identified an optimal PS sampling strategy for abdominal DCE MRI, and demonstrated feasibility in a PDAC patient. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma (PDAC) stromal viscoelasticity can be measured using MR elastography (MRE). Bowel preparation regimens could affect MRE quality and knowledge on repeatability is crucial for clinical implementation. Purpose: To assess effects of four bowel preparation regimens on MRE quality and to evaluate repeatability and differentiate patients from healthy controls. Study Type: Prospective. Population: 15 controls (41 ± 16 years; 47% female), 16 PDAC patients (one excluded, 66 ± 12 years; 40% female) with 15 age‐/sex‐matched controls (65 ± 11 years; 40% female). Final sample size was 25 controls and 15 PDAC. Field Strength/Sequence: 3‐T, spin‐echo echo‐planar‐imaging, turbo spin‐echo, and fast field echo gradient‐echo. Assessment: Four different regimens were used: fasting; scopolaminebutyl; drinking 0.5 L water; combination of 0.5 L water and scopolaminebutyl. MRE signal‐to‐noise ratio (SNR) was compared between all regimens. MRE repeatability (test–retest) and differences in shear wave speed (SWS) and phase angle (ϕ) were assessed in PDAC and controls. Regions‐of‐interest were defined for tumor, nontumorous (n = 8) tissue in PDAC, and whole pancreas in controls. Two radiologists delineated tumors twice for evaluation of intraobserver and interobserver variability. Statistical Tests: Repeated measures analysis of variance, coefficients of variation (CoVs), Bland–Altman analysis, (un)paired t‐test, Mann–Whitney U‐test, and Wilcoxon signed‐rank test. P‐value<0.05 was considered statistically significant. Results: Preparation regimens did not significantly influence MRE‐SNR. Therefore, the least burdensome preparation (fasting only) was continued. CoVs for tumor SWS were: intrasession (12.8%) and intersession (21.7%), and intraobserver (7.9%) and interobserver (10.3%) comparisons. For controls, CoVs were intrasession (4.6%) and intersession (6.4%). Average SWS for tumor, nontumor, and healthy tissue were: 1.74 ± 0.58, 1.38 ± 0.27, and 1.18 ± 0.16 m/sec (ϕ: 1.02 ± 0.17, 0.91 ± 0.07, and 0.85 ± 0.08 rad), respectively. Significant differences were found between all groups, except for ϕ between healthy–nontumor (P = 0.094). Data Conclusion: The proposed bowel preparation regimens may not influence MRE quality. MRE may be able to differentiate between healthy tissue–tumor and tumor–nontumor. Level of Evidence: 2 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma (PDAC) stromal disposition is thought to influence chemotherapy efficacy and increase tissue stiffness, which could be quantified noninvasively via MR elastography (MRE). Current methods cause position‐based errors in pancreas location over time, hampering accuracy. It would be beneficial to have a single breath‐hold acquisition. Purpose: To develop and test a single breath‐hold three‐dimensional MRE technique utilizing prospective undersampling and a compressed sensing reconstruction (CS‐MRE). Study Type: Prospective. Population: A total of 30 healthy volunteers (HV) (31 ± 9 years; 33% male) and five patients with PDAC (69 ± 5 years; 80% male). Field Strength/Sequence: 3‐T, GRE Ristretto MRE. Assessment: First, optimization of multi breath‐hold MRE was done in 10 HV using four combinations of vibration frequency, number of measured wave‐phase offsets, and TE and looking at MRE quality measures in the pancreas head. Second, viscoelastic parameters delineated in the pancreas head or tumor of CS‐MRE were compared against (I) 2D and (II) 3D four breath‐hold acquisitions in HV (N = 20) and PDAC patients. Intrasession repeatability was assessed for CS‐MRE in a subgroup of healthy volunteers (N = 15). Statistical Tests: Tests include repeated measures analysis of variance (ANOVA), Bland–Altman analysis, and coefficients of variation (CoVs). A P‐value <.05 was considered statistically significant. Results: Optimization of the four breath‐hold acquisitions resulted in 40 Hz vibration frequency, five wave‐phases, and echo time (TE) = 6.9 msec as the preferred method (4BH‐MRE). CS‐MRE quantitative results did not differ from 4BH‐MRE. Shear wave speed (SWS) and phase angle differed significantly between HV and PDAC patients using 4BH‐MRE or CS‐MRE. The limits of agreement for SWS were [−0.09, 0.10] m/second and the within‐subject CoV was 4.8% for CS‐MRE. Data Conclusion: CS‐MRE might allow a single breath‐hold MRE acquisition with comparable SWS and phase angle as 4BH‐MRE, and it may still enable to differentiate between HV and PDAC. Level of Evidence: 2 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]

Aim: This study aimed to quantify displacement of urogenital organs after abdominoperineal resection (APR), and to explore patient and treatment characteristics associated with displacement. Method: Patients from 16 centres who underwent APR for primary or recurrent rectal cancer (2001–2018) with evaluable preoperative and 6–18 months postoperative radiological imaging were included in the study. Anatomical landmarks on sagittal images were related to a coordinate system based on reference lines between fixed bony structures and absolute displacements were calculated using the Pythagorean theorem. Rotation of landmarks was measured relative to a pubic‐S5 reference line. Results: There were 248 patients included of which 171 were men and 77 women. The median displacement of the internal urethral orifice was 25 mm in men (maximum 65), and 17 mm in women (maximum 50). Rotation of the internal urethral orifice was in a caudal direction in 160/170 (94%) of men and 65/73 (89%) of women, with a median of 32 degrees (maximum 85) and 33 degrees (maximum 83), respectively. Displacements of the posterior bladder wall, distal end of prostatic urethra and cervix were significantly correlated with the internal urethral orifice. In linear regression analysis, biological mesh reconstruction of the pelvic floor and visceral interposition were significantly associated with increased displacement of the internal urethral orifice, and female gender and any filling of the presacral space with decreased displacement. Conclusions: Substantial absolute displacement and rotation of urogenital organs after APR for rectal cancer were observed, but with high variability among both men and women, and being significantly associated with reconstructive interventions. [ABSTRACT FROM AUTHOR]

Background and objective: Patients with coronavirus disease 2019 (COVID‐19) pneumonia present with typical findings on chest computed tomography (CT), but the underlying histopathological patterns are unknown. Through direct regional correlation of imaging findings to histopathological patterns, this study aimed to explain typical COVID‐19 CT patterns at tissue level. Methods: Eight autopsy cases were prospectively selected of patients with PCR‐proven COVID‐19 pneumonia with varying clinical manifestations and causes of death. All had been subjected to chest CT imaging 24–72 h prior to death. Twenty‐seven lung areas with typical COVID‐19 patterns and two radiologically unaffected pulmonary areas were correlated to histopathological findings in the same lung regions. Results: Two dominant radiological patterns were observed: ground‐glass opacity (GGO) (n = 11) and consolidation (n = 16). In seven of 11 sampled areas of GGO, diffuse alveolar damage (DAD) was observed. In four areas of GGO, the histological pattern was vascular damage and thrombosis, with (n = 2) or without DAD (n = 2). DAD was also observed in five of 16 samples derived from areas of radiological consolidation. Seven areas of consolidation were based on a combination of DAD, vascular damage and thrombosis. In four areas of consolidation, bronchopneumonia was found. Unexpectedly, in samples from radiologically unaffected lung parenchyma, evidence was found of vascular damage and thrombosis. Conclusion: In COVID‐19, radiological findings of GGO and consolidation are mostly explained by DAD or a combination of DAD and vascular damage plus thrombosis. However, the different typical CT patterns in COVID‐19 are not related to specific histopathological patterns. Microvascular damage and thrombosis are even encountered in the radiologically normal lung. [ABSTRACT FROM AUTHOR]

Background: Chronic intestinal pseudo‐obstruction (CIPO) is a severe intestinal motility disorder of which the pathophysiology is largely unknown. This study aimed at gaining insight in fasted and fed small bowel motility in CIPO patients using cine‐MRI with caloric stimulation. Methods: Eight adult patients with manometrically confirmed CIPO were prospectively included. Patients underwent a cine‐MRI protocol after an overnight fast, comprising fasting‐state scans and scans after ingestion of a meal (Nutridrink, 300 kcal). Small bowel motility was quantified resulting in a motility score in arbitrary units (AU) and visually assessed by three radiologists. Findings were compared with those in 16 healthy volunteers. Key Results: Motility scores (median, IQR) in CIPO patients were 0.21 (0.15–0.30) in the fasting state and 0.23 (0.15–0.27) directly postprandially. In healthy volunteers, corresponding motility scores were 0.15 (0.13–0.18) and 0.22 (0.19–0.25), respectively. The postprandial change in motility score was +1% (−19 to +21%) in CIPO and +39% (+23 to +50%) in healthy volunteers (p = 0.001*). Visual analysis revealed increased small bowel contractility in four, normal in two, and decreased in two CIPO patients. Conclusions & Inferences: Surprisingly, we found hyperactive small bowel motility in half of the CIPO patients, suggestive of uncoordinated motility. A wide variation in motility patterns was observed, both higher, lower, and comparable contractility compared with healthy subjects. No clear postprandial activation was seen in patients. Cine‐MRI helps to gain insight in this complex disease and can potentially impact treatment decisions in the future. [ABSTRACT FROM AUTHOR]

Purpose: Magnetic resonance imaging (MRI) is increasingly used in radiation oncology for target delineation and radiotherapy treatment planning, for example, in patients with gynecological cancers. As a consequence of pelvic radiotherapy, a part of the bowel is irradiated, yielding risk of bowel toxicity. Existing dose‐effect models predicting bowel toxicity are inconclusive and bowel motion might be an important confounding factor. The exact motion of the bowel and dosimetric effects of its motion are yet uncharted territories in radiotherapy. In diagnostic radiology methods on the acquisition of dynamic MRI sequences were developed for bowel motility visualization and quantification. Our study aim was to develop an imaging technique based on three‐dimensional (3D) cine‐MRI to visualize and quantify bowel motion and demonstrate it in a cohort of gynecological cancer patients. Methods: We developed an MRI acquisition suitable for 3D bowel motion quantification, namely a balanced turbo field echo sequence (TE = 1.39 ms, TR = 2.8 ms), acquiring images in 3.7 s (dynamic) with a 1.25 × 1.25 × 2.5 mm3 resolution, yielding a field of view of 200 × 200 × 125 mm3. These MRI bowel motion sequences were acquired in 22 gynecological patients. During a 10‐min scan, 160 dynamics were acquired. Subsequent dynamics were deformably registered using a B‐spline transformation model, resulting in 159 3D deformation vector fields (DVFs) per MRI set. From the 159 DVFs, the average vector length was calculated per voxel to generate bowel motion maps. Quality assurance was performed on all 159 DVFs per MRI, using the Jacobian Determinant and the Harmonic Energy as deformable image registration error metrics. In order to quantify bowel motion, we introduced the concept of cumulative motion–volume histogram (MVH) of the bowel bag volume. Finally, interpatient variation of bowel motion was analyzed using the MVH parameters M10%, M50%, and M90%. The M10%/M50%/M90% represents the minimum bowel motion per frame of 10%/50%/90% of the bowel bag volume. Results: The motion maps resulted in a visualization of areas with small and large movements within the bowel bag. After applying quality assurance, the M10%, M50%, and M90% were 4.4 (range 2.2–7.6) mm, 2.2 (range 0.9–4.1) mm, and 0.5 (range 0.2–1.4) mm per frame, on average over all patients, respectively. Conclusion: We have developed a method to visualize and quantify 3D bowel motion with the use of bowel motion specific MRI sequences in 22 gynecological cancer patients. This 3D cine‐MRI‐based quantification tool and the concept of MVHs can be used in further studies to determine the effect of radiotherapy on bowel motion and to find the relation with dose effects to the small bowel. In addition, the developed technique can be a very interesting application for bowel motility assessment in diagnostic radiology. [ABSTRACT FROM AUTHOR]

Summary: Background: Positive effects of hyperbaric oxygen on perianal fistulas in Crohn's disease have been reported. Aim: To assess efficacy, safety and feasibility of hyperbaric oxygen in Crohn's disease patients with therapy‐refractory perianal fistulas. Methods: Twenty consecutive patients were recruited at the out‐patient fistula clinic of the Amsterdam UMC. Crohn's disease patients with high perianal fistula(s) failing conventional treatment for over 6 months were included. Exclusion criteria were presence of a stoma, rectovaginal fistula(s) and recent changes in treatment regimens. Patients received treatment with 40 hyperbaric oxygen sessions and outcome parameters were assessed at Week 16. Results: Seven women and 13 men were included (median age 34 years). At Week 16, median scores of perianal disease activity index and modified van Assche index (co‐primary outcome parameters) decreased from 7.5 (95% CI 6‐9) to 4 (95% CI 3‐6, P < 0.001), and from 9.2 (95% CI 7.3‐11.2) to 7.3 (95% CI 6.9‐9.7, P = 0.004) respectively. Perianal disease activity index scores ≤4 (representing inactive perianal disease) were observed in 13/20 patients (65%). Twelve patients showed a clinical response (60%) and four (20%) clinical remission, assessed with fistula drainage assessment. Median C‐reactive protein and faecal calprotectin levels decreased from 4.2 mg/mL (95% CI 1.6‐8) to 2.2 (95% CI 0.9‐4.3, P = 0.003) and from 399 µg/g (95% CI 52‐922) to 31 (95% CI 16‐245, P = 0.001), respectively. Conclusions: We found significant clinical, radiological and biochemical improvement in Crohn's disease patients with therapy‐refractory perianal fistulas after treatment with hyperbaric oxygen. Clinical trial registration: www.trialregister.nl/trial/6489. [ABSTRACT FROM AUTHOR]

Patient stratification based on biological variation in pancreatic ductal adenocarcinoma (PDAC) subtypes could help to improve clinical outcome. However, noninvasive assessment of the entire tumor microenvironment remains challenging. In this study, we investigate the biological basis of dynamic contrast‐enhanced (DCE), intravoxel incoherent motion (IVIM), and R2*‐derived magnetic resonance imaging (MRI) parameters for the noninvasive characterization of the PDAC tumor microenvironment and evaluate their prognostic potential in PDAC patients. Patients diagnosed with treatment‐naïve resectable PDAC underwent MRI. After resection, a whole‐mount tumor slice was analyzed for collagen fraction, vessel density, and hypoxia and matched to the MRI parameter maps. MRI parameters were correlated to immunohistochemistry‐derived tissue characteristics and evaluated for prognostic potential. Thirty patients were included of whom 21 underwent resection with whole‐mount histology available in 15 patients. DCE Ktrans and ve, ADC, and IVIM D correlated with collagen fraction. DCE kep and IVIM f correlated with vessel density and R2* with tissue hypoxia. Based on MRI, two main PDAC phenotypes could be distinguished; a stroma‐high phenotype demonstrating high vessel density and high collagen fraction and a stroma‐low phenotype demonstrating low vessel density and low collagen fraction. Patients with the stroma‐high phenotype (high kep and high IVIM D, n = 8) showed longer overall survival (not reached vs. 14 months, P = 0.001, HR = 9.1, P = 0.004) and disease‐free survival (not reached vs. 2 months, P < 0.001, HR 9.3, P = 0.003) compared to the other patients (n = 22). Median follow‐up was 41 (95% CI: 36–46) months. MRI was able to accurately characterize tumor collagen fraction, vessel density, and hypoxia in PDAC. Based on imaging parameters, a subgroup of patients with significantly better prognosis could be identified. These first results indicate that stratification‐based MRI‐derived biomarkers could help to tailor treatment and improve clinical outcome and warrant further research. [ABSTRACT FROM AUTHOR]

High field 31P spectroscopy has thus far been limited to diffuse liver disease. Unlike lower field‐strength scanners, there is no body coil in the bore of the 7 T and despite inadequate penetration depth (<10 cm), surface coils are the current state‐of‐the‐art for acquiring anatomical images to support multinuclear studies. We present a system of proton antennas and phosphorus loops for 31P spectroscopy and provide the first ultrahigh‐field phosphorus metabolic imaging of a tumor in the abdomen. Herein we characterize the degree to which antennas are isolated from underlying loops. Next, we evaluate the penetration depth of the two antennas available during multinuclear examinations. Finally, we combine phosphorus spectroscopy (two loops) with parallel transmit imaging (eight antennas) in a patient. The loops and antennas are inherently decoupled (no added circuitry, <0.1% power coupling). The penetration depth of two antennas gives twice that of conventional loops. The liver and full axial slice of the abdomen were imaged with eight transmit/receive antennas using parallel transmit B1‐shimming to overcome image voids. Phosphorus spectroscopy from a liver metastasis resolved individual peaks for phosphocholine and phosphoethenalomine. Proton antennas are inherently decoupled from phosphorus loops. By using two proton antennas it is possible to perform region‐of‐interest image‐based shimming in over 80% of the liver volume, thereby enabling phosphorus spectroscopy of localized disease. Shimming of the full extent of the abdominal cross‐section is feasible using a parallel transmit array of eight antennas. A system architecture capable of supporting eight‐channel parallel transmit and multinuclear spectroscopy is optimal for supporting multiparametric body imaging, including metabolic imaging, for monitoring the response of patients with liver metastases to cancer treatments and for patient risk stratification. In the meantime, the existing infrastructure using two antennas is sufficient for preliminary studies in metabolic imaging of tumors in the liver. [ABSTRACT FROM AUTHOR]

Background: Pharmacokinetic (PK) models can describe microvascular density and integrity. An essential component of PK models is the arterial input function (AIF) representing the time-dependent concentration of contrast agent (CA) in the blood plasma supplied to a tissue.Purpose/hypothesis: To evaluate a novel method for subject-specific AIF estimation that takes inflow effects into account.Study Type: Retrospective study.Subjects: Thirteen clinical patients referred for spine-related complaints; 21 patients from a study into luminal Crohn's disease with known Crohn's Disease Endoscopic Index of Severity (CDEIS).Field Strength/sequence: Dynamic fast spoiled gradient echo (FSPGR) at 3T.Assessment: A population-averaged AIF, AIFs derived from distally placed regions of interest (ROIs), and the new AIF method were applied. Tofts' PK model parameters (including vp and Ktrans ) obtained with the three AIFs were compared. In the Crohn's patients Ktrans was correlated to CDEIS.Statistical Tests: The median values of the PK model parameters from the three methods were compared using a Mann-Whitney U-test. The associated variances were statistically assessed by the Brown-Forsythe test. Spearman's rank correlation coefficient was computed to test the correlation of Ktrans to CDEIS.Results: The median vp was significantly larger when using the distal ROI approach, compared to the two other methods (P < 0.05 for both comparisons, in both applications). Also, the variances in vp were significantly larger with the ROI approach (P < 0.05 for all comparisons). In the Crohn's disease study, the estimated Ktrans parameter correlated better with the CDEIS (r = 0.733, P < 0.001) when the proposed AIF was used, compared to AIFs from the distal ROI method (r = 0.429, P = 0.067) or the population-averaged AIF (r = 0.567, P = 0.011).Data Conclusion: The proposed method yielded realistic PK model parameters and improved the correlation of the Ktrans parameter with CDEIS, compared to existing approaches.Level Of Evidence: 3 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2018;47:1197-1204. [ABSTRACT FROM AUTHOR]

Gaucher disease ( GD) is a lysosomal storage disorder characterized by the storage of glycosphingolipids in macrophages. Despite effective therapy, residual disease is present in varying degrees and may be associated with late complications, such as persistent bone or liver disease and increased cancer risk. Gaucher macrophages are capable of storing iron and locations of residual disease may thus be detectable with iron imaging. Forty type 1 GD ( GD1) patients and 40 matched healthy controls were examined using a whole-body magnetic resonance imaging protocol consisting of standard sequences, allowing analysis of iron content per organ, expressed as R2* (Hz). Median R2* values were significantly elevated in GD1 patients as compared to healthy controls in liver [41 Hz (range 29-165) vs. 38 Hz (range 28-53), P < 0·01], femoral bone marrow [54 Hz (range 37-129) vs. 49 Hz (range 39-69), P = 0·036] and vertebral bone marrow (118 Hz (range 82-210) vs. 105 Hz (range 76-149), P < 0·01). In the spleen, primarily focal Gaucher lesions known as Gaucheroma were found to have increased R2* values. R2* values of liver, spleen and vertebral bone marrow strongly correlated with serum ferritin levels. GD1 patients with persistent hyperferritinaemia demonstrate increased iron levels in liver and bone marrow, which may carry a risk for liver fibrosis and cancer. [ABSTRACT FROM AUTHOR]

Purpose To determine the role of diffusion-weighted imaging (DWI) in evaluating response to chemoradiotherapy in patients with uterine cervical cancer. Materials and Methods A search was performed in MEDLINE and EMBASE from January 2005 to April 2014 using search terms related to uterine cervical cancer and magnetic resonance imaging. Two reviewers independently checked the studies for inclusion criteria, patient population, magnetic resonance imaging (MRI) parameters and analysis, follow-up for treatment response, apparent diffusion coefficient (ADC) values, and quality assessment. Results Nine studies with 231 patients were included. International Federation of Gynecology and Obstetrics (FIGO) staging varied from Ib1 to IVb and mean age from 42 to 67 years. When baseline and after treatment pooled mean ADC values were compared, complete responders showed higher increase (0.88 × 10−3 mm2/s to 1.50 × 10−3 mm2/s; Δ0.62 × 10−3 mm2/s) compared to partial responders (1.03 × 10−3 mm2/s to 1.42 × 10−3 mm2/s; Δ0.39 × 10−3 mm2/s) and to nonresponders (0.87 × 10−3 mm2/s to 1.18 × 10−3 mm2/s; Δ0.31 × 10−3 mm2/s). Individual studies also showed that an ADC of ≤0.31 was only seen in nonresponders and an increase of ADC of ≥0.62 was only seen in complete responders. The number of datasets for monitoring early response (at 2 or 4 weeks of therapy) were low and comparable increases in pooled mean ADC values between complete responders, partial responders, and nonresponders were seen. Data on quality assessment showed high risk of bias concerning patient selection, DWI evaluation, and flow and timing. Conclusion DWI can be used for monitoring treatment response after treatment, but not for the early response monitoring. J. Magn. Reson. Imaging 2015;42:572-594. [ABSTRACT FROM AUTHOR]

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Objective Nonalcoholic fatty liver disease (NAFLD) has been recognized as an independent risk factor for cardiovascular disease in adults. It has not been established whether NAFLD is related to early atherosclerotic changes in children. Methods In a cross-sectional study, 78 non diabetic, non smoking children with severe obesity were evaluated for NAFLD. Proton magnetic resonance spectroscopy was used to detect liver steatosis and serum ALT was used as a surrogate marker for steatohepatitis. Carotid intima-media thickness (CIMT) and arterial wall stiffness were measured using ultrasound. Results Steatosis was present in 41 (53%) of subjects. Of these children, 26 out of 41 (63%) had elevated ALT levels. No differences in CIMT and arterial wall stiffness were observed between those without and with steatosis and those with steatosis plus elevated ALT levels [CIMT = 0.47 (±0.06), 0.48 (±0.06) and 0.48 (±0.07) mm, respectively; stiffness = 2.78 (±0.50), 3.00 (±0.81), and 2.90 (±0.78), respectively]. Steatosis and ALT were not correlated to CIMT ( r = −0.02 and −0.14, respectively) or arterial wall stiffness ( r = 0.13 and −0.11, respectively). Conclusions In this study, no relationship between NAFLD and early atherosclerotic changes in children was observed. An atherogenic effect of steatohepatitis (NASH) on pediatric age and long-term atherogenic consequences of simple steatosis cannot be excluded based on this study. [ABSTRACT FROM AUTHOR]

Purpose: In radiation therapy of pancreatic cancer, tumor alignment prior to each treatment fraction is improved when intratumoral gold fiducial markers (from here onwards: markers), which are visible on computed tomography (CT) and cone beam CT, are used. Visibility of these markers on magnetic resonance imaging (MRI) might improve image registration between CT and magnetic resonance (MR) images for tumor delineation purposes. However, concomitant image artifacts induced by markers are undesirable. The extent of visibility and artifact size depend on MRI-sequence parameters. The authors' goal was to determine for various markers their potential to be visible and to generate artifacts, using measures that are independent of the MRI-sequence parameters. Methods:The authors selected ten different markers suitable for endoscopic placement in the pancreas and placed them into a phantom. The markers varied in diameter (0.28-0.6 mm), shape, and iron content (0%-0.5%). For each marker, the authors calculated T2*-maps and ΔB0-maps using MRI measurements. A decrease in relaxation time T2* can cause signal voids, associated with visibility, while a change in the magnetic field B0 can cause signal shifts, which are associated with artifacts. These shifts inhibit accurate tumor delineation. As a measure for potential visibility, the authors used the volume of low T2*, i.e., the volume for which T2* differed from the background by >15 ms. As a measure for potential artifacts, the authors used the volume for which |ΔB0| > 9.4 × 10-8 T (4 Hz). To test whether there is a correlation between visibility and artifact size, the authors calculated the Spearman's correlation coefficient (Rs) between the volume of low T2* and the volume of high |ΔB0|. The authors compared the maps with images obtained using a clinical MR-sequence. Finally, for the best visible marker as well as the marker that showed the smallest artifact, the authors compared the phantom data with in vivo MR-images in four pancreatic cancer patients. Results:The authors found a strong correlation (Rs = 1.00, p < 0.01) between the volume of low T2* and the volume with high |ΔB0|. Visibility in clinical MR-images increased with lower T2*. Signal shift artifacts became worse for markers with high |ΔB0|. The marker that was best visible in the phantom, a folded marker with 0.5% iron content, was also visible in vivo, but showed artifacts on diffusion weighted images. The marker with the smallest artifact in the phantom, a small, stretched, ironless marker, was indiscernible on in vivo MR-images. Conclusions:Changes in T2* and ΔB0 are sequence-independent measures for potential visibility and artifact size, respectively. Improved visibility of markers correlates strongly to signal shift artifacts; therefore, marker choice will depend on the clinical purpose. When visibility of the markers is most important, markers that contain iron are optimal, preferably in a folded configuration. For artifact sensitive imaging, small ironless markers are best, preferably in a stretched configuration. [ABSTRACT FROM AUTHOR]

Purpose To compare whole-body magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), to computed tomography (CT) for staging newly diagnosed lymphoma. Materials and Methods In all, 108 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI (T1-weighted and T2-weighted short inversion time inversion recovery [ n = 108], and DWI [ n = 104]) and CT. Ann Arbor stages were assigned according to whole-body MRI and CT findings. Staging disagreements were resolved using bone marrow biopsy, FDG-PET, and follow-up studies. The results were descriptively analyzed. Results Staging results of whole-body MRI without DWI were equal to those of CT in 66.6%, higher in 24.1%, and lower in 9.3%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 15/7/4 and 9/1 patient(s), respectively. Staging results of whole-body MRI with DWI were equal to those of CT in 65.4%, higher in 27.9%, and lower in 6.7%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 18/6/5 and 6/1 patient(s), respectively. Conclusion The results of this study suggest that whole-body MRI staging equals CT staging in the majority of patients with newly diagnosed lymphoma. No advantage of additional DWI was demonstrated. Whole-body MRI can be a good alternative to CT if radiation exposure should be avoided. J. Magn. Reson. Imaging 2014;40:26-36. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose To assess the prognostic implications of whole-body bone marrow MRI findings in diffuse large B-cell lymphoma (DLBCL) patients with a negative blind bone marrow biopsy (BMB). Materials and Methods Thirty-eight patients with newly diagnosed DLBCL and negative blind BMB prospectively underwent whole-body MRI (T1-weighted, T2-weighted short inversion time inversion recovery, and diffusion-weighted sequences), which were scored as positive or negative for lymphomatous bone marrow involvement. Proportions of patients who experienced disease relapse/progression or died during follow-up were calculated and compared between whole-body MRI-positive and whole-body MRI-negative patients. Results The median follow-up time of surviving patients was 973 days (range, 391-1655 days). Disease relapse/progression occurred in 33% (5/15) of patients with a positive whole-body MRI and in 13% (3/23) of patients with a negative whole-body MRI. In addition, 20% (3/15) of patients with a positive whole-body MRI died during follow-up, compared with 9% (2/23) of patients with a negative whole-body MRI. Conclusion The results of this study show that disease relapse or progression and death may occur more frequently in whole-body MRI-positive patients than in whole-body MRI-negative patients, which suggests that whole-body bone marrow MRI findings in DLBCL patients with a negative BMB may have prognostic implications. J. Magn. Reson. Imaging 2014;39:1394-1400. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose To evaluate continuously tagged 3 Tesla MRI for monitoring glucagon-induced bowel motility changes in healthy volunteers. Materials and Methods After standardized oral bowel preparation, 10 healthy volunteers underwent a free-breathing, continuously tagged three-dimensional (3D) dynamic fast-field-echo (FFE), at a 3.36 Hz sampling frequency. One milligram of glucagon was administered intravenously during data acquisition. Each dataset was divided into four temporal sets of 2 min (period 1 to 4). Taglines were tracked automatically using a scale spaced based algorithm. Assessment of global spectral resolution was performed for three frequency intervals: 0.008-0.300 Hz (motility), 0.300-0.400 Hz (breathing motion), and 0.400-0.533 Hz (higher order motion). Additional analyses were performed at fine spectral resolution in frequency bands of 0.033 Hz. Glucagon-induced motility changes were investigated by means of a motility index (spectral power normalized to the maximal spectral power per-volunteer), resulting in a range of 0 to 1 (no motion to maximal motion). Statistical comparison was done for period 1 and 4 (Wilcoxon-signed rank test). Results After glucagon administration, a significant decrease in the motility index was found for the low- (0.008-0.300 Hz) ( P < 0.0001) and high-frequency interval (0.400-0.533 Hz) ( P < 0.0001). Around breathing motion frequencies, no decrease in motility index was detected. Conclusion Free-breathing, continuously tagged MR imaging is a noninvasive method for automated bowel motility assessment and allows for detection of drug-induced changes. J. Magn. Reson. Imaging 2014;39:9-16. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background: Accurate prediction scores for liver steatosis are demanded to enable clinicians to noninvasively screen for nonalcoholic fatty liver disease (NAFLD). Several prediction scores have been developed, however external validation is lacking. Objective: The aim was to determine the diagnostic accuracy of four existing prediction scores in severely obese children, to develop a new prediction score using novel biomarkers and to compare these results to the performance of ultrasonography. Design and Results: Liver steatosis was measured using proton magnetic resonance spectroscopy in 119 severely obese children (mean age 14.3 ± 2.1 years, BMI z-score 3.35 ± 0.35). Prevalence of steatosis was 47%. The four existing predictions scores ('NAFLD liver fat score,' 'fatty liver index,' 'hepatic steatosis index,' and the pediatric prediction score) had only moderate diagnostic accuracy in this cohort (positive predictive value (PPV): 70, 61, 61, 69% and negative predictive value (NPV) 77, 69, 68, 75%, respectively). A new prediction score was built using anthropometry, routine biochemistry and novel biomarkers (leptin, adiponectin, TNF-alpha, IL-6, CK-18, FGF-21, and adiponutrin polymorphisms). The final model included ALT, HOMA, sex, and leptin. This equation (PPV 79% and NPV 80%) did not perform substantially better than the four other equations and did not outperform ultrasonography for excluding NAFLD (NPV 82%). Conclusion: The conclusion is in severely obese children and adolescents existing prediction scores and the tested novel biomarkers have insufficient diagnostic accuracy for diagnosing or excluding NAFLD. [ABSTRACT FROM AUTHOR]

Background and Aim: We aimed to prospectively determine patient burden and patient preference for magnetic resonance enteroclysis, capsule endoscopy and balloon-assisted enteroscopy in patients with suspected or known Crohn's disease (CD) or occult gastrointestinal bleeding (OGIB). Methods: Consecutive consenting patients with CD or OGIB underwent magnetic resonance enteroclysis, capsule endoscopy and balloon-assisted enteroscopy. Capsule endoscopy was only performed if magnetic resonance enteroclysis showed no high-grade small bowel stenosis. Patient preference and burden was evaluated by means of standardized questionnaires at five moments in time. Results: From January 2007 until March 2009, 76 patients were included (M/F 31/45; mean age 46.9 years; range 20.0-78.4 years): 38 patients with OGIB and 38 with suspected or known CD. Seventeen patients did not undergo capsule endoscopy because of high-grade stenosis. Ninety-five percent (344/363) of the questionnaires were suitable for evaluation. Capsule endoscopy was significantly favored over magnetic resonance enteroclysis and balloon-assisted enteroscopy with respect to bowel preparation, swallowing of the capsule (compared to insertion of the tube/scope), burden of the entire examination, duration and accordance with the pre-study information. Capsule endoscopy and magnetic resonance enteroclysis were significantly preferred over balloon-assisted enteroscopy for clarity of explanation of the examination, and magnetic resonance enteroclysis was significantly preferred over balloon-assisted enteroscopy for bowel preparation, painfulness and burden of the entire examination. Balloon-assisted enteroscopy was significantly favored over magnetic resonance enteroclysis for insertion of the scope and procedure duration. Pre- and post-study the order of preference was capsule endoscopy, magnetic resonance enteroclysis and balloon-assisted enteroscopy. Conclusion: Capsule endoscopy was preferred to magnetic resonance enteroclysis and balloon-assisted enteroscopy; it also had the lowest burden. Magnetic resonance enteroclysis was preferred over balloon-assisted enteroscopy for clarity of explanation of the examination, bowel preparation, painfulness and burden of the entire examination, and balloon-assisted enteroscopy over magnetic resonance enteroclysis for scope insertion and study duration. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the feasibility of measuring motion in the abdomen using a continuously tagged magnetic resonance imaging sequence. Materials and Methods: To assess (nonperiodic) motion in the abdomen, a nontriggered, continuously tagged transient field echo (TFE) sequence was implemented that acquires one complete 3D dataset per prepulse after a fixed delay. In postprocessing, a frequency analysis approach was developed for compact reviewing of the data and noise suppression. For proof of principle, a simulation was made and one free-breathing dynamic in vivo scan was acquired in a healthy volunteer. During the dynamic scan the volunteer received glucagon intravenously. Results: The simulation showed that this frequency analysis enables the extraction of motion at low signal-to-noise ratio levels. Motion information was successfully gathered from the in vivo scan. The decline in bowel motion caused by the administration of glucagon could be quantitatively measured using the continuously tagged sequence. Conclusion: Continuously tagged imaging in the abdomen for the purpose of automated gathering of motion information is feasible and could aid the study of bowel motion. J. Magn. Reson. Imaging 2012;36:492-497. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose: Typically spatial modulation of the magnetization (SPAMM) tagged magnetic resonance imaging (MRI) requires many repeated motion cycles limiting the applicability to highly repeatable tissue motions only. This paper describes the validation of a novel SPAMM tagged MRI and post-processing framework for the measurement of complex and dynamic 3D soft tissue deformation following just three motion cycles. Techniques are applied to indentation induced deformation measurement of the upper arm and a silicone gel phantom. Methods: A SPAMM tagged MRI methodology is presented allowing continuous (3.3-3.6 Hz) sampling of 3D dynamic soft tissue deformation using non segmented 3D acquisitions. The 3D deformation is reconstructed by the combination of three mutually orthogonal tagging directions, thus requiring only three repeated motion cycles. In addition a fully automatic post-processing framework is presented employing Gabor scale-space and filter-bank analysis for tag extrema segmentation and triangulated surface fitting aided by Gabor filter bank derived surface normals. Deformation is derived following tracking of tag surface triplet triangle intersections. The dynamic deformation measurements were validated using indentation tests (∼20 mm deep at 12 mm/s) on a silicone gel soft tissue phantom containing contrasting markers which provide a reference measure of deformation. In addition, the techniques were evaluated in vivo for dynamic skeletal muscle tissue deformation measurement during indentation of the biceps region of the upper arm in a volunteer. Results: For the phantom and volunteer tag point location precision were 44 and 92 μm, respectively resulting in individual displacements precisions of 61 and 91 μm, respectively. For both the phantom and volunteer data cumulative displacement measurement accuracy could be evaluated and the difference between initial and final locations showed a mean and standard deviation of 0.44 and 0.59 mm for the phantom and 0.40 and 0.73 mm for the human data. Finally accuracy of (cumulative) displacement was evaluated using marker tracking in the silicone gel phantom. Differences between true and predicted marker locations showed a mean of 0.35 mm and a standard deviation of 0.63 mm. Conclusions: A novel SPAMM tagged MRI and fully automatic post-processing framework for the measurement of complex 3D dynamic soft tissue deformation following just three repeated motion cycles was presented. The techniques demonstrate dynamic measurement of complex 3D soft tissue deformation at subvoxel accuracy and precision and were validated for 3.3-3.6 Hz sampling of deformation speeds up to 12 mm/s. [ABSTRACT FROM AUTHOR]

Purpose: This study presents and validates a novel (non-ECG-triggered) MRI sequence based on spatial modulation of the magnetization (SPAMM) to noninvasively measure 3D (quasistatic) soft tissue deformations using only six acquisitions (three static and three indentations). In the current SPAMM tagged MRI approaches, data are typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g., cardiac deformation). In biomechanical applications where soft tissue deformation is artificially induced, often by indentation, significant repeatability constraints exist, and for clinical applications, discomfort and health issues generally preclude a large number of repetitions. Methods: A novel (non-ECG-triggered) SPAMM tagged MRI sequence is presented, whereby a single 1-1 (first order) SPAMM set is acquired following a 3D transient field echo acquisition. Full 3D deformation measurement is achieved through the combination of only six acquisitions (three static and three motion cycles). The 3D deformation measurements were validated using quasistatic indentation tests and marker tracking in a silicone gel soft tissue phantom. In addition, the technique's ability to measure 3D soft tissue deformation in vivo was evaluated using indentation of the biceps region of the upper arm in a volunteer. Results: Following comparison to marker tracking in the silicone gel phantom, the SPAMM tagged MRI based displacement measurement demonstrated subvoxel accuracy with a mean displacement difference of 72 μm and a standard deviation of 289 μm. In addition, precision of displacement magnitude was evaluated for both the phantom and the volunteer data. The standard deviations of the displacement magnitude with respect to the average displacement magnitude were 75 and 169 μm for the phantom and volunteer data, respectively. Conclusions: The subvoxel accuracy and precision demonstrated in the phantom in combination with the precision comparison between the phantom and the volunteer data provide confidence in the methods presented for measurement of soft tissue deformation in vivo. To the author's knowledge, since only six acquisitions are required, the presented methodology is the fastest SPAMM tagged MRI method currently available for the noninvasive measurement of quasistatic 3D soft tissue deformation. [ABSTRACT FROM AUTHOR]

Living donors with marked (> 33%) macrovesicular steatosis (MaS) are excluded from living donor liver transplantation procedures. Experimental studies have shown that the development of steatosis can be prevented by supplementation with omega-3 fatty acids (FA), but no studies have investigated the reduction of steatosis using omega-3 FA. The aim of the present study was to investigate whether administration of omega-3 FA is effective in reducing steatosis. After fatty liver (FL) induction by a 3-week methionine/choline-deficient (MCD) diet, male Wistar rats were daily administered per gavage omega-3 FA (FL+Omega-3), omega-3-poor lipid solution (FL+Lipid), or NaCl (FL+NaCl) during 2 weeks. Control animals received standard chow without treatment. Determination of steatosis degree was performed before, during, and after treatment by clinical 3.0T H-magnetic resonance spectroscopy (H-MRS) and by histology and gas chromatography at the end of the 2-week treatment period. Hepatic fat content (H-MRS) was significantly reduced after 1 and 2 weeks of omega-3 FA treatment. Histological analysis revealed a mild (5-33%) MaS degree in omega-3-treated animals vs severe (> 66%) MaS in the FL+Lipid and FL+NaCl groups. Hepatic omega-6 : 3 FA ratio and total FA content were reduced in the FL+Omega-3 group. Furthermore, de novo lipogenesis (C16, C16 : 1ω7, C18 : 1ω9) was also lowered. The reduction in hepatic fat content was associated with decreased lobular inflammation and hepatic tumor necrosis factor- α and interleukin levels as well as an increased antioxidative capacity. Omega-3 FA are capable of reversing severe hepatic MaS and ameliorating pathophysiological features of non-alcoholic steatohepatitis such as hepatocellular damage, lobular inflammation, and a reduced antioxidative capacity. [ABSTRACT FROM AUTHOR]

Objectives: The objective was to evaluate the diagnostic accuracy of clinical features and laboratory test results in detecting acute appendicitis. Methods: Clinical features and laboratory test results were prospectively recorded in a consecutive series of 1,101 patients presenting with abdominal pain at the emergency department (ED) in six hospitals. Likelihood ratios (LRs) and the areas under the receiver operating characteristic curve (AUC) were calculated for the individual features. Variants of clinical presentation, based on different combinations of clinical features, were investigated and the accuracies of combinations of clinical features were evaluated. Results: The discriminative power (AUC) of the individual features in patients with suspected appendicitis ranged from 0.50 to 0.65. For five of the 23 predictor sets, the accuracy for appendicitis was more than 85%. This accuracy was only found in male patients. The relative frequency of these predictor sets ranged from 2% to 13% of patients with suspected appendicitis. A combination of the clinical features migration of pain to the right lower quadrant (RLQ), and direct tenderness in the RLQ, was present in only 28% (120/422) of clinically suspected patients, of whom no more than 85 patients had appendicitis (71%). A “classical” presentation (combination of migration of pain to the RLQ, tenderness in the RLQ, and rigidity) occurred in only 6% (25/422) of patients with suspected appendicitis and yielded an accuracy of 100% in males but only 46% in females. Conclusions: The discriminative power (AUC) of individual clinical features and laboratory test results for appendicitis was weak in patients with suspected appendicitis. Combinations of clinical features and laboratory tests with high diagnostic accuracy are relatively infrequent in patients with suspected appendicitis. [ABSTRACT FROM AUTHOR]

Purpose To investigate reproducibility of proton magnetic resonance spectroscopy (1H-MRS) to measure hepatic triglyceride content (HTGC). Materials and Methods In 24 subjects, HTGC was evaluated using 1H-MRS at 3.0 Tesla. We studied 'between-weeks' reproducibility and reproducibility of 1H-MRS in subjects with fatty liver. We also studied within liver variability and within day reproducibility. Reproducibility was assessed by coefficient of variation (CV), repeatability coefficient (RC), and intraclass correlation coefficient (ICC). Results The CV of between weeks reproducibility was 9.5%, with a RC of 1.3% HTGC (ICC 0.998). The CV in fatty livers was 4.1%, with a RC of 1.3% HTGC (ICC 0.997). Within day CV was 4.5%, with a RC of 0.4% HTGC (ICC 0.999). CV for within liver variability was 14.5%. Conclusion Reproducibility of 1H-MRS to measure HTGC for 'between-weeks' measurements and in fatty livers is high, which is important for follow-up studies. Within liver variability displays a larger variation, meaning that liver fat is not equally distributed and during consecutive measurements the same voxel position should be used. J. Magn. Reson. Imaging 2009;30:444-448. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To determine the feasibility of T1-mapping and calculation of Gadolinium-values in luminal Crohn's Disease (CD). Materials and Methods Nine patients with active CD were included. For each patient disease activity was determined, based on endoscopic and histopathological results. The Crohn's Disease Endoscopic Index of Severity (CDEIS), the Harvey-Bradshaw index (HBI) and C-reactive protein (CRP) were also determined as reference standards. T1-measurements were performed before and after intravenous administration of Gadodiamide in 14 slices in a single breath-hold using the Look-Locker (LL) sequence in combination with a segmented three-dimensional Turbo Field Echo sequence. A Region of Interest (ROI) was drawn around inflamed bowel loops and the mean Gadolinium-concentration within the ROI was calculated. Gadolinium-concentrations were compared between patients with mild and marked disease, as determined by the reference standards. Results Mean Gadolinium-concentrations were higher in bowel loops of patients with more active disease, as defined by endoscopic and histopathological examination, CRP, and HBI. Conclusion By using a breath-hold LL sequence in the bowel quantitative assessment of contrast agent concentration is possible, thus permitting objective evaluation of physiological changes in actively inflamed tissue in an area that suffers from motion problems. J. Magn. Reson. Imaging 2009;29:488-493. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To prospectively compare single-shot spin-echo echo-planar imaging (SSSE-EPI) using b = 0, 10, 150, and 400 seconds/mm2 with standard MRI techniques after intravenous super paramagnetic iron oxide (SPIO) in the detection and characterization of focal liver lesions with focus on small (<10 mm) focal liver lesions. Materials and Methods A total of 25 patients suspected for colorectal liver metastases were included. Number of detected lesions was evaluated. Image quality was compared between SSSE-EPI sequence and post-SPIO (fat-suppressed T1-weighted [T1w] gradient echo [GE], T2-weighted [T2w] turbo spin echo [TSE] and T2* GE) sequences using rank order statistic (RIDIT). Lesion characterization was performed for SSSE-EPI and for all remaining sequences pre- and post-SPIO. Reference standard comprised surgery, biopsy, and/or follow-up. Results Reference standard demonstrated 25 hemangiomas and 70 metastases. Best lesion detection respectively best image quality ( P < 0.05) was achieved with SSSE-EPI (b = 10 seconds/mm2) post-SPIO T1w GE and T2w turbo spin echo. Lesion characterization using all sequences pre- and post-SPIO performed best for lesion characterization compared with SSSE-EPI. Conclusion This preliminary study shows the potential of SSSE-EPI as a stand-alone sequence for the detection of liver hemangiomas and metastases when compared with SPIO-enhanced imaging. Sequences pre- and post-SPIO are needed for qualitative lesion characterization. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To prospectively compare three strategies of magnetic resonance colonography (MRC) with fecal tagging. Materials and Methods Three strategies were compared: (S1) gadolinium as oral tagging agent and a gadolinium-water mixture for rectal filling (bright lumen), (S2) oral barium and water rectally, and (S3) oral barium and air rectally. In S2 and S3 (both dark lumen) gadolinium was injected intravenously. Three-dimensional (3D) T1-weighted and two-dimensional (2D) T2-weighted sequences were used. Two observers scored diagnostic confidence and image quality (contrast, homogeneity, artifacts), analyzed by chi-squared and Fisher's exact test. Patient experience and preference were determined by questionnaire (Mann-Whitney test). Results A total of 45 patients were included, 15 were randomly assigned per strategy. Diagnostic confidence of S1 and S3 is significantly better than for S2. S1 has the additional advantage of showing significantly better contrast between bowel wall and lumen, and showing significantly better homogeneity on both T1- and T2-weighted sequences, but with significantly more artifacts on the T1-weighted sequences. S3 showed significantly better contrast and homogeneity than S2 on the T2-weighted sequences. Bowel preparation of S1 was rated significantly better. Patient preference was comparable. Conclusion Image quality was best using the bright lumen strategy or the dark lumen strategy using air for rectal filling. Although bowel preparation was rated best using the bright lumen strategy, patient preference was comparable. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To determine whether abdominal 3.0T MRI can be used for evaluation of Crohn's disease (CD) compared with ileocolonoscopy (CS), and to determine patient preference for MRI as opposed to CS. Materials and Methods Twenty patients scheduled for CS underwent MRI. At CS, disease severity was graded and the Crohn's Disease Endoscopic Index of Severity (CDEIS) was determined. Radiological grading (by two observers) was compared with endoscopic grading and CDEIS. Patient experience and preference were determined. Results In respectively 10 (observer 1) and 13 patients (observer 2) exact agreement between radiological and endoscopic grading was found. In respectively 10 and 7 patients radiological and endoscopic grading differed one level. No statistically significant correlation was found between radiological grading and CDEIS. Between bowel wall thickness and CDEIS weak to moderate correlations were found, and between bowel wall enhancement and CDEIS weak correlations were found. All patients preferred MRI over CS. Conclusion It is feasible to perform abdominal 3.0T MRI using orally administered contrast medium for evaluation of CD, and this method can be considered a patient-friendly alternative to CS. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Technological developments have extended the role of MRI in the evaluation of the gastrointestinal tract. The potential of MRI to evaluate disease activity in Crohn's disease has been investigated extensively, as MRI has intrinsic advantages over other techniques, including noninvasiveness and the absence of ionizing radiation. For perianal fistulizing disease MRI has become a mainstay in evaluation of disease, as localization and extent of disease can be very well appreciated using both T2-weighted and T1-weighted sequences, fat suppression, and intravenous contrast medium. Imaging of the small bowel and colon in Crohn's disease is more complicated due to bowel peristalsis and respiratory movement. However, using fast breathhold sequences and intravenous spasmolytic medication, images of good diagnostic quality can be acquired. To obtain sufficiently distended bowel, which in our estimation is a prerequisite for evaluation of the bowel, MR enteroclysis can be performed. However, applicability of different oral contrast media has been studied, as a noninvasive method for bowel distension would be preferable. Abdominal MRI is a valuable imaging technique for evaluation of luminal, transmural, and extraintestinal manifestations of Crohn's disease as degree of disease activity, presence of luminal pathology (e.g., stenoses), and extraintestinal manifestations of disease (e.g., abscesses, fistulas) can be accurately assessed. J. Magn. Reson. Imaging 2005;22:1-12. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Background: Continuously tagged MRI during free breathing can assess bowel motility at frequencies as low as the slow wave, motility pattern range. This study aimed to evaluate noninvasive gastrointestinal‐tagged MRI for small bowel motility assessment and to observe the physiological response to a 300‐kcal meal challenge in healthy, overnight‐fasted volunteers. Methods: After overnight fasting, 16 healthy subjects (7 women, mean age 25.5, range 19‐37 years) underwent a free breathing, tagged MRI scan to capture small bowel motility. Each subject underwent a (a) baseline motility scan, (b) food challenge, (c) postchallenge scan, and (d) second postchallenge scan (after 20 minutes). Motility was quantified using a frequency analysis technique for measuring the spectral power of the strain, referred to as motility score. Motility score was assessed in 20 frequency intervals between 1 and 20 contractions per minute (cpm), and the data were analyzed with linear mixed‐effect models. Key Result: The stimulation protocol demonstrated an immediate, food‐induced, motility response in the low‐frequency range (2‐10 cpm), which is consistent with the stomach and small bowel frequency range (3‐12 cpm). Conclusions and Inferences: This study shows that this MRI tagging technique is able to quantify the fasted‐to‐fed response to a 300‐kcal meal challenge within the specific small bowel motility frequency range in healthy subjects. The food provocation MRI protocol provides a tool to explore the gut's response to a stimulus in specific motility frequency ranges in patients with gastrointestinal dysmotility and functional disorders. [ABSTRACT FROM AUTHOR]

Objective: MRI is increasingly used to evaluate small bowel contractility. The objective of this study was to validate a clinically practical stimulation test (300‐kcal meal) for small bowel motility. Methods: Thirty‐one healthy subjects underwent dynamic MRI to capture global small bowel motility after ±10h fasting, of which 15 underwent bowel preparation consisting of 1 L 2.5% mannitol solution and 16 did not. Each subject underwent (1) a baseline motility scan (2) a food challenge (3) a post‐challenge scan, and (4) second post‐challenge scan (after ±20 minutes). This protocol was repeated within 2 weeks. Motility was quantified using a validated motility assessment technique. Key Results: Motility in prepared subjects at baseline was significantly higher than motility in unprepared subjects (0.36 AU vs 0.18 AU, P < 0.001). In the prepared group, the food challenge produced an 8% increase in motility (P = 0.33) while in the unprepared subjects a significant increase of 30% was observed (P < 0.001). Responses to food remained insignificant (P = 0.21) and significant (P = 0.003), for the prepared and unprepared subjects, respectively, ±20 minutes post food challenge. These results were confirmed in the repeated scan session. Conclusion & Inferences: A significant response to a 300‐kcal meal was measured within 10 minutes in unprepared bowel, supporting the clinical use of this challenge to provoke and assess motility changes. A caloric challenge did not produce an observable increase in motility in mannitol prepared subjects. In this article, we present a practical MRI stimulation test and validate it in both mannitol prepared and unprepared healthy subjects to evaluate the stimulation test and provide guidance on MRI preparation for future MRI motility studies. [ABSTRACT FROM AUTHOR]

Discusses the use of imaging techniques in the diagnosis of colorectal cancer. Changes in management which have been introduced to prevent the disease and improve survival as of 2003; Major aspects of imaging in the prevention and management of colorectal cancer.

The current imaging technique and clinical application of MR cholangiopancreatography (MRCP) is reviewed. MRCP has evolved into a feasible method of non-invasively evaluating the pancreaticobiliary system and has considerable clinical utility. If endoscopic retrograde cholangiopancreatography (ERCP) is incomplete or has failed, or in patients with biliary and gastrointestinal surgical procedures, MRCP is a useful alternative modality. In the near future, MRCP may supplant diagnostic ERCP such that ERCP is reserved primarily for therapeutic interventions. Furthermore, when MRCP is performed in conjunction with abdominal MR and MR angiography, the‘all-in-one’ examination can evaluate the solid organs and vessels of the abdomen as well as the ductal systems. [ABSTRACT FROM AUTHOR]

A hitherto unknown combination of congenital anomalies was found in an anatomical specimen of a female neonate. External examination and additional CT and MRI studies showed thanatophoric dysplasia type II with cloverleaf skull and concomitant parietal meningoencephalocele and hypoplasia of the descending aorta. The possibilities of causal correlations are discussed., (Copyright 2003 Wiley-Liss, Inc.)