Using MRC analysis of patients with long-term IBD, we found the prevalence of PSC to be around 3-fold higher than that detected based on symptoms. Sixty-five percent of patients had subclinical PSC associated with progressive IBD, with no biochemical abnormalities and mild disease, based on radiology findings. PSC appears to progress in patients with subclinical disease, but long-term outcomes are not known.

Our data revealed a high prevalence of ankylosing spondylitis, axial spondyloarthritis, and inflammatory back pain 20 years after the IBD diagnosis. HLA-B27 but not NOD-2 was a predisposing factor for the inflammatory back disorders in IBD patients. Axial spondyloarthritis was associated with a more chronic active IBD disease course.

Purpose: To assess image quality, vessel visualization, preliminary diagnostic properties, and interobserver variability of a novel balanced turbo field echo (b-TFE) sequence and contrast-enhanced T1 fast field echo (CE-FFE) sequence with blood pool agent (BPA). Materials and Methods:A total of 15 healthy volunteers and six patients with ultrasound-verified proximal deep vein thrombosis (DVT) were examined from the inferior vena cava (IVC) to the proximal calf veins.Results: The great majority of deep veins were completely visualized on both sequences. In healthy volunteers the IVC was completely visualized in five b-TFE and 11 CE-FFE scans, and partially in seven b-TFE and four CE-FFE scans (P ¼ 0.008). Poorest image quality was in the pelvis. Contrast-to-noise ratio (CNR) was higher on b-TFE compared to CE-FFE, with significant difference in calf images (P ¼ 0.036). Sensitivity was 100% for proximal DVT with both methods. Specificity was 70% (CE-FFE) and 80% (b-TFE) for proximal femoral DVT; 100% in distal femoral. Interobserver reliability was kappa 1.0 (b-TFE), 0.9 (CE-FFE) for proximal, and overall poor for distal DVT.Conclusion: Contrast-enhancement did not add valuable information in visualizing deep veins of the lower limbs compared to b-TFE, though the IVC was slightly better visualized. Diagnostic properties and interobserver reliability of both sequences were good for proximal DVT and poor for distal DVT.

Purpose: To implement a dynamic contrast-based multi-echo MRI sequence in assessment of rectal cancer and evaluate associations between histopathologic data and the acquired dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) -MRI parameters. Materials and Methods: This pilot study reports results from 17 patients with resectable rectal cancer. Dynamic contrast-based multi-echo MRI (1.5T) was acquired using a three-dimensional multi-shot EPI sequence, yielding both DCE-and DSC-data following a single injection of contrast agent. The Institutional Review Board approved the study and all patients provided written informed consent. Quantitative analysis was performed by pharmacokinetic modeling on DCE data and tracer kinetic modeling on DSC data. Mann-Whitney U-test and receiver operating characteristics curve statistics was used to evaluate associations between histopathologic data and the acquired DCE-and DSC-MRI parameters. Results: For patients with histologically confirmed nodal metastasis, the primary tumor demonstrated a significantly lower K trans and peak change in R Ã 2 , R Ã 2 -peak enh , than patients without nodal metastasis, showing a P-value of 0.010 and 0.005 for reader 1, and 0.043 and 0.019 for reader 2, respectively. Conclusion: This study shows the feasibility of acquiring DCE-and DSC-MRI in rectal cancer by dynamic multi-echo MRI. A significant association was found between both K trans and R Ã 2 -peak enh in the primary tumor and histological nodal status of the surgical specimen, which may improve stratification of patients to intensified multimodal treatment.

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I n 2018, rectal cancer was the eighth most common cancer in the world (1). Survival rates have increased in the past decade mainly because of total mesorectal excision surgery and neoadjuvant treatment, when indicated. However, patients with metastatic disease remain a challenge. Norwegian patients with metastatic rectal cancer have a 5-year survival rate of 18.3% for men and 20.6% for women (2). To enable a more adapted treatment, there is a need to assess individual tumor characteristics that can be used to identify patients who will respond poorly to conventional therapies and have higher risk of metastatic disease. Anatomic MRI is important for staging rectal cancer. Many studies have also examined the predictive and prognostic value of functional MRI, especially dynamic contrast-enhanced (DCE) MRI that can be analyzed qualitatively, semiquantitatively, or quantitatively. Recently, Dijkhoff et al (3) demonstrated value for DCE MRI in rectal cancer, despite large variability in the performed studies, and called for larger studies to be undertaken.

Background Dynamic contrast‐based MRI and intravoxel incoherent motion imaging (IVIM) MRI are both methods showing promise as diagnostic and prognostic tools in rectal cancer. Both methods aim at measuring perfusion‐related parameters, but the relationship between them is unclear. Purpose To investigate the relationship between perfusion‐ and permeability‐related parameters obtained by IVIM‐MRI, T1‐weighted dynamic contrast‐enhanced (DCE)‐MRI and T2*‐weighted dynamic susceptibility contrast (DSC)‐MRI. Study Type Prospective. Subjects In all, 94 patients with histologically confirmed rectal cancer. Field Strength/Sequence Subjects underwent pretreatment 1.5T clinical procedure MRI, and in addition a study‐specific diffusion‐weighted sequence (b = 0, 25, 50, 100, 500, 1000, 1300 s/mm2) and a multiecho dynamic contrast‐based echo‐planer imaging sequence. Assessment Median tumor values were obtained from IVIM (perfusion fraction [f], pseudodiffusion [D*], diffusion [D]), from the extended Tofts model applied to DCE data (Ktrans, kep, vp, ve) and from model free deconvolution of DSC (blood flow [BF] and area under curve). A subgroup of the excised tumors underwent immunohistochemistry with quantification of microvessel density and vessel size. Statistical Test Spearman's rank correlation test. Results D* was correlated with BF (rs = 0.47, P < 0.001), and f was negatively correlated with kep (rs = –0.31, P = 0.002). BF was correlated with Ktrans (rs = 0.29, P = 0.004), but this correlation varied extensively when separating tumors into groups of low (rs = 0.62, P < 0.001) and high (rs = –0.06, P = 0.68) BF. Ktrans was negatively correlated with vessel size (rs = –0.82, P = 0.004) in the subgroup of tumors with high BF. Data Conclusion We found an association between D* from IVIM and BF estimated from DSC‐MRI. The relationship between IVIM and DCE‐MRI was less clear. Comparing parameters from DSC‐MRI and DCE‐MRI highlights the importance of the underlying biology for the interpretation of these parameters. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1114–1124.

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