Six months of treatment with liraglutide 1.2 mg/d significantly reduced LFC in patients with inadequately controlled type 2 diabetes and this effect was mainly driven by body weight reduction. Further studies are needed to confirm that this reduction in LFC may significantly reduce fibrosis progression.
Objectives
To determine whether bi‐ or tri‐exponential models, and full or segmented fittings, better fit the intravoxel incoherent motion (IVIM) imaging signal of healthy livers.
Methods
Diffusion‐weighted images were acquired with a 3 T scanner using a respiratory‐triggered echo‐planar sequence and 16 b‐values (0–800 s/mm2). Eighteen healthy volunteers had their livers scanned twice in the same session, and then once in another session. Liver parenchyma region‐of‐interest‐based measurements were processed with bi‐exponential and tri‐exponential models, with both full fitting and segmented fitting (threshold b‐value = 200 s/mm2).
Results
With the signal of all scans averaged, bi‐exponential model full fitting showed Dslow = 1.14 × 10−3 mm2/s, Dfast = 193.6 × 10−3 mm2/s, and perfusion fraction (PF) = 16.9%, and segmented fitting showed Dslow = 0.98 × 10−3 mm2/s, Dfast = 42.2 × 10−3 mm2/s, and PF = 23.3%. IVIM parameters derived from the tri‐exponential model were similar for full fitting and segmented fitting, with slow (D'slow = 0.98 × 10−3 mm2/s; F'slow = 76.4 or 76.6%), fast (D'fast = 15.1 or 15.4 × 10−3 mm2/s; F'fast = 11.8 or 11.7%) and very fast (D'Vfast = 445.0 or 448.8 × 10−3 mm2/s; F'Vfast = 11.8 or 11.7%) diffusion compartments. The tri‐exponential model provided an overall better fit than the bi‐exponential model. For the bi‐exponential model, full fitting provided a better fit at very low and low b‐values compared with segmented fitting, with the latter tending to underestimate Dfast; however, the segmented method demonstrated lower error in signal prediction for high b‐values. Compared with full fitting, tri‐exponential segmented fitting offered better scan‐rescan reproducibility.
Conclusion
For healthy liver, tri‐exponential modeling is preferred to bi‐exponential modeling. For the bi‐exponential model, segmented fitting underestimates Dfast, but offers a more accurate estimation of Dslow.
Background: Recently a small cohort study demonstrated that intravoxel incoherent motion (IVIM) diffusion MRI can detect early stage liver fibrosis. Using modified IVIM data acquisition parameters, the current study aims to confirm this finding. Methods: Twenty-six healthy volunteers, three patients of chronic viral hepatitis-b but without fibrosis and one mild liver steatosis subject, and 12 viral hepatitis-b patients with fibrosis (stage 1-2=7, stage 3-4=5) were included in this study. With a 1.5-T MR scanner and respiration-gating, IVIM diffusion imaging was acquired using a single-shot echo-planar sequence with a b-value series of 2, 0
Background: Angiomyolipoma (AML) is the most common renal benign tumor. Treatment should be considered for symptomatic patients or for those at risk for complications, especially retroperitoneal bleeding which is correlated to tumor size, grade of the angiogenic component and to the presence of tuberous sclerosis complex (TSC). This study reports our single-center experience with the use of selective arterial embolization (SAE) in the management of symptomatic and asymptomatic renal AMLs.
Methods:In this retrospective mono-centric study, all demographic and imaging data, medical records, angiographic features, outpatient charts and follow-up visits of patients who underwent prophylactic or emergency SAE for AMLs between January 2005 and July 2016 were reviewed. Tumor size and treatment outcomes were assessed at baseline and after the procedure during follow-up. Computed tomography (CT), magnetic resonance imaging (MRI) or ultrasonography was used to evaluate AML shrinkage. Renal function was measured pre-and post-procedure.Results: Twenty-three patients (18 females, 5 males; median age, 45 years; range, 19-85 years) who underwent SAE either to treat bleeding AML (n=6) or as a prophylactic treatment (n=17) were included.Overall, 34 AMLs were embolized. TSC status was confirmed for 6 patients. Immediate technical success rate was 96% and 4 patients benefitted from an additional procedure. Major complications occurred in 3 patients and minor post-embolization syndrome (PES) in 14 patients. The mean AML size reduction rate was 26.2% after a mean follow-up was 20.5 months (range, 0.5-56 months), and only non-TSC status was significantly associated with better shrinkage of tumor (P=0.022). Intralesional aneurysms were significantly more frequent in patients with hemorrhagic presentation (P=0.008). There was no change in mean creatinine level after SAE.Conclusions: SAE is a safe and effective technique to manage renal AMLs as a preventive treatment as well as in emergency setting, with significant reduction in tumor size during follow-up. A multidisciplinary approach remains fundamental, especially for TSC patients. In addition to size, the presence of intralesional aneurysms should be considered in any prophylactic treatment decision.
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