Hedgehog Signaling Antagonist Promotes Regression of Both Liver Fibrosis and Hepatocellular Carcinoma in a Murine Model of Primary Liver Cancer

Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3) develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC) emerges spontaneously in such mice by 50–60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2−/− mice to investigate the hypothesis that activation of the hedgehog (Hh) signaling pathway promotes development of both liver fibrosis and HCC

Coronary MR imaging: navigator echo biofeedback increases navigator efficiency--initial experience

The aim of this study was to investigate whether a respiratory biofeedback system could increase navigator efficiency and maintain image quality compared to conventional respiratory-gated magnetic resonance coronary angiography (MRCA). Eighteen healthy volunteers underwent MRCA using three different respiratory-gating protocols. A conventional expiratory free-breathing (FB) sequence was compared to two approaches using navigator echo biofeedback (NEB), a midinspiratory approach (NEBin) and an expiratory approach (NEBex). Navigator data reflecting the position of the diaphragm relative to a 3-mm gating window were made available to the subject using a video projector in combination with a Plexiglas screen and mirror goggles. Image quality was graded by two radiologists in consensus using a visual score ranging from 1 (not visible) to 4 (excellent vessel depiction). The NEB approaches improved navigator efficiency (71.1% with NEBex and 68.0% with NEBin vs 42.2% with FB), thus reducing total imaging time. This difference was statistically significant (P(NEBin)=.007; P(NEBex)=.001). Image quality in the NEBex group was comparable to that in the FB group (median score, 2.44 vs 2.52), but it proved to be significantly lower (median score, 1.94 vs 2.52) for the right coronary artery and the left anterior descending coronary artery in the NEBin group. NEB maintains image quality and significantly increases navigator efficiency, thereby decreasing total imaging time by about 40% compared to a conventional FB acquisition strategy

Effectiveness and Safety of Prostatic Artery Embolization for the Treatment of Lower Urinary Tract Symptoms from Benign Prostatic Hyperplasia in Men with Concurrent Localized Prostate Cancer

To assess the effectiveness and safety of prostatic artery embolization (PAE) on lower urinary tract symptoms (LUTS) in the setting of localized prostate cancer (PCa). This was a retrospective, single-center, institutional review board-approved study from December 2016 to June 2020 of 21 patients (median age, 72; range, 63–83 years) with moderate LUTS and localized PCa. Clinical effectiveness was evaluated at 6 and 12 weeks using International Prostate Symptom Score (IPSS) and quality of life (QoL) improvement. Seventeen patients were scheduled to receive definitive radiotherapy (RT) after PAE; 13 patients completed RT. Short-term imaging signs of oncologic progression were evaluated at 6 and 12 weeks defined by at least one of the following on magnetic resonance imaging: increased Prostate Imaging-Reporting and Data System score of index lesion(s) to at least 4, new extracapsular extension, seminal vesicle involvement, or pelvic lymphadenopathy. Nonparametric Wilcoxon signed-rank test was used for analysis. IPSS improved by a median of 12 (n = 19, P < .0001) and 14 (n = 14, P < .0001) at 6 and 12 weeks, respectively. QoL improved by a median of 2 (n = 19, P < .0001) and 3 (n = 3, P < .0001) at 6 and 12 weeks. Prostate volume decreased by a median of 24% (n = 19, P < .0001) and 36% (n = 12, P = .015) at 6 and 12 weeks. No patients demonstrated disease progression at 6 (n = 16) or 12 (n = 8) weeks by imaging. No patients experienced increased prostate-specific antigen after RT, grade ≥3 adverse events, or greater genitourinary toxicity. PAE is effective and safe for the treatment of men with LUTS from benign prostatic hyperplasia in the setting of concomitant, localized, non-obstructive PCa

Reproducibility of dynamic contrast-enhanced mr imaging part ii. Comparison of intra- and interobserver variability with manual region of interest placement versus semiautomatic lesion segmentation and histogram analysis

Purpose:To compare the inter- and intraobserver variability with manual region of interest (ROI) placement versus that with software-assisted semiautomatic lesion segmentation and histogram analysis with respect to quantitative dynamic contrast material-enhanced (DCE) MR imaging determinations of the volume transfer constant (K(trans)).Materials and Methods:The study was approved by the institutional review board and compliant with HIPAA. The requirement to obtain informed consent was waived. Fifteen DCE MR imaging studies of the female pelvis defined the study group. Uterine fibroids were used as a perfusion model. Three varying types of lesion measurements were performed by five readers on each study by using DCE MR imaging perfusion analysis software with manual ROI placement and a semiautomatic lesion segmentation and histogram analysis solution. Intra- and interreader variability of measurements of K(trans) with the different measurement types was calculated.Results:The overall interobserver variability of K(trans) with manual ROI placement (mean, 28.5% ± 9.3) was reduced by 42.5% when the semiautomatic, software-assisted lesion measurement method was used (16.4% ± 6.2). Whole-lesion measurement showed the lowest interobserver variability with both measurement methods (20.1% ± 4.3 with the manual method vs 10.8% ± 2.6 with the semiautomatic method). The overall intrareader variability with the manual ROI method (7.6% ± 10.6) was not significantly different from that with the semiautomatic method (7.3% ± 10.8), but the intraclass correlation coefficient for intrareader reproducibility improved from 0.86 overall with the manual method to 0.99 with the semiautomatic method.Conclusion:A semiautomatic lesion segmentation and histogram analysis approach can provide a significant reduction in interobserver variability for DCE MR imaging measurements of K(trans) when compared with manual ROI methods, whereas intraobserver reproducibility is improved to some extent.© RSNA, 2012

The role of rectal magnetic resonance imaging in accurate localization and designation of colorectal cancer for optimal management: Case study

Colorectal cancer, developing from malignant transformation of the distal gut epithelium, is the second leading cause of cancer death in the United States. We present a gentleman in his 60s who was diagnosed with colorectal cancer during a routine screening colonoscopy with no evidence of distant metastasis on subsequent staging with positron emission tomography and computed tomography (PET-CT). The outside rectal MR (magnetic resonance) imaging report localized a mass to the upper rectum. Review of the MRI at an institutional, Multidisciplinary Tumor Board designated the tumor as “rectosigmoid,” straddling the rectosigmoid junction at the level of the “sigmoid take-off” (STO) or alternatively at the level of the last sigmoid artery take-off (SAT) at the origin of the superior rectal artery. The anatomic differentiation between upper rectal and lower sigmoid colon cancers carries clinical importance which is highlighted in this case report and brief literature review. Optimal anatomic localization of colorectal cancers helps direct the clinical team to tailor an individualized patient care plan