Rosa Cervelli

Secretin-stimulated MR cholangiopancreatography: spectrum of findings in pancreatic diseases

AbstractMR cholangiopancreatography (MRCP) is an imaging technique that has evolved over the past 2 decades and that continues to have a fundamental role in the non-invasive detection of morphologic features of the pancreatic ducts. In several studies, MRCP has shown a good correlation with endoscopic retrograde cholangiopancreatography in the evaluation of diseases and anatomic variants of the pancreatic ductal system. However, in physiologic conditions the pancreatic ducts are not always easily recognisable. More recently, secretin-enhanced MRCP protocols have been developed for a more complete assessment of pancreatic ducts and glandular function, including monitoring of pancreatic flow dynamics and duodenal filling after pancreatic hormonal stimulation with secretin. The injection of this hormone causes temporary dilation of the pancreatic ducts, principally by increasing pancreatic exocrine secretions, and thus improving MRCP detection of the ducts and characterisation of pancreatic disorders and allowing the assessment of the exocrine pancreatic reserve. The purpose of this pictorial review is to summarise the technical aspects of secretin-stimulated MRCP, to report the secretin-stimulated MRCP findings of pancreatic duct abnormalities and to review the diagnostic capabilities of secretin-stimulated MRCP in various pancreatic ductal system conditions.Main Messages• MRCP has a fundamental role in the non-invasive detection of pancreatic ducts. • In physiologic conditions pancreatic ducts are not always well detected on MRCP. • Secretin injection causes temporary dilation of pancreatic ducts and thus improves MRCP detection. • Secretin-stimulated MRCP may allow the assessment of the exocrine pancreatic reserve. • Secretin increases the diagnostic capabilities of MRCP for evaluating pancreatic disorders.

Predictive value of angiographic scores for the integrated management of the ischemic diabetic foot

OBJECTIVE To retrospectively evaluate the agreement between the angiographic scores and the clinical outcomes after endoluminal revascularization in diabetic patients with Fontaine stage IV critical limb ischemia (CLI). METHODS Clinical and procedural data were retrospectively collected of consecutive diabetic patients with Fontaine stage IV CLI who underwent percutaneous lower limb endoluminal revascularization from January 2009 to June 2011. Pre- and postprocedural angiographic images were retrospectively reviewed to classify lower limb arterial involvement according to four systems: (1) TransAtlantic Inter-Society Consensus [TASC] I; (2) TASC II; (3) Grazianis morphologic classification; and (4) Joint Vascular Society Council calf and foot scores. Foot lesions were graded according to the University of Texas wound classification system. Clinical results (healing, nonhealing, or major amputation) were compared with baseline clinical data and angiographic results. RESULTS In the study period, 202 percutaneous procedures were performed, with an immediate technical success rate of 94%. Preprocedurally, the mean ± standard deviation calf and foot scores were 7.8 ± 1.6 and 7.3 ± 2.3, respectively; 132 patients (65%) were in Grazianis morphologic classes from 4 to 7; in 112 (55%) cases, TASC II was considered inapplicable, for the absence of femoropopliteal lesions; and finally, 93% of limbs were classified as TASC I type D lesions. After the procedure, mean calf and foot scores were 4.8 ± 2.3 and 5.9 ± 2.6, respectively, and 87% of cases were in Grazianis classes 1 and 2; TASC II was inapplicable in all cases, whereas 80% of cases remained TASC I type D lesions. Healing rate was 67% and major amputation rate was 4%. Among all the clinical and angiographic variables included in the analysis, only pre- and postprocedural foot scores were significantly associated to the clinical outcome (P < .05). CONCLUSIONS Endoluminal revascularization represents a valuable treatment option in diabetic patients with CLI. TASC classifications are inadequate to describe peripheral arterial involvement in the vast majority of diabetic patients with CLI. Pre- and postprocedural foot scores represent the most significant angiographic parameters to evaluate treatment success.

Liver investigations: Updating on US technique and contrast-enhanced ultrasound (CEUS)

Over the past few years, the cross sectional imaging techniques (Computed Tomography - CT and Magnetic Resonance - MR) have improved, allowing a more efficient study of focal and diffuse liver diseases. Many papers had been published about the results of a routinely clinical use of the dual source/dual energy CT techniques and the use of hepatobiliary contrast agents in MR liver studies. As a consequence, these new improvements have diverted the attention away from the Ultrasound technique and its technical and conceptual evolutions. In these years of disinterest, US and especially Contrast Enhanced Ultrasound (CEUS) have consolidated and grown in their application in clinical routine for liver pathologies. In particular, thanks to the introduction of new, dedicated software packages, CEUS has allowed not only qualitative, but also quantitative analysis of lesion microcirculation, thus opening a new era in the evaluation of lesion characterization and response to therapy. Moreover, the renewed interest in liver elastography, a baseline ultrasound-based imaging modality, has led to the development of a competitive technique to assess liver stiffness and then for the evaluation of the progression towards cirrhosis, and characterization of focal liver lesions, opening the way to avoid, in selected cases, liver biopsy. The aim of this review is to offer an up-to-date overview on the state of the art of clinical applications of US and CEUS in the study of focal and diffuse liver pathologies. Besides, it aims to highlight the emerging role of perfusion techniques in the assessment of local and systemic treatment response and to show how the liver evolution from steatosis to fibrosis can be revealed by elastography.

3T diffusion-weighted MRI in the response assessment of colorectal liver metastases after chemotherapy: correlation between ADC value and histological tumour regression grading

PURPOSE The purpose of the study was to correlate the apparent diffusion coefficient (ADC) values of diffusion-weighted MR imaging (DW-MRI) by 3T device with the histological tumour regression grading (TRG) analysis of colorectal liver metastases after preoperative chemotherapy. MATERIALS AND METHODS Our study included thirty-five patients with colorectal liver metastases who had undergone MRI by 3T device (GE DISCOVERY MR750; GE Healthcare) after preoperative chemotherapy. DW-MRI was performed using a single-shot spin-echo echo-planar sequence with multiple b-values (0, 150, 500, 1000, 1500s/mm2), thus obtaining an ADC map. For each liver lesion (more than 1cm in diameter) the fitted ADC values were calculated by two radiologists in conference and three ROIs were drawn: around the entire tumour (ADCe), at the tumour periphery (ADCp) and at the tumour center (ADCc). All ADC values were correlated with histopathological findings after surgery. Hepatic metastases were pathologically classified into five groups on the basis of TRG. Statistical analysis was performed on a per-lesion basis utilizing the one-way analysis of variance (ANOVA). This retrospective study was approved by our institutional review board; written informed consent was obtained from all patients. RESULTS A total of 106 colorectal liver metastases were included for image analysis. TRG1, TRG2, TRG3, TRG4 and TRG5 were observed in 4, 14, 36, 35 and 17 lesions, respectively. ADCe and ADCp values were significantly higher in lesions classified as TRG1 (2.40±0.12×10-9m2/s and 2.28±0.26×10-9m2/s, respectively) and as TRG2 (1.40±0.31×10-9m2/s and 1.44±0.35×10-9m2/s), compared to TRG3 (1.16±0.13×10-9m2/s and 1.01±0.18×10-9m2/s), TRG4 (1.10±0.26×10-9m2/s and 0.97±0.24×10-9m2/s), and TRG5 (0.93±0.17×10-9m2/s and 0.82±0.28×10-9m2/s). ADCe, ADCp and ADCc values were significantly different in TRG classes (p<0.0001). Statistical correlations were found between the ADCe, ADCp, ADCc values and the TRG classes (Spearman correlation coefficient were -0.568, -0.542 and -0.554, respectively). CONCLUSION Our study showed a significant correlation between ADC values of 3T DW-MRI and histological TRG of colorectal liver metastases after preoperative chemotherapy.