Image quality and diagnostic performance of dual-energy CT with spectral imaging in hepatocellular carcinoma: radiologic-pathologic correlation.

Purpose: To retrospectively evaluate image quality and diagnostic accuracy of dual-energy CT (DECT) in the diagnosis of hepatocellular carcinoma (HCC) in a series of transplanted cirrhotic patients. Materials and Methods: Institutional Review Board approval was obtained. The study included all consecutive cirrhotic patients who underwent liver transplantation (LTx) <120 days after multiphasic DECT with spectral imaging in late arterial phase from March 2013 to December 2014. Three sets of images (A: 140kVp polychromatic; B: 70keV monochromatic; C: “iodine-based” material decomposition images) were reviewed, assessing image quality (scale 1-5), lesion conspicuity (scale 1-3) and lesion-to-liver contrast-to-noise ratio (CNR). Using the pathological findings on the explanted livers as gold standard, sensitivity, specificity, positive and negative predictive values and accuracy were assessed and compared by DeLong method. Results: Fifty-three patients (41 males; mean age 54.4 ± 8.2 years) were included, with 31 HCC nodules identified at pathology in 23 (43.4%) patients (mean diameter 19.1 ± 8.5 mm). Group B showed significantly higher image quality (4.91 ± 0.35) compared to groups A (4.83 ± 0.54; P=.04) and C (4.70 ± 0.57; P=.0035). Lesion conspicuity scores were 2.58 ± 0.65, 2.83 ± 0.48 and 2.92 ± 0.28 for groups A, B and C, respectively; the difference was significant comparing group A and C (P=.03). CNR was significantly higher in group C (4.72 ± 2.94) compared to groups A (2.47 ± 1.5; P<.0001) and B (3.44 ± 1.63; P=.02). On the nodule-by-nodule and patient-by-patient analyses, group C had the highest diagnostic accuracy (area-under-the-curve, AUC 0.90 and 0.96, respectively), compared to groups A (AUC 0.81 and 0.87) and B (AUC 0.87 and 0.92); the difference was significant comparing groups A and C (P=.009 and .039). Conclusions: DECT with spectral imaging provides high quality images; by increasing CNR, iodine-based images are able to increase sensitivity in HCC diagnosis with >90% diagnostic accuracy

Automated contrast medium monitoring system for computed tomography - Intra-institutional audit

The aim of this study was to analyze the usage and the data recorded by a RIS-PACS-connected contrast medium (CM) monitoring system (Certegra®, Bayer Healthcare, Leverkusen, Germany) over 19 months of CT activity. The system used was connected to two dual syringe power injectors (each associated with a 16-row and a high definition 64-row multidetector CT scanner, respectively), allowing to manage contrast medium injection parameters and to send and retrieve CT study-related information via RIS/PACS for any scheduled contrast-enhanced CT examination. The system can handle up to 64 variables and can be accessed via touchscreen by CT operators as well as via a web interface by registered users with three different hierarchy levels. Data related to CM injection parameters (i.e. iodine concentration, volume and flow rate of CM, iodine delivery rate and iodine dose, CM injection pressure, and volume and flow rate of saline), patient weight and height, and type of CT study over a testing period spanning from 1 June 2013 to 10 January 2015 were retrieved from the system. Technical alerts occurred for each injection event (such as system disarm due to technical failure, disarm due to operator's stop, incomplete filling of patient data fields, or excessively high injection pressure), as well as interoperability issues related to data sending and receiving to/from the RIS/PACS were also recorded. During the testing period, the CM monitoring system generated a total of 8609 reports, of which 7629 relative to successful injection events (88.6%). 331 alerts were generated, of which 40 resulted in injection interruption and 291 in CM flow rate limitation due to excessively high injection pressure (&gt;325psi). Average CM volume and flow rate were 93.73±17.58mL and 3.53±0.89mL/s, and contrast injection pressure ranged between 5 and 167psi. A statistically significant correlation was found between iodine concentration and peak IDR (rs=0.2744, p&lt;0.0001), as well as between iodine concentration and iodine dose (rs=0.3862, p&lt;0.0001) for all CT studies. Automated contrast management systems can provide a full report of contrast use with the possibility to systematically compare different contrast injection protocols, minimize errors, and optimize organ-specific contrast enhancement for any given patient and clinical application. This can be useful to improve and harmonize the quality and consistency of contrast CT procedures within the same radiological department and across the hospital, as well as to monitor potential adverse events and overall costs

Radiological diagnosis of hepatocellular carcinoma

Diagnosis of hepatocellular carcinoma (HCC) still remains a challenging issue. In the setting of liver cirrhosis, international guidelines have set the noninvasive criteria for HCC diagnosis, represented by the detection of contrast hyperenhancement in the arterial phase (wash-in) and hypoenhancement in the portal or delayed phase (wash-out) with dynamic multi-detector computer tomography or magnetic resonance (MR) imaging. Although highly specific, this typical enhancement pattern has relatively low sensitivity, since approximately one-third of HCC nodules are characterized by atypical enhancement patterns. In atypical HCC nodules larger than 1 cm, the majority of international guidelines recommend liver biopsy. However, there is an increasing interest in exploiting new noninvasive diagnostic tools, to increase the sensitivity of radiological diagnosis of HCC. Diffusion-weighted MR imaging and MR hepatobiliary contrast agents may represent useful tools for the detection and characterization of borderline hypovascular lesions by providing functional information such as water molecule motion in diffusion-weighted imaging and residual hepatobiliary function, which can be impaired early during the course of hepatocarcinogenesis. Also, dual-energy computed tomography (CT) represents an interesting new CT technology that could increase detectability and conspicuity of hypervascular lesions, thus possibly improving CT sensitivity in small HCCs. However, more data and further developments are needed to verify the usefulness of these new technologies in the diagnosis of HCC and to translate these recent advances into clinical practice

Trends in utilization of transarterial treatments for hepatocellular carcinoma: Results of a survey by the Italian Society of Interventional Radiology

Purpose: This study was designed to provide an overview of the practice of locoregional treatments for HCC by the Italian centers of Interventional Radiology (IR) with particular reference to transarterial modalities. Methods: A questionnaire of 11 questions on locoregional treatment of HCC was e-mailed to 134 Italian IR centers. Results: The response rate was 64.9 % (87/135 centers). Of 8,959 procedures in 2011, 67 % were transarterial treatments, 31 % percutaneous ablations, and 2 % Y90-radioembolizations. Regarding (chemo)embolization, approximately 59 % of procedures were performed in the intermediate stage, 28 % in the early stage, and 12.8 % in the advanced stage. TACE techniques varied greatly; approximately 52 % of procedures were performed with drug-eluting particles and 32 % with lipiodol, drug, and reabsorbable particles. In selected cases, 53 of 78 (68 %) centers combine chemoembolization and ablation, whereas 28 centers (35.9 %) combine Sorafenib and chemoembolization. In 2011, 13 of 78 (16.7 %) responding centers performed Y90-radioembolization, with approximately 52 % of procedures performed in the advanced stage and 46 % in the intermediate stage. Approximately 62 % of Y90-radioembolizations were performed using resin spheres and 38 % using glass spheres. Conclusions: With almost 9,000 procedures performed each year, locoregional treatments of HCC, most of all transarterial (chemo)embolizations, represent a major part of daily clinical practice in many Italian IR centers. The high variability in responses regarding transarterial treatments for HCC patients highlights the need for solid scientific evidence allowing better definition of clinical indications and standardization of technical approaches. \ua9 2013 Springer Science+Business Media and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE)

General Anesthesia Versus Conscious Sedation and Local Anesthesia During Thrombectomy for Acute Ischemic Stroke

As numerous questions remain about the best anesthetic strategy during thrombectomy, we assessed functional and radiological outcomes in stroke patients treated with thrombectomy in presence of general anesthesia (GA) versus conscious sedation (CS) and local anesthesia (LA)