Mélanie Chiaradia

C-arm cone-beam computed tomography in interventional oncology: technical aspects and clinical applications

C-arm cone-beam computed tomography (CBCT) is a new imaging technology integrated in modern angiographic systems. Due to its ability to obtain cross-sectional imaging and the possibility to use dedicated planning and navigation software, it provides an informed platform for interventional oncology procedures. In this paper, we highlight the technical aspects and clinical applications of CBCT imaging and navigation in the most common loco-regional oncological treatments.

Intravoxel incoherent motion (IVIM) MR imaging of colorectal liver metastases: Are we only looking at tumor necrosis?

To determine if intra‐voxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI) parameters, including free molecular‐based (D) and perfusion‐related (D*, f) diffusion parameters, correlate with the degree of tumor necrosis and viable tumor in colo‐rectal cancer (CRC) metastasis.

Differentiation of focal nodular hyperplasia from hepatocellular adenoma: Role of the quantitative analysis of gadobenate dimeglumine-enhanced hepatobiliary phase MRI.

To determine the value of quantitative analysis of the hepatobiliary phase (HBP) in gadobenate dimeglumine (Gd‐BOPTA)‐enhanced magnetic resonance imaging (MRI) to differentiate focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA).

Ruptured visceral artery aneurysms

Visceral artery aneurysms are rare but their estimated mortality due to rupture ranges between 25 and 70%. Treatment of visceral artery aneurysm rupture is usually managed by interventional radiology. Specific embolization techniques depend on the location, affected organ, locoregional arterial anatomy, and interventional radiologist skill. The success rate following treatment by interventional radiology is greater than 90%. The main complication is recanalization of the aneurysm, showing the importance of post-therapeutic monitoring, which should preferably be performed using MR imaging.

Liver magnetic resonance diffusion weighted imaging: 2011 update.

Diffusion-Weighted-Imaging (DWI) assesses proton motion on a cellular scale. Owing to recent instrumentation developments, diffusion sequences are now routinely used for liver imaging. This review will go through the physical principles that underlie this technique, and then highlight up-to-date liver applications including quantification of liver fibrosis, focal lesions detection and characterization, and therapy response monitoring.

Imaging strategies before beginning treatment of colorectal liver metastases

The management of colorectal intrahepatic metastases before resection is multidisciplinary and radiologists and nuclear medicine specialists play a major role. In accordance with the French National Guide for appropriate use of diagnostic imaging, the approach should be multimodal: a chest-abdomen and pelvic (CAP) CT scan and hepatic MRI are mandatory while PET-CT provides important additional information, in particular on intra-abdominal extrahepatic metastases. This multimodal approach emphasizes the importance of early and appropriate use of imaging in these patients, as well as the central role of multidisciplinary meetings in oncology.

Imaging benign hepatocellular tumors: atypical forms and diagnostic traps.

Management of patients with a benign hepatocellular tumor relies largely on imaging data; the diagnosis of focal nodular hyperplasia (FNH) must be made with certainty using MRI, because no other clinical or laboratory data can help diagnosis. It is also essential to identify adenomas to manage them appropriately. The radiological report in these situations is therefore of major importance. However, there are diagnostic traps. The aim of this paper is to present the keys to the diagnosis of benign lesions and to warn of the main diagnostic pitfalls.

Post-procedure bleeding in interventional radiology

Following interventional radiology procedures, bleeding can occur in 0.5 to 4% of the cases. Risk factors are related to the patient, to the procedure, and to the end organ. Bleeding is treated usually by interventional radiologists and consists mainly of embolization. Bleeding complications are preventable: before the procedure by checking hemostasis, during the procedure by ensuring the accurate puncture site (with ultrasound or fluoroscopy guidance) or by treating the puncture path using gelatin sponge, curaspon(®), biological glue or thermocoagulation, and after the procedure by carefully monitoring the patients.

Accuracy of a Cone-Beam CT Virtual Parenchymal Perfusion Algorithm for Liver Cancer Targeting during Intra-arterial Therapy

PURPOSE To evaluate accuracy of virtual parenchymal perfusion (VPP) algorithm developed for targeting liver cancer during intra-arterial therapy (IAT) using cone-beam CT guidance. MATERIALS AND METHODS VPP was retrospectively applied to 15 patients who underwent IAT for liver cancer. Virtual territory (VT) was estimated after positioning a virtual injection point on nonselective dual-phase (DP) cone-beam CT images acquired during hepatic arteriography at the same position chosen for selective treatment. Targeted territory (TT) was used as the gold standard and was defined by parenchymal phase enhancement of selective DP cone-beam CT performed before treatment start. Qualitative evaluation of anatomic conformity between VT and TT was performed using a 3-rank scale (poor, acceptable, excellent) by 3 double-blinded readers. VT and TT were also quantitatively compared using spatial overlap-based (Dice similarity coefficient [DSC], sensitivity, and positive predictive value), distance-based (mean surface distance [MSD]), and volume-based (absolute volume error and correlation between pairwise volumes) metrics. Interreader agreement was evaluated for the 2 evaluation methods. RESULTS Eighteen DP cone-beam CT scans were performed. Qualitative evaluation showed excellent overlap between VT and TT in 88.9%-94.4%, depending on the readers. DSC was 0.78 ± 0.1, sensitivity was 80%, positive predictive value was 83%, and MSD was 5.1 mm ± 2.4. Absolute volume error was 15%, and R2 Pearson correlation factor was 0.99. Interreader agreement was good for both qualitative and quantitative evaluations. CONCLUSIONS VPP algorithm is accurate and reliable in identification of liver arterial territories during IAT using cone-beam CT guidance.