Patch-based field-of-view matching in multi-modal images for electroporation-based ablations.

Various multi-modal imaging sensors are currently involved at different steps of an interventional therapeutic work-flow. Cone beam computed tomography (CBCT), computed tomography (CT) or Magnetic Resonance (MR) images thereby provides complementary functional and/or structural information of the targeted region and organs at risk. Merging this information relies on a correct spatial alignment of the observed anatomy between the acquired images. This can be achieved by the means of multi-modal deformable image registration (DIR), demonstrated to be capable of estimating dense and elastic deformations between images acquired by multiple imaging devices. However, due to the typically different field-of-view (FOV) sampled across the various imaging modalities, such algorithms may severely fail in finding a satisfactory solution. In the current study we propose a new fast method to align the FOV in multi-modal 3D medical images. To this end, a patch-based approach is introduced and combined with a state-of-the-art multi-modal image similarity metric in order to cope with multi-modal medical images. The occurrence of estimated patch shifts is computed for each spatial direction and the shift value with maximum occurrence is selected and used to adjust the image field-of-view. The performance of the proposed method - in terms of both registration accuracy and computational needs - is analyzed in the practical case of on-line irreversible electroporation procedures. In total, 30 pairs of pre-/per-operative IRE images are considered to illustrate the efficiency of our algorithm. We show that a regional registration approach using voxel patches provides a good structural compromise between the voxel-wise and "global shifts" approaches. The method was thereby beneficial for CT to CBCT and MRI to CBCT registration tasks, especially when highly different image FOVs are involved. Besides, the benefit of the method for CT to CBCT and MRI to CBCT image registration is analyzed, including the impact of artifacts generated by percutaneous needle insertions. Additionally, the computational needs using commodity hardware are demonstrated to be compatible with clinical constraints in the practical case of on-line procedures. The proposed patch-based workflow thus represents an attractive asset for DIR at different stages of an interventional procedure.

Suspicious liver nodule in chronic liver disease: Usefulness of a second biopsy.

PURPOSE: To assess the usefulness of a second biopsy when the first one was inconclusive in patients with a liver nodule found during the follow-up for chronic liver disease. MATERIALS AND METHODS: Among 381 patients (544 nodules) included in a prospective study designed to evaluate the accuracy of imaging for the diagnosis of small hepatocellular carcinoma (HCC) in chronic liver disease, 254 nodules were biopsied. The following histological results were considered as conclusive: HCC, dysplastic or regenerative nodule, and other identified tumors (benign or malignant). For nodules with inconclusive results (e.g. fibrosis or no definite focal lesion), a second biopsy was suggested, but was not mandatory. RESULTS: A total of 242 patients (194 men, 48 women; mean age, 61.9±9.5 [SD]; range: 40.2-89.0years) with 254 nodules underwent a first biopsy. Mean nodule diameter was 19.2±5.4mm (range: 10-33mm). The first biopsy was conclusive in 189/254 nodules (74.4%): 157 HCCs (83.1%), 11 regenerative nodules (5.8%), 10 dysplastic nodules (5.3%), 3 cholangiocarcinomas (1.6%), and 8 other tumors (4.2%). Among the 65 nodules for which the first biopsy was inconclusive, a second biopsy was performed for 17 nodules in 16 patients within 6 months of the first one. It was conclusive in 13/17 nodules (76.5%): 10 HCCs (76.9%), 2 dysplastic nodules (15.4%), and 1 other tumor (7.7%). In 4/17 nodules (23.5%), no definitive diagnosis could be provided. CONCLUSION: The diagnostic yield of a second biopsy of a suspicious lesion suggestive of HCC in chronic liver disease is not decreased compared to the first one. Repeated biopsy after a first negative one could be an alternative option to the follow-up of patients with chronic liver disease.

Percutaneous treatment of extrahepatic recurrence of hepatocellular carcinoma.

PURPOSE: The goal of this study was to retrospectively evaluate the results of imaging-guided percutaneous ablation in patients with controlled intrahepatic hepatocellular carcinoma (HCC) with limited extrahepatic disease. MATERIALS AND METHODS: Eleven patients with limited extrahepatic disease and/or potential short-term clinical manifestations with controlled primary intrahepatic HCC were included into the study. There were nine men and two women, with a mean age of 67.4 years±10.2 (SD) (range: 54-85 years). All patients had extrahepatic disease treated by either radiofrequency ablation or electroporation. Extrahepatic disease consisted of lymph node metastases (5 patients), tumor seeding along a needle tract (3 patients), adrenal gland metastasis, bone metastasis and pulmonary metastasis (one patient each). RESULTS: Response to treatment was complete in 7/11 patients (64%). The mean survival time after treatment was 18.8±12.7 (SD) months (median, 16 months; range: 4-42 months). No severe complications associated with percutaneous treatment were observed. CONCLUSION: Our results suggest that imaging-guided percutaneous ablation techniques should be considered as a useful option for the treatment of extrahepatic disease in patients with HCC. Further studies are needed, however to fully determine the potential role of these techniques in this elective application.

Ablative therapies: Advantages and disadvantages of radiofrequency, cryotherapy, microwave and electroporation methods, or how to choose the right method for an individual patient?

Several ablation techniques are currently available. Except for electroporation, all of these methods cause fatal damage at a cellular level and irreversible architectural deconstruction at a tissue level by thermal effects. Ablation of a tumor using one of these techniques, whether thermal or otherwise, requires applicators to be positioned from which the energy is delivered in situ. Some techniques, however, require several applicators to be inserted (multibipolar radiofrequency, cryotherapy and electroporation) whereas a single applicator is often sufficient with other technologies (monopolar radiofrequency and microwave). These methods are conceptually very similar but are distinguished from each other in practice through the technologies they use. It is essential to understand these differences as they influence the advantages and limitations of each of the techniques. There is no such thing as the perfect multifunctional ablation device and choice is dictated on an individual patient basis depending on the aim of treatment, which itself depends on each patient's clinical situation.

Percutaneous hepatic ablation: what needs to be known in 2014.

Percutaneous treatments for liver tumors were initially reserved for patients deemed to be inoperable and whose tumors were small in both size and number. As a result of the widening range of both techniques and technologies these treatments have gradually become incorporated into increasingly complex treatment strategies for increasingly broad patient groups. The place reserved for these techniques, which are still dominated by monopolar radiofrequency ablation, which is now facing strong competition from second-generation microwaves, is governed by each center's knowledge and skills in the techniques. This review describes the possible indications for percutaneous ablation depending on clinical findings and the technical and technological choices made.

[Results of percutaneous radiofrequency ablation of hepatocellular carcinoma in patients with cirrhosis aged 75 years and over]. / Résultats du traitement par radiofréquence du carcinome hépatocellulaire chez le cirrhotique âgé de 75 ans et plus.

PURPOSE: The objective of this study was to assess the results and tolerance of radiofrequency ablation in patients with cirrhosis and hepatocellular carcinoma (HCC) older than 75 years. PATIENTS AND METHODS: Over a period of 9 years from January 2001, 235 patients with cirrhosis and 3 or less HCC≤5 cm of diameter were treated by radiofrequency ablation. Among them, 52 patients older than 75 years were selected for this study. RESULTS: The mean age was 79.4±3. 5 years. There were 36 males, cirrhosis was classified Child-Pugh class A (n=52) related to alcohol (n=13), HCV infection (n=33), or other causes (n=6). The mean tumour diameter was 32.5±10.6 mm, and 14 patients had a multifocal HCC. A complete ablation was obtained in 50/52 patients (96%). No severe complication occurred. The estimated overall survival rates were 62%, 52% and 36% at 3 years, 4 years and 5 years, respectively; it was similar to those observed in patients younger than 75 years. CONCLUSION: In patients with cirrhosis older than 75 years, radiofrequency ablation of 3 or less HCC≤5cm is well tolerated and survivals rates are similar to those of younger patients.

[Percutaneous radiofrequency and other liver ablation techniques: 2011 update]. / Radiofréquences et autres techniques d'ablation hépatique percutanée : ce qu'il faut savoir en 2011.

Percutaneous ablation of liver tumors was initially limited to patients that were not surgical candidates and with a limited number of relatively small liver lesions. Because of the diversification of techniques and technologies, percutaneous liver ablation has progressively been integrating to more and more complex therapeutic strategies available to a wider group of patients. Local knowledge and expertise with these techniques, largely dominated by radiofrequency ablation, often dictate the role of these techniques in the management of patients with liver tumors. We will review the clinical indications of percutaneous ablation techniques for liver tumors based on clinical considerations as well as ablation techniques.

[The impact of large vessel proximity on effectiveness of radiofrequency ablation of hepatocellular carcinoma: a controlled study]. / Influence de la proximité des gros vaisseaux sur les résultats du traitement des carcinomes hépato-cellulaires par radiofréquence: une étude contrôlée.

PURPOSE: To evaluate the risk of radiofrequency ablation treatment failure for hepatocellular carcinomas (HCC) next to large vessels. MATERIALS AND METHODS: Between May 2000 and October 2002, from a total of 83 patients treated by radiofrequency ablation for HCC in a single center, 13 patients with tumoror=3 mm in diameter (Group A) were matched with 13 patients with similar size tumors located away from large vessels (Group B). Immediate response and recurrence rate were evaluated on CT. RESULTS: After mean follow-up interval of 39+/-16.5 months for Group A and 39+/-14 months for Group B, local recurrence rates were 7/12 versus 1/12 respectively (p=0.03). For Group A, 6/7 local recurrences clearly contacted a large vessel. CONCLUSION: The cooling effect from flowing blood in large vessels markedly increases the rate of local failure of radiofrequency ablation for small HCC located near large vessels.

[Susceptibility weighted imaging. Theory and applications]. / L'imagerie de susceptibilité magnétique: théorie et applications.

Susceptibility Weighted Imaging (SWI) is a new MR imaging technique using the BOLD effect (Blood Oxygen Level Dependent) and the differences of susceptibility between tissues. It is a 3D gradient echo, fully velocity compensated sequence. The echo time is chosen to maximize the signal cancellation in veins and a specific post-processing is applied using the phase images as a complementary source of contrast. It is very useful for the visualization of veins either normal or abnormal. It shows hemorrhage, even of small quantity, better than conventional gradient echo sequences. Its use is still limited by a long acquisition time and some remaining artifacts.

[Current problems in geriatrics and radiology. Teleradiology: organization and evaluation]. / Problématiques de l'imagerie en gériatrie: pertinence, objectifs et réalisation de l'examen radiologique. Téléradiologie: organisation et évaluation.

The realization of radiological examinations in the elderly population must be adjusted to the needs of patients that usually have health problems and very little patience. Its organization must be thought as a whole: appointment, reception of an awaited patient, human accompaniment allowing good cooperation, nursing support, and prompt availability of reports. Adapted equipment facilitates the examination: stretchers to raise and carry invalid patients, digital radiography. Structural linking of radiology and geriatric units with a departmental support avoids the isolation of medical and ancillary staff, reinforce the bonds with geriatricians and facilitates the access to CT before any contrast-enhanced (barium, iodinated) examination. Teleradiology is a complementary tool of making the medical support available and reinforce the interactivity with geriatricians. The simplicity of the questions in current geriatrics makes it possible to use teleradiology in daily practice.

[Ovarian vein thrombophlebitis and post-partum fever]. / Thrombophlébite de la veine ovarienne et fièvre du post-partum.

INTRODUCTION: Ovarian vein thrombophlebitis (OVT) is a rare but potentially threatening complication of the postpartum period. Diagnosing it may be of some difficulty especially in case of symptoms mimicking appendicitis or pyelonephritis. EXEGESIS: We report 2 patients with postpartum right OVT. The clinical presentation included high grade fever, and pain, lumbar in one case, of the right flank in the other. Pulmonary embolism complicated both cases. CONCLUSION: Diagnostic and therapeutic management of OVT was transformed by progresses in medical imaging during the 1980's. However, optimal duration of anticoagulant treatment and secondary prevention indications have to be determined.

[Pseudotumoral enterocolic phlebitis of the cecum and rutoside. A case report]. / Phlébite entérocolique pseudotumorale du caecum et rutoside. Une nouvelle observation.

INTRODUCTION: Enterocolic phlebitis is an entity characterized by ischemic injury of the gastrointestinal tract caused by thrombophlebitis of the mesenteric veins without arterial involvement or systemic disease. EXEGESIS: We report a case of enterocolic phlebitis in a 57-year-old female treated by rutoside, revealed by intestinal obstruction related to a pseudotumoral lesion of the caecum. CONCLUSION: This case adds to the four cases of enterocolic phlebitis under rutoside already reported in the literature, suggesting a possible involvement of this drug in this rare disease.

Latent autoimmune thyroiditis in untreated patients with HCV chronic hepatitis: a case-control study.

In order to establish a relationship between Hepatitis C virus (HCV) chronic infection and autoimmune thyroiditis, 97 untreated patients with biopsy-proven HCV chronic hepatitis and 97 controls were studied. An ultrasound examination of the thyroid and an assay of serum thyroid-stimulating hormone (TSH), thyroid hormones and anti-thyroid antibodies were performed in all cases. The overall prevalence of thyroid abnormalities was higher in patients than in controls (17 vs. 4%, P<0.01) and the prevalence of anti-thyroid antibodies was significantly different between the two groups (P<0. 02). HCV patients with (n=13) compared to HCV patients without anti-thyroid antibodies (n=84) were older, predominantly female, and more frequently had increased serum TSH levels or a hypoechogenic pattern of the thyroid gland, while Knodell's score and prevalence of cirrhosis were similar. Latent autoimmune thyroiditis is more frequent in untreated HCV patients than in controls. This finding raises questions about the mechanism of autoimmunity induced by HCV and provides an explanation for the high rate of overt autoimmune thyroiditis during interferon treatment in these patients.

A case of malrotation and situs ambiguus.

Isolated levocardia is a rare condition in which intestinal malrotation may be encountered. The case herein reported is particularly uncommon and raises a number of questions about the development of abdominal symmetry.

[Cranial pachymeningitis]. / Les pachyméningites crâniennes.

INTRODUCTION: Pachymeningitis is a fibrous inflammatory process with non-specific symptoms, involving the dura mater. Due to MRI development, diagnosis is both easier and earlier. CURRENT KNOWLEDGE AND KEY POINTS: We report seven cases and review current literature. Clinical features are headaches and cranial nerve palsies. CSF shows inflammatory changes, while MRI evidences thickening of the dura mater. Disease etiologies in the present study were tuberculosis in two cases, sarcoidosis, Lyme disease, lymphoma and dural puncture; in one case only the disease was of unknown origin. The condition of six patients improved with specific treatment. FUTURE PROSPECTS AND PROJECTS: Further MRI development should allow detection of new forms of pachymeningitis and standardization of patients' management through the study of more important series.

Aortitis with antiphospholipid antibodies: CT and MR findings.

Two cases of aortitis associated with the presence of antiphospholipid antibodies (APAs) are reported. Only CT and MR imaging were able to show these unusual form of aortitis preferentially affecting the outer aortic tunics. We conclude that aortitis could be a new manifestation of primary antiphospholipid syndrome (APS) and the initial pathological process before the development of aortic thrombosis, reported as a classical complication of APS.