Immediate Hypersensitivity to Contrast Agents: The French 5-year CIRTACI Study.

BACKGROUND: Iodinated and gadolinium-based contrast media (ICM; GBCM) induce immediate hypersensitivity (IH) reactions. Differentiating allergic from non-allergic IH is crucial; allergy contraindicates the culprit agent for life. We studied frequency of allergic IH among ICM or GBCM reactors. METHODS: Patients were recruited in 31 hospitals between 2005 and 2009. Clinical symptoms, plasma histamine and tryptase concentrations and skin tests were recorded. Allergic IH was diagnosed by intradermal tests (IDT) with the culprit CM diluted 1:10, "potentially allergic" IH by positive IDT with pure CM, and non-allergic IH by negative IDT. FINDINGS: Among 245 skin-tested patients (ICM = 209; GBCM = 36), allergic IH to ICM was identified in 41 (19.6%) and to GBCM in 10 (27.8%). Skin cross-reactivity was observed in 11 patients with ICM (26.8%) and 5 with GBCM (50%). Allergy frequency increased with clinical severity and histamine and tryptase concentrations (p < 0.0001). Cardiovascular signs were strongly associated with allergy. Non-allergic IH was observed in 152 patients (62%) (ICM:134; GBCM:18). Severity grade was lower (p < 0.0001) and reaction delay longer (11.6 vs 5.6 min; p < 0.001). Potentially allergic IH was diagnosed in 42 patients (17.1%) (ICM:34; GBCM:8). The delay, severity grade, and mediator release were intermediate between the two other groups. INTERPRETATION: Allergic IH accounted for < 10% of cutaneous reactions, and > 50% of life-threatening ones. GBCM and ICM triggered comparable IH reactions in frequency and severity. Cross-reactivity was frequent, especially for GBCM. We propose considering skin testing with pure contrast agent, as it is more sensitive than the usual 1:10 dilution criteria.

Prospective Evaluation of Magnetic Resonance Imaging and [18F]Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography at Diagnosis and Before Maintenance Therapy in Symptomatic Patients With Multiple Myeloma Included in the IFM/DFCI 2009 Trial: Results of the IMAJEM Study.

Purpose Magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) are important imaging techniques in multiple myeloma (MM). We conducted a prospective trial in patients with MM aimed at comparing MRI and PET-CT with respect to the detection of bone lesions at diagnosis and the prognostic value of the techniques. Patients and Methods One hundred thirty-four patients received a combination of lenalidomide, bortezomib, and dexamethasone (RVD) with or without autologous stem-cell transplantation, followed by lenalidomide maintenance. PET-CT and MRI were performed at diagnosis, after three cycles of RVD, and before maintenance therapy. The primary end point was the detection of bone lesions at diagnosis by MRI versus PET-CT. Secondary end points included the prognostic impact of MRI and PET-CT regarding progression-free (PFS) and overall survival (OS). Results At diagnosis, MRI results were positive in 127 of 134 patients (95%), and PET-CT results were positive in 122 of 134 patients (91%; P = .33). Normalization of MRI after three cycles of RVD and before maintenance was not predictive of PFS or OS. PET-CT became normal after three cycles of RVD in 32% of the patients with a positive evaluation at baseline, and PFS was improved in this group (30-month PFS, 78.7% v 56.8%, respectively). PET-CT normalization before maintenance was described in 62% of the patients who were positive at baseline. This was associated with better PFS and OS. Extramedullary disease at diagnosis was an independent prognostic factor for PFS and OS, whereas PET-CT normalization before maintenance was an independent prognostic factor for PFS. Conclusion There is no difference in the detection of bone lesions at diagnosis when comparing PET-CT and MRI. PET-CT is a powerful tool to evaluate the prognosis of de novo myeloma.

The value of a rapid contrast-enhanced angio-MRI protocol in the detection of head and neck paragangliomas in SDHx mutations carriers: a retrospective study on behalf of the PGL.EVA investigators.

OBJECTIVES: To assess the performance of a simplified MRI protocol consisting of a contrast-enhanced three-dimensional MR angiography (CE-MRA) in association with a post-contrast T1-weighted sequence (T1WIV) for the detection of HNPGLs in SDHx mutation carriers. METHODS: This retrospective sub-study is based on the multicenter PGL.EVA cohort, which prospectively enrolled SDHx mutation carriers from 2005 to 2009; 157 index cases or relatives were included. CE-MRA and the T1WIV images were read solely with knowledge of the clinical data but blind to the diagnosis. Sensitivity, specificity and likelihood ratios for the simplified MRI protocol were compared to the full MRI protocol reading results and to the gold standard status obtained through the consensus of an expert committee. RESULTS: The sensitivity and specificity of the readings of the simplified MRI protocol were, respectively, 88.7 % (95 % CI = 78.1-95.3) and 93.7 % (95 % CI = 86.8-97.7) versus 80.7 % (95 % CI = 68.6-89.6) and 94.7 % (95 % CI = 88.1-98.3) for the readings of the full MRI protocol. CONCLUSIONS: The simplified post-contrast MRI with shorter duration (5 to 10 minutes) showed no performance difference compared to the lengthy standard full MRI and can be proposed for the detection of head and neck paragangliomas (HNPGLs) in SDHx mutation carriers. KEY POINTS: • Rapid angio-MRI protocol and the usual lengthy protocol show equal diagnostic performance. • The CE-MRA is the key sequence for the detection of HNPGLs. • The T1WIV sequence assists in localizing HNPGLs.

Serum S100ß Neuroprotein Reduces Use of Cranial Computed Tomography in Children After Minor Head Trauma.

Minor head trauma is a common reason for consultation in pediatric emergency departments. In 2009, the Pediatric Emergency Care Applied Research Network (PECARN) published a clinical decision rule for its management. It aimed to help clinicians identify children with a very low risk of developing intracranial lesions, so that unnecessary cranial computed tomography (CCT) scan radiation could be avoided, as such exposure is associated with a rising risk of cancer in this young population. In the meantime, the serum S100ß neuroprotein showed encouraging results, with a 30% potential decrease in CCTs for the management of minor head traumas in adults and children. The aim of this study was to determine if the serum S100ß neuroprotein, associated with the PECARN clinical decision rule, could safely reduce the use of CCTs. We included children who were examined at the pediatric emergency department for minor head trauma, who underwent a CCT, whose blood samples were analyzed to determine the level of the serum S100ß protein. They were managed according to the PECARN clinical decision rule. We afterward assessed the potential decrease in the number of CCTs, according to a modified PECARN clinicobiological decision rule, had we taken into account the result of the blood tests. One hundred nine children were included, and nine of them had clinically important traumatic brain injury. Four of them had a negative S100ß value but were classified as high risk of developing intracranial lesion according to the PECARN clinical decision rule. Had we taken into account the modified PECARN clinicobiological decision rule, none of them would have been missed. However, there were 32 true negatives of the rule, allowing a potential decrease in CCTs rated at 29% (95% confidence interval, 21-38). Integrating the serum S100ß neuroprotein assessment in the PECARN clinical decision rule could avoid deleterious exposure to CCT radiation, with the condition of using a clinicobiological rule to avoid missing clinically important traumatic brain injuries. Those results have yet to be confirmed relying on a large multicentric study.

Giant cell arteritis with or without aortitis at diagnosis. A retrospective study of 22 patients with longterm followup.

OBJECTIVE: Studies have shown that aortitis may be present in half the patients with recent-onset giant cell arteritis (GCA). We assessed whether aortitis at diagnosis affects longterm outcome in patients with GCA. METHODS: We retrospectively analyzed the longterm outcome of a prospective cohort of 22 patients with biopsy-proven GCA who all had aortic computed tomography (CT) evaluation at the time of diagnosis of GCA between May 1998 and November 1999. Longterm outcome, especially vascular events such as aortic aneurysm, mortality, relapses of GCA, and requirement for steroids, was assessed in 2011 by chart review and patient/physician interviews. RESULTS: At disease onset, 10/22 patients had aortitis on CT scan. Patients with and without aortitis had similar baseline characteristics, including cardiovascular risk profile. At the time of the study, 12/22 (57%) patients had died. Vascular causes of death were more frequent in patients with aortitis (5/7 vs 0/5; p = 0.02). A higher number of vascular events was noted in patients with aortitis (mean events per patient 1.33 vs 0.25; p = 0.009). Stroke was more frequent in patients with aortitis. These patients seemed to exhibit a more chronic or relapsing disease course, and they were less likely to completely discontinue steroid therapy (p = 0.009, log-rank test). CONCLUSION: Our study suggests for the first time that inflammatory aortic involvement present at onset of GCA could predict a more chronic/relapsing course of GCA, with higher steroid requirements and an increased risk for vascular events in the long term.

¹8F-FDG-PET/CT in initial staging and assessment of early response to chemotherapy of pediatric rhabdomyosarcomas.

PURPOSE: The objective of this retrospective study was to compare positron emission tomography/computed tomography using fluorine-18-fluorodeoxyglucose (18F-FDG-PET/CT) and conventional imaging modalities (CIM) in initial staging and early assessment of response to chemotherapy in children and young adults treated for rhabdomyosarcoma (RMS). PATIENTS AND METHODS: At initial staging, 23 patients (9 months to 21 years) with histologically proven RMS underwent 18F-FDG-PET/CT in addition to CIM (MRI of the primary site, whole-body CT, and bone scintigraphy). After three courses of chemotherapy, 13 patients underwent 18F-FDG-PET/CT in addition to CIM. RECIST criteria and visual analysis of 18F-FDG uptake were used for assessment of response. The standard of reference was determined by an interdisciplinary tumor board on the basis of imaging material, histopathology, and follow-up data (median = 5 years). RESULTS: 18F-FDG-PET/CT sensitivity was superior to that of CIM for determination of lymph node involvement (100 vs. 75%) and detection of metastases (100 vs. 66%). 18F-FDG-PET/CT results changed therapeutic management in 13% of cases. After three courses of chemotherapy 18F-FDG-PET/CT was able to detect 92% of objective responses compared with 84% by CIM. The rate of complete response was 69% with 18F-FDG-PET/CT compared with 8% with CIM. CONCLUSION: This study confirms that 18F-FDG-PET/CT reveals important additional information at initial staging of pediatric RMS, which suggests a superior prognostic value of 18F-FDG-PET/CT in early response to chemotherapy assessment.

Magnetic resonance imaging versus endoscopic ultrasonography for the detection of pancreatic tumours in multiple endocrine neoplasia type 1.

OBJECTIVE: In multiple endocrine neoplasia type 1, the main risk factor for metastases is pancreatic tumour size. We and others recommend limiting surgery to non-functioning pancreatic tumors ≥20 mm or growing, based on their size measured with endoscopic ultrasonography. Because endoscopic ultrasonography is invasive, we compared endoscopic ultrasonography (EUS) to non-invasive magnetic resonance imaging (MRI) for the detection of pancreatic tumours ≥10 mm in multiple endocrine neoplasia type 1 patients. METHODS: A prospective study was performed in nine participating centres; 90 patients with multiple endocrine neoplasia type 1 underwent EUS and MRI with gadolinium infusion. Gastroenterologists and radiologists were blinded to the results, magnetic resonance images were reviewed centrally. RESULTS: EUS detected 86 tumours ≥10 mm, and 48 (53.3%) patients had at least one tumour ≥10 mm. MRI detected 67 tumours ≥10 mm, and 46 (51.1%) patients had at least one tumour ≥10 mm. EUS and MRI agreement was moderate for detection of tumours ≥10 mm (Kappa coefficient=0.49), and for selection of patients with tumours ≥10 mm (Kappa coefficient=0.55). EUS and MRI missed 11/24 and 4/24 lesions ≥20 mm, respectively. EUS failed to identify 9/57 (15.7%) patients with pancreatic tumours ≥10 mm, and MRI failed to identify 11/57 (19.3%) patients with pancreatic tumours ≥10 mm. CONCLUSIONS: EUS and MRI are complementary and should be performed at initial evaluation in multiple endocrine neoplasia type 1 patients. Whether follow-up should be based on either technique or both, requires further evaluation.

18F-FDG PET/CT in the characterization and surgical decision concerning adrenal masses: a prospective multicentre evaluation.

PURPOSE: This prospective multicentre study assesses the usefulness of FDG PET/CT in characterizing and making the therapeutic decision concerning adrenal tumours that are suspicious or indeterminate in nature after conventional examinations (CE). METHODS: Seventy-eight patients (37 men, 41 women, 81 adrenal lesions) underwent FDG PET/CT after CE including CT scan, biological tests and optionally (131)I-metaiodobenzylguanidine (MIBG) and/or (131)I-norcholesterol scans. FDG adrenal uptake exceeding that of the liver was considered positive. PET results were not decisive. Surgery was discussed when at least one of the following criteria was found during CE: size >3 cm, spontaneous attenuation value >10 HU, heterogeneous aspect, abnormal MIBG or norcholesterol scan or hormonal hypersecretion. RESULTS: Following the gold standard (histology analysis or >or=9 months follow-up), 49 lesions potentially qualified for surgery (malignant = 27, benign secreting = 22) and 32 benign non-secreting lesions did not. PET was negative in 97% of non-surgical lesions and positive in 73% of potentially surgical ones which included all the malignant lesions, except 3 renal cell metastases, and 12 of 22 benign secreting lesions. The negative predictive value for malignancy was 93% (41/44) and positive predictive value for detecting surgical lesions was 97% (36/37). A high FDG uptake (maximum standardized uptake value >or= 10) was highly predictive of malignancy. CONCLUSION: Adrenal FDG uptake is a good indicator of malignancy and/or of secreting lesions and should lead one to discuss surgery. If there is no prior history of poorly FDG-avid cancer, the absence of FDG uptake should avoid unnecessary removal of benign adrenal lesions.

A corticotroph pituitary adenoma as the initial presentation of familial glucocorticoid deficiency.

UNLABELLED: CONTEXT; Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive ACTH-resistance syndrome characterized by glucocorticoid deficiency in the absence of mineralocorticoid deficiency. Here, we report the case of a young woman with a corticotroph pituitary adenoma as the initial presentation of FGD. CASE REPORT: A 15-year-old girl was referred to our institution for a 16 mm pituitary adenoma associated with glucocorticoid deficiency. Clinical and biological features were evocative of FGD. DNA sequencing did not identify mutations in either the melanocortin 2 receptor (MC2R) or the MC2R accessory protein genes, indicating type 3 FGD. Despite adequate glucocorticoid replacement, plasma ACTH levels remained increased and pituitary magnetic resonance imaging (MRI) showed a progression of the tumour size resulting in optic chiasm compression with intra-tumoural haemorrhaging. When the patient was 26 years old, it was decided that she would undergo transsphenoidal surgery. The histomorphological analysis identified a well-individualized pituitary adenoma immunoreactive for ACTH. The proband's sister also exhibited type 3 FGD associated with pituitary hyperplasia upon MRI. CONCLUSION: This case highlights the relationship between FGD and hyperplasia of ACTH-producing cells, potentially leading to histologically proven pituitary corticotroph adenomas. This observation raises the question of the pituitary MRI's significance in the follow-up of FGD.

[Abdominal aortic involvement in active giant cell (temporal) arteritis: a study of 20 patients by Doppler ultrasonography and computed tomographic angiography]. / Fréquence de l'atteinte de l'aorte abdominale au diagnostic de maladie de Horton : étude de 20 patients par échographie-Doppler et angiotomodensitométrie.

OBJECTIVE: This study used Doppler ultrasonography and computed tomographic angiography (CTA) to assess the prevalence of abdominal aortic lesions that suggested abdominal aortitis at diagnosis of giant-cell or temporal arteritis (GCA). We also evaluated the contribution of these 2 techniques to diagnosis. METHODS: This single-center study included patients admitted to the internal medicine department of the Nantes (France) University Hospital, between May 1999 and May 2002 at the time of their diagnosis with biopsy-proven GCA. In the 8 weeks after diagnosis, patients underwent a thorough workup, including the collection of clinical and laboratory data. Imaging tests for each patient included Doppler ultrasonography and a CTA scan of the abdominal aorta, looking for aneurysms, ectasia, and thickening of the aortic wall. RESULTS: This study included 20 patients (17 women, mean age 73.9+/-7.2 years, mean CRP=116+/-75.9mg/L). Doppler ultrasonography suggested aortitis in 8 cases (40%): 7 patients (35%) had a hypoechoic halo, 3 (15%) a small aneurysm (diameter < 30mm), and 2 (10%) both. CTA scans of the aorta showed aortitis in 5 cases (25%), all with abnormal thickening of the aortic wall. CTA did not identify any aneurysms. Overall, abdominal aortitis was suspected in 10 patients (50%). CONCLUSION: At the time of GCA diagnosis, both Doppler ultrasonography and CTA can detect morphological abnormalities of the abdominal aorta. Here they suggested asymptomatic abdominal aortitis in half the patients. Doppler ultrasonography appears more effective for detecting aortic aneurysms, while CTA seems helpful for the diagnosis of parietal thickening. The risk factors associated with abdominal aortitis in GCA remain to be identified.

Aortic involvement in recent-onset giant cell (temporal) arteritis: a case-control prospective study using helical aortic computed tomodensitometric scan.

OBJECTIVE: The prevalence of the involvement of large vessels in giant cell arteritis (GCA) is 3-13%. Aortitis is the most serious complication of GCA. Computed tomodensitometric (CT) scan allows analysis of both the aortic wall and endoluminal part of the aorta. Therefore, we conducted a study using CT scan to analyze aortic abnormalities in patients with recent-onset GCA. METHODS: This prospective controlled study compared patients with biopsy-proven GCA with a matched control group based on sex, age, and cardiovascular risk factors. During the 4-week period following diagnosis of GCA, patients underwent an aortic CT scan. The aortic imaging results were blindly compared between both groups. RESULTS: From January 5, 1998 to January 11, 1999, 22 patients and 22 controls were screened by CT scan for aortic involvement. Thickening of the aortic wall was more frequent among patients than controls (45.4% versus 13.6%; P = 0.02). Aortic thickening (mean 3.3 mm) was located on the ascending part of the thoracic aorta in 22.7% of the patients, with no evidence of thickening in the controls (P = 0.05). Thickening of the abdominal aortic wall was noted in 27.3% of the patients and none of the controls (P = 0.02). CONCLUSION: This study suggests that inflammatory aortic thickening, detected by CT scan, occurs frequently at the time of diagnosis of GCA, and that this condition predominantly occurs on the ascending part of the aorta.

Investigation of FDG-PET/CT imaging to guide biopsies in the detection of histological transformation of indolent lymphoma.

Positron emission tomography using 18F-fluorodeoxyglucose (FDG-PET) has been successfully evaluated in the management of non-Hodgkin's lymphoma (NHL).1-3 Histological transformation (HT) of indolent lymphoma is a dramatic event that occurs in 5-10% of the patients and carries a dismal prognosis.4,5 Previous studies prove that indolent lymphoma entities show a lower FDG uptake when compared with aggressive lymphomas.6-8 We therefore postulated that FDG-PET/CT identifies aggressive transformation sites and can guide biopsies.

Evaluation of response to fractionated radioimmunotherapy with 90Y-epratuzumab in non-Hodgkin's lymphoma by 18F-fluorodeoxyglucose positron emission tomography.

BACKGROUND: The study aimed to evaluate FDG-PET imaging for early prediction of response to radioimmunotherapy in patients with non-Hodgkin's lymphoma. DESIGN AND METHODS: Twenty-seven patients from a large ongoing, multicenter, phase I/II trial of fractionated radioimmunotherapy using anti-CD22 (90)Y-epratuzumab underwent FDG-PET imaging. They also underwent assessment by conventional diagnostic methods that included chemotherapy at baseline and six weeks post-radioimmunotherapy, and every three months until progression. Responses evaluated from conventional methods were classified using International Workshop Response Criteria as complete response, unconfirmed CR, partial response, stable disease, or progression of disease. FDG-PET images were evaluated visually and were classified as complete response, partial response or progression of disease. The gold standard was histology and follow-up. RESULTS: A total of 81 paired imaging studies were obtained post-radioimmunotherapy (including 3 patients after retreatment) and evaluated as complete response (n=34), partial response (n=24) or progression of disease (n=23) by FDG-PET, and complete response (n=12), unconfirmed complete response (n=31), partial response (n=15), stable disease (n=8) or progression of disease (n=15) by conventional methods. Of the 31 responses evaluated as unconfirmed complete response by conventional methods, 20 (65%) were classified as negative for disease (complete response) by PET while the other 11 (35%) were positive for disease (7 partial response and 4 progression of disease). Among 22 assessable PET images acquired at six weeks post-radioimmunotherapy, the mean time-to-progression was 15.6 months when PET was negative for disease (complete response), compared with 5.4 months when PET was positive (partial response or progression of disease) (p=0.008). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET six weeks after radioimmunotherapy were 86%, 63%, 80%, 71% and 77% respectively, compared with 36%, 87%, 83%, 44% and 55% respectively using conventional methods. CONCLUSIONS: A positive assessment of disease by PET acquired six weeks after radioimmunotherapy corresponded with a shorter time to progression.

Experimental and clinical radiofrequency ablation: proposal for standardized description of coagulation size and geometry.

BACKGROUND: Radiofrequency (RF) ablation is used to obtain local control of unresectable tumors in liver, kidney, prostate, and other organs. Accurate data on expected size and geometry of coagulation zones are essential for physicians to prevent collateral damage and local tumor recurrence. The aim of this study was to develop a standardized terminology to describe the size and geometry of these zones for experimental and clinical RF. METHODS: In a first step, the essential geometric parameters to accurately describe the coagulation zones and the spatial relationship between the coagulation zones and the electrodes were defined. In a second step, standard terms were assigned to each parameter. RESULTS: The proposed terms for single-electrode RF ablation include axial diameter, front margin, coagulation center, maximal and minimal radius, maximal and minimal transverse diameter, ellipticity index, and regularity index. In addition a subjective description of the general shape and regularity is recommended. CONCLUSIONS: Adoption of the proposed standardized description method may help to fill in the many gaps in our current knowledge of the size and geometry of RF coagulation zones.

Electrodes and multiple electrode systems for radio frequency ablation: a proposal for updated terminology.

OBJECTIVE: Research on technology for soft tissue radio frequency (RF) ablation is ever advancing. A recent proposal to standardize terminology of RF electrodes only deals with the most frequently used commercial electrodes. The aim of this study was to develop a logical, versatile, and unequivocal terminology to describe present and future RF electrodes and multiple electrode systems. MATERIALS AND METHODS: We have carried out a PubMed search for the period from January 1st 1990 to July 1st 2004 in seven languages and contacted the six major companies that produce commercial RF electrodes for use in the liver. In a first step, names have been defined for the five existing basic designs of single-shaft electrode. These names had to be unequivocal, descriptive of the electrode's main working principle and as short as possible. In a second step, these basic names have been used as building blocks to describe the single-shaft electrodes in combination designs. In a third step, using the same principles, a logical terminology has been developed for multiple electrode systems, defined as the combined use of more than one single-shaft RF electrode. RESULTS: Five basic electrode designs were identified and defined: plain, cooled, expandable, wet, and bipolar electrodes. Combination designs included cooled-wet, expandable-wet, bipolar-wet, bipolar-cooled, bipolar-expandable, and bipolar-cooled-wet electrodes. Multiple electrode systems could be characterized by describing several features: the number of electrodes that were used (dual, triple, etc.), the electric mode (monopolar or bipolar), the activation mode (consecutive, simultaneous or switching), the site of the inserted electrodes (monofocal or multifocal), and the type of single-shaft electrodes that were used. CONCLUSION: In this terminology, the naming ofthe basic electrode designs has been based on objective criteria. The short and unequivocal names of the basic designs can easily be combined to describe current and future combination electrodes. This terminology provides an exact and complete description of the versatile novel multiple electrode systems.

Electrodes and multiple electrode systems for radiofrequency ablation: a proposal for updated terminology.

Research on technology for soft tissue radiofrequency (RF) ablation is ever advancing. A recent proposal to standardise terminology of RF electrodes only deals with the most frequently used commercial electrodes. The aim of this study was to develop a logical, versatile and unequivocal terminology to describe present and future RF electrodes and multiple electrode systems. We have carried out a PubMed search for the period from January 1 1990 to July 1 2004 in seven languages and contacted the six major companies that produce commercial RF electrodes for use in clinic. In a first step, names have been defined for the five existing basic designs of single-shaft electrode. These names had to be unequivocal, descriptive of the electrode's main working principle and as short as possible. In a second step, these basic names have been used as building blocks to describe the single-shaft electrodes in combination designs. In a third step, using the same principles, a logical terminology has been developed for multiple electrode systems, defined as the combined use of more than one single-shaft RF electrode. Five basic electrode designs were identified and defined: plain, cooled, expandable, wet and bipolar electrodes. Combination designs included cooled-wet, expandable-wet, bipolar-wet, bipolar-cooled, bipolar-expandable and bipolar-cooled-wet electrodes. Multiple electrode systems could be characterised by describing several features: the number of electrodes that were used (dual, triple, ...), the electric mode (monopolar or bipolar), the activation mode (consecutive, simultaneous or switching), the site of the inserted electrodes (monofocal or multifocal), and the type of single shaft electrodes that were used. In this terminology, the naming of the basic electrode designs has been based on objective criteria. The short and unequivocal names of the basic designs can easily be combined to describe current and future combination electrodes. This terminology provides an exact and complete description of the versatile novel multiple electrode systems.

Computed tomography scanning of the sciatic nerve posterior to the femur: Practical implications for the lateral midfemoral block.

BACKGROUND AND OBJECTIVES: Using computed tomography (CT) scans of the thighs, this study addresses sciatic nerve anatomy at the injection site for the lateral midfemoral sciatic nerve block. It addresses the recommendation of neutral leg rotation to facilitate block placement. METHOD: This prospective and descriptive study involves 21 patients scheduled for CT scan imaging of the lower limbs. Transverse CT scans were analyzed at 20, 25, and 30 cm distal to the upper border of the greater trochanter (GT) of the femur with the knee externally rotated by 30 degrees. The angle alpha formed by the broad axis of the sciatic nerve and the coronal plane, skin-to-nerve distance, great vessel-to-nerve distance, division of the sciatic nerve, and widths of the perineural space were assessed. Values are expressed as mean +/- SD. RESULTS: At 20, 25, and 30 cm distal to the GT, the alpha angle was 50 degrees +/- 14 degrees, 55 degrees +/- 13 degrees, and 56 degrees +/- 26 degrees, respectively. This angle increased to nearly 90 degrees when the knee was rotated to a neutral position. The skin-to-nerve distance was 5.9 +/- 1.1 cm, 5.4 +/- 0.9 cm, and 5.7 +/- 1.1 cm. The section width of the perineural space was 1.8 +/- 0.9 cm(2), 3.9 +/- 2 cm(2), and 5.6 +/- 2.4 cm(2). The sciatic nerve was divided in 27% of subjects at 20 cm and in 90% at 30 cm distal. CONCLUSION: The characteristics of sciatic nerve anatomy described in this study support observations and clinical recommendations regarding lateral midfemoral sciatic nerve block.

Radio-frequency tissue ablation of the liver: in vivo and ex vivo experiments with four different systems.

The aim of this study was to test the efficacy of four different radio-frequency ablation (RFA) systems in normal hepatic parenchyma in large animals. The RFA was applied to pig livers in vivo and to calf livers ex vivo using the Radionics cluster needle, RITA starburst XL needle, Radiotherapeutics Le Veen 4.0 needle, and the Berchtold 14-G saline-perfused 15-mm active-tip needle based on constructor specifications. The volume of tissue coagulation from RF was calculated from measurements of the vertical diameter (Dv) and transverse diameter (Dt). Lesion shape was characterized using the ratio between Dt/Dv. Radiotherapeutics and RITA produced in vivo lesion volume of 42+/-10, 39+/-4 cm3 with a reproducible spherical shape (Dt/Dv of 1.01+/-0.16 and 0.97+/-0.1, respectively). Radionics produced in vivo RF lesions volume of 29+/-11 cm3) with an ovoid shape (Dt/Dv 0.88+/-0.09). The RF lesions with the Berchtold device could not be assessed in vivo as 5 of 8 animals died during treatment. Ex vivo RF lesions had similar volumes with each system; however, the Radiotherapeutics device produced more reproducible shaped lesions than the other systems. In our experimental study, we found no difference between expandable needle systems in vivo. Cooled needles produced slightly smaller and ovoid shape in vivo lesions.

Superior mesenteric artery dissection: case report.

Spontaneous dissections of the superior mesenteric artery are exceptional events because only 26 reports have been published. We present a new case, revealed with an acute abdominal syndrome. Computed tomographic angiography and arteriography allowed a rapid diagnosis and urgent surgical intervention. Progress in imagery makes diagnosis and follow-up examination easier. Surgery is indicated for acute symptomatic forms with suspicion of mesenteric ischemia. In the other cases, a simple follow-up examination may be appropriate.