Left ventricular summit premature ventricular contractions treated by venous ethanol infusion: Scar assessment by magnetic resonance imaging.

Left ventricular (LV) summit premature ventricular contractions (PVCs) are often unresponsive to radiofrequency (RF) ablation. Retrograde venous ethanol infusion (RVEI) can be a valuable alternative in this scenario. A 43-year-old woman without structural heart disease presented with LV summit PVCs unresponsive to RF ablation because of their deep-seated origin. Unipolar pace mapping performed through a wire inserted into a branch of the distal great cardiac vein (GCV) demonstrated 12/12 concordance with the clinical PVCs thus indicating close proximity to PVCs' origin. RVEI abolished the PVCs without complications. Subsequently, magnetic resonance imaging (MRI) evidenced an intramural myocardial scar produced by ethanol ablation. In conclusion, RVEI effectively and safely treated PVC arising from a deep site in the LVS. The scar provoked by chemical damage was well characterized by MRI imaging.

Predictive value for paravalvular regurgitation of 3-dimensional anatomic aortic annulus shape assessed by multidetector computed tomography post-transcatheter aortic valve replacement.

AIMS: Paravalvular regurgitation (PAR) remains a serious complication after trans-catheter aortic valve replacement (TAVR). Multidetector computed tomography (MDCT)-based measurements of the aortic basal virtual ring (BVR) are considered the gold standard for trans-catheter heart valve (THV) sizing. However, the real anatomic aortic annulus is a 3-dimensional structure. To compare measurement of 3D-anatomic annulus with BVR and secondly to assess independent predictive parameters that may impact on PAR > mild post-TAVR (PAR+). METHODS AND RESULTS: MDCT was performed in 92 patients before and after balloon or self-expandable TAVR. 3D-AA shape was obtained point by point following the semilunar attachment of aortic cusps (Osirix-MD 2.8.2). 3D-oversizing index (nominal THV area/3D-AA area - 1) × 100 was calculated as well as 2D-oversizing index using BVR area instead of 3D-AA area. PAR was quantified by planimetry of vena-contracta in transthoracic echocardiography short-axis view. Valvular calcium volume and annulus calcium area were measured using Hounsfield-intensity detection. ROC curves and logistic regression for PAR(+) were performed. BVR area overall underestimated 3D-AA area by 19 ± 9% (P< 0.001), significantly more in PAR(+) (26 ± 7%) vs. PAR(-) (17 ± 9%, P< 0.001). 3D-oversizing index had greater predictive value for PAR > mild (area under the curve, AUC = 0.88) with 88% sensibility (Se) and 82% specificity (Sp) than 2D-oversizing index (AUC = 0.68) with 84% Se, but only 41% Sp (P< 0.0001). Also, valvular calcium volume and annulus calcium area were less predictors for PAR > mild (AUC = 0.68, respectively, AUC = 0.75, P = 0.002). In a multivariate analysis, only 3D-oversizing index showed an independent value for PAR > mild (OR = 18.6, P< 0.001). CONCLUSION: Basal ring CT measurement significantly underestimated the real 3D-anatomic aortic annulus area. This may impact on THV sizing and PAR incidence. 3D-oversizing index is the most predictive factor for PAR > mild.

Pelvic magnetic resonance imaging in the ewe: a model for experimental gynecologic research.

AIM: Our goal was to demonstrate the feasibility of pelvic magnetic resonance imaging (MRI) in the ewe. MATERIAL AND METHODS: Two ewes underwent a pelvic 3 Tesla MRI scan, under light anesthesia, with T2-weighted fast spin-echo images and T1-weighted spoiled gradient-echo images. Multiplan T1 weighted images were also obtained after the intravenous injection of a contrast product. One ewe was anestrous and the other one had undergone ovarian stimulation. RESULTS: No incident occurred during the examination. Both the uterus (with two horns) and the ovaries were identified. The intensity of the endometrial, myometrial and ovarian signals was similar to that encountered in women. The uterus and ovaries could be enhanced in both cases. Pelvic vasculature was also studied. In the case of hormonal stimulation, the endometrium was thicker, follicular growth was identified and enhancement seemed greater. CONCLUSION: MRI in the ewe is feasible and could be helpful in experimental gynecologic research, especially in uterus transplantation.

Tumoral hypoxia in osteosarcoma in rats: preliminary study of blood oxygenation level-dependent functional MRI and 18F-misonidazole PET/CT with diffusion-weighted MRI correlation.

OBJECTIVE: The prognostic implication of oxygen concentration as a factor in recurrence of solid tumors has been proved. Hypoxic osteosarcoma, imaged with (18)F-misonidazole PET/CT, is the most frequent primary malignant bone tumor. The aim of our study was to determine the role of blood oxygenation level-dependent (BOLD) functional MRI in an osteosarcoma rodent model by comparison of oxygenation levels in BOLD functional MRI and (18)F-misonidazole PET/CT and correlating the findings with those of diffusion-weighted MRI (DWI). MATERIALS AND METHODS: After validation of a hypoxic rodent model, 3-T MRI of osteosarcoma grafted in eight rats, including anatomic, DWI, and BOLD sequences in ambient air and after 2 and 3 minutes of impregnation of 8 L/min of oxygen, was performed on days 10, 17, and 24 after tumor grafting. (18)F-misonidazole PET/CT was performed on day 26, and the rats were sacrificed on day 27 for specific screening of markers of hypoxia. We measured BOLD signal intensity in tumors and normal tissue and compared these results with those on apparent diffusion coefficient maps and (18)F-misonidazole uptake according to maximum standardized uptake value ratio between tumor and healthy spongy bone. RESULTS: Hypoxia was confirmed by histologic study in all cases. We found a significant difference (day 17, p = 0.0038; day 24, p = 0.0051) in the decrease in signal intensity of hypoxic tumor in the presence of oxygen compared with ambient air without relation to duration of oxygen impregnation (p = 0.06). We found a significant correlation (p = 0.003) between BOLD signal intensity and maximum standardized uptake value at (18)F-misonidazole PET/CT. We found no correlation between the decrease in BOLD signal intensity and apparent diffusion coefficient (p = 0.07). CONCLUSION: BOLD functional MRI may be a promising tool for noninvasive functional imaging of bone tumors, but additional developments are necessary to permit its use in clinical practice.

Lymph node assessment with (18)F-FDG-PET and MRI in uterine cervical cancer.

BACKGROUND: To assess pelvic (P) and/or paraaortic (PA) lymph node (LN) involvement in patients with primary stage IA-IVA cervical cancer, (18)F-fluorodeoxyglucose (FDG)-PET, and MRI were compared with histological results. MATERIALS AND METHODS: Forty patients were prospectively evaluated. Twenty-eight patients underwent radio-chemotherapy (RT-CT) after initial staging and lymph node dissection (LND). RESULTS: PLN metastases were present in 6/31 patients. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) and accuracy in detecting PLN metastases were 67%, 84%, 50%, 91% and 81%, with MRI, and 33%, 92%, 50%, 85% and 81%, with FDG-PET. PALN metastases were present in 5/27 patients. Sensitivity, specificity, PPV, NPV and accuracy were 60%, 73%, 33%, 89% and 70% with MRI and 100%, 77%, 50%, 100% and 81% with FDG-PET in detecting PALN metastasis. CONCLUSION: FDG-PET is less accurate than MRI for PLN, but more accurate for PALN; FDG-PET cannot replace PA surgical procedures, but could guide them.

The mamillothalamic tract is a good landmark for the anterior border of the subthalamic nucleus on axial MR images.

BACKGROUND: Identification of the subthalamic nucleus (STN) on MR images is difficult, and the use of external landmarks could be of interest for STN targeting in deep brain stimulation (DBS). OBJECTIVES: Our aim was to explore the relationship between the anteroposterior coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN on axial MR images. PATIENTS AND METHODS: The brains of 16 healthy volunteers were imaged on a 3T MR system. Four millimeters under the anterior-posterior commissure plane, we noted the y coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN. RESULTS: The coordinates were y(STN) = 14.7 ± 1.23 mm and y(Tmth) = 14.3 ± 1.13 mm from the posterior commissure for the STN and the mamillothalamic tract, respectively. The mean difference was 0.4 mm (range 0-1 mm). Pearson's coefficient was 0.97 (p < 0.01). CONCLUSION: We observed a strong correlation between the anteroposterior coordinates of the mamillothalamic tract and the anterior border of the STN (which is located between 0 and 1 mm in front of the mamillothalamic tract). The mamillothalamic tract could be a good anterior landmark for STN targeting. It could also be tested for target determination in DBS for severe obsessive-compulsive disorder.

Uterine junctional zone at magnetic resonance imaging: a predictor of in vitro fertilization implantation failure.

AIM: To prospectively study the influence of the uterine junctional zone thickness measured on pelvic magnetic resonance imaging (MRI), on implantation rates during in vitro fertilization (IVF). METHODS: A prospective clinical-imaging study was conducted and included 152 female patients. Patients had a positive diagnosis of infertility and an indication for IVF. All patients had a pelvic MRI scan on a 1.5T magnet with T2-weighted sequences prior to IVF. The average junctional zone thickness value and the maximal junctional zone thickness values were measured. Implantation outcomes were correlated with junctional zone values and with infertility subtypes (endometriosis, tubal, dysovulation, male, unexplained). RESULTS: The mean number of embryo transfers per patient was 1.63, with a total pregnancy rate of 54%. Junctional zone thickness increase was significantly correlated with implantation failure at IVF: implantation failure rate was 95.8% for patients with an average junctional zone superior to 7 mm and a maximal junctional zone superior to 10 mm, versus 37.5% in other patient groups (P < 0.0001), independently from the cause of infertility or patients' age. CONCLUSION: In a group of infertile patients engaged in an IVF program, a pelvic MRI scan showing a thickened uterine junctional zone is a negative predictive factor for embryo implantation after IVF.

Fertility after embolization of the uterine arteries to treat obstetrical hemorrhage: a review of 53 cases.

OBJECTIVE: To study subsequent fertility of patients who underwent embolization of the uterine arteries to treat postpartum hemorrhage. DESIGN: Retrospective cohort study between January 2000 and June 2006 with two patient groups: exposed and nonexposed to embolization for postpartum hemorrhage. SETTING: Level 3 maternity unit. PATIENT(S): Fifty-three patients exposed to embolization and 106 nonexposed patients were included and paired according to several criteria: date of delivery, age, parity, whether the pregnancy was spontaneous or with fertility assistance, and mode of delivery. INTERVENTION(S): None. MAIN OUTCOMES MEASURE(S): Occurence of pregnancy. RESULT(S): Among patients exposed to embolization, 14 had been exposed to pregnancy and 12 had been pregnant. There was no statistically significant difference of occurrence of pregnancy between the nonembolized and embolized groups (P=.30). CONCLUSION(S): According to the results, it seems that embolization does not alter subsequent fertility. This study nevertheless suggests a trend toward fewer pregnancies in the embolization group and reports three severe complications in that group. This trend deserves to be explored by further studies with higher statistical power. However, even if it would be difficult to provide complete reassurance to patients who have undergone embolization, better information regarding their subsequent fertility and potential risks could relieve them of their worries regarding a new pregnancy.

[Imaging of the Alzheimer's disease: MRI and functional imaging]. / Imagerie de la maladie d'Alzheimer : IRM et imagerie fonctionnelle.

The MRI is often the initial exploration proposed to a patient presenting a confusion of memory. This examination has for purpose first to eliminate surgical differential diagnoses, such as a chronic hydrocephalus of the adult. It can then help in the differential diagnosis between the various insane syndromes, like Alzheimer's disease.

Transcranial puncture through the parietal and mastoid foramina for the treatment of dural fistulas. Report of four cases.

In this report the authors describe the endovascular treatment of dural arteriovenous fistulas (DAVFs) through transcranial puncture of the feeding arteries. Four patients had DAVFs that were fed by occipital arteries (OAs) that supplied blood to the intracranial meningeal arteries via the transcranial branches and coursed through the parietal and mastoid foramina. Due to the excessive tortuosity of the OA, conventional endovascular navigation had failed in all cases. Transcranial puncture of the meningeal feeding arteries was performed through the parietal or mastoid foramen, allowing navigation with a microcatheter until the level of the shunts. Complete cure of the DAVF was attained in all patients after injection of acrylic glue.

Quantitative assessment of pleural effusion in critically ill patients by means of ultrasonography.

OBJECTIVE: To assess the ability of ultrasonography to identify the presence and assess the volume of pleural effusion in the intensive care unit setting. DESIGN: Prospective descriptive clinical study. SETTING: Medical-surgical intensive care unit of a teaching hospital. PATIENTS: Initial study group (group I) consisted of 97 patients (mean [+/-SD] Simplified Acute Physiology Score II, 40 +/- 14) with clinically suspected pleural effusion. Fifty-one patients were mechanically ventilated and 55 patients underwent a unilateral or bilateral thoracentesis (58 procedures). All patients underwent supine chest radiography and pleural ultrasonography at bedside. The testing group (group II) consisted of 19 additional patients (17 under ventilation) who underwent thoracentesis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Maximal interpleural distance was measured at the base and apex of the pleural space, at both end-expiration and end-inspiration. In group I, interpleural distances were compared to actual volume of fluid in the subset of patients who underwent a complete thoracentesis (n = 49). Prediction of the volume of pleural effusion was subsequently tested prospectively in group II (25 complete thoracenteses). Portable chest radiography and pleural ultrasonography yielded discordant results for 47 patients (48%) in the diagnosis of pleural effusion. The expiratory interpleural distance measured at the thoracic base with ultrasonography was significantly correlated with the volume of fluid (p < .0001; coefficient of determination: right, 0.78; left, 0.51). A pleural effusion > or =800 mL was predicted when this distance was >45 mm (right) or >50 mm (left), with a sensitivity of 94% and 100% and a specificity of 76% and 67%, respectively. In group II, the mean bias between the predicted and observed volumes of pleural effusion determined by thoracentesis was 24 +/- 355 mL, and this decreased to 28 +/- 146 mL for the prediction of pleural effusion <1400 mL. CONCLUSIONS: Bedside ultrasonography is well suited for the quantitative assessment of unloculated pleural effusions in intensive care unit patients.

Embolization of rectal arteries: an alternative treatment for hemorrhagic shock induced by traumatic intrarectal hemorrhage.

Rectal injuries caused by foreign bodies or iatrogenic insertions may lead to severe complications whose therapeutic management remains controversial. At times, both the rapid identification and treatment of subsequent active rectal bleeding may be challenging, especially when endoscopy fails to locate and control the arterial hemorrhage. We present the first two successful cases of middle rectal artery embolization in patients presenting with sustained bleeding and hemorrhagic shock.

[MRI evaluation of primary chemotherapy response in breast cancer]. / Evaluation par IRM de la réponse à la chimiothérapie d'induction dans les cancers du sein.

The aim of this work was to evaluate the value of contrast enhanced MRI for determination of response to neoadjuvant chemotherapy (type FEC) in breast cancer according to two parameters: size of the enhancing tumor and the maximum relative enhancement curve (MRC) in the same tumor area. Twenty women with breast cancer (15 invasive ductal carcinomas and 5 invasive lobular carcinomas) T2 (n = 8) or T3 (n = 12) were evaluated by physical examination and MRI after a minimal of three courses of FEC and prior to surgery. Data from physical examination and imaging studies were compared to histopathological findings. Physical examination estimated correctly the residual tumor size in 45% of cases and MRI in 60% with 3 false negative cases. Among evaluated patients with MRI measurable residual tumor, tumor size was underestimated in 69% of the cases and overestimated in 31% of the cases. A MRC flattening was observed in 5 cases among the patients with a partial response or clinical stable disease correlated with a poor cellular density in the microscopic findings. MRI monitoring of chemotherapy response can be useful for guiding surgery. Therefore, underestimation of the residual tumor size and false negative rate are remaining problems.

Thrombotic complications of implanted central venous access devices: prospective evaluation.

Implanted venous access devices (IVAD) are routinely used in oncologic patients. Thrombotic complication is a source of morbidity. During one year 246 patients with different solid neoplastic diseases received IVAD for chemotherapy administration. Two hundred forty-nine IVAD were placed percutaneously or by surgical cutdown. IVAD were flushed immediately after implantation with 3-5 mL of heparinized saline (100 U/mL). No monthly flush was required. A prospective evaluation of thrombotic complications was realised. in event of catheter dysfunction and/or clinical symptoms of phlebitis, a catheter opacification and/or a Doppler ultrasonography were performed. Twenty-three catheter dysfunctions were noted, corresponding to 13 catheter occlusions. Twelve patients presented clinical symptoms of phlebitis. Eleven venous thrombosis were diagnosed in this group; 10 by echo-Doppler and one by scanography. A unvaried statistic analysis using Fisher's test was performed to detect risk factors. Two factors were identified: the position of catheter tip above T4 (p < 0.001) and mediastinal or cervical lymph nodes larger than 6 cm (p < 0.001). The first increased the risk of catheter occlusion and the second increased the risk of phlebitis.

[Duodenal bleeding revealing a renal cell carcinoma]. / Hémorragie digestive révélatrice d'un carcinome rénal à cellules claires.

The pancreas is an uncommon site of metastasis from renal cell carcinoma. The metastasis is generally diagnosed during the follow-up of patients who underwent nephrectomy for renal cell carcinoma. In our observation, duodenal bleeding led to the diagnosis of both pancreatic metastasis and renal carcinoma. The diagnosis of pancreatic metastasis should be suspected when a pancreatic mass is associated with past or synchronous renal carcinoma. The outcome after resection of pancreatic metastasis is better than after resection of pancreatic adenocarcinoma. Surgical resection of pancreatic metastasis should be considered when possible.