Contrast-enhanced CT and MR imaging of renal vessels.

In the evaluation of renal vessels, the accepted diagnostic gold standard digital subtraction angiography is now being challenged by state of the art CT and MR imaging. Currently in many centers, cross-sectional imaging modalities are being used as a first line diagnostic tool to evaluate arterial and venous system of the kidneys and conventional angiography has been reserved only for therapeutic intervention. CT and MR imaging display not only the lumen of the vessel as in conventional angiography, but also allow the visualization of the vessel wall, renal parenchyma, collecting system, and other adjacent soft tissue structures. Therefore, CT and MRI have each become a one-stop shop for a thorough evaluation of kidneys. In this pictorial essay, we reviewed normal anatomical variants and wide range of pathologies involving renal arteries and veins with illustrated contrast-enhanced CT and MR imaging samples

Incidence and clinical sequelae of portal and hepatic venous thrombosis following percutaneous cryoablation of liver tumors.

PURPOSE: To assess the incidence and sequelae of portal and hepatic venous thrombosis after percutaneous cryoablation of hepatic tumors. METHODS: From November 1998 through December 2010, 223 hepatic tumors were cryoablated during 170 ablation procedures in 135 patients. 24-h post-procedure MR images were reviewed retrospectively by two abdominal radiologists in consensus to identify tumor ablations that developed one or more new portal or hepatic venous thromboses in or outside the ablation zone. On follow-up MRI and CT examinations the outcomes of thromboses were classified as resolved, partially recanalized, persistent, or propagated. RESULTS: Venous thrombosis developed in association with 54 (24%) of 223 tumor ablations treated during 53 (31%) ablation procedures in 39 (28.8%) patients (15 women, 24 men; age range 40-82 years, mean 59 years). Of these 54 thromboses, 49 (91%) were located in portal vein branches, four (7%) in both portal and hepatic vein branches, and one (2%) in a hepatic vein branch. Thrombosed veins were outside but abutted the ablation zone in 36 (66.7%), and within it in 18 (33.3%). On follow-up imaging (n = 49), thrombi resolved in 29 (59%), partially recanalized in two (4%), persisted in 18 (37%) and propagated from sub-segmental or segmental branches to the left or right portal branches in five (10%). No thrombus propagated to the main portal vein or inferior vena cava. CONCLUSION: Portal and hepatic vein branch thromboses are common in small branches following percutaneous cryoablation of hepatic tumors and most resolve spontaneously without sequelae

Brief communication: Pituitary volume and function in competing and retired male boxers

Background: Pituitary consequences of chronic head trauma in boxing have not been investigated in detail

Structural connectivity–based segmentation of the thalamus and prediction of tremor improvement following thalamic deep brain stimulation of the ventral intermediate nucleus

Objectives: Traditional targeting methods for thalamic deep brain stimulation (DBS) performed to address tremor have predominantly relied on indirect atlas-based methods that focus on the ventral intermediate nucleus despite known variability in thalamic functional anatomy. Improvements in preoperative targeting may help maximize outcomes and reduce thalamic DBS–related complications. In this study, we evaluated the ability of thalamic parcellation with structural connectivity–based segmentation (SCBS) to predict tremor improvement following thalamic DBS. Methods: In this retrospective analysis of 40 patients with essential tremor, hard segmentation of the thalamus was performed by using probabilistic tractography to assess structural connectivity to 7 cortical targets. The volume of tissue activated (VTA) was modeled in each patient on the basis of the DBS settings. The volume of overlap between the VTA and the 7 thalamic segments was determined and correlated with changes in preoperative and postoperative Fahn-Tolosa-Marin Tremor Rating Scale (TRS) scores by using multivariable linear regression models. Results: A significant association was observed between greater VTA in the supplementary motor area (SMA) and premotor cortex (PMC) thalamic segment and greater improvement in TRS score when considering both the raw change (P = .001) and percentage change (P = .011). In contrast, no association was observed between change in TRS score and VTA in the primary motor cortex thalamic segment (P ≥ .19). Conclusions: Our data suggest that greater VTA in the thalamic SMA/PMC segment during thalamic DBS was associated with significant improvement in TRS score in patients with tremor. These findings support the potential role of thalamic SCBS as an independent predictor of tremor improvement in patients who receive thalamic DBS. Keywords: Brain connectomics, Deep brain stimulation, Diffusion tensor imaging, Essential tremor, Ventral intermediate nucleus, Ventral thalamic nucle

Safety of Intradiaphragmatic Delivery of Adeno-Associated Virus-Mediated Alpha-Glucosidase (rAAV1-CMV- hGAA

A first-in-human trial of diaphragmatic gene therapy (AAV1-CMV-GAA) to treat respiratory and neural dysfunction in early-onset Pompe disease was conducted. The primary objective of this study was to assess the safety of rAAV1-CMV-hGAA vector delivered to the diaphragm muscle of Pompe disease subjects with ventilatory insufficiency. Safety was assessed by measurement of change in serum chemistries and hematology, urinalysis, and immune response to GAA and AAV, as well as change in level of health. The data demonstrate that the AAV treatment was safe and there were no adverse events related to the study agent. Adverse events related to the study procedure were observed in subjects with lower baseline neuromuscular function. All adverse events were resolved before the end of the study, except for one severe adverse event determined not to be related to either the study agent or the study procedure. In addition, an anti-capsid and anti-transgene antibody response was observed in all subjects who received rAAV1-CMV-hGAA, except for subjects who received concomitant immunomodulation to manage reaction to enzyme replacement therapy, as per their standard of care. This observation is significant for future gene therapy studies and serves to establish a clinically relevant approach to blocking immune responses to both the AAV capsid protein and transgene product

Safety of intradiaphragmatic delivery of adeno-associated virus-mediated alpha-glucosidase (rAAV1-CMV-hGAA) gene therapy in children affected by Pompe disease

A first-in-human trial of diaphragmatic gene therapy (AAV1-CMV-GAA) to treat respiratory and neural dysfunction in early-onset Pompe disease was conducted. The primary objective of this study was to assess the safety of rAAV1-CMV-hGAA vector delivered to the diaphragm muscle of Pompe disease subjects with ventilatory insufficiency. Safety was assessed by measurement of change in serum chemistries and hematology, urinalysis, and immune response to GAA and AAV, as well as change in level of health. The data demonstrate that the AAV treatment was safe and there were no adverse events related to the study agent. Adverse events related to the study procedure were observed in subjects with lower baseline neuromuscular function. All adverse events were resolved before the end of the study, except for one severe adverse event determined not to be related to either the study agent or the study procedure. In addition, an anti-capsid and anti-transgene antibody response was observed in all subjects who received rAAV1-CMV-hGAA, except for subjects who received concomitant immunomodulation to manage reaction to enzyme replacement therapy, as per their standard of care. This observation is significant for future gene therapy studies and serves to establish a clinically relevant approach to blocking immune responses to both the AAV capsid protein and transgene product

Anatomical study of axis for odontoid screw thickness, length, and angle

Anterior odontoid screw fixation is a safe and effective method for treatment of odontoid fractures. The screw treads should fit into the odontoid medulla, should pass the fracture line, and should pull fractured odontoid tip against body of axis in order to achieve optimum screw placement and treatment. This study has demonstrated optimal anterior odontoid screw thickness, length, and optimal angle for safe and strong anterior odontoid screw placement. Dry bone axis vertebrae were evaluated by direct measurements, X-ray measurements, and computerized tomography (CT) measurements. The screw thickness (inner diameter of the odontoid) was measured as well as screw length (distance between anterior-inferior point body of axis and tip of odontoid), and screw angle (the angle between basis of axis and tip of odontoid). The inner diameter of odontoid bone was measured as 6.5 ± 1.9 mm, the screw length was 37.6 ± 3.3 mm, and the screw angle was 62.4 ± 4.7 on CT. There was no statistical difference between X-ray and CT in the measurements of screw thickness and angle. X-ray and CT measurements are both safe methods to determine the inner odontoid diameter and angle preoperatively. Screw length should be measured on CT only. To provide safe and strong anterior odontoid screw fixation, screw thickness, length, and angle should be known preoperatively, and these can be measured on X-ray and CT