Techniques of adrenal venous sampling in patients with inferior vena cava or renal vein anomalies.

PURPOSE: To review the techniques and technical success rate of adrenal venous sampling (AVS) in patients with inferior vena cava (IVC) or renal vein anomalies. MATERIALS AND METHODS: The techniques and success rate of AVS in 15 patients with anomalies [8 with double IVC (dIVC), 3 with left IVC (ltIVC), 2 with retroaortic left renal vein (LRV), and 2 with circumaortic LRV] underwent AVS was retrospectively reviewed. RESULTS: Among 11 patients with IVC anomalies, the success rates for sampling the right and left adrenal veins (RAV and LAV) were 81.8 and 90.9%, respectively. In dIVC, the LAV was selected using the following four methods: approaching through the right IVC from the right femoral vein, flipping the LAV catheter tip in the LRV (n = 4) or the interiliac-communicating vein (n = 1), or through the ltIVC from the right (n = 1) or left (n = 2) femoral vein. Among the four patients with LRV anomalies, the success rate was 100% for each adrenal vein. CONCLUSION: AVS can be successfully performed in patients with anomalies. The key to technical success is understanding the venous anatomy based on pre-procedural CT images and choosing appropriate methods.

Image Fusion Guidance with Pre-procedural CT with Real-Time Fluoroscopy for Adrenal Venous Sampling.

PURPOSE: To assess the effectiveness of image fusion guidance (IF) with pre-procedural computed tomography (CT) with intraprocedural fluoroscopy for adrenal venous sampling (AVS). MATERIALS AND METHODS: AVS before and after ACTH stimulation including bilateral segmental sampling of effluent tributaries was performed in 62 patients with IF. A 3D volume rendering image, including adrenal glands and veins extracted from previously obtained contrast-enhanced CT images, was manually registered to the real-time X-ray fluoroscopy. The technical success rates, procedure time, radiation exposure, and volume of contrast medium used were compared with 49 patients who underwent AVS without IF. RESULTS: No significant differences in the technical success rates with and without IF were observed (98.4 vs. 91.8% for the right adrenal veins, p = 0.168, and 98.4 vs. 100% for the left adrenal veins, p = 1.000). The procedure time with IF was significantly shorter than that without IF (95.6 ± 18.8 vs. 108.4 ± 20.0 min, p = 0.001). The total dose-area product with IF was significantly lower than that without IF (43.1 ± 30.7 vs. 72.2 ± 45.3 Gy cm2, p < 0.001). The contrast medium volume used with IF was significantly lower than that without IF (54.6 ± 21.9 vs. 65.7 ± 27.6 mL, p = 0.020). CONCLUSIONS: Although the contribution to improving the technical success rates was small in our study, IF can effectively reduce procedure time, radiation exposure, and volume of contrast medium during AVS.

Quantitative accuracy of computed tomography perfusion under low-dose conditions, measured using a hollow-fiber phantom.

PURPOSE: The purpose of this study was to investigate the quantitative accuracy under low-dose conditions on computed tomography (CT) perfusion using a hollow-fiber phantom that had the theoretical absolute values of perfusion indices. MATERIALS AND METHODS: Our phantom comprised two components, i.e., a hollow-fiber hemodialyzer to pump the diluted contrast material and a surrounding syringe-shaped X-ray-absorbing body to simulate the absorption of X-rays by a brain and cranium. We performed CTP scans on the phantom under various dose conditions ranging from 20 to 140 mA using a 64-row CT scanner, measuring experimental cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) values using a deconvolution algorithm. RESULTS: The theoretical value of the CBV was within the 95% confidence interval of CBV values measured under 80 mA. The CBV measured under low-dose settings and all CBF values measured were smaller than the theoretically calculated ones, and all MTT values measured were larger. All measured values of the CBV, CBF, MTT, and TTP decreased with an increase in image noise under lower dose conditions. CONCLUSION: It is difficult to define a low-dose limit in clinical scan conditions because of the complex characteristics of perfusion indices.

Reduction of Radiation Exposure Using Dynamic Trace Digital Angiography and Spot Fluoroscopy During Adrenal Venous Sampling.

PURPOSE: To compare radiation exposure of adrenal venous sampling (AVS) using dynamic trace digital angiography (DTDA) and spot fluoroscopy with that using conventional methods. MATERIALS AND METHODS: AVS was performed in 11 patients using DTDA and spot fluoroscopy (Group A) and 11 patients using conventional digital subtraction angiography (DSA) with collimation (Group B). Radiation exposure and image quality of adrenal venography using a five-point scale were compared between the groups. RESULTS: The acquisition dose-area product (DAP) using DTDA and fluoro-DAP using spot fluoroscopy in Group A were lower than those using conventional DSA (5.3 ± 3.7 vs. 29.1 ± 20.1 Gy cm2, p < 0.001) and collimation (33.3 ± 22.9 vs. 59.1 ± 35.7 Gy cm2, p = 0.088) in Group B. The total DAP in Group A was significantly lower than that in Group B (38.6 ± 25.9 vs. 88.2 ± 53.6 Gy cm2, p = 0.006). The peak skin dose for patients and operator radiation exposure in Group A were significantly lower than those in Group B (403 ± 340 vs. 771 ± 416 mGy, p = 0.030, and 17.1 ± 14.8 vs. 36.6 ± 21.7 µSv, p = 0.013). The image quality of DTDA (4.4 ± 0.6) was significantly higher than that of digital angiography (3.8 ± 0.9, p = 0.011) and equivalent to that of DSA (4.3 ± 0.8, p = 0.651). CONCLUSIONS: Radiation exposure during AVS can be reduced by approximately half for both patients and operators by using DTDA and spot fluoroscopy without sacrificing image quality.

Technique and Theory of Hollow-fiber Phantom for Cerebral CT Perfusion.

We developed a phantom using a hollow-fiber hemodialyzer to evaluate the quantitative reliability of cerebral computed tomography (CT) perfusion. Our phantom consisted of a hollow-fiber hemodialyzer and a syringe-shaped X-ray device made up of resin. The phantom can give theoretical true values for cerebral blood volume, cerebral blood flow, and mean transit time. We compared the values measured in the phantom with predicted theoretical values. The purpose of the current report is to describe the theory and experimental technique used to obtain an absolute value in a phantom.

Abeta upregulates and colocalizes with LGI3 in cultured rat astrocytes.

1. The leucine-rich glioma inactivated (LGI) family of genes encodes a leucine-rich repeat (LRR) protein, proteins that are thought to be specifically involved in protein-protein and protein-matrix interactions. Since amyloid beta peptide (Abeta) has been previously shown to induce the expression of another LRR-encoding gene in neural cells, we assessed how Abeta affects LGI gene expression in rat primary cerebral cortical cultures and astrocyte cultures. Both RT-PCR and Western Blotting analyses revealed that Abeta robustly induced the expression of LGI3 in rat astrocyte cultures.2. Western Blotting analyses also showed that both glial fibrillary acidic protein (GFAP) and apolipoprotein E (ApoE) significantly increased coincidentally with the Abeta-induced upregulation of LGI3. Immunocytochemistry showed that LGI3 colocalized with Abeta at plasma membranes and also with internalized Abeta in astrocytes. These findings suggest that activated LGI3 may be involved in the astroglial response against Abeta.

Behavioral alterations in response to fear-provoking stimuli and tranylcypromine induced by perinatal exposure to bisphenol A and nonylphenol in male rats.

The purpose of this study was to examine whether perinatal exposure to two major environmental endocrine-disrupting chemicals, bisphenol A (BPA; 0.1 mg/kg/day orally) and nonylphenol [NP; 0.1 mg/kg/day (low dose) and 10 mg/kg/day (high dose) orally] daily from gestational day 3 to postnatal day 20 (transplacental and lactational exposures) would lead to behavioral alterations in the male offspring of F344 rats. Neither BPA nor NP exposure affected behavioral characteristics in an open-field test (8 weeks of age), in a measurement of spontaneous motor activity (12 weeks of age), or in an elevated plus-maze test (14 weeks of age). A passive avoidance test (13 weeks of age) showed that both BPA- and NP-treated offspring tended to delay entry into a dark compartment. An active avoidance test at 15 weeks of age revealed that BPA-treated offspring showed significantly fewer avoidance responses and low-dose NP-treated offspring exhibited slightly fewer avoidance responses. Furthermore, BPA-treated offspring significantly increased the number of failures to avoid electrical unconditioned stimuli within 5-sec electrical shock presentation compared with the control offspring. In a monoamine-disruption test using 5 mg/kg (intraperitoneal) tranylcypromine (Tcy), a monoamine oxidase inhibitor, both BPA-treated and low-dose NP-treated offspring at 22-24 weeks of age failed to show a significant increment in locomotion in response to Tcy, whereas control and high-dose NP-treated offspring significantly increased locomotion behavior after Tcy injection. In addition, when only saline was injected during a monoamine-disruption test, low-dose NP-treated offspring showed frequent rearing compared with the control offspring. The present results indicate that perinatal low-dose BPA or NP exposure irreversibly influenced the reception of fear-provoking stimuli (e.g., electrical shock), as well as monoaminergic neural pathways. Key words: behavior, bisphenol A, fear, learning, monoamine, nonylphenol.