Radiation Exposure and Protection in Computed Tomography Fluoroscopy.

Computed tomography (CT) fluoroscopy-guided procedures, such as those used for percutaneous biopsy, drainage, and radiofrequency ablation, are highly safe and quite often very successful due to the precision offered by the real-time, high-resolution tomographic images. Even so, international guidelines raised concerns regarding operator exposure to high doses of radiation during these procedures. In light of these concerns, operators conducting CT fluoroscopy-guided procedures not only need to be cognizant of the exposure risk but also exhibit sufficient knowledge of radiation protection. This paper reviews the current literature on experimental and clinical studies of radiation exposure doses to operators during CT fluoroscopy-guided procedures. In addition to the literature review, this paper also introduces different approaches that can be implemented to ensure appropriate radiation protection.

Percutaneous Transsplenic Embolization of Gastric Varices in Left-sided Portal Hypertension.

An 81-year-old man with previously diagnosed cancer of the pancreatic body presented with melena and anemia. Upper gastrointestinal endoscopy showed gastric varices with bleeding in the entire stomach. Contrast-enhanced computed tomography identified a splenic vein occlusion resulting from invasion by the pancreatic body cancer and dilated collateral pathways from the splenic hilum to the gastric fundus. The patient was diagnosed with gastric varices associated with left-sided portal hypertension caused by obstruction of the splenic vein and underwent percutaneous transsplenic embolization with n-butyl-2-cyanoacrylate mixed with lipiodol. Splenic subcapsular hematoma occurred and was treated conservatively. The patient died of advanced cancer 5 months after the procedure, without experiencing rebleeding. Percutaneous transsplenic embolization was effective in treating gastric variceal bleeding caused by left-sided portal hypertension.

Practical Radiation Protection for Interventional Radiologist.

As per the International Commission on Radiological Protection 2010 recommendation, it was stated that "interventional radiologists performing difficult procedures with high workloads may be exposed to high doses" and that education and training of medical staffs in radiation exposure is "an urgent priority." There are many reports on the textbook aspects of radiation protection, but reports on the practical aspects of radiation protection have remained to be scarce. Various methods of reducing radiation exposure are described as "useful" or "can be reduced," but the priority of these methods and the "extent" to which they contribute to reducing radiation exposure are not clear. Thus, in this article, we will look into the protection of interventional radiologist from radiation exposure in a practical way, giving priority to clarity rather than academic accuracy.

A Case of Percutaneous Transesophageal Jejunostomy after Subtotal Esophagectomy.

An 80-year-old woman who underwent subtotal esophagectomy with gastric tube reconstruction for esophageal cancer developed carcinoma of the left upper gingiva. The local recurrence of the gingival carcinoma resulted in trismus and prevented oral intake. Then she underwent a percutaneous transesophageal jejunostomy tube placement in the preserved cervical esophagus. Enteral feeding continued for three months with no complications until oral intake was possible. A percutaneous transesophageal jejunostomy is possible using the postoperatively preserved cervical esophagus.

The Impact of Sorafenib in Combination with Intermittent Hepatic Arterial Infusion Chemotherapy for Unresectable Hepatocellular Carcinoma with Major Vascular Invasion.

The aim of the current study was to investigate the efficacy and safety of sorafenib and intermittent hepatic arterial infusion chemotherapy with cisplatin for unresectable hepatocellular carcinoma (HCC) with severe portal vein invasion. The antitumor effect was a complete response in 1 of 38 patients, a partial response in 12 patients, stable disease in 16 patients, and progressive disease in 9 patients, for a 34.2% response rate and a 76.3% disease control rate. This regimen had favorable efficacy and acceptable safety and may be feasible for unresectable HCC with severe portal vein invasion.

Simultaneous Drainage of the Abscess Cavity and Intestinal Tract for an Intra-abdominal Abscess Secondary to Major Leakage: A Case Report.

This case report describes a 72-year-old man who developed an intra-abdominal abscess and major postoperative anastomotic leakage. He reported a history of pancreaticoduodenectomy, partial hepatectomy, and segmental colectomy for hepatic and colonic invasion of extrahepatic cholangiocarcinoma. Three catheters, (one in the transverse colon and two in the abscess cavity) were placed simultaneously through the drainage tract formed by the intraoperatively placed Pleats drain. The intra-abdominal abscess resolved following this intervention and has not recurred since. Postoperative drainage and starvation were continued for 52 and 84 days, respectively. This case report describes a novel technique of catheter insertion from the abscess cavity into the intestine through the site of rupture to reduce intestinal pressure and partially block the enteric fistula.

Central venous access port placement by translumbar approach using angio-CT unit in patients with superior vena cava syndrome.

PURPOSE: To evaluate the clinical results of central venous access port (CV port) placement by translumbar inferior vena cava cannulation using angio-CT unit for cancer patients with superior vena cava syndrome. MATERIALS AND METHODS: A CV port was placed by translumbar inferior vena cava cannulation using an angio-CT unit, in 14 consecutive patients. All patients had occlusion or advanced stenosis of the superior vena cava due to cancer progression. RESULTS: The technical success rate of the percutaneous translumbar CV port placement was 100%. The only complication related to port placement was bleeding in the right iliopsoas muscle seen on CT in one patient, but it stopped with conservative treatment. The mean initial device service interval was 125 days (range 6-448 days). Complications in the chronic phase occurred in two patients, one with catheter-related infection and the other with catheter breakage, for a rate of 0.44/1000 catheter days. In the patient with the broken catheter, the port chamber placement site was cut and replaced with a new catheter by guidewire exchange. CONCLUSIONS: CV port placement with translumbar inferior vena cava cannulation using an angio-CT unit for cancer patients with superior vena cava syndrome was safe and effective.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery.

PURPOSE: This study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route. METHODS: Data were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5-1:20). RESULTS: Clinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped. CONCLUSIONS: TDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Scaffold protein enigma homolog 1 overcomes the repression of myogenesis activation by inhibitor of DNA binding 2.

Enigma Homolog 1 (ENH1) is a scaffold protein for signaling proteins and transcription factors. Previously, we reported that ENH1 overexpression promotes the differentiation of C2C12 myoblasts. However, the molecular mechanism underlying the role of ENH1 in the C2C12 cells differentiation remains elusive. ENH1 was shown to inhibit the proliferation of neuroblastoma cells by sequestering Inhibitor of DNA binding protein 2 (Id2) in the cytosol. Id2 is a repressor of basic Helix-Loop-Helix transcription factors activity and prevents myogenesis. Here, we found that ENH1 overcome the Id2 repression of C2C12 cells myogenic differentiation and that ENH1 overexpression promotes mice satellite cells activation, the first step toward myogenic differentiation. In addition, we show that ENH1 interacted with Id2 in C2C12 cells and mice satellite cells. Collectively, our results suggest that ENH1 plays an important role in the activation of myogenesis through the repression of Id2 activity.

[Feasibility and Safety of Dexmedetomidine Sedation in Transarterial Embolization for Hepatocellular Carcinoma with Hepatitis C-Related Cirrhosis].

BACKGROUND: Dexmedetomidine (Precedex®)is an agonist of a2-adrenergic receptors in certain parts of the brain. It was approved for "procedural sedation in the non-intubation in under local anesthesia" in June 2013 in Japan. However, because of metabolism delay, dexmedetomidine has to be administered carefully to patients with liver dysfunction. PURPOSE: To evaluate the feasibility and safety of sedation using dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction. METHODS: Thirty consecutive cases of percutaneous arterial chemoembolization for hepatocellular carcinoma with hepatitis C-related cirrhosis(male, 23; female, 7; age, 74±5.9; weight, 62.7±12.3 kg; Child-Pugh A, 23; Child-Pugh B, 7)were analyzed retrospectively. Dexmedetomidine was administered at 3 mg/kg/h for 15 minutes as the initial loading dose and at 0.4 mg/kg/h as the maintenance dose. The sedation level was evaluated using the Ramsay sedation scale. RESULTS: In 30 of 30 cases, percutaneous arterial chemoembolization therapy could be performed with dexme- detomidine sedation. In 27 of 30 cases, the procedure was completed with the maintenance dose of 0.4 mg/kg/h. In 3 of 30 cases, the maintenance dose was increased to 0.6 mg/kg/h because of patient body motion. The mean administration time of dexmedetomidine was 82±30 minutes. The level of sedation measured with the Ramsay sedation scale at the end of the procedure was 3 points in 29 cases and 5 points in one case. Adverse events occurred in 3 of 30 cases. Intravenous drip leakage occurred in one case, vertigo occurred in one case, and vomiting occurred in one case. There were no adverse events requiring treatment. CONCLUSION: Sedation with dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction was feasible and safe.

Evaluation of an aspiration-type semiautomatic cutting biopsy needle.

PURPOSE: The purpose of this study was to evaluate an aspiration-type semiautomatic cutting biopsy needle for biopsy of bovine tissue. MATERIAL AND METHODS: Aspiration-type semiautomatic cutting biopsy needles (18 gauge × 160 mm) with aspiration (Group A), aspiration-type semiautomatic biopsy needles without aspiration (Group Wo), or normal-type semiautomatic biopsy needles (18 gauge × 150 mm) (Group N) were used in 10 biopsies each of bovine liver or lung. The specimens were weighed with an electronic balance. RESULTS: Mean (standard deviation) weights for bovine liver specimens in Groups A, Wo, and N were 6.80 (0.615) mg, 5.62 (0.843) mg, and 4.19 (0.140) mg, respectively. Mean weights of bovine lung specimens from Groups A, Wo, and N were 2.98 (0.828) mg, 2.67 (0.832) mg, and 1.94 (0.864) mg, respectively. A significant difference was seen between the 3 groups for bovine liver. However, a significant difference was only seen between Groups A and N for bovine lung. CONCLUSION: Bovine liver and lung specimens obtained using the aspiration-type semiautomatic cutting biopsy needle were heavier than those obtained using the normal-type semiautomatic biopsy needle.

Radiation dose of nurses during IR procedures: a controlled trial evaluating operator alerts before nursing tasks.

PURPOSE: To compare radiation exposure of nurses when performing nursing tasks associated with interventional procedures depending on whether or not the nurses called out to the operator before approaching the patient. MATERIALS AND METHODS: In a prospective study, 93 interventional radiology procedures were randomly divided into a call group and a no-call group; there were 50 procedures in the call group and 43 procedures in the no-call group. Two monitoring badges were used to calculate effective dose of nurses. In the call group, the nurse first told the operator she was going to approach the patient each time she was about to do so. In the no-call group, the nurse did not say anything to the operator when she was about to approach the patient. RESULTS: In all the nursing tasks, the equivalent dose at the umbilical level inside the lead apron was below the detectable limit. The equivalent dose at the sternal level outside the lead apron was 0.16 µSv ± 0.41 per procedure in the call group and 0.51 µSv ± 1.17 per procedure in the no-call group. The effective dose was 0.018 µSv ± 0.04 per procedure in the call group and 0.056 µSv ± 0.129 per procedure in the no-call group. The call group had a significantly lower radiation dose (P = .034). CONCLUSIONS: Radiation doses of nurses were lower in the group in which the nurse called to the operator before she approached the patient.

Intranodal lymphangiogram: technical aspects and findings.

PURPOSE: To report the technical results and imaging findings of intranodal lymphangiogram (INL). MATERIALS AND METHODS: we studied four patients (three men, one woman) who had persistent chylous leakage despite conservative treatment after esophageal cancer surgery. Their mean age was 68 years (range 61-74 years). The inguinal or femoral lymph node was punctured under ultrasound guidance using a 60-mm-long, 23-gauge needle. If the lipiodol injected via the needle showed granular nodules on fluoroscopy, lipiodol injection was continued manually at a rate of 1 mL/3 min for INL. If the cisterna chyli was detectable on the lymphangiogram, it was punctured percutaneously via the abdomen by a needle under fluoroscopy, and thoracic duct embolization was performed. RESULTS: INL was successful in all patients. Lymphaticovenous anastomoses at the femoral or pelvic region were confirmed in all four patients. In one case, a different ipsilateral lymph node was punctured because major flow of lipiodol into the veins through a lymphaticovenous anastomosis occurred. Catheter cannulation and embolization were successful for three of the four patients. In unsuccessful procedures, the cisterna chyli was not visualized, and puncture was not possible. CONCLUSIONS: INL succeeded in all patients. Lipiodol leaked into the vein through a lymphaticovenous anastomosis at the femoral or pelvic region in all patients.

Comparison of Tc-99m GSA scintigraphy and CT volumetry for evaluation in portal vein embolization.

PURPOSE: To determine the correlation of the rate of change of each future remnant liver (FRL) before and after portal vein embolization (PVE), by CT volumetry and Tc-99m galactosyl human serum albumin scintigraphy (GSA scintigraphy). MATERIAL AND METHODS: From December 2007 to July 2012, ten patients underwent PVE before hepatic resection. CT volumetry and GSA scintigraphy were performed before and after PVE. The FRL was divided at Cantlie's line for CT volumetry, and volume change rates before and after PVE were calculated. The maximum removal rate (Rmax) was calculated using a radiopharmacokinetic model in GSA scintigraphy. The FRL Rmax change rates before and after PVE were calculated. The correlation between the volume change rates and the Rmax change rates was analyzed. RESULTS: The FRL volume change rate was 1.28 ± 0.26 (mean ± SD); the FRL hypertrophied in all patients significantly (p = 0.005). The FRL Rmax change rate was 1.66 ± 0.75; excluding one patient, there was significant FRL Rmax increase (p = 0.022). Although both increased significantly, no correlation between the volume change rate and the Rmax change rate was observed. CONCLUSION: No correlation was observed between the FRL volume rate and the Rmax rate.

Intra-arterial infusion of thrombin: animal experiments.

PURPOSE: Thrombin inhibits cadherin on vascular endothelial cells, rapidly and reversibly increasing endothelial permeability. The purpose of this study was to evaluate the feasibility of trans-arterial infusion with thrombin. MATERIAL AND METHODS: Ten rabbits with right thigh tumor were randomly divided into two groups: A thrombin group and a control group. In the thrombin group, a suspension of thrombin (300 IU), cisplatin (3 mg), lipiodol (0.3 ml) and iopamidol (0.3 ml) was infused into the right femoral artery. In the control group, a suspension of cisplatin, lipiodol and iopamidol was infused. Platinum concentrations in plasma were measured five and ten minutes after administration. Platinum concentrations were also measured in tumor specimens excised 30 minutes after infusion. RESULTS: At both five and ten minutes after infusion, platinum concentrations in plasma were significantly lower for the thrombin group than for the control group. Platinum concentration in tumor tissue was significantly higher for the thrombin group than for the control group. CONCLUSION: The present results suggest that transarterial infusion with thrombin may offer a number of pharmacological advantages.

Direct puncture embolization using N-butyl cyanoacrylate for a hepatic artery pseudoaneurysm.

Massive hemobilia caused by hepatic artery pseudoaneurysm is an uncommon but potentially fatal complication that can occur after biliary intervention. Previous intervention or surgery, atherosclerotic disease, inflammation and even anatomic variants may make the pseudoaneurysm inaccessible to transcatheter approach, therefore it is not always feasible. The present report describes a case of successful embolization of a hepatic artery pseudoaneurysm with N-butyl cyanoacrylate via direct puncture as an alternative approach. The case presentation is followed by the technical points and the properties of N-butyl cyanoacrylate that are particularly advantageous for use in direct puncture procedures.

Does vertebroplasty affect radiation dose distribution?: comparison of spatial dose distributions in a cement-injected vertebra as calculated by treatment planning system and actual spatial dose distribution.

Purpose. To assess differences in dose distribution of a vertebral body injected with bone cement as calculated by radiation treatment planning system (RTPS) and actual dose distribution. Methods. We prepared two water-equivalent phantoms with cement, and the other two phantoms without cement. The bulk density of the bone cement was imported into RTPS to reduce error from high CT values. A dose distribution map for the phantoms with and without cement was calculated using RTPS with clinical setting and with the bulk density importing. Actual dose distribution was measured by the film density. Dose distribution as calculated by RTPS was compared to the dose distribution measured by the film dosimetry. Results. For the phantom with cement, dose distribution was distorted for the areas corresponding to inside the cement and on the ventral side of the cement. However, dose distribution based on film dosimetry was undistorted behind the cement and dose increases were seen inside cement and around the cement. With the equivalent phantom with bone cement, differences were seen between dose distribution calculated by RTPS and that measured by the film dosimetry. Conclusion. The dose distribution of an area containing bone cement calculated using RTPS differs from actual dose distribution.

Analysis of factors influencing accuracy and complications in CT-guided lung biopsy.

INTRODUCTION: This study aimed to analyze factors influencing accuracy and complications in patients who underwent computed tomography (CT)-guided lung biopsy at our medical center. MATERIAL AND METHODS: This study included all 107 patients (72 men, 35 women; mean age, 69 years; range, 41-83 years) who underwent CT-guided lung biopsy between January 2006 and October 2009. CT fluoroscopy was used in 45.7% of cases. Final diagnosis, when surgical resection was performed, was histopathological diagnosis from the lung lesion specimen, and when resection was not performed, clinical diagnosis after ≥6 months of follow-up. The accuracy of lung biopsy was assessed by comparison of biopsy results and final diagnosis. The influence of factors on accuracy was statistically analyzed. RESULTS: Accuracy of CT-guided lung biopsy was 89.4%. None of the factors, including lesion size, lesion depth from pleura, lesion location, patient position, final diagnosis, and use or non-use of CT fluoroscopy, had any significant influence on accuracy. The only complications were Grade 1 and 2 pneumothorax and Grade 1 pulmonary bleeding. The incidence of pneumothorax and bleeding was significantly increased with smaller lesion size and significantly increased with greater lesion depth. In patients with pulmonary emphysema, bleeding was significantly less (p = 0.022). When CT fluoroscopy was used, bleeding was significantly increased (p < 0.001). CONCLUSIONS: None of the factors had any significant influence on accuracy. The incidence of pneumothorax and bleeding was affected by lesion size and lesion depth. When CT fluoroscopy was used, bleeding was significantly increased.

Metallic stent placement for malignant airway stenosis.

The purpose of this study was to evaluate the utility of metallic stents for treating central airway stenosis caused by malignant tumors. The subjects were 72 patients (16 women, 56 men; mean age, 61 years; age range, 28-87 years) treated with metallic stents for dyspnea due to tracheobronchial stenotic lesions caused by malignant tumors between May 1990 and August 2010. The underlying disorder was primary lung cancer in 42 patients, metastatic lung cancer in 29, and mediastinal tumor in one patient. In 69 of 72 patients (95.8%), dyspnea began to improve following completion of the procedure. The average Hugh-Jones classification score improved from 4.2 before stenting to 2.8 after stenting. The patients' average survival following stent placement was 3.6 months (two days-33 months). Thirteen lesions developed re-obstruction during follow-up. Of these 13 lesions, eight patients with dyspnea underwent re-interventions with metallic stent replacement and improved. Airway stent placement is an immediate and effective method of treatment for dyspnea caused by stenotic lesions of the central airway due to malignant tumor. It is effective for treating stenosis due to either tracheobronchial intraluminal tumor or extrinsic compression. Restenting is also useful to treat dyspnea caused by restenosis following stent placement.

Pancreatitis after transcatheter embolization of a splenic aneurysm.

A 52-year-old woman was treated for a splenic aneurysm that was found on abdominal computed tomography (CT) during a preoperative assessment for rectal cancer. The aneurysm was embolized using the "double coil-delivered microcatheter technique," and 4 ml of a mixture of N-butyl 2-cyanoacrylate (NBCA) and iodized oil (Lipiodol) (NBCA/Lipiodol = 1.0: 2.5) were injected into the aneurysm. The patient complained of left upper quadrant abdominal pain immediately after the procedure. A blood test 2 days after the procedure showed an increased white blood cell count (13,100/microl), C-reactive protein (13.36 mg/dl), and pancreatic amylase (428 U/l). Abdominal CT scan showed a huge cystic lesion at the pancreatic tail, in the center of which was a highly enhanced area due to accumulated NBCA-Lipiodol. Postembolization pancreatitis was diagnosed, and treatment with fasting and a drip infusion of nafamostat mesilate was started. The patient's abdominal pain became less severe within 3 days, and the pancreatic enzyme level had normalized 14 days after treatment. On CT, the cystic lesion at the pancreatic tail was smaller 20 days after the procedure, and it had disappeared completely 75 days after the procedure.