IVR 会誌 Jpn J Intervent Radiol Vol.20 No.2 2005

State of the Art

1. Principles of Radiation Protection in Fluoroscopically Guided Interventional Radiologic Procedures
Department of Radiology, Aichi Medical University
Tsuneo Ishiguchi, Seiji Kamei, Kazuko Ohno

While interventional radiological procedures are minimally invasive and beneficial to patients, some complex and lengthy fluoroscopically guided procedures may cause radiation-induced skin injuries. Interventional radiologists should be aware of threshold doses, actual dose rates of a particular x-ray equipment, and proper techniques to control the patient’s cumulative skin dose. The International Commission on Radiation Protection recommends that informed consent be obtained about the risk of radiation injury, that the maximum dose to the skin be recorded when it approaches 1 Gy (for procedures that may be repeated) or 3 Gy (for any procedure) and that patient follow-up be provided in the latter situation. To reduce operator exposure, it is essential to avoid direct exposure of the primary beam to the hands in procedures such as transhepatic biliary drainage. During vascular interventions, the majority of operator exposure is caused by scatter radiation from the patient. Almost every effort to reduce patient dose secondarily reduces scatter radiation to the operator as well. The overhead x-ray tube system is associated with higher exposure to the hands and eyes, and should not be used for complicated procedures. Appropriate shields help in reducing scatter to the operator.

Key words
● Fluoroscopy
● Interventional radiology
● Radiation injury

2. Basic Knowledge of Radiation Exposure in CT-guided IVR
Department of Radiology, Fujita Health University School of Medicine1)
Faculty of Radiological Technology, Fujita Health University School of Health Sciences2)
Ryoichi Kato, Tatsuo Banno, Kazuhiro Katada1), Shoichi Suzuki, Hirofumi Anno2)

This article discussed the exposure dose to the patient and the operator in CT-guided IVR, and radiological protection. The CT dose index (CTDI) has commonly been used as the most specific dose quantity for CT examinations because it includes all relevant scan parameters: kV, tube current, slice thickness, pitch factor, and others. The exposure dose exceeded the diagnostic reference value in an abdominal high-resolution CT examination using 64-DAS MSCT. We also discussed the exposure dose to the patient during CT fluoroscopy. Because the X-ray beams used in CT fluoroscopy are narrow and the dose rate is low, radiation damage does not occur in usual use. One of the major limitations of CT fluoroscopy is excessive radiation exposure to the operator, in particular, to his or her hands. Therefore, we previously developed biopsy needle holders that permit the operator to manipulate the needle without placing his or her hands in the direct X-ray. We previously investigated the use of needle holders and protective goggles and aprons to reduce the exposure dose, and confirmed their effectiveness. These protective devices are considered to be indispensable in performing non-vascular interventional procedures under CT-fluoroscopic guidance. It had been confirmed that the occupational radiation doses in CT fluoroscopy do not exceed the limit specified by the ICRP when adequate protective devices are applied.

Key words
● CT fluoroscopy
● Radiological protection

3. Patient and Physician Doses during Interventional Procedures
Department of Radiology, Teikyo University School of Medicine
Shigeru Suzuki, Shigeru Furui, Hiroshi Kohtake

Interventional radiology (IVR) procedures have recently spread quickly and achieved success with low invasiveness in the treatment of various diseases. However, radiation skin injuries in patients have been reported with the spread of IVR. The International Commission on Radiological Protection recommended to record an identification of those areas of the patient’s skin that received an absorbed dose during IVR procedures that may approach or exceed 1 Gy (for procedures that may be repeated) ; 3 Gy (for any procedure). We reviewed patient and interventional physician doses during interventional procedures based on previous reports and our experience. Patient’s exposure in IVR is affected by fluoroscopy time, number of acquisitions, beam angle, dose rate, and patient size. The interventional physician should understand generally the standard skin dose of the IVR procedure, the dose rate of the X-ray apparatus to be used, and the dose per DSA, etc. The high occupational exposures in IVR require adequate monitoring for staff. It is important for interventional physicians to estimate patient and staff radiation doses in individual procedures and make efforts to reduce the exposure doses.

Key words
● Interventional Radiology
● Exposure dose
● Radiation injury

Original Article
Radiation Exposure to Patients during Interventional Radiologic Procedures : Evaluation for Neuroembolization, Percutaneous Coronary Intervention, and Implantation of Infuser Port
Department of Radiology, Teikyo University School of Medicine
 Shigeru Suzuki, Shigeru Furui
Department of Environmental Health, National Institute of Public Health
 Ichiro Yamaguchi
Department of Radiology, Fukuoka University School of Medicine
 Masatoshi Okazaki
Department of Radiology, Osaka University Faculty of Medicine
 Hironobu Nakamura
Department of Radiology, Kohka Public Hospital
 Tsutomu Sakamoto
Department of Radiology, Aichi Medical University
 Tsuneo Ishiguchi
Department of Medicine, Teikyo University School of Medicine
 Takaaki Isshiki
Department of Radiology, Toranomon Hospital
 Hidenori Takebe
Department of Radiological Technology, Saitama Cancer Center
 Kunihiko Morozumi
Department of Radiology, Teikyo University Hospital
 Masafumi Yamagishi
Department of Radiology, Osaka University Hospital
 Kazuya Yamaguchi
Department of Radiology, Fukuoka University Hospital
 Kunihiro Matsumoto

 Purpose : We evaluated radiation exposure to the skin of patients undergoing three kinds of interventional radiology procedures.
Material and Methods : Skin doses were assessed for 36 patients (12 neuroembolizations, 11 percutaneous coronary interventions[PCI], and 13 implantations of infuser port) at four institutes. Entrance skin doses were evaluated with 3 packs of thermoluminescent dosimeters in each patient. The measurement points were forehead, right temporal surface, and occipital surface in neuroembolization, and inferior angle of the left scapula, its median, and its lateral aspect in PCI. In implantation of infuser port, thermoluminescent dosimeters were placed behind the left clavicle, Th12-L1, and right lobe of the liver.
Result : Maximum skin dose was 512 ± 330cGy (range, 110-1217cGy) in neuroembolization, 201±244cGy(range, 28-781cGy) in PCI, and, 649±753cGy (range, 35-2405cGy) in implantation of infuser port. The maximum skin doses exceeded 1 Gy in 4 of all the 36 procedures.
Conclusions : Skin injury can be induced in these procedures. Therefore it is important for physicians to estimate exposure dose in individual cases and make efforts to reduce the exposure dose.

Key words
●Interventional radiology
●Skin dose
●Radiation injury
●Thermoluminescent dosimeter

Original Article
Effectiveness of prophylactic transcatheter arterial embolization for unruptured renal angiomyolipomas
Department of Radiology and Urology1), Kumamoto Red Cross Hospital
 Takeshi Sugawara, Ryuichi Saito, Ryuji Murakami, Shinichi Takano1)
 Naohisa Mizukami, Yumi Yanaga
Department of Radiological Sciences, School of Health Sciences, Kumamoto University School of Medicine
 Hirotada Butsuzaka
Department of Radiology, Amakusa Medical Center
 Yoshinori Shigematsu, Yutaka Nakasone
Department of Urology, Kumamoto Rosai Hospital
 Junzo Kudo

Six patients with unruptured renal angiomyolipomas (AML) 4b or larger are presented, two of whom had tuberous sclerosis. In all patients, transcatheter arterial embolization (TAE) was performed in an attempt to prevent future life-threatening rupture. Renal angiograms showed that tumor vessels were not tortuous and a few in number, and superselective TAE could be achieved successfully. Post-TAE angiograms showed devascularization of the tumor. There were no serious complications and follow-up period of five to 180 months (mean, 54 months) revealed no bleeding. We consider that prophylactic superselective TAE for unruptured renal AML may be feasible and effective in the prevention of future bleeding.

Key words
●Angiomyolipoma (AML)
●Transcatheter arterial embolization

Case Report
Transcatheter Arterial Embolization of Pseudoaneurysm of the Profunda Femoris Artery after Total Hip Arthroplasty : A Case Report
Department of Radiology, Fukuyama Medical Center, National Hospital Organization
Hiroe Morita, Yoshihiro Kono, Norihisa Katayama, Tomio Nakagawa
Department of Radiology, Graduate School of Medicine and Dentistry, Okayama University
Susumu Kanazawa

Pseudoaneurysm of the profunda femoris artery is rare, but is known as one of the vascular injuries occurring after orthopedic operations of the upper thigh. We report a case of pseudoaneurysm of the profunda femoris artery after total hip arthroplasty, which was successfully treated by transcatheter arterial embolization (TAE).
A 79-year-old woman with a mass in the left thigh had undergone a total hip arthroplasty. Since anemia and thigh swelling developed after the surgery, the existence of pseudoaneurysm was suspected. We performed angiography, which showed a huge pseudoaneurysm of the left profunda femoris artery. We performed TAE using multiple metallic coils. At 6 months after TAE, dynamic CT scans revealed no recurrence of the pseudoaneurysm or hematoma.

Key words
●Profunda femoris artery
●Transcatheter arterial embolization(TAE)

Case Report
A Case of Emphysematous Cystitis Presenting Severe Hematuria ; Successful Treatment by Transcatheter Arterial Embolization
Department of Radiology, Department of Urology1), Nakatsu Municipal Hospital
Daisuke Tsurumaru, Hiromu Hidaka, Naohito Iwabuchi1)
Department of Radiology, Matsuyama Red Cross Hospital
Hiroyuki Nomiyama

We experienced a case of emphysematous cystitis presenting severe hematuria. A 75-year-old woman was taken to our hospital with gross hematuria. Abdominal X-ray and CT showed intramural gas of the urinary bladder, which suggested the diagnosis of emphysematous cystitis. The patient presented severe hematuria and hypotension on the 27th hospital day. Pelvic angiography revealed extravasation from the left superior vesical artery. A microcatheter was advanced into the artery and transcatheter arterial embolization (TAE) using gelatin sponge particles was performed. Hemostasis was obtained, but rebleeding occurred 20 days later. Pelvic angiography revealed extravasation from another branch of the left superior vesical artery. TAE of the bilateral internal iliac artery using gelatin sponge particles was performed. Thereafter no bleeding occurred and the patient was discharged. TAE was a useful treatment for severe hematuria caused by emphysematous cystitis.

Key words
●Emphysematous cystitis
●Transcatheter Arterial Embolization

Technical Note
A Newly Designed Nursing Manual for Interventional Radiology
Department of Nursing and Radiology1), Nara Prefectural Nara Hospital
Meiko Kitamura, Megumi Kusumoto, Naomi Sakamoto, Motoko Matsushita, Yumi Takagi, Etsumi Hagihara, Yoshie Fujii, Takeshi Wada1), Tetsuya Yoshioka1)

It is our object to edit and supply a newly designed nursing manual for interventional radiology(IVR) to be used at clinical training. This manual is being redesigned to increase the quality of support and to improve the level of care between nursing and assisting doctors during the IVR procedure. This manual provides a Gantt chart. The horizontal axis shows step-by-step instructions for both nursing and assisting doctors during the medical procedure. The vertical axis shows time the passage of for the patient from his first entering the angiography suite to leaving the angiography suite. The use of this manual will allow nurses to effectively and efficiently perform their duties regardless of their past experience or level of training. This manual will also shorten their training period by providing hands-on experience, thus increasing their learning curve. It has been demonstrated that this manual will increase the quality and level of care for IVR patients and will be especially useful in those institutions with no designated IVR nursing staff.

Key words
●Interventional Radiology

Technical Note
Experimental Investigation of Pluronic F-127 for Clinical Application
Department of Radiology, Shiga University
Norihisa Nitta, Shinichi Ota, Toyohiko Tanaka, Ryutaro Takazakura
 Michio Yamasaki, Masaru Sakota, Naoaki Kono, Akira Furukawa
 Masashi Takahashi, Kiyoshi Murata
Department of Radiology, Kohka Public Hospital
Katsuji Imoto, Tsutomu Sakamoto

Pluronic (polyoxyethylene-polyoxypropylene) is a substance in widespread use in the medical and pharmaceutical fields. Most notably, Pluronic F127 has the properties of being liquid at 20 degrees centigrade or lower, and gelatinous from 20 to 40 degrees centigrade, where the gelatification temperature depends upon concentration. Taking advantage of this substance’s property-changing characteristic of gelatification at body temperatures, we have performed an experimental investigation regarding its properties including conductivity of radiofrequency (at 500 kHz) and absorbability following subcutaneous infusion. Its potential has also been explored for its use as a spacer (for securing routes for biopsy or in radio frequency ablation(RFA)), an embolic material, and a submucosal injection substance for endoscopic mucosal resection. Pluronic F127 was found to be potentially useful in various interventional radiology applications.

Key words
●Pluronic F-127
●Gelation and gel melting
●Embolic material