Backscatter from radiation protective drapes in fluoroscopically guided interventions - a patient dose to consider?

From the Circulation Family of Journals.

Backgrounds: Reducing radiation exposure is the basic principle for performing percutaneous coronary intervention (PCI). Many studies have confirmed the effect of radiation protection for medical staff, but studies about the effectiveness of protection for patients and real measurement of radiation dose in patients’ specific organs are lacking. Aim: To measure the radiation doses absorbed by patients’ radiosensitive organs during PCI and the effectiveness of radiation protection. Methods: A total of 120 patients were included and allocated into three groups as the ratio of 1:1:2. A total of 30 patients received PCI at 15 frames rate per second (fps), 30 patients at 7.5 fps, and 60 patients wore radiation protective hat and glasses during PCI at 7.5 fps. The radiation doses were measured at right eyebrow (lens), neck (thyroid), back (skin), and inguinal area (genital organs) by using thermoluminescent dosimeters (TLDs). Results: Dose-area product (DAP) reduced by 58.8% (from 534,454 ± 344,660 to 220,352 ± 164,101 mGy·cm2, p < 0.001) after reducing the frame rate, without affecting successful rate of PCI. Radiation doses measured on skin, lens, genital organs, and thyroid decreased by 73.3%, 40.0%, 40.0%, and 35.3%, respectively (from 192.58 ± 349.45 to 51.10 ± 59.21; 5.29 ± 4.27 to 3.16 ± 2.73; 0.25 ± 0.15 to 0.15 ± 0.15; and 17.42 ± 12.11 to 11.27 ± 8.52 μSv, p < 0.05). By providing radiation protective equipment, radiation doses at lens and thyroid decreased further by 71.8% and 65.9% (from 3.16 ± 2.73 to 0.89 ± 0.79; 11.27 ± 8.52 to 3.84 ± 3.49 μSv, p < 0.05). Conclusions: By lowering the frame rate and providing protective equipment, radiation exposure in radiosensitive organs can be effectively reduced in patients.

Consistent with the increasing prevalence of obesity in the general population, obesity has become more prevalent among patients undergoing cardiac catheterization. This study evaluated the association between patient body mass index (BMI) and physician radiation dose during coronary angiography. Real-time radiation exposure data were collected during consecutive coronary angiography procedures. Patient radiation dose was estimated using dose area product. Physician radiation dose in each case was recorded by a dosimeter worn by the physician and is reported as the personal dose equivalent (Hp10). Patient BMI was categorized as <25.0, 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and ≥40. Among 1119 coronary angiography procedures, significant increases in dose area product and physician radiation dose were observed across increasing patient BMI categories ( P<0.001). Compared with a BMI <25, a patient BMI ≥40 was associated with a 2.1-fold increase in patient radiation dose (dose area product, 91.8 [59.6-149.2] versus 44.5 [25.7-70.3] Gy×cm2; P<0.001) and a 7.0-fold increase in physician radiation dose (1.4 [0.2-7.1] versus 0.2 [0.0-2.9] μSv; P<0.001). By multiple regression analysis, patient BMI remained independently associated with physician radiation dose (dose increase, 5.2% per unit increase in BMI; 95% CI, 3.0%-7.5%; P<0.0001). Among coronary angiography procedures, increasing patient BMI was associated with a significant increase in physician radiation dose. Additional studies are needed to determine whether patient obesity might have adverse effects on physicians, in the form of increased radiation doses during coronary angiography.

Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography.

Currently, computed tomographic (CT) imaging of the heart is mainly used for the quantification of coronary artery calcification as an indirect measure of coronary plaque burden1,2 and, less frequently, for minimally invasive coronary angiography.3 CT imaging of the heart and coronary arteries without unsharpness due to motion artifact first became possible with the introduction of electron beam computed tomography (EBCT) in 1983.4 More recently, so-called multislice spiral computed tomographic (MSCT) scanners with gantry rotation speeds fast enough to produce diagnostic images of the heart under certain conditions have become widely available.5 As a consequence, cardiac CT imaging, most often performed for the purpose of calcium scoring,2 is increasingly applied to the general public. In many centers, patients have access to such studies without physician referral. This has created concerns for public health because of the radiation dose associated with CT imaging.6–8 Many clinicians and researchers working with patients with cardiovascular diseases may yet be unfamiliar with the radiation doses that are received during various cardiac CT imaging protocols and how they differ between the various scanner types that are currently used. To further complicate matters, radiation dose estimates can be expressed in various ways. For these reasons, the doses reported in previous publications on cardiac CT have varied widely, and it is not always clear what parameters were being reported.3,9–11 The purpose of this article is to discuss the current concepts of radiation dose measurement and estimation in CT imaging and to provide comparative estimates for radiation doses received during cardiac examinations with use of EBCT or MSCT. This information may be helpful to physicians who perform calcium scoring, counsel patients contemplating cardiac calcium scoring, or are considering referring their patients for such studies. EBCT scanners acquire 1 scan at a time, using …

Plain Film Radiography, Pregnancy, and Therapeutic Abortion Revisited

2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging: Best Practices for Safety and Effectiveness.

Intra-articular hip injections (IHI) are routinely performed for both diagnostic and therapeutic purposes. The procedure can be performed via either an anterior or a lateral approach with fluoroscopic guidance being widely practised. There is a risk of radiation exposure associated with fluoroscopy assisted IHI. This may be influenced either by the surgical approach or the patient's body mass index (BMI) or both. This study was undertaken to compare the relationships of the respective approaches to BMI, fluoroscopic exposure time (FET) and radiation dose (RD). A retrospective study was conducted comprising 74 patients who underwent IHI with 37 patients in each group (anterior and lateral). Patients were assessed pre-operatively and post operatively for any complications. The intra-operative radiation dose, fluoroscopic exposure time and BMI data were collected and analyzed. The mean age of the patients in anterior and lateral groups was 61.18±14.08 and 67.21±14.39 years respectively. No complications were noted in either group. However, there was a significant increase in FET (P=0.002) and RD (P<0.001) in patients with BMI ≥ 30. In the lateral group, this trend was markedly noted with increase in FET (P<0.001) and RD (P<0.001) in patients with BMI ≥ 30. On the other hand, in the anterior group there was no statistically significant increase in FET (P=0.155) and only a moderate increase in RD (P=0.020) in patients with BMI ≥ 30. Both anterior and lateral approaches to fluoroscopic guided IHI are equally safe in terms of complications involved. There is statistically significant increase in both radiation dose and fluoroscopic exposure time in patients with BMI ≥ 30. This is more pronounced in lateral approach. The anterior approach is most effective in reducing both radiation dose and fluoroscopic exposure time, more so in patients with BMI of 30 and above.

Mo1458 Patients, Endoscopist's and Nursing Staff Radiation Exposure During Interventional ERCP Procedures

Radiation dose is an important performance indicator of a dedicated breast CT (DBCT). In this paper, the method of putting thermoluminescent dosimeters (TLD) into a breast shaped PMMA phantom to study the dose distribution in breasts was improved by using smaller TLDs and a new half-ellipsoid PMMA phantom. Then the weighted CT dose index (CTDIw) was introduced to average glandular assessment in DBCT for the first time and two measurement modes were proposed for different sizes of breasts. The dose deviations caused by using cylindrical phantoms were simulated using the Monte Carlo method and a set of correction factors were calculated. The results of the confirmatory measurement with a cylindrical phantom (11 cm/8 cm) show that CTDIw gives a relatively conservative overestimate of the average glandular dose comparing to the results of Monte Carlo simulation and TLDs measurement. But with better practicability and stability, the CTDIw is suitable for dose evaluations in daily clinical practice. Both of the TLDs and CTDIw measurements demonstrate that the radiation dose of our DBCT system is lower than conventional two-view mammography.

Fluoroscopically guided interventional procedures are performed in large numbers in Europe and in the United States. The number of procedures performed annually throughout the world has increased over the past 20 years [1]. The benefits of interventional radiology to patients are both extensive and beyond dispute, but many of these procedures also have the potential to produce patient radiation doses high enough to cause radiation effects and occupational doses to interventional radiologists high enough to cause concern [1–4]. A joint SIR–CIRSE guideline on patient radiation management has addressed patient issues [3]. This guideline is intended to serve as a companion to that document and provides guidance to help minimize occupational radiation dose. The radiation dose received by interventional radiologists can vary by more than an order of magnitude for the same type of procedure and for similar patient dose [4]. Recently, there has been particular concern regarding occupational dose to the lens of the eye in interventional radiologists [2]. New data from exposed human populations suggest that lens opacities (cataracts) occur at doses far lower than those previously believed to cause cataracts [5, 6]. Statistical analysis of the available data suggests absence of a threshold dose, although if one does exist, it is possible that it is less than 0.1 Gy [7, 8]. Additionally, it appears that the latency period for radiation cataract formation is inversely related to the radiation dose [5]. Occupational radiation protection is a necessity whenever radiation is used in the practice of medicine. It is especially important for image-guided medical procedures [4, 9]. These procedures may involve high radiation dose rates in the interventional laboratory [10, 11]. Occupational radiation protection is necessary, not only during fluoroscopically guided procedures but also during CT-guided procedures, including CT fluoroscopy. CT fluoroscopy is not really fluoroscopy at all. It differs from conventional fluoroscopy in both equipment and technique. The radiation protection concerns for CT fluoroscopy differ somewhat, particularly in terms of avoiding an excessive radiation dose to the interventional radiologist’s hands [12, 13]. Occupational radiation protection requires both the appropriate education and training for the interventional radiologist and the availability of appropriate protection tools and equipment. Occupational radiation protection measures must also comply with local and national regulations, and should also consider the ergonomic detriment caused by personal protective devices [14–16]. Occupational radiation protection measures are necessary for all individuals who work in the interventional fluoroscopy suite. This includes not only technologists and nurses, who spend a substantial amount of time in a radiation environment, but also individuals such as anesthesiologists who may be in a radiation environment only occasionally. All of these individuals may be considered radiation workers, depending on their level of exposure and on national regulations. All workers require appropriate monitoring, as well as protection tools and equipment. They must also receive education and training appropriate to their jobs [14]. The level of training should be based on the level of risk. This guideline is intended to offer a basic review of the medical physics relevant to occupational radiation safety and to provide advice and guidance to interventional radiologists who perform procedures with the guidance of ionizing radiation and their staff. In this document, the emphasis is radiation protection during fluoroscopically guided procedures.

Occupational Radiation Protection in Interventional Radiology: A Joint Guideline of the Cardiovascular and Interventional Radiology Society of Europe and the Society of Interventional Radiology

Radiation exposure to patients during endoscopic retrograde cholangiopancreatography: A multicentre study in Finland

Practical Strategies to Reduce Pediatric CT Radiation Dose

X-ray-computed tomography (CT) has become one of the most important investigation procedures worldwide. The study aimed to assess image quality parameters, mainly noise, and radiation doses during abdominal examination. This study examined the diagnostic parameters (kilo voltage, tube current time product, slice thickness, and pitch) and their effects on image quality as well as the radiation doses received from computed tomography scanners using phantom. The study carried out in four CT centers in Sudan. The study applied prospective and experimental methods. The study demonstrated there was a linear correlation between diagnostic parameters and image noise. The reduction in milli-ampere second and peak kilo voltage increased the image noise. Moreover increasing the pitch led to an increase in the image noise, whereas increasing the slice thickness, reduced the image noise. There was also a linear relationship between kilo voltage and radiation dose at Elnileen diagnostic center characterized by an increase kilo voltages values which led to an increase in the radiation dose by 92% and a reduction in the image noise by 83%. However, at Antalya medical center, increasing in kilo voltage values led to an increase in the radiation dose by 35% and a reduction in the image noise by 26%. Also increasing in milli-ampere second values led to an increase in the radiation dose by 49% and a reduction in the image noise by 46% in a phantom compared with an increase in radiation dose by 82% and a reduction in the image noise by 51% in patients .The study found that an optimal protocol for adult abdominal scan at Antalya medical center was 4.22HU for image noise and 10.45 mGy for radiation dose when using 120 kVp, 300 mAs, 5 mm slice thickness and pitch of 0.8. At Elnileen diagnostic center, however, the optimal protocol was 5.4 HU for image noise and 5.4 mGy for radiation dose using 130 kVp, 50 mAs, 10 mm slice thickness and pitch of 2. In addition, the quality control tests for image quality parameters carried out at the two centers were performed by using the Chat Phan phantom and all the tests were within the acceptable limits, according to Sudan Atomic Energy Commission (SAEC) Standardizations. The study concludes with a number of recommendations, such as; the necessity for an extensive collaboration among manufacturers, radiologists, technologists and physicists to find a plan to decrease patient radiation dose (ALARA Principle) from computed tomography scanner.