Diagnostic Radiology Procedures Research Articles

An assessment of scattered radiation during fluoroscopic procedures in diagnostic radiology

The results of measurements of scattered radiation in the vicinity of a fluoroscopic X-ray facility are presented in this paper. Two different fluoroscopic systems, one with an undercouch tube and one with an overcouch tube, were compared. The dose rate was measured during the simulation of a fluoroscopy procedure, using an ionization chamber as a dosemeter. The distribution of scattered radiation has been determined and results show a much higher dose rate in cases of an overcouch tube arrangement. When X-ray units with an undercouch tube are concerned, under same exposure conditions, the dose rate is higher in cases of a vertical beam. Prior to the measurements, the ionization chamber was examined in order to evaluate its suitability as a survey meter used in diagnostic radiology. Measurements show that below 1.2 s, the ionization chamber gives an underestimation of dose rates. Therefore, in order to perform accurate measurements using this instrument, exposure times should be above 1.2 s.

Multiple gigantic renal cysts

Cystic renal lesions are very heterogeneous lesions which differ in ethiopathogenesis, morphological and clinical manifestations, and also in evolution and therapy. Classification of cystic lesions is complex, symptomatology is poor, and diagnosis is based on complete radiological diagnostic procedures. We presented a 20-year old patient with mild subjective symptoms. Objectively, he was without positive clinical signs and changes in biochemistry of blood. Using ultrasonography (US) multiple serous simple cysts were found in both kidneys. Using computed tomography (CT) multiple serous cysts were found, without changes in cystic walls, with preserved renal parenchyma and without cystic changes on other parenchymatous organs. Although renal cystic lesions are frequent in adult population, this is a rare example of a young adult man with simple, gigantic, serous cysts which do not produce clinical manifestations nor functional renal difficulty so far.

Controlling radiation exposure during interventional procedures in childhood cancer patients

Many pediatric cancer patients undergo multiple diagnostic and therapeutic radiologic procedures over the course of their illnesses and are therefore at high risk for radiation exposure. There are a variety of measures that radiologists can employ to reduce this risk. These include limiting the use of radiation whenever possible, using specific strategies to reduce radiation exposure during interventional procedures, using quality assurance programs to ensure compliance, and maintaining continuing staff radiation safety educational programs. Some of the diagnostic and therapeutic interventional radiologic procedures that are performed in pediatric oncology patients are discussed here, along with specific tips for managing radiation exposure.

Children's exposure to diagnostic medical radiation and cancer risk: epidemiologic and dosimetric considerations.

While the etiology of most childhood cancers is largely unknown, epidemiologic studies have consistently found an association between exposure to medical radiation during pregnancy and risk of childhood cancer in offspring. The relation between early life diagnostic radiation exposure and occurrence of pediatric cancer risks is less clear. This review summarizes current and historical estimated doses for common diagnostic radiologic procedures as well as the epidemiologic literature on the role of maternal prenatal, children's postnatal and parental preconception diagnostic radiologic procedures on subsequent risk of childhood malignancies. Risk estimates are presented according to factors such as the year of birth of the child, trimester and medical indication for the procedure, and the number of films taken. The paper also discusses limitations of the methods employed in epidemiologic studies to assess pediatric cancer risks, the effects on clinical practice of the results reported from the epidemiologic studies, and clinical and public health policy implications of the findings. Gaps in understanding and additional research needs are identified. Important research priorities include nationwide surveys to estimate fetal and childhood radiation doses from common diagnostic procedures, and epidemiologic studies to quantify pediatric and lifetime cancer risks from prenatal and early childhood exposures to diagnostic radiography, CT, and fluoroscopically guided procedures.

MEDICAL RADIATION AND PREGNANCY

Many pregnant women are exposed to radiation either as a patient or as an employee. Ignorance of the issues surrounding the radiation exposure of pregnant females is encountered among medical and other professionals, often leading to undue concern. The exposure of pregnant patients has to be justified and the risk/benefit carefully assessed. Diagnostic radiological and nuclear medicine procedures do not usually pose an increased risk to the fetus but therapeutic procedures and radiotherapy may do so. Risks are greatest during organogenesis and the first trimester. Informed consent and counseling of the patient are important. Pregnant females working with radiation also need separate consideration and careful monitoring. The author has personal experience of this working as an interventional radiologist throughout pregnancy. Education of professionals working with radiation and in medicine is essential and international organizations in radiation protection should continue to provide and support this role.

SU‐BB‐AUD B‐01: Ethics for Medical Physicists

Medical physicists frequently encounter situations that call for ethical decisions in their research, education, clinical practice and professional activities. Research medical physicists deal with ethical challenges such as conflicts of interest, experimental studies involving animals and human participants, peer review of papers and grant applications of colleagues, and co‐authorship of scientific publications and presentations. Physicists in clinical practice often are required to exercise professional judgment that may be at odds with their clinical and technology colleagues, and take responsibility for the accuracy of radiation delivery in radiation oncology and optimization of imaging procedures in diagnostic and nuclear radiology. Many physicists are mentors to graduate students and postdoctoral fellows, a special privilege that includes major ethical obligations to nurture and protect the young physicists in their care. At the professional level, medical physicists are expected to establish and sustain relationships with their colleagues that are a model of forthrightness and integrity.The AAPM's Code of Ethics establishes a foundation for ethical decisions and relationships by and among medical physicists. One fruitful way to interpret the Code of Ethics is by learning through discussion of case studies. Several case studies will be presented as time permits, focusing on ethical topics such as financial conflicts of interest, informed consent in human research studies employing normal volunteers, plagiarism of scientific publications, advertising of clinical technologies as a marketing strategy, high‐dose protocols in imaging, responsible mentoring of students towards graduation, and interviewing for a medical physics position.Every medical physicist faces ethical decisions, irrespective of the focus of his or her practice. Making the right decisions requires a solid grasp of ethical principles and experience in applying the principles in practice. This session is intended to provide some of the needed experience.A draft version of a Code of Ethics for AAPM members has been written by Task Group 109. This Code of Ethics will replace current discrete AAPM ethics policies into a single document and expand their scope. Current AAPM ethics policies primarily address medical physics members. The new code of ethics will also encompass other member types such as health physicists, regulators, vendors, physicians, scientists, engineers, those in training, or other health care professionals. The new code will address significant ethical issues for members: professional conduct, research ethics, education ethics, and business ethics. The format of the Code is a concise summary or core ethical values of AAPM members — Principles, followed by more extensive Guidelines that are intended to assist members to interpret and implement the Principles. This Code of Ethics replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4‐B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5‐C); Guidelines for Ethical Practice for Medical Physicists (PP 8‐D); and Ethics Complaint Procedure (PP 21‐A).

Complications of chronic otitis media with cholesteatoma during a 10-year period in Kosovo

We review and discuss the results of treatments for complications of cholesteatomatous chronic otitis media (CCOM) in a tertiary health care center. In a retrospective study, the medical records of patients with complications of CCOM who had undergone surgical treatment at the ENT Clinic of the University Clinical Center of Kosovo for the period 1994-2004 were reviewed. From a total of 1,803 patients suffering from CCOM, in 91 patients, 55 (60.4%) men and 36 (39.6) women, one or two complications are recorded. The mean age of the subjects was 30 years, and the age range was from 1 to 76 years. Extracranial (EC) complications were observed in 52 cases (57.1%), and intracranial (IC) complications were seen in 29 patients (31.9%). Twelve patients (11%) had multiple complications. For the EC cases, we found that subperiostal mastoidal abscess occurred in 26% of the all patients, facial nerve palsy was seen in 16.48% and labyrinthine fistula occurred in 10%. For the IC cases, meningitis (19.7%) and perisinusal abscess (15.3%) were the most common complications. The most often isolated pathogen from ear swabs was Proteus mirabilis in 33.3% of cases. The most frequent radiological diagnostic procedures were mastoid tip X-rays, which were performed in 77% of the patients, and computed tomography in 24%; magnetic resonance imaging was not performed on any of the patients during the study period. Patients with EC complications were treated in the ENT Clinic, whereas patients with IC complications, after otologic surgical procedures, were transferred to the Neurosurgery Clinic or to the Clinic for Infectious Diseases. In this series, three patients (3.3%) died as a result of complications, while the remaining 96.7% survived. Complications of COM with cholesteatoma can represent life-threatening conditions, and close cooperation between otosurgeons, neurosurgeons and infectious disease specialists is mandatory.

Diagnostic radiation procedures and risk of prostate cancer.

Exposure to ionising radiation is an established risk factor for many cancers. We conducted a case–control study to investigate whether exposure to low dose ionisation radiation from diagnostic x-ray procedures could be established as a risk factor for prostate cancer. In all 431 young-onset prostate cancer cases and 409 controls frequency matched by age were included. Exposures to barium meal, barium enema, hip x-rays, leg x-rays and intravenous pyelogram (IVP) were considered. Exposures to barium enema (adjusted odds ratio (OR) 2.06, 95% confidence interval (CI) 1.01–4.20) and hip x-rays (adjusted OR 2.23, 95% CI 1.42–3.49) at least 5 years before diagnosis were significantly associated with increased prostate cancer. For those with a family history of cancer, exposures to hip x-rays dating 10 or 20 years before diagnosis were associated with a significantly increased risk of prostate cancer: adjusted OR 5.01, 95% CI 1.64–15.31 and adjusted OR 14.23, 95% CI 1.83–110.74, respectively. Our findings show that exposure of the prostate gland to diagnostic radiological procedures may be associated with increased cancer risk. This effect seems to be modified by a positive family history of cancer suggesting that genetic factors may play a role in this risk association.

Sedating children for radiological procedures: an intensivist’s perspective

There has been a phenomenal increase in the number of diagnostic and interventional radiology procedures in the past decade. Consequently, the demand for fast, effective and safe sedation for children has grown exponentially as well. The parents expect a relatively pain and anxiety free experience for their children. The radiologists expect the child to be cooperative and not move. Meanwhile, the regulatory standards for sedation have become more stringent. Moreover, with the advent of PACS and digital radiology, the radiologist reading the diagnostic studies may not be in the same room, or even in the same country as the patient undergoing the tests. The time pressures has increased tremendously on the pediatric radiologists and the ‘opportunity costs’ of supervising the sedation of a child is steep. The “scanner-time” is scarce and there is no scope for ineffective and inefficient sedation regimen. Many different models are being introduced in different institutions for providing effective, efficient and safe sedation to children undergoing radiological procedures. The following viewpoint reflects the perspective of a pediatric intensivist-based sedation program.

Pharmaceutical Innovation and U.S. Cancer Survival, 1992-2003: Evidence from Linked SEER-MEDSTAT Data

This study examines the impact of pharmaceutical innovation and other factors on the survival of U.S. cancer patients during the period 1992-2003. In particular, it investigates whether cancer survival rates increased more for those cancer sites that had the largest increases in the proportion of chemotherapy treatments that were "new" treatments. We control for other types of medical innovation, i.e. other pharmaceutical innovation, and innovation in surgical procedures, diagnostic radiology procedures, and radiation oncology procedures.Data on observed survival rates, the number of people diagnosed, mean age at diagnosis, and stage distribution are obtained from the National Cancer Institute’s SEER public-use data. Estimates of rates of innovation in chemotherapy and other treatment and diagnostic procedures are constructed from the MEDSTAT MarketScan database and other data sources. Treatment innovation indicators based on MEDSTAT data are likely to be useful, albeit noisy, indicators of the treatment innovation experienced by patients in SEER registries. This sampling error is likely to bias the coefficients on the treatment innovation measures towards zero.We compute weighted least-squares estimates of 6 versions of a survival model, based on different survival intervals and functional forms. The chemotherapy vintage coefficient is positive and significant in every model. This indicates that the cancer sites whose chemotherapy vintage (measured by the share of post-1990 treatments) increased the most during the period 1992-2003 tended to have larger increases in observed survival rates, ceteris paribus.We estimate how much lower the survival rate from all cancer sites combined would have been during 1993-2001 in the absence of post-1992 chemotherapy innovation. The estimates indicate that chemotherapy innovation accounted for 74% of the increase in the 1-year observed survival rate for all cancer sites combined during the period 1992-2001. Chemotherapy innovation accounted for smaller fractions of the increases in the 2-year and 3-year observed survival rates for all cancer sites combined during the same period: 51% and 29%, respectively.The coefficients on measures of non-pharmaceutical medical innovation (in radiation oncology, diagnostic radiology, and surgery innovation) are generally not significant. However these measures may be less reliable than the drug innovation measure. They were based upon the year in which the AMA established a new procedure code, which may be a far less meaningful indicator of innovation than the year in which the FDA first approved a drug. This topic warrants further research.

Gadolinium-induced nephrotoxicity

Because of the well-documented risk of acute renal failure with the iodinated contrast media in patients with underlying chronic renal insufficiency, the use of intravenous gadolinium-based contrast media in magnetic resonance imaging for diagnostic and interventional radiology procedures has become a well-established clinical practice in the recent years. Although originally thought to be safe and lack the nephrotoxic effects of iodinated contrast media, gadolinium-based contrast media have recently been reported to induce a usually reversible decrease of glomerular filtration rate in a high-risk population group, especially in patients with altered baseline renal function. Here we present the current experimental and clinical evidence on this new challenge for the nephrologist, gadolinium-induced nephrotoxicity in patients with chronic kidney disease.

A Case of Biliary Cystadenocarcinoma with Intracystic Bleeding

Biliary cystadenocarcinomas are rare cystic tumors arising from the biliary epithelium. Symptoms vary and are sometimes absent. Most lesions are found incidentally during diagnostic radiologic procedures or surgical exploration for unrelated conditions. We describe an 80-year-old man with anemia due to intracystic bleeding. A computed tomographic scan showed a low-density hepatic lesion with thick, irregular walls and septa. Left lobectomy with cholecystectomy was performed. Histological examination revealed that the surgical specimen was a biliary cystadenocarcinoma. The concentrations of both carcinoembryonic antigen and CA19-9 were high in the cyst contents. The patient died of pneumonia 1 year 4 months after the operation, without the recurrence of cystadenocarcinoma.

Anaesthesia in the radiological suite (remote location) on an outpatient basis

The recent advances in diagnostic radiology and imaging studies have made these techniques an important part of the preoperative work-up of surgical patients. Today, most preoperative examinations are scheduled and performed on an outpatient basis. Most of these examinations are brief and cause no discomfort, but some are long and require immobility for a prolonged period. This presents a challenge for adults and is a virtual impossibility for young children. Other examinations can be painful or extremely uncomfortable and will require sedation/analgesia. In many institutions the anaesthesiologists have taken a lead role in providing an essential service to children undergoing radiological diagnostic and/or therapeutic procedures. This ranges from providing general anaesthesia, deep sedation, sedation analgesia, or supervising the provision of other types of sedation that is administered by the radiology staff. This paper will describe the anaesthesia/sedation service as performed at Children’s National Medical Center (CNMC) in Washington, DC, USA, as an example of how a team approach can best utilise very scarce resources to best provide comfort to and ensure the safety of paediatric patients.

Endobronchialer Ultraschall zur Diagnostik im Mediastinum

The development of endobronchial ultrasound (EBUS) is one of the most important advances in bronchoscopy in recent years. Two different techniques are available which improve sonographic diagnostics of the mediastinum and staging in patients with lung and non-lung cancer. Radial EBUS and the technique of ultrasound-controlled transbronchial needle aspiration (TBNA) are now routine practice in many pulmonary centers. Their clinical application and diagnostic benefit have been established in many studies comparing them with conventional radiologic methods and other diagnostic procedures. Endobronchial ultrasound as a diagnostic tool is expected to gain importance in the near future. Especially the method combining EBUS and TBNA may replace more invasive methods such as mediastinoscopy for evaluating patients with unknown mediastinal lesions or for staging patients with lung cancer.

Diagnostic Imaging: Radiation Dose and Patients' Concerns

Exposure to ionizing radiation during diagnostic radio-logic procedures carries small but real risks, and children, young adults, and pregnant women are especially vulnerable. Exposure of patients to diagnostic energy levels of ionizing radiation should be kept to the minimum necessary to provide useful clinical information and allay patients' concerns about radiation-related risks.

Diffusion of Medical Progress: Early Spinal Immobilization in the Emergency Department

To examine the spread of new techniques of spinal care through one state's emergency departments (EDs). This was a telephone survey of all 36 EDs in a single state. One physician from each ED was contacted and given a short structured survey instrument to determine when patients who arrived at the ED on backboards were removed from the backboards. Removal was classified as "immediate" if it was done before clinical or radiographic exclusion of cervical spine injury and "delayed" if it was done only after interpretation of any indicated diagnostic radiologic procedures. Further questions were asked to determine if all physicians in the group used the same technique and how this technique had been adopted. In all but four hospitals, patients were removed from backboards in the same manner by all physicians, using a protocol or standard procedure. Fifteen of these did immediate and seventeen did delayed removal. In all but one case, the approach of immediate removal was initiated at the hospital by a physician trained or recently working at a university facility. Eight respondents stated that transport service requirements influenced their decision. Although logic and the medical literature support removing all patients from a backboard immediately, physicians were unlikely to change their practice after their formal training had been completed until a new member of their group had done so.

Renal consequences of HIV and HIV therapy

To highlight the latest data documenting new concerns about renal function in HIV-infected patients, with regard to acute renal failure with its known burden of mortality and prolonged hospitalization, antiretroviral medication errors potentially enhancing the risk of the emergence of viral resistance, outcome of HIV dialysis patients, and renal involvement in the immune restoration inflammatory syndrome. The incidence of acute renal failure in HIV-infected patients is increasing, secondary to ageing, chronic kidney disease and liver disease. Histological documentation is critical for the best diagnosis. Antiretroviral medication errors are very frequently encountered in HIV-infected patients, which may be associated with decreased survival as a result of the under/over-prescription of highly active antiretroviral therapy in chronic kidney disease or end-stage renal disease. Evaluating the glomerular filtration rate with plasma creatinine and one of the validated formulae is critical in HIV-infected patients to determine the optimum follow-up strategy and critical therapeutic measures, such as drug dosage adaptation. High-risk radiological diagnostic procedures or potentially nephrotoxic drugs should be used with caution. These measures should reduce the rate of progression of chronic kidney disease. Increasing numbers of dialysed HIV-infected patients emphasize the need for the better coordination of care.

The diagnostic performance characteristics of imaging techniques used in the management of scaphoid fractures

Purpose of review: To evaluate the available scientific evidence regarding various radiological diagnostic techniques for scaphoid fractures in terms of diagnostic performance characteristics that take disease prevalence into account. Recent findings: Modified radiographs, bone scans, computed tomography, high-resolution ultrasound, and magnetic resonance imaging are all able to detect radiographically occult fractures. An analysis of current data suggests that magnetic resonance imaging is optimal, but the potential for false positives with magnetic resonance imaging is a concern that has not been fully addressed. Diagnosis of fracture displacement is less well studied, but magnetic resonance imaging and computed tomography are both useful. Summary: The shortcomings of diagnostic imaging in scaphoid fracture management are magnified by the low prevalence of true fractures among suspected fractures and of displaced fractures among radiographically visible fractures. The diagnostic performance characteristics of scaphoid imaging can be improved as much by developing better clinical diagnostic criteria that increase the prevalence of true fractures and fracture displacement among patients in whom these are suspected as it can by developing diagnostic imaging techniques with fewer false positive tests.

SU-FF-T-211: Evaluation of Diagnostic Radiation Exposure Risks From CT Scans for a Radiosensitive Patient

Purpose: To estimate the effective radiationdose a radiosensitive patient received from a series of computed tomography(CT) scans and to make estimates for the excessive cancer risk due to that exposure. Method and Materials: The Imaging Performance Assessment of Computed Tomography Scanners/NRPB (ImPACT, St. George's Hospital, Tooting, London) dose estimation spreadsheet was used to estimate effective dose from 14 CTimage series obtained from an Ataxia‐telangiectasia (A‐T) patient. The scans were all taken within 4 months. For each exam, scanner parameters (i.e. kVp, mAs, etc) were retrieved from the dicom header. Excessive leukemia and cancer risks were calculated based upon the findings of a 15‐country long‐term study of nuclear power plant workers (Cardis et al. 2005). Results: The estimated effective dose for the CT scans was a combined 124 mSv and an average dose of 8.9 mSv per exam. The excessive cancer risk was 12% and the excessive leukemia risk was 24%, using estimates for normal subjects. Conclusions: This case indicates that diagnosticradiation exposure can pose an unintentional risk to radiosensitive patients. Given the clinical hypersensitivity to radiation and cancer predisposition for A‐T patients, most have been protected from receiving standard radiation therapy to treat their cancers. On the other hand, they readily undergo diagnostic radiological procedures which incur smaller radiation exposure. The effective dose and cancer risk estimates from this study show a need for monitoring the radiation exposure from all medical sources for radiosensitive patients. Other diagnostic modalities can be suggested for radiosensitive patients in order to monitor medical responses and progress, such as magnetic resonance imaging or ultrasound.

Patient dose measurements in diagnostic radiology procedures in Korea

This study is the first nationwide investigation aimed at estimating the patient dose for radiographic examinations in Korea including gastrointestinal studies, computed tomography and mammography. The survey data from 161 hospitals and the dose data from 32 hospitals were analysed. The third quartile entrance surface dose, dose area product (DAP), weighted CT dose index (CTDIw) and mean glandular dose (MGD) were reported. All the estimated doses were less than the stated International Atomic Energy Agency (IAEA) reference levels for radiographic examinations. However, DAPs for the fluoroscopic examinations had higher dose values than the IAEA reference levels. In addition, the CTDIw and MGD were lower than the IAEA reference levels.