ABSTRACT
The radiation exposure of an unborn child should be principally avoided, whenever it is medically reasonably possible; therefore, the identification of pregnant patients is the first and the most important step in radiation protection of the unborn child. However, in cases of emergency saving the life of the patient has a higher priority than the radiation protection of the unborn child. In this review article, we present a longitudinal section through the national and international literature and guidelines as a basis for radiological management of a (possibly) pregnant patient. We also list some radiological procedures recommended in the literature for a series of maternal indications considering the contraindications of each method during pregnancy and radiation protection of the unborn child.
Subject(s)
Magnetic Resonance Imaging/standards , Practice Guidelines as Topic , Pregnancy Complications/diagnostic imaging , Radiation Injuries/congenital , Radiation Injuries/prevention & control , Radiation Protection/standards , Female , Germany , Humans , Magnetic Resonance Imaging/adverse effects , Pregnancy , Pregnancy Complications/surgery , Radiation Dosage , Radiation Injuries/etiology , Radiography , Radiometry/standardsABSTRACT
CLINICAL/METHODICAL ISSUE: Problems arise due to the increased clinical use of computed tomography (CT) and the high radiosensitivity of children. STANDARD RADIOLOGICAL METHODS: The ALARA concept (as low as reasonably achievable) prevails in pediatric radiology. METHODICAL INNOVATIONS: Justified indications and full utilization of available dose optimization methods. PERFORMANCE: Medical physicists and the manufacturers should support pediatric radiology in the implementation of the ALARA concept. ACHIEVEMENTS: The referring physicians and radiology staff should be integrated into training programs. PRACTICAL RECOMMENDATIONS: Sufficient diagnostic image quality is paramount and not the pretty images.
Subject(s)
Neoplasms, Radiation-Induced/prevention & control , Pediatrics/methods , Radiation Dosage , Radiation Protection/methods , Radiometry/methods , Tomography, X-Ray Computed/methods , Child , Humans , Risk Management/methodsABSTRACT
Rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma are the most common malignant tumors of the musculoskeletal system in childhood and adolescence representing about 10% of newly diagnosed cancers in children and adolescents.In the last two decades the prognosis of patients with such malignancies improved significantly. On the one hand because of the advances in chemotherapy and orthopedic surgery, on the other hand also because of the innovations in radiological diagnostics. The precise pre-therapeutical staging of tumors of the musculoskeletal system provides important prognostic information and has impact on the entire therapy management. During respectively after therapy, imaging is extremely important in the follow-up and in diagnosing a possible recurrent disease.Modern imaging diagnostics of musculoskeletal tumors basically consist of conventional X-ray, of computed tomography (CT) and magnetic resonance imaging (MRI), and of modalities of nuclear medicine such as szintigraphy, positron emission tomography (PET) and PET CT.
Subject(s)
Bone Neoplasms/diagnostic imaging , Muscle Neoplasms/diagnostic imaging , Osteosarcoma/diagnostic imaging , Prostatic Neoplasms/diagnosis , Rhabdomyosarcoma/diagnostic imaging , Sarcoma, Ewing/diagnostic imaging , Tomography, X-Ray Computed/methods , Adolescent , Adult , Age Factors , Bone Neoplasms/diagnosis , Child , Child, Preschool , Diagnosis, Differential , Female , Femoral Neoplasms/diagnosis , Femoral Neoplasms/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Muscle Neoplasms/diagnosis , Osteosarcoma/diagnosis , Prognosis , Rhabdomyosarcoma/diagnosis , Sarcoma, Ewing/diagnosisABSTRACT
PURPOSE: The purpose of this study was to define objective and reproducible standards for the quality of CT images as a function of radiation doses and therapeutic validity. MATERIALS AND METHODS: CT images of the paranasal sinuses of 145 patients (77 female, 68 male; 5-83 years old; mean age, 39.9 years) were classified both subjectively (with a view toward their validity for the planning of functional endoscopic sinus surgery, FESS) and objectively by defining the pixel noise (the standard deviation, STD, of the CT number) in a homogeneous region of interest (ROI), centered on the M. masseter and on the frontal lobe. These measurements were then compared to measurements obtained from scan images of a water-filled Perspex phantom. RESULTS: The pixel noise measured in the phantom images was nearly identical to the respective values on the M. masseter on the patient images. The use of an edge-enhancing reconstruction algorithm and low-dose protocols, with a pixel noise amounting to 70-90 Hounsfield Units (HU), are indicated for children, chronic sinusitis, and septum deviation, while standard protocols, with a pixel noise of 50-70 HU, are recommended for the preoperative planning and postoperative control of FESS. The pixel noise for high-dose protocols is less than 50 HU; nonetheless, such protocols should generally be avoided. CONCLUSION: The pixel noise measured in a water-filled Perspex phantom is indicative of the clinical potential and image quality of paranasal sinus CT scans. Alternatively, the M. masseter can be chosen as an ROI to measure the pixel noise in order to obtain a rough estimate of the image quality or radiation dose class.
Subject(s)
Dose-Response Relationship, Radiation , Paranasal Sinus Diseases/diagnosis , Paranasal Sinuses/diagnostic imaging , Tomography, X-Ray Computed/standards , Adolescent , Adult , Aged , Aged, 80 and over , Algorithms , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Phantoms, Imaging , Radiographic Image Enhancement/methods , Reproducibility of Results , Tomography, X-Ray Computed/methodsABSTRACT
In the past years, multislice CT (MS-CT) has become an important diagnostic modality for the radiological evaluation of the thorax in children and adolescents. However, the higher stochastic radiation risks in pediatric patients, as compared to adults, necessitate a prudent use of MS-CT. This article presents an overview of the benefits of multislice CT and a variety of possibilities for radiation reduction in pediatric patients of different ages.
Subject(s)
Image Processing, Computer-Assisted , Radiographic Image Enhancement , Radiography, Thoracic , Thoracic Diseases/diagnostic imaging , Tomography, Spiral Computed , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Radiation Dosage , Sensitivity and Specificity , Technology Assessment, Biomedical , Thoracic Diseases/congenitalABSTRACT
Recent studies in the USA and Europe state that computed tomography (CT) scans compromise only 3-5% of all radiological exams, but they contribute 35-45% of total radiation dose to the patient population. These studies lead to concern by several public authorities. Basis of CT-dose measurements is the computed tomography dose index (CTDI), which was established 1981. Nowadays there are several modifications of the CTDI values, which may lead to confusion. It is suggested to use the standardized CTDI-100 w. value together with the dose length product in all CT-examinations. These values should be printed on all CT-images and allows an evaluation of the individualized patient dose. Nowadays, radiologist's aim must be to work at the lowest maximal diagnostic acceptable signal to noise ratio. To decrease radiation dose radiologist should use low kV and mA, but high pitches. Newly developed CT-dose-reduction soft-wares and filters should be installed in all CT-machines. We should critically compare the average dose used for a specific examination with the reference dose used in this country and/or Europe. Greater differences should caution the radiologist. Finally, we as radiologists must check very carefully all indications and recommend alternative imaging methods. But we have also to teach our customers-patients and medical doctors who are non-radiologists-that a 'good' image is not that which show all possible information, but that which visualize 'only' the diagnostic necessary information.
Subject(s)
Tomography, Spiral Computed/methods , Europe , Humans , Radiation Dosage , Radiation Protection/standards , Tomography, Spiral Computed/standards , United StatesABSTRACT
Technological improvements in digital radiography and computed tomography have led to a substantial increase of radiation dose that subjectively cannot be detected. In order to reduce dose in a form that may be used in clinical practise, the quality of digital radiograms and computed tomography images should be classified in three classes. Low-dose investigations are indicated in children, in case of therapy control and for imaging organs with high differences in tissue contrast. High-dose investigations are scarcely indicated and middle-dose investigations should be performed in all other remaining clinical situations. Dose recommendations given by vendors in radiology should be viewed critically.
