| ICRP Ref 4836-8337-6684 | ||||
| Annals of the ICRP Publication 1XX: DRLs in Medical Imaging | ||||
| Last Name | First Name | Page # | Line # | Comment |
| Frush | Don | 6 | 16 | " . . . this tool, application of the DRL . . ." |
| Frush | Don | 6 | 17 | newer imaging technologies, and additional difficulties in pediatric practice expecially due to the wide variety of patient sizes." |
| Frush | Don | 6 | 18 | guidance on these issues. A corrective action plan should be impemented and documented without undue delay to determine possible reasons. |
| Frush | Don | 12 | 6 | . . . Appropriate. Variation in patient radiation dose for two paediatric patients that are the same size when the area of anatomy irradiated is the same for the same clinical indication is not appropriate if it is due . . . |
| Strauss | Keith | 17 | 18 | may include SSDE conversion factors from CTDIvol based on attenuation data of the patient acquired during the projection scan(s) of the scanned patient (AAPM, 2011). |
| Strauss | Keith | 70 | 14 | . . .performed. While data can be found in the literature that provides Ka,r, PKA, or fluoroscopy time at multiple sites for adult interventional fluoroscopic procedures, this type of data has only been published recently for paediatric examinations and the number of cases in these studies typically are more limited than desired. (A) |
| Strauss | Keith | A. Strauss KJ, Racadio JM, Johnson N, et.al. Estimates of diagnostic reference levels for pediatric peripheral and abdominal fluoroscopically guided procedures. AJR2015; 204:W713-W719. Doi:102214/AJR.14.13630 | ||
| Strauss | Keith | 81 | 25 | " . . . Range), the LAT or AP dimension of the actual patient is easily determined by a radiological technologist equiped with a standard caliper designed to measure patient thickness, or to utilize . . . " |
| Strauss | Keith | 82 | 6 | "estimates (SSDE) may be a better choice as a recommended CT DRL quantity when DRLs are established for patient sizes with attenuation characteristics that are not reasonably modeled by one of the two standard CTDI phantoms, e.g.the vast majority of pediatric patients and adult patients larger than standard size. |
| Strauss | Keith | 83 | 21 | "data reflect values for more than one standard-sized patient. |
| Strauss | Keith | 92 | 8 | imaging. Ideally, seven or more size ranges should be established between premature infants (< 2 kg) and teenages, ~ 60 kg, that are smaller than standard sized adults. |
| Strauss | Keith | 92 | 16 | " . . . Paediatrics. For CT, precise definition of the scan length that excludes primary irratiation of unnecessary regions of the paediatric body is extremely important in managing the patient''s DRL. |
| Strauss | Keith | 92 | 20 | ". . . Indicator. While the thickness of the body region imaged (easily measured with standard calipers) provides the most accurate classification of paediatric patient size, the current weight of the patient is the next best substitute if available. |
| Strauss | Keith | 92 | 24 | ". . . Measure. The most accurate classification of patient size is based on the thickness of the patient body region imaged. |
| Strauss | Keith | 92 | 30 | " . . . The typical DRL quantities . . . " |
| Strauss | Keith | 92 | 36 | " . . . Quantities to provide a more accurate estimate of paediatric patient dose as a function of patient size as opposed to typical DRL quantities that estimate the dose delivered to standard phantoms that poorly model the attenuation characteristics of paediatric patients." |
| Strauss | Keith | 93 | 10 | ". . . (ICRP, 2013). The geometry and spacing of the three sensors of AEC systems are designed for an adult-sized body which limits the application of AEC controlled exposures for paediatric patients. The small size of the trunk of the smallest patients and of the limbs of most paediatric patients require manual as opposed to AEC controlled exposures because small bodies cannot adequately cover the entire area of the individual AEC sensors." SHORT EXPOSURE TIMES ARE NOT AN ISSUE. THE TUBE CURRENT SHOULD BE LOWERED FOR SMALL PATIENTS SO THE EXPOSURE TIME RANGES BETWEEN 5 - 10 MILLISECONDS. |
| Frush | Don | 93 | 15 | ''. . .dose may occur for two similar sized patients undergoing the same type of clinical exam, due to inappropirate technique . . ." |
| Strauss | Keith | 93 | 24 | " . . . apply for children which must recognize the unique design characteristics of a given manufacturer''s fluoroscopic unit and configure the unit in a manner to take advantage of the unit''s strengths while minimizing the effects of its design weaknesses." |
| 93 | 28 | ". . . premature infant (< 1 kg) to that of an obese . . ." | ||
| Frush | Don | 94 | 4 | ". . . entail radiation risk. Independent of variation in patient size, establishment of DRLs should involve a broad scope of practice types. Routine patient doses in academic centers may be different than typical patient doses in non academic practices due to differences in confidence levels/familiarity with paediatric diseases and body sizes." |
| Strauss | Keith | 94 | 10 | ". . . Available measure. While the thickness of the body region imaged (easily measured with standard calipers) provides the most accurate classification of paediatric patient size, the current weight of the patient is the next best substitute if available. In the future, the equivalent thickness of the patient based on the physical thickness of the patient and attenuation characteristics of the anatomy as determined by the CT scanner may result in the automated calculation and display of SSDE on the display of the CT scanner. |
| Strauss | Keith | 94 | 28 | ". . . grouping survey data into attenuation-bands, i.e., small ranges of patient thickness which results in a small change of the total attenuation of the x-rays between the smallest and largest patient within a given group of patient sizes." |
| Strauss | Keith | 94 | 29 | "For radiography and fluoroscopy, weight can be used to group paediatric patients into size groups for the purpose of determining DRL values and evaluating local practice. |
| Frush | Don | 94 | 36 | . . . in most hospitals, compared to the number of adult examinations, data collection . . ." |
| Frush | Don | 96 | 21 | Phantom size does not address the variability in size of children or adults, and patient size has a . . . |
| Strauss | Keith | 96 | 25 | " . . . standard coefficients. While the thickness of the body region imaged (LAT dimension easily measured with standard calipers) provides the most accurate classification of paediatric patient size, the current weight of the patient is the next best substitute if available. In the future, the equivalent thickness of the patient based on both the physical thickness of the patient and attenuation characteristics of the anatomy as determined by the CT scanner may result in the automated calculation and display of SSDE on the display of the CT scanner. |
| Strauss | Keith | 96 | 30 | " . . . its effect on patient dose could be accounted for." |
| Strauss | Keith | 96 | 36 | ". . . Reduce patient doses. Likewise, if iterative reconstruction is available and used by the operator at a given strength, the properly revised CT scan protocols may reduce patient dose. |
| Strauss | Keith | 97 | 10 | to age (ICRU, 2005). This type of data (AP and LAT size) is also suppled by Kleinman et.al (2010) allowing calculation of effective diameter as a function of age. |
| Frush | Don | 97 | 16 | " . . . Procedures. The DRL metrics recommended for adults . . ." |
| Strauss | Keith | 97 | 19 | "paediatric DRLs. For radiography and fluoroscopy, weight can be used to establish paediatric patient group "sizes". However, this can be performed more accurately by measuring the thickness of the patient anatomy that will be directly irradiated with a set of calipers . This is particularly applicable to radiography performed with digital detectors during which numerous variables make it a challenge to deliver the correct entrance air kerma to the image receptor as a function of wide variation of paediatric patient size. Any variable that can be eliminated by a simple measurement, such as patient thickness with a calipers, helps to standardize the dose used for a given size patient and allows more accurate development of DRLs as a function of patient size. |
| Strauss | Keith | 107 | 3 | . . . future. Additional information on the audit process and steps that can be taken to improve the acquisition process for pediatric patients can be found elsewhere. (B) |
| B. IAEA Human Health Series No. 24 Dosimetry in Diagnostic Radiology for Paediatric Patients. 2013, Vienna, Austria, 159 pp. | ||||
| Strauss | Keith | 108 | 18 | . . . subsections and elsewhere. (B) When medium to large adult patients are imaged, the challenge for the equipment manufacturer is producing radiation at a high rate to reduce the exposure time required to acquire the image and freeze the motion within the patient''s body. In the case of imaging the small bodies of paediatric patients steps are required to address the significantly reduced necessary air kerma rate at the entrance plane of the patient. The imaging equipment manufacturer may not be aware of the need for this type of reconfiguration of acquisition parameters when imaging the small paediatric patient. |
| Strauss | Keith | 110 | 7 | . . . dose. This is especially true when imaging the small trunk or head of the young paediatric patient or the extremities of any patient, paediatric or adult sized. |
| Strauss | Keith | 112 | 14 | . . . Protection, especially for paediatric examinations. For the majority of procedures, adult or paediatric, technique . . . |
| Strauss | Keith | 112 | 21 | . . . This may be more of a problem for manufacturer suggested protocols for paediatric examination than for adult examinations. As discussed in Section . . . |
| Strauss | Keith | 112 | 26 | . . . identical models running identical revisions of system software. |
| Strauss | Keith | 113 | 10 | . . . patients. One should not assume that acceptable noise levels for CT image of small and average sized adults will be acceptable for small paediatric patients. Typically, lower levels of quantum mottle are required in paediatric images of the smallest patients which requires unique settings of image quality indicators as a function of patient size. |
| Strauss | Keith | 113 | 19 | . . . area. If the scanner manufacturer''s application specialists do not have recommendations for changes to adult protocols for paediatric patients performed on their scanner, universal protocols for paediatric patients based on the protocols recommended on the Image Gently website should be helpful in establishing reference CTDIvol, DLP, or SSDE values as a function of patient size.(C) Once reference dose indices as a function of patient size are determined by a particular site, the radiologists, technologists, and medical physicist(s) at the site should work in collaboration with application specialists and other resource individuals from the manufactuer to ensure that the necessary modifications to paediatric protocols have been made to deliver the desired image quality and patient radiation dose. |
| Strauss | Keith | C. Strauss KJ. Dose indices: Everybody wants a number. Pediatr Radiol (2014) 44 (Suppl 3):pp. S450-S459. | ||
| Strauss | Keith | 115 | 35 | . . . testing is necessary to confirm that this is not the case must be completed and analyzed prior to first clinical use of the chnages. |
| Strauss | Keith | 119 | 3 | . . . being evaluated, to the specific study being performed, and to the specific size of the patient. |
| Strauss | Keith | 119 | 28 | . . . (SSDE) provides more accurate estimates of paediatric patient doses, than CTDIvol or DLP which are both indices of the dose to standardized phantoms. |
| Strauss | Keith | 121 | 24 | or different paediatric patient sizes |
| Strauss | Keith | 122 | 28 | . . .DRLs. This requires adjustment for the varying sizes of different patients.The method illustrated in Figure 6.1 may be a reasonable way to present the limited paediatric data. |
| Strauss | Keith | 123 | 34 | examination and the actual size of the of the paediatric patient irradiated. |