Scoliosis Radiography Research Articles

Investigation of the Relationship Between Cobb Angle and Inflammatory Markers in Patients with Adolescent Idiopathic Scoliosis

Introduction: The role of inflammation and immune system pathologies in individuals with Adolescent Idiopathic Scoliosis (AIS) has recently been the focus of research. It has been reported that neutrophil/lymphocyte (NLR), platelet/lymphocyte (PLR) and monocyte/lymphocyte (MLR) ratios may be markers of inflammation severity. In addition, systemic immune inflammation index (SII), including peripheral neutrophils, lymphocytes, monocytes and platelets, systemic inflammatory response index (SIRI) and systemic inflammation total index (AISI) are also known as inflammation marker indexes. This study aimed to investigate the relationship between NLR, PLR, MLR, SII, SIRI, AISI and Cobb angle in individuals with AIS. Materials and Methods: Pediatric patients aged 10-18 years who were requested to have scoliosis radiography with a preliminary diagnosis of AIS were retrospectively screened. Cobb angles, neutrophil, lymphocyte, platelet, monocyte, neutrophil percentage, white blood cell (WBC), hemoglobin values ​​were recorded. NLR, PLR, MLR, SII, SIRI, AISI values ​​were calculated. Patients were divided into 4 groups according to their Cobb angles. It was examined whether there was a difference between the groups in terms of neutrophil, lymphocyte, platelet, monocyte, neutrophil percentage, WBC, Hemoglobin, NLR, PLR, MLR, SII, SIRI, AISI values. It was examined whether there was a correlation between the Cobb angle and NLR, PLR, MLR, SII, SIRI, AISI in patients diagnosed with scoliosis and having a Cobb angle greater than 10 degrees. Results: A significant difference was observed between Groups 2 and 4 in NLR. While a positive correlation was observed between Groups 2, 3, and 4 patients with a Cobb angle greater than 0 and NLR; no correlation was observed between PLR, MLR, SII, SIRI, AISI. Conclusion: NLR, which is known to be associated with the severity of inflammation, is a marker that correlates with the scoliosis angle in patients with AIS. Larger-scale studies are needed to elucidate the relationship between AIS and NLR.

Performance and reliability assessment of a lower dose, task-based scoliosis radiography protocol in pediatric patients.

Follow-up scoliosis radiographs are performed to assess the degree of spinal curvature and skeletal maturity, which can be done at lower radiation exposures than those in standard-dose radiography. Describe and evaluate a protocol that reduced the radiation in follow-up frontal-view scoliosis radiographs. We implemented a postero-anterior lower dose modified-technique for scoliosis radiography with task-based definition of adequate image quality and use of technique charts based on target exposure index and patient's height and weight. We subsequently retrospectively evaluated 40 consecutive patients who underwent a follow-up radiograph using the modified-technique after an initial standard-technique radiograph. We evaluated comparisons of proportions for subjective assessment with chi-squared tests, and agreements of reader's scores with intraclass correlation coefficients and Bland-Altman plots. We determined incident air kerma, exposure index, deviation index/standard deviation, dose-area product (DAP), and effective dose for each radiograph. We set statistical significance at P<0.05. Forty patients (65% female), aged 4-17years. Median effective dose was reduced from 39 to 10 µSv (P<0.001), incident air kerma from 139 to 29 µSv (P<0.001), and DAP from 266 to 55mGy*cm2 (P<0.001). All modified-technique parameters were rated with a mean score of acceptable or above. All modified-technique measurements obtained inter- and intra-observer correlation coefficient agreements of 0.86 ("Good") or greater. Substantial dose reduction on follow-up scoliosis imaging with existing radiography units is achievable through task-based definition of adequate image quality and tailoring of radiation to each patient's height and weight, while still allowing for reliable assessment and reproducible measurements.

PROSEDUR PEMERIKSAAN RADIOGRAFI VERTEBRA THORAKOLUMBAL PADA KLINIS SKOLIOSIS

The procedure of radiographic examination of thoracolumbar vertebrae of scoliosis according to Lampignano and Kendrick (2018), journal by Gray (1983) and journal by Levy (1996) in erect patient position further recommends the PA projections because the dose to organs that are sensitive to radiation such as breast, thyroid and gonad and the risk of getting cancer in these organs is significantly reduced compared to AP projections. While the procedure for radiographic examination of thoracolumbar vertebrae of scoliosis in the Radiology Installation RSUD Bendan Pekalongan uses AP and AP right and left bending projections in erect patient position. This study aims to determine the radiographic examination procedures of thoracolumbar vertebrae in scoliosis and the reasons for using AP and AP right and left bending projections in erect patient position. This type of research is a qualitative research with a case study approach. Data was collected in March-April 2020 in the Radiology Installation RSUD Bendan Pekalongan by observation, interview and documentation. Research subjects are patients, radiographers, radiology specialists, and sending doctors. The data obtained were processed and analyzed using open coding and then presented in the form of images, plot and quotations so that conclusions can be drawn. The results showed that the thoracolumbar vertebra radiographic examination procedure in scoliosis clinical in Radiology Installation RSUD Bendan Pekalongan used AP and right and left bending AP projections in erect position because to place the object as close as possible to IR with the hope to minimize the magnification of the object on the radiograph and has been informative to assess the cobb angle in scoliosis curvature. The suggestion from the author is that Radiology Installation should coordinate with related parties such as radiology specialists, radiographers and sending doctors in order to determine what projections are needed in the case of scoliosis because there are many projections on the scoliosis radiography examination.

BONE HEALTH AND GROWTH IN SPINAL MUSCULAR ATROPHY TYPE 2 AND 3

Objective: Spinal muscular atrophy is a lower motor neuron disease, but other parts of the body could be affected. This study compared bone mineral density with bone metabolism and physical growth rates in patients diagnosed with spinal muscular atrophy type 2 and type 3. Material and Methods: Twenty-six patients with spinal muscular atrophy were included in the study (15 patients for type 2 and 11 for type 3). Weights and heights of patients were measured, standard deviation scores were determined, and the body-mass index was calculated. Motor function and pubertal assessment were performed. Serum calcium, phosphorus, alkaline phosphatase, parathormone, and 25-hydroxyvitamin vitamin D levels were compared. Spine radiography for scoliosis and bone densitometry for bone mineral density were performed, and volumetric bone mineral density was calculated for age and sex. Results: Medians of height standard deviation scores were significantly lower in type 2 patients. There was no difference between the two groups in terms of serum calcium, phosphorus, alkaline phosphatase, parathormone, and 25-hydroxyvitamin D levels. The ratio of scoliosis was higher in type 2 patients as was its severity, but Z-scores of volumetric bone mineral density was lower in the same group. Conclusion: This study showed that bone mineralization and growth rates were significantly lower in spinal muscular atrophy, mainly in type 2. Further studies are needed to evaluate bone health in spinal muscular atrophy patients.

BONE HEALTH AND GROWTH IN SPINAL MUSCULAR ATROPHY TYPE 2 AND 3

Objective: Spinal muscular atrophy is a lower motor neuron disease, but other parts of the body could be affected. This study compared bone mineral density with bone metabolism and physical growth rates in patients diagnosed with spinal muscular atrophy type 2 and type 3. Material and Methods: Twenty-six patients with spinal muscular atrophy were included in the study (15 patients for type 2 and 11 for type 3). Weights and heights of patients were measured, standard deviation scores were determined, and the body-mass index was calculated. Motor function and pubertal assessment were performed. Serum calcium, phosphorus, alkaline phosphatase, parathormone, and 25-hydroxyvitamin vitamin D levels were compared. Spine radiography for scoliosis and bone densitometry for bone mineral density were performed, and volumetric bone mineral density was calculated for age and sex. Results: Medians of height standard deviation scores were significantly lower in type 2 patients. There was no difference between the two groups in terms of serum calcium, phosphorus, alkaline phosphatase, parathormone, and 25-hydroxyvitamin D levels. The ratio of scoliosis was higher in type 2 patients as was its severity, but Z-scores of volumetric bone mineral density was lower in the same group. Conclusion: This study showed that bone mineralization and growth rates were significantly lower in spinal muscular atrophy, mainly in type 2. Further studies are needed to evaluate bone health in spinal muscular atrophy patients.

Reducing the Breast Cancer Risk and Radiation Dose of Radiography for Scoliosis in Children: A Phantom Study.

Full-spinal radiographs (FRs) are often the first choice of imaging modality in the investigation of scoliosis. However, FRs are strongly related to breast cancer occurrence due to multiple large-field radiographic examinations taken during childhood and adolescence, which may increase the risk for breast cancer in adulthood among women with scoliosis. The purpose of this study was to consider various technical parameters to reduce the patient radiation dose of FRs for scoliosis. To evaluate breast surface doses (BSDs) in FRs, radio photoluminescence dosimeters were placed in contact with a child phantom. Using the PC-based Monte Carlo (PMC) program for calculating patient doses in medical X-ray examinations, the breast organ dose (BOD) and the effective dose were calculated by performing Monte Carlo simulations using mathematical phantom models. The BSDs in the posteroanterior (PA) view were 0.15–0.34-fold those in the anteroposterior (AP) view. The effective dose in the PA view was 0.4–0.61-fold that in the AP view. BSD measurements were almost equivalent to the BODs obtained using PMC at all exposure settings. During FRs, the PA view without an anti-scatter grid significantly reduced the breast dose compared to the AP view with an anti-scatter grid.

The heritability of coronal and sagittal phenotype in idiopathic scoliosis: a report of 12 monozygotic twin pairs

PurposeOne of the pathways through which genetics may act in the causation of idiopathic scoliosis is inheritance of a specific sagittal profile that predisposes for its development. In this study, coronal and sagittal parameters were compared in an international collection of monozygotic twins with idiopathic scoliosis.MethodsTwelve monozygotic twin pairs who underwent biplanar radiography for idiopathic scoliosis were systematically identified in existing scoliosis databases in The Netherlands, Sweden, and Denmark. On the first available radiographs, the coronal and sagittal curve parameters (Roussouly and Abelin types, thoracic kyphosis, lumbar lordosis and length of the posteriorly inclined segment) were determined.ResultsIn all 12 monozygotic twin pairs, both twins were affected by AIS. Four (33%) twin pairs had similar coronal and sagittal spinal phenotype, whereas two (17%) had different coronal phenotype and similar sagittal profiles, and six (50%) pairs had different coronal as well as sagittal phenotype.ConclusionsAnalysis of biplanar curve characteristics in monozygotic twins showed that all twin pairs were affected by idiopathic scoliosis. However, only 33% of the pairs had similar coronal and sagittal spinal phenotypes. Based on this limited dataset, the hypothesis can be formulated that besides genetic pre-disposition, the individual (inherited) sagittal profile plays a role in the development of different coronal curve type.

Accurate calculation of limb length discrepancy using scoliosis radiography

Aim: When we want to determine the difference in leg height by using only scoliosis radiographs in patients with scoliosis; we have looked for answer to the question of where should be the accurate measurement point for values that are closest to reality.Material and Methods: In this study 129 patients of our hospital between December 2016and 2018 with scoliosis radiography and leg height graphies were detected. The actual leg height difference was calculated on leg height graphies. Afterwards, the right and left femoral head top points were determined on scoliosis graphy. A parallel line was drawn from the top of the right femoral head. By measuring the distance of this line to the top point of left femur; difference between right and left legs was calculated. The same procedure was repeated after determining the right and left acetabulum top points and right and left iliac wing top points Results: A total of 129 patients, including 45 male and 84 female patients, were evaluated. Significant results were obtained from the correlation analysis between the leg length difference of the total patients and the distance between the acetabulum (p0,0001).Statistically significant correlation was found between iliac wing distance and femur length difference measurements (p0,0001).A significant correlation was detected between Femur head top spot difference measurements and length differences that were measured with orthoroentgenogram (p0,0001). Conclusion: The difference between the top point of the femoral head, the acetabulum or the iliac wing can be used on scoliosis graphy which was taken during the follow-up of leg length discrepancy in scoliosis patients.Keywords: Scoliosis; limb length discrepancy; radiography; osteogenesis.

Dose Reduction of the Adolescent Female Breast during Scoliosis Radiography

The purpose of this study was to investigate quantitative data on the difference in breast entrance surface dose with changes in focus-film distance, patient posture (anteroposterior-posteroanterior), thoracic wall thickness, rib bone thickness, lung tissue thickness, tube voltage, and high-voltage rectification method in Whole Spine Scanography, which is necessary for the treatment of scoliosis patients. Given a tube voltage of 90 kVp, kerma of 0.1 mGy, focus-film distance of 260 cm, tube voltage ripple rate of 0, filter thickness of 3.5 mm, and thickness of patient's thoracic wall of 120 mm as an X-ray exposure condition, from the simulation results using the Simulation of X‐ray Spectra program to confirm the reduction effect of breast entrance surface dose according to the patient's posture (AP and PA), there was a dose reduction effect in aluminum filter thickness of 2.6 times at 3.5 mm, 25.7 times the thoracic wall thickness at 120 mm, 1.43 times higher tube voltage, and 0 to 1.14 times the tube voltage ripple rate. The total dose reduction effect was about 109 times. In order to confirm the dose reduction effect of RANDO phantom posture (AP and PA), from the results of the measurements taken under the conditions that the focus-film distance was 260 cm, the tube voltage was 90 kVp, the tube current was 270 mA, the exposure time was 0.31 sec, and the tube voltage ripple rate of X-ray generators was 0, the entrance surface dose reduction effect of the breast in the PA position was found to be 20.56 times lower than that of the AP position.

The impact of curve severity on obstetric complications and regional anesthesia utilization in pregnant patients with adolescent idiopathic scoliosis: a preliminary analysis.

OBJECTIVE Adolescent idiopathic scoliosis (AIS), the most common type of scoliosis, often presents immediately prior to a woman's childbearing years; however, research investigating the impact of AIS on women's health, particularly pregnancy delivery outcomes, is sparse, with existing literature reporting mixed findings. Similarly limited are studies examining the change in scoliotic curve during or after pregnancy. Therefore, this study aims to determine 1) the impact of scoliotic curvature on obstetric complications (preterm births, induction of labor, and urgent/emergency caesarean section delivery), 2) regional anesthetic decision making and success during delivery for these patients, and 3) the effect of pregnancy on curve progression. METHODS Records of all pregnant patients diagnosed with AIS at the authors' institution who delivered between January 2002 and September 2016 were retrospectively reviewed. Demographic information, pre- and postpartum radiographic Cobb angles, and clinical data for each pregnancy and delivery were recorded and analyzed. The Wilcoxon rank-sum test and the Wilcoxon signed-rank test were used for statistical analyses. RESULTS Fifty-nine patients (84 deliveries) were included; 14 patients had undergone prior posterior spinal fusion. The median age at AIS diagnosis was 15.2 years, and the median age at delivery was 21.8 years. Overall, the median major Cobb angle prior to the first pregnancy was 25° (IQR 15°-40°). Most births were by spontaneous vaginal delivery (n = 45; 54%); elective caesarean section was performed in 17 deliveries (20%). Obstetric complications included preterm birth (n = 18; 21.4%), induction of labor (n = 20; 23.8%), and urgent/emergency caesarean section (n = 12; 14.0%); none were associated with severity of scoliosis curve or prior spinal fusion. Attempts at spinal anesthesia were successful 99% of the time (70/71 deliveries), even among the patients who had undergone prior spinal fusion (n = 13). There were only 3 instances of provider refusal to administer spinal anesthesia. In the subset of 11 patients who underwent postpartum scoliosis radiography, there was no statistically significant change in curve magnitude either during or immediately after pregnancy. CONCLUSIONS The results of this study suggest that there was no effect of the severity of scoliosis on delivery complications or regional anesthetic decision making in pregnant patients with AIS. Moreover, scoliosis was not observed to progress significantly during or immediately after pregnancy. Larger prospective studies are needed to further investigate these outcomes, the findings of which can guide the prenatal education and counseling of pregnant patients with AIS.

Evaluation of Manual Angulation Fixed Focal Approach Using Flat Panel Detector in Digital Radiography of Scoliosis

Scoliosis patient underwent numerous spine radiographs during their monitor and treatment period, thus, may expose them to high accumulative radiation dose. In this study, the diagnostic performance of the flat panel detector (FPD) fixed focal approach with manual angulation was evaluated in term of accuracy and consistency of Cobb angle measurement, spatial accuracy as well as radiation dose to the patients compared to the conventional photostimulable phosphor (PSP) approach. Cobb angle measurements were evaluated with two special constructed human vertebrae phantoms. The intraclass correlation coefficients (ICC) for interobserver variation and percentage of accuracy in Cobb angle measurement were calculated. The significant differences in angle measurement between both approaches were assessed. The spatial accuracy was evaluated with TO.M1 phantom. Dose measurements were performed with radiochromic film and 20 cm polymethyl methacrylate (PMMA) slabs. The FPD fixed focal approach showed excellent interobserver reproducibility (ICC, r = 0.99, p 0.05) for the Cobb angle measured from both approaches. The FPD fixed focal approach resulted in higher accuracy (3%) of angle measurement compared to the conventional PSP approach. The spatial accuracy was within the recommended limit of AAPM report 93. An average entrance surface dose (ESD) reduction of 20% was achieved with FPD fixed focal approach. We developed and evaluated a manual tube angulation method which facilitates the use of existing FPD digital radiography system to produce full spine image. It has good consistency and high accuracy in the measurement of Cobb angle. The acquired images are suitable for angle measurement for scoliosis patients with substantial dose reduction.

SU‐E‐I‐15: Comparison of Radiation Dose for Radiography and EOS in Adolescent Scoliosis Patients

Purpose:To estimate patient radiation dose for whole spine imaging using EOS, a new biplanar slot‐scanning radiographic system and compare with standard scoliosis radiography.Methods:The EOS imaging system (EOS Imaging, Paris, France) consists of two orthogonal x‐ray fan beams which simultaneously acquire frontal and lateral projection images of a standing patient. The patient entrance skin air kerma was measured for each projection image using manufacturer‐recommended exposure parameters for spine imaging. Organ and effective doses were estimated using a commercially‐available Monte Carlo simulation program (PCXMC, STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland) for a 15 year old mathematical phantom model. These results were compared to organ and effective dose estimated for scoliosis radiography using computed radiography (CR) with standard exposure parameters obtained from a survey of pediatric radiographic projections.Results:The entrance skin air kerma for EOS was found to be 0.18 mGy and 0.33 mGy for posterior‐anterior (PA) and lateral projections, respectively. This compares to 0.76 mGy and 1.4 mGy for CR, PA and lateral projections. Effective dose for EOS (PA and lateral projections combined) is 0.19 mSv compared to 0.51 mSv for CR.Conclusion:The EOS slot‐scanning radiographic system allows for reduced patient radiation dose in scoliosis patients as compared to standard CR radiography.

Effective dose and breast dose reduction in paediatric scoliosis X-ray radiography by an optimal positioning

The purpose of this article is to recommend positioning to reduce the effective and breast-absorbed-doses in paediatric scoliosis radiography. Effective and breast-absorbed-doses were evaluated using Monte Carlo simulations. Head directed towards the anode (HTA) positioning rather than head directed towards the cathode (HTC) reduces the effective dose to 98 % in anterior posterior (AP), 98 % in left lateral (L LAT) and 96 % in right lateral (R LAT) projections. HTC in posterior anterior (PA) projection contributes a smaller effective dose than HTA by <1 %, but causes a breast-absorbed-dose excess (HTA/HTC breast dose ratios were 85 and 87 % for 10- and 15-y- olds). With the preferential HTA positioning, R LAT projection reduced effective dose to 85 and 84 % compared with L LAT, for 10 and 15 y olds. AP-HTA projection caused 183 and 181 % larger effective doses than PA-HTA and breast-absorbed-dose excesses of 550 and 879 %, for 10 and 15 y olds. When possible, use R LAT and PA projections to reduce effective dose; Of secondary importance, whenever possible, use HTA, with the exception that for 15 y olds, PA-HTC reduces the effective dose more than HTA (1 %) but causes a breast-absorbed-dose excess.

Effective dose for scoliosis patients undergoing full spine radiography

Scoliotic patients underwent many radiological examinations during their control and treatment periods. Nowadays, few studies have calculated effective dose which is the primary indicator of radiation risk. In this study, the PCXMC program is used to calculate the effective doses associated with scoliosis radiography. Five age groups of patients, proposed by the National Radiological Protection Board, have been chosen: <1, 1-4, 5-9, 10-15 and ≥16 y (adult patients). Patient and radiographic data were collected from 99 patient examinations for both anteroposterior and lateral full spine X-ray projections. Results showed the effective dose ranged from 118 to 1596 μSv for the frontal projection and from 97 to 1370 μSv for the lateral projection, with patient age varying from 3 months to 22 y. This study presents the effective dose against patient age and demonstrates the necessity to optimise patient protection for this type of examination.

Radiation Dose Reduction in Scoliosis Patients: Low-Dose Full-Spine Radiography with Digital Flat Panel Detector and Image Stitching System

To evaluate the exposure dose reduction with a digital flat panel detector (FPD) and an image stitching system (ISS) in full-spine radiography for scoliosis patients. During a 6-month period, all consecutive scoliosis patients with a clinical indication for full-spine radiography (n=50) were examined with an FPD and ISS. Automatic exposure control adjusted to speed class 1600 was used together with age-adjusted tube voltage and filtration. Dose area products were recorded for all images (antero-posterior n=50, lateral n=18). Images were evaluated by two radiologists for the possibility (possible, impossible) of typical scoliosis measurements (Cobb angle, Stagnara angle, lateral deviation, Risser stage). All measurements assessed as impossible underwent a second evaluation categorizing the reason why a measurement was impossible (underlying pathology, projection, image quality). Patient characteristics influencing exposure were recorded (sex, age, weight, height). Mean dose area products were compared to the literature with consideration of patient group and image quality. The mean dose area product was 16.8µGym (2) for antero-posterior images and 26.6µGym (2) for lateral images. A comparison to published values showed an exposure dose reduction of 47% to 93%. Measurement of the Cobb and Stagnara angle, lateral deviation and Risser stage was possible in 96% (n=50), 83% (n=18), 100% (n=50) and 100% (n=50) of cases. The reasons for impossible measurements were independent of image quality (underlying pathologies, projection). When imaging scoliosis patients, an FPD combined with an ISS can substantially reduce the exposure dose.

Measurement of effective dose for paediatric scoliotic patients

Purpose Paediatric radiation dose from scoliosis X-ray examinations is of concern because of its routine nature. Few studies have calculated effective dose which is the primary indicator of radiation risk. This study reports on the use of a new flexible Monte Carlo software package PCXMC14 for such calculation from documented radiographic and patient data. Method Patient and radiographic data were collected from 54 patient examinations for both postero-anterior (PA) and lateral X-ray projections. A spreadsheet mainly based on radiographic calibration was used to process the raw data and compute entrance air kerma for input in the PCXMC program. A partitioning model was developed to more accurately estimate the effect of an aluminium wedge filter. Results Results showed the effective dose ranged from 81 to 123 μSv for the PA projection and 124 to 207 μSv for the lateral projection, with patient weights varying from 20 to 70 kg. Conclusions This study demonstrates the usefulness of the PCXMC program to evaluate the effective dose in paediatric scoliosis radiography.

Optimisation of scoliosis examinations in children.

To present results of optimising scoliosis examination by changing from a conventional film/grid (F/G) to air-gap technique using computed radiography (CR), and to evaluate different methods for estimating effective radiation doses. Forty-nine children and adolescents were examined with an F/G technique, and 21 with air-gap and CR techniques. Entrance surface doses (ESD) were determined with lithium fluoride thermoluminescence dosimeters. For all patients, the effective radiation doses were determined using a hermaphrodite PCXMC computer program. For all F/G radiographs, the effective doses were also determined according to the NRPB-R279 report, and for 22 children (>9 years and/or >40 kg) also with the ODS-60 program, which allows separate gender calculations. Accumulated doses for 37 children examined more than once with F/G examinations were assessed. For F/G techniques, the ESDs for both frontal and lateral views varied with age and were significantly correlated to the patients' thickness. The calculated effective doses using the PCXMC program and the NRPB-R279 did not differ significantly for all frontal and lateral radiographs, respectively, but ODS-60 gave significantly higher values in female subjects. With air-gap and CR techniques, the mean effective doses were reduced by a factor over 10. The mean accumulated effective dose for 37 children with a mean of seven F/G examinations was 6.1 mSv, implying a risk of death of about 1:2,000 for boys and at least 1:1,000 for girls. Paediatric scoliosis radiography should be considered a specialised procedure, which has to be optimised using a non-grid technique.

Radiation doses to patients undergoing scoliosis radiography.

In this study we computed the radiation doses associated with scoliosis radiography and investigated how these radiation doses are influenced by the weight of the patient. We recorded the radiographic technique factors of 61 consecutive patients (46 females and 15 males) undergoing scoliosis radiography. A wedge-shaped aluminium filter attenuated the X-ray beam in the "chest region" relative to the "abdomen region". X-ray tube air kerma output factors (microGy mAs-1) and half value layers (HVLs) were determined experimentally for the "chest region" and "abdomen region". The energy imparted to each patient was computed from the air kerma area product, X-ray beam HVL and measured patient thickness. Values of patient effective dose were obtained using effective dose-to-energy conversion factors for specified radiographic projections, taking into account each patient's weight. The median patient age was 17 years, and the median patient weight was 53 kg. Entrance skin air kerma values in the "chest region" were approximately a factor of four lower than those in the "abdomen region". The air kerma values increased by a factor of two when the patient weight increased from 30 kg to 70 kg. Approximately 80% of the total energy imparted to a patient undergoing a scoliosis examination was in the "abdomen region", with the remaining 20% imparted to the "chest region". Energy imparted increased with patient weight, and was approximately 3 mJ for a 30 kg patient and approximately 8 mJ for a 70 kg adult patient. Effective doses showed little correlation with patient weight, with an average-sized patient (50 kg) receiving an effective dose of approximately 140 microSv. Patients undergoing scoliosis radiography receive effective doses that are low in comparison with other types of radiographic examination.

Computed Radiography in Scoliosis

The diagnostic information and radiation dose in scoliosis examinations performed with air-gap technique using stimulable phosphor imaging plates were determined in a prospective study. Overlapping p.a. images of the thoracic and lumbar spine in 9 patients were obtained with 4 different exposure settings according to patient size. Equal exposure settings were used for the 2 images. Two images of 18 were judged inferior in depicting the landmarks of scoliosis measurement, requiring re-exposure. Sixteen images were judged of adequate or good quality. The mean entrance doses in the central beam for the 4 patient groups were in the interval of 0.05 to 0.12 mGy for both images. The skin doses on the breasts were in the range of 0.00 to 0.03 mGy. The presented technique thus results in a low radiation dose with sufficient diagnostic information in radiography of scoliosis.

Radiation Exposure to Patients Receiving Routine Scoliosis Radiography Measured at Depth in an Anthropomorphic Phantom

Concern about the amount of radiation received during scoliosis evaluation and treatment led us to measure radiation exposure in an anthropomorphic phantom to determine the increased risk of breast cancer in young women with scoliosis. Assuming that 22 radiographic examinations were performed over the course of scoliosis treatment, the increased relative risk of breast cancer was determined to be 0.22% in these patients.