Projecting the lifetime risk of cancer from exposure to diagnostic ionizing radiation for adolescent idiopathic scoliosis

Intraoperative navigation increases the projected lifetime cancer risk in patients undergoing surgery for adolescent idiopathic scoliosis

BACKGROUND CONTEXT

Adolescent idiopathic scoliosis (AIS) is a common condition, often requiring surgical correction. Computed tomography (CT) based navigation technologies, which rely on ionizing radiation, are increasingly being utilized for surgical treatment. Although this population is highly vulnerable to radiation, given their age and female predominance, there is little available information elucidating modeled iatrogenic cancer risk.

PURPOSE

To model lifetime cancer risk associated with the use of intraoperative CT-based navigation for surgical treatment of AIS.

STUDY DESIGN/SETTING

This retrospective cross-sectional study took place in a quaternary care academic pediatric hospital in the United States.

PATIENT SAMPLE

Adolescents aged 10-18 who underwent posterior spinal fusion for a diagnosis of AIS between July 2014 and December 2019.

OUTCOMES MEASURES

Effective radiation dose and projected lifetime cancer risk associated with intraoperative doses of ionizing radiation.

METHODS

Clinical and radiographic parameters were abstracted, including total radiation dose during surgery from flat plate radiographs, fluoroscopy, and intraoperative CT scans. Multivariable regression analysis was used to assess differences in radiation exposure between patients treated with conventional radiography versus intraoperative navigation. Radiation exposure was translated into lifetime cancer risk using well-established algorithms.

RESULTS

In total, 245 patients were included, 119 of whom were treated with navigation. The cohort was 82.9% female and 14.4 years of age. The median radiation exposure (in millisieverts, mSv) for fluoroscopy, radiography, and navigation was 0.05, 4.14, and 8.19 mSv, respectively. When accounting for clinical and radiographic differences, patients treated with intraoperative navigation received 8.18 mSv more radiation (95%CI: 7.22-9.15, p<.001). This increase in radiation projects to 0.90 iatrogenic malignancies per 1,000 patients (95%CI 0.79-1.01).

CONCLUSIONS

Ours is the first work to define cancer risk in the setting of radiation exposure for navigated AIS surgery. We project that intraoperative navigation will generate approximately one iatrogenic malignancy for every 1,000 patients treated. Given that spine surgery for AIS is common and occurs in the context of a multitude of other radiation sources, these data highlight the need for radiation budgeting protocols and continued development of lower radiation dose technologies.

LEVEL OF EVIDENCE

Therapeutic, III.

The Prevalence of Cancer in Dutch Female Patients with Idiopathic Scoliosis Compared with the General Population

Background and Objectives: Epidemiological studies have demonstrated the potential oncogenic effects of cumulative radiation exposure, particularly during childhood. One group experiencing repeated exposure to radiation at an early age for multiple years is patients treated for idiopathic scoliosis (IS). This study aimed to determine the relationship between childhood radiological exposure and adult cancer prevalence in children treated for IS. Materials and Methods: Data from 337 predominantly female patients treated at our hospital between January 1981 and January 1995 were gathered and compared to the Dutch national cancer rates. The standardized prevalence ratios for cancer in IS patients were compared with the cancer prevalence rates from the general Dutch population. Results: The overall cancer prevalence in women was 5.0%, with no significant difference compared to the general population (p = 0.425). The results of this study do not suggest that female patients treated for idiopathic scoliosis during childhood have an increased risk of cancer later in life. Conclusion: Despite being the largest recent study in its field, the modest participant number limits its ability to draw conclusions. However, the detailed data collected over a long observation period, alongside data from a period with comparable radiation rates, contributes to refining clinical practice and laying the groundwork for future systematic reviews.

Monitoring of Curve Progression in Patients with Adolescent Idiopathic Scoliosis Using 3-D Ultrasound

OBJECTIVE

The aim of the work described here was to determine whether 3-D ultrasound can provide results comparable to those of conventional X-ray examination in assessing curve progression in patients with adolescent idiopathic scoliosis (AIS).

METHODS

One hundred thirty-six participants with AIS (42 males and 94 females; age range: 10-18 y, mean age: 14.1 ± 1.9 y) with scoliosis of different severity (Cobb angle range: 10º- 85º, mean: of 24.3 ± 14.4º) were included. Each participant underwent biplanar low-dose X-ray EOS and 3-D ultrasound system scanning with the same posture on the same date. Participants underwent the second assessment at routine clinical follow-up. Manual measurements of scoliotic curvature on ultrasound coronal projection images and posterior-anterior radiographs were expressed as the ultrasound curve angle (UCA) and radiographic Cobb angle (RCA), respectively. RCA and UCA increments ≥5º represented a scoliosis progression detected by X-ray assessment and 3-D ultrasound assessment, respectively.

RESULTS

The sensitivity and specificity of UCA measurement in detecting scoliosis progression were 0.93 and 0.90, respectively. The negative likelihood ratio of the diagnostic test for scoliosis progression by the 3-D ultrasound imaging system was 0.08.

CONCLUSION

The 3-D ultrasound imaging method is a valid technique for detecting coronal curve progression as compared with conventional radiography in follow-up of AIS. Substituting conventional radiography with 3-D ultrasound is effective in reducing the radiation dose to which AIS patients are exposed during their follow-up examinations.

Efficacy and safety of the orthopaedic manipulation techniques of the Lin School of Lingnan Region in the treatment of adolescent idiopathic scoliosis: protocol of a participant-and-assessor-blinded randomized controlled study

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common developmental spine disorder among children. It is characterized by a lateral deviation of the spine that gives rise to the distinctive "S" or "C" shaped bending of the spine. The Lin School of Lingnan Region (LSLR), one of the prominent schools for bare-handed orthopaedic manipulation in southern China, provides preliminary evidences that the orthopaedic manipulation techniques help to correct deviations of the spine. Previous research found that Orthopaedic Manipulation Techniques of LSLR (OMT-LSLR) could reduce the Cobb's angles in patients with AIS. Therefore, the current study aims to investigate the effectiveness and safety of the OMT-LSLR in treating teenagers with AIS.

METHODS

In this participant-and-assessor-blinded randomized controlled clinical trial, 50 participants identified AIS without surgical indications will be recruited and randomized into two groups to receive physiotherapy scoliosis-specific exercises training with either orthopaedic manipulation or sham manipulation treatment for 16 weeks, followed by post-treatment visits at week 24. Primary outcome measure is the change of Scoliosis Research Society-22 (SRS-22) questionnaire score. Secondary outcome measures include Traditional Chinese version of Spinal Appearance Questionnaire (TC-SAQ) score, Italian Spine Youth Quality of Life (ISYQOL) score, the change of Cobb's angle measured by Xray, and the change of Cobb's angle, spinal rotation and muscle volume measured by three-dimensional (3D) ultrasound. The trial will be conducted at the Chinese University of Hong Kong Chinese Medicine Specialty Clinic cum Clinical Teaching and Research Centre in Hong Kong (CUHK-CMSCTRC).

DISCUSSION

The results of this study will establish comprehensive clinical evidence about the efficacy and safety of the Orthopaedic Manipulation Techniques of the Lin School of Lingnan Region in the Treatment of Adolescent Idiopathic Scoliosis. One of the characteristics of this trial is that it is a participant-and-assessor-blinded randomized controlled clinical trial with sham manipulation. The study would also apply three-dimensional (3D) ultrasound technology to investigate the relationship between the change of the muscle volume and the spinal curve.

TRIAL REGISTRATION

The trial is registered on ClinicalTrials.gov (Identifier: NCT05639023 ) on December 6, 2022.

Deep Learning Model to Classify and Monitor Idiopathic Scoliosis in Adolescents Using a Single Smartphone Photograph

Importance

Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal disorder. Routine physical examinations by trained personnel are critical to diagnose severity and monitor curve progression in AIS. In the presence of concerning malformation, radiographs are necessary for diagnosis or follow-up, guiding further management, such as bracing correction for moderate malformation and spine surgery for severe malformation. If left unattended, progressive deterioration occurs in two-thirds of patients, leading to significant health concerns for growing children.

Objective

To assess the ability of an open platform application (app) using a validated deep learning model to classify AIS severity and curve type, as well as identify progression.

Design, Setting, and Participants

This diagnostic study was performed with data from radiographs and smartphone photographs of the backs of adolescent patients at spine clinics. The ScolioNets deep learning model was developed and validated in a prospective training cohort, then incorporated and tested in the AlignProCARE open platform app in 2022. Ground truths (GTs) included severity, curve type, and progression as manually annotated by 2 experienced spine specialists based on the radiographic examinations of the participants' spines. The GTs and app results were blindly compared with another 2 spine surgeons' assessments of unclothed back appearance. Data were analyzed from October 2022 to February 2023.

Exposure

Acquisitions of unclothed back photographs using a mobile app.

Main Outcomes and Measures

Outcomes of interest were classification of AIS severity and progression. Quantitative statistical analyses were performed to assess the performance of the deep learning model in classifying the deformity as well as in distinguishing progression during 6-month follow-up.

Results

The training data set consisted of 1780 patients (1295 [72.8%] female; mean [SD] age, 14.3 [3.3] years), and the prospective testing data sets consisted of 378 patients (279 [73.8%] female; mean [SD] age, 14.3 [3.8] years) and 376 follow-ups (294 [78.2%] female; mean [SD] age, 15.6 [2.9] years). The model recommended follow-up with an area under receiver operating characteristic curve (AUC) of 0.839 (95% CI, 0.789-0.882) and considering surgery with an AUC of 0.902 (95% CI, 0.859-0.936), while showing good ability to distinguish among thoracic (AUC, 0.777 [95% CI, 0.745-0.808]), thoracolumbar or lumbar (AUC, 0.760 [95% CI, 0.727-0.791]), or mixed (AUC, 0.860 [95% CI, 0.834-0.887]) curve types. For follow-ups, the model distinguished participants with or without curve progression with an AUC of 0.757 (95% CI, 0.630-0.858). Compared with both surgeons, the model could recognize severities and curve types with a higher sensitivity (eg, sensitivity for recommending follow-up: model, 84.88% [95% CI, 75.54%-91.70%]; senior surgeon, 44.19%; junior surgeon, 62.79%) and negative predictive values (NPVs; eg, NPV for recommending follow-up: model, 89.22% [95% CI, 84.25%-93.70%]; senior surgeon, 71.76%; junior surgeon, 79.35%). For distinguishing curve progression, the sensitivity and NPV were comparable with the senior surgeons (sensitivity, 63.33% [95% CI, 43.86%-80.87%] vs 77.42%; NPV, 68.57% [95% CI, 56.78%-78.37%] vs 72.00%). The junior surgeon reported an inability to identify curve types and progression by observing the unclothed back alone.

Conclusions

This diagnostic study of adolescent patients screened for AIS found that the deep learning app had the potential for out-of-hospital accessible and radiation-free management of children with scoliosis, with comparable performance as spine surgeons experienced in AIS management.

Three-Dimensional Spinal Evaluation Using Rasterstereography in Patients with Adolescent Idiopathic Scoliosis: Is It Closer to Three-Dimensional or Two-Dimensional Radiography?

(1) Background: Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional (3D) spine deformity. The Cobb angle, evaluated with 2D radiography, is the gold standard to determine curve severity. The primary aim of this study was to evaluate the 3D spinal evaluation with rasterstereography in patients with AIS. The hypothesis was that rasterstereography reached higher accuracy than the gold standard 2D radiography. The second aim was to compare rasterstereography with 3D radiography. The hypothesis was that the rasterstereographic evaluation of patients with severe major scoliosis curves is closer to 3D radiography compared to the gold standard (2D radiography). (2) Methods: This is a prospective comparative study of a consecutive series of 53 patients, with the scoliosis curve evaluated with two 3D methods and the gold standard (2D radiography). (3) Results: The hypothesis that rasterstereography reached higher accuracy than the gold standard 2D radiography was validated for all curves. Even if all curves were highly correlated, both rasterstereography and 2D radiography scoliosis evaluation were underestimated for moderate/severe curves compared to 3D radiography. (4) Conclusions: The rasterstereographic evaluation of major curve scoliosis is not accurate enough to replace 2D radiography for moderate/severe curves. A longitudinal follow-up should be assessed in future studies to define the sensitivity of the detection of a significant change in the scoliotic mild and moderate curve (<40°).

The use of MRI in the study of patients with idiopathic scoliosis: a systematic review of the literature

Objective. To analyze the frequency of hidden neuraxial pathology in idiopathic scoliosis (IS), to substantiate the need for MRI in IS and to identify promising areas for the use of MRI in the examination of patients with IS.Material and Methods. The literature review was carried out using the PubMed and Google Scholar databases. Of the 780 papers on the research topic, 65 were selected after removing duplicates and checking for inclusion/exclusion criteria. As a result, 49 original studies were included in the analysis. Level of evidence – II.Results. According to modern literature, the main direction of using MRI in idiopathic scoliosis is the search for predictors of latent pathology of the spinal cord and craniovertebral junction. The frequency of neuraxial pathology in idiopathic scoliosis is 8 % for adolescent IS and 16 % for early IS. The main predictors of neuraxial pathology are male sex, early age of deformity onset, left-sided thoracic curve and thoracic hyperkyphosis. MRI in IS may be a useful addition to radiological diagnostic methods to identify risk factors and to study degenerative changes in the spine.Conclusion. MRI of the spine should be performed in the early stages of IS to detect latent spinal cord tethering. In type I Chiari anomalies, there is a possibility that early neurosurgery can prevent the development of scoliosis. The main signs of latent neuraxial pathology in IS are early progression of spinal deformity, left-sided thoracic curve, male gender and thoracic kyphosis over 40° according to Cobb.MRI can be used as an effective non-invasive tool in research aimed at identifying risk factors for IS, including helping to track early degeneration of intervertebral discs.

Validation of Scolioscan Air-Portable Radiation-Free Three-Dimensional Ultrasound Imaging Assessment System for Scoliosis

To diagnose scoliosis, the standing radiograph with Cobb's method is the gold standard for clinical practice. Recently, three-dimensional (3D) ultrasound imaging, which is radiation-free and inexpensive, has been demonstrated to be reliable for the assessment of scoliosis and validated by several groups. A portable 3D ultrasound system for scoliosis assessment is very much demanded, as it can further extend its potential applications for scoliosis screening, diagnosis, monitoring, treatment outcome measurement, and progress prediction. The aim of this study was to investigate the reliability of a newly developed portable 3D ultrasound imaging system, Scolioscan Air, for scoliosis assessment using coronal images it generated. The system was comprised of a handheld probe and tablet PC linking with a USB cable, and the probe further included a palm-sized ultrasound module together with a low-profile optical spatial sensor. A plastic phantom with three different angle structures built-in was used to evaluate the accuracy of measurement by positioning in 10 different orientations. Then, 19 volunteers with scoliosis (13F and 6M; Age: 13.6 ± 3.2 years) with different severity of scoliosis were assessed. Each subject underwent scanning by a commercially available 3D ultrasound imaging system, Scolioscan, and the portable 3D ultrasound imaging system, with the same posture on the same date. The spinal process angles (SPA) were measured in the coronal images formed by both systems and compared with each other. The angle phantom measurement showed the measured angles well agreed with the designed values, 59.7 ± 2.9 vs. 60 degrees, 40.8 ± 1.9 vs. 40 degrees, and 20.9 ± 2.1 vs. 20 degrees. For the subject tests, results demonstrated that there was a very good agreement between the angles obtained by the two systems, with a strong correlation (R2 = 0.78) for the 29 curves measured. The absolute difference between the two data sets was 2.9 ± 1.8 degrees. In addition, there was a small mean difference of 1.2 degrees, and the differences were symmetrically distributed around the mean difference according to the Bland-Altman test. Scolioscan Air was sufficiently comparable to Scolioscan in scoliosis assessment, overcoming the space limitation of Scolioscan and thus providing wider applications. Further studies involving a larger number of subjects are worthwhile to demonstrate its potential clinical values for the management of scoliosis.

Decreased Vertical Trunk Inclination Angle and Pelvic Inclination as the Result of Mid-High-Heeled Footwear on Static Posture Parameters in Asymptomatic Young Adult Women

The influence of high-heel footwear on the lumbar lordosis angle, anterior pelvic tilt, and sacral tilt are inconsistently described in the literature. This study aimed to investigate the impact of medium-height heeled footwear on the static posture parameters of homogeneous young adult standing women. Heel geometry, data acquisition process, as well as data analysis and parameter extraction stage, were controlled. Seventy-six healthy young adult women with experience in wearing high-heeled shoes were enrolled. Data of fifty-three subjects were used for analysis due to exclusion criteria (scoliotic posture or missing measurement data). A custom structured light surface topography measurement system was used for posture parameters assessment. Three barefoot measurements were taken as a reference and tested for the reliability of the posture parameters. Two 30-degree wedges were used to imitate high-heel shoes to achieve a repeatable foot position. Our study confirmed the significant (p < 0.001) reduced vertical balance angle and pelvis inclination angle with large and medium-to-large effects, respectively, due to high-heel shoes. No significant differences were found in the kyphosis or lordosis angles. High-heeled shoes of medium height in young asymptomatic women can lead to a straightening effect associated with a reduced vertical balance angle and decreased pelvic inclination.

Non-ionizing method of screening adolescent idiopathic scoliosis in schoolchildren

Adolescent idiopathic scoliosis (AIS) affects 2% to 4% of young people in Brazil. Repeated exposures to radiation used in the monitoring of the deformity can be harmful to the health. This study aimed to present a photogrammetry protocol as a non-ionizing method to quantify scoliosis and relate it to the Cobb radiological method. Sixteen individuals with idiopathic scoliosis (age: 21.4 ± 6.1 years, body mass index: 19.8 ± 0.2 kg/m2) underwent standing posteroanterior X-ray examination of the trunk. Additionally, markers were placed on the spinal processes of the C7 to L5 vertebrae, and posterior trunk photographs were taken. All images were sent for independent analysis by two examiners who were trained in the quantification of scoliosis. The average of the thoracic curvature evaluated through the photogrammetry and Cobb methods were 36.43° and 36.14°, respectively. With an average difference of 4.1°, the methods were not statistically different (p < 0.05). As a non-ionizing method that is low cost and portable, photogrammetry may represent a suitable alternative to the radiological method. Further studies are needed for the improvement of non-ionizing techniques in AIS screening.

Dose Reduction Protocol for Full Spine X-ray Examination Using Copper Filters in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

A prospective case series.

OBJECTIVE

The aim of this study was to assess a new protocol for full spine X-ray using copper (Cu) filters to reduce radiation exposure in patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Radiation exposure is associated with an increased risk of cancer development in children. To reduce the radiation exposure without compromising the image quality using existing radiographic equipment, a new computed radiography protocol was optimized using a variety of heavy metal filters.

METHODS

Study 1: Whole spine radiographs were obtained using a human body phantom, and radiation doses without and with 0.1, 0.2, and 0.3 mm thick Cu filters were compared. Study 2: Patients with AIS who underwent posterior fusion were radiographically evaluated at follow-ups; the X-ray protocols with or without the use of 0.2-mm Cu filters were alternated between consecutive follow-ups. The image quality was independently evaluated using six points in the anterior-posterior (AP) view and seven in the lateral [left-right (LR)] view by three spine surgeons using a three-point grading system.

RESULTS

Study 1: The surface doses while obtaining nonfiltered X-rays in AP and LR views were 0.31 and 0.93 mGy, respectively, whereas those with 0.1-, 0.2-, and 0.3-mm Cu filters were 0.16 and 0.52, 0.11 and 0.36, and 0.08 and 0.27 mGy, respectively.Study 2: In patients with AIS, the percentage of grade 3 scores (both endplates were identifiable) on AP-view images was 85% with nonfiltered X-rays and 75% with the filtered X-rays. However, there were no significant differences between the two protocols. On LR images, the frequency of grade 3 scores was significantly lower at Th2 and Th12 on filtered images than on nonfiltered ones.

CONCLUSION

Whole spine radiographs using 0.2-mm Cu filters in patients with AIS could reduce radiation exposure more than 60% while preserving the image quality.

LEVEL OF EVIDENCE

4.

Accuracy of photogrammetry for detecting adolescent idiopathic scoliosis progression

BACKGROUND

The gold standard method of monitoring the evolution of scoliosis has been serial standing, posteroanterior, full-length spine radiographs with curvature measurements using the Cobb method. However, over the course of follow-up, patients can receive high radiation doses. Various studies have shown that repeated exposure to radiation in children and adolescents can be harmful to their health.

PURPOSE

To determine the accuracy of photogrammetry in evaluating the progression of adolescent idiopathic scoliosis in comparison with radiography.

STUDY DESIGN

Diagnostic study.

PATIENT SAMPLE

Ninety adolescents subjected to radiographic follow-up of idiopathic scoliosis.

OUTCOME MEASURES

The angle of scoliotic curvature was measured using the Cobb radiographic method and photogrammetry. An increase of 5° or more between two radiographic exams was considered a progression of the curvature and was defined as the standard for calculations of sensitivity, specificity, predictive value, and accuracy of the photogrammetric method for measuring scoliosis progression.

METHODS

Patients were subjected to radiographic and photogrammetric exams concomitantly and were reevaluated after an average of 8.6 months. The exams were analyzed separately and independently by two examiners for progression of scoliosis.

RESULTS

The measurements of the curves at the beginning of the study were 39.5±16.7° and 39.5±14.3° for radiographic and photogrammetric exams, respectively (p=1.0). At the end of the study, the measurements of the curves were 40.2±16.2° and 41.3±15.1° for the radiographic and photogrammetric exams, respectively (p=.310). The photogrammetric method had an accuracy of 89% (Confidence interval [CI] 95%=82.5-95.5) for the detection of scoliosis progression, with a sensitivity of 94.4% (CI 95%=89.6-99.2), a specificity of 86.7% (CI 95%=79.7-93.7), a positive predictive value of 75.5% (CI 95%=66.6-84.4), a negative predictive value of 97.2% (CI 95%=93.8-100), and a Kappa index of 0.75 (CI 95%=66.1-83.9). The interclass correlation coefficient between the two methods was 0.74 (CI 95%=0.65-0.81; p=0).

CONCLUSIONS

The photogrammetric method showed good performance for detecting the progression of adolescent idiopathic scoliosis in comparison with the radiographic exam method.

Standard reference values of the upper body posture in healthy young female adults in Germany: an observational study

OBJECTIVE

Classifications of posture deviations are only possible compared with standard values. However, standard values have been published for healthy male adults but not for female adults.

DESIGN

Observational study.

SETTING

Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe-University Frankfurt/Main.

PARTICIPANTS

106healthy female volunteers (21-30 years old; 25.1±2.7 years) were included. Their body weight ranged from 46 to 106 kg (60.3±7.9 kg), the heights from 1.53 to 1.82 m (1.69±0.06 m) and the body mass index from 16.9 kg/m² to 37.6 kg/m² (21.1±2.6 kg/m²).

OUTCOME MEASURES

A three-dimensional back scan was performed to measure the upper back posture in habitual standing. The tolerance ranges and CI were calculated. Group differences were tested by the Wilcoxon Mann-Whitney U test.

RESULTS

In normal posture, the spinal column was marginally twisted to the left, and the vertebrae were marginally rotated to the right. The kyphosis angle is larger than the lumbar angle. Consequently, a more kyphotic posture is observed in the sagittal plane. The habitual posture is slightly scoliotic with a rotational component (scapular depression right, right scapula marginally more dorsally, high state of pelvic right, iliac right further rotated anteriorly).

CONCLUSIONS

Healthy young women have an almost ideally balanced posture with minimal ventral body inclination and a marginal scoliotic deviation. Compared with young males, women show only marginal differences in the upper body posture. These values allow a comparison to other studies, both for control and patient data, and may serve as guideline in both clinical practice and scientific studies.

Validity and Reliability of Spine Rasterstereography in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

Test-retest study.

OBJECTIVE

This study aimed to evaluate the validity and reliability of rasterstereography in patients with adolescent idiopathic scoliosis (AIS) with a major curve Cobb angle (CA) between 10° and 40° for frontal, sagittal, and transverse parameters.

SUMMARY OF BACKGROUND DATA

Previous studies evaluating the validity and reliability of rasterstereography concluded that this technique had good accuracy compared with radiographs and a high intra- and interday reliability in healthy volunteers. To the best of our knowledge, the validity and reliability have not been assessed in AIS patients.

MATERIALS

Thirty-five adolescents with AIS (male = 13) aged 13.1 ± 2.0 years were included. To evaluate the validity of the scoliosis angle (SA) provided by rasterstereography, a comparison (t test, Pearson correlation) was performed with the CA obtained using 2D EOS® radiography (XR). Three rasterstereographic repeated measurements were independently performed by two operators on the same day (interrater reliability) and again by the first operator 1 week later (intrarater reliability). The variables of interest were the SA, lumbar lordosis, and thoracic kyphosis angle, trunk length, pelvic obliquity, and maximum, root mean square and amplitude of vertebral rotations. The data analyses used intraclass correlation coefficients (ICCs).

RESULTS

The CA and SA were strongly correlated (R = 0.70) and were nonsignificantly different (P = 0.60). The intrarater reliability (same day: ICC [1, 1], n = 35; 1 week later: ICC [1, 3], n = 28) and interrater reliability (ICC [3, 3], n = 16) were globally excellent (ICC > 0.75) except for the assessment of pelvic obliquity.

CONCLUSION

This study showed that the rasterstereographic system allows for the evaluation of AIS patients with a good validity compared with XR with an overall excellent intra- and interrater reliability. Based on these results, this automatic, fast, and noninvasive system can be used for monitoring the evolution of AIS in growing patients instead of repetitive radiographs, thereby reducing radiation exposure and decreasing costs.

LEVEL OF EVIDENCE

4.

Radiation dose of digital radiography (DR) versus micro-dose x-ray (EOS) on patients with adolescent idiopathic scoliosis: 2016 SOSORT- IRSSD "John Sevastic Award" Winner in Imaging Research

BACKGROUND

Patients with adolescent idiopathic scoliosis (AIS) frequently receive x-ray imaging at diagnosis and subsequent follow monitoring. The ionizing radiation exposure has accumulated through their development stage and the effect of radiation to this young vulnerable group of patients is uncertain. To achieve the ALARA (as low as reasonably achievable) concept of radiation dose in medical imaging, a slot-scanning x-ray technique by the EOS system has been adopted and the radiation dose using micro-dose protocol was compared with the standard digital radiography on patients with AIS.

METHODS

Ninety-nine participants with AIS underwent micro-dose EOS and 33 underwent standard digital radiography (DR) for imaging of the whole spine. Entrance-skin dose was measured using thermoluminescent dosimeters (TLD) at three regions (i.e. dorsal sites at the level of sternal notch, nipple line, symphysis pubis). Effective dose and organ dose were calculated by simulation using PCXMC 2.0. Data from two x-ray systems were compared using independent-samples t-test and significance level at 0.05. All TLD measurements were conducted on PA projection only. Image quality was also assessed by two raters using Cobb angle measurement and a set of imaging parameters for optimization purposes.

RESULTS

Entrance-skin dose from micro-dose EOS system was 5.9-27.0 times lower at various regions compared with standard DR. The calculated effective dose was 2.6 ± 0.5 (μSv) and 67.5 ± 23.3 (μSv) from micro-dose and standard DR, respectively. The reduction in the micro-dose was approximately 26 times. Organ doses at thyroid, lung and gonad regions were significantly lower in micro-dose (p < 0.001). Data were further compared within the different gender groups. Females received significantly higher (p < 0.001) organ dose at ovaries compared to the testes in males. Patients with AIS received approximately 16-34 times lesser organ dose from micro-dose x-ray as compared with the standard DR. There was no significant difference in overall rating of imaging quality between EOS and DR. Micro-dose protocol provided enough quality to perform consistent measurement on Cobb angle.

CONCLUSIONS

Entrance-skin dose, effective dose and organ dose were significantly reduced in micro-dose x-ray. The effective dose of a single micro-dose x-ray (2.6 μSv) was less than a day of background radiation. As AIS patients require periodic x-ray follow up for surveillance of curve progression, clinical use of micro-dose x-ray system is beneficial for these young patients to reduce the intake of ionizing radiation.

Breast Radiation Exposure in Female Orthopaedic Surgeons

BACKGROUND

Breast cancer prevalence is higher among female orthopaedic surgeons compared with U.S. women. The most common breast cancer site, the upper outer quadrant (UOQ), may not be adequately shielded from intraoperative radiation. Factors associated with higher breast radiation exposure (protective apron size and type, surgeon position, and C-arm position) have yet to be established.

METHODS

An anthropomorphic torso phantom, simulating the female surgeon, was placed adjacent to a standard operating table. Dosimeters were placed over the UOQ and lower inner quadrant (LIQ) of the breast, bilaterally. Scatter radiation dose-equivalent rates were measured during continuous fluoroscopy to a pelvic phantom (simulating the patient). Four apron sizes (small, medium, large, and extra-large), 2 apron types (cross-back and vest), 2 surgeon positions (facing the table and 90° to the table), and 2 C-arm positions (anteroposterior and cross-table lateral projection) were tested.

RESULTS

The median dose-equivalent rate of scatter radiation to the UOQ (0.40 mrem/hr) was higher than that to the LIQ of the breast (0.06 mrem/hr) across all testing, although this was not statistically significant (p = 0.05). The cross-back aprons provided higher protection to the LIQ compared with the vests (p < 0.05). Lead protection in sizes that were too small or too large for the torso had higher breast radiation dose-equivalent rates. C-arm cross-table lateral projection was associated with higher breast radiation exposure (0.98 mrem/hr) compared with anteroposterior projection (0.13 mrem/hr) (p < 0.001).

CONCLUSIONS

Breast radiation exposure is higher in a C-arm lateral projection compared with an anteroposterior projection. Higher dose-equivalent rates were observed for the UOQ compared with the LIQ of the breast and for aprons that were too small or too large, although these differences did not reach significance. Factors that may reduce radiation exposure include lead protection of appropriate size and distancing the axilla from the patient and x-ray tube.

CLINICAL RELEVANCE

Increased breast cancer prevalence has been reported for female orthopaedic surgeons. The UOQ of the breast may be at risk for intraoperative radiation exposure. Methods of reducing exposure are warranted.

Effect of spinal immobilisation devices on radiation exposure in conventional radiography and computed tomography

Trauma patients at risk for, or suspected of, spinal injury are frequently transported to hospital using full spinal immobilisation. At the emergency department, immobilisation is often maintained until radiological work-up is completed. In this study, we examined how these devices influence radiation exposure and noise, as a proxy for objective image quality. Conventional radiographs (CR) and computer tomography (CT) scans were made using a phantom immobilised on two types of spineboard and a vacuum mattress and using two types of headblocks. Images were compared for radiation transmission and quantitative image noise. In CR, up to 23 % and, in CT, up to 11 % of radiation were blocked by the devices. Without compensation for the decreased transmission, noise increased by up to 16 % in CT, depending on the device used. Removing the headblocks led to a statistically significant improvement in transmission with automatic exposure control (AEC) enabled. Physicians should make an informed decision whether the increased radiation exposure outweighs the risk of missing a clinically significant injury by not making a CR or CT scan. Manufacturers of immobilisation devices should take radiological properties of their devices into account in the development and production process.

The Validity of Rasterstereography: A Systematic Review

To investigate and monitor the progression of scoliosis and other spinal deformities in patients following idiopathic scoliosis (IS), non-invasive and radiation-free techniques are recommended because of the need for repeated radiographs. In a clinical setting, spine parameters can be quickly, cheaply and easily assessed using rasterstereography (RS). To assess the validity of the radiation-free technique RS based on surface topography compared with radiographs. MEDLINE, the Cochrane Library and EMBASE were systematically searched for studies which investigate the validity of rasterstereography compared with x-ray measurements. Studies published between January 1, 1990 and July 31, 2013 in English, German and French were included. Studies dealing with magnetic resonance imaging were excluded. Twelve studies with 570 patients were included; these articles were published between 1990 and 2013. The majority of studies investigated patients with IS, but other spinal pathologies included were thoracic hyperkyphosis and Scheuermann’s disease. With regard to the quality assessment criteria for the included studies, three out of twelve studies were evaluated using a twelve point scale and two used a scale with eleven points. We conclude that RS facilitates clinical practice by analysing the spinal column. It is completely radiation-free and could help to monitor scoliosis progression.

Radiation exposure during scoliosis surgery: a prospective study

BACKGROUND CONTEXT

The present literature on the cancer risks related to radiation exposure in patients and surgeons during scoliosis surgery is sparse.

PURPOSE

To assess the radiation exposure in patients and surgeons during scoliosis surgery and estimate the increased cancer risk of both groups.

STUDY DESIGN

Over a 6-month period, we conducted a prospective study to monitor the intraoperative radiation dose received by both patients and surgeons during scoliosis cases.

PATIENT SAMPLE

It included 30 consecutive patients undergoing scoliosis surgery by a team of two surgeons (S1 and S2).

OUTCOME MEASURES

We measured the radiation exposure to the eyes, thyroid, and hands for each surgeon; measured the difference of radiation exposure between the two surgeons; the difference in radiation exposure with respect to the proximity of the surgeon to the X-ray tube, and the radiation exposure for each patient.

METHODS

An electronic dosimeter was attached over the thyroid guard and a thermoluminescent dosimeter ring on both hands of each surgeon. The patients were monitored using the dose area product (DAP) measurements from the image intensifier, and their radiation exposure was calculated with the Monte Carlo calculation.

RESULTS

The mean eye dose per procedure for the two surgeons S1 and S2 was 0.8 μSv and 1.3 μSv, respectively. The mean thyroid dose for S2 and S1 was 1.2 μSv and 1.4 μSv, respectively. The dose recorded by the surgeon on the same side of the patient as the X-ray tube was significantly higher than for the surgeon on the far side (p<.05). Mean DAP per procedure was 91.3 cGycm(2) and the mean radiation dose for patients was 252.9 μSv. The increase in cancer risk for patients and surgeons was 0.001% and 0.0005%, respectively, for each year of exposure.

CONCLUSIONS

A significantly higher dose of radiation during scoliosis surgery was received by the surgeon standing on the same side as the X-ray tube. However, both surgeons received a total radiation dose of less than 1% of the recommended dose limit per year and, therefore, the total radiation exposure in both surgeons and patients was well within the recommended safe limits.

Comparison of parameters characterizing lumbar lordosis in radiograph and photogrammetric examination of adults

OBJECTIVE

The purpose of this study was to test validity of photogrammetry compared with radiography as a method of measuring the Cobb angle and the size of anterior-posterior spine curvatures in adults.

METHODS

The study included 50 volunteers, 23 men and 27 women whose mean age was 52.6 years. The average weight of the subjects was 81.3 kg, average body height was 172.0 cm, and the average body mass index was 27.4. Based on radiologic examination, the length and depth of lumbar lordosis were determined and the size of the Cobb angle of lumbar scoliosis. After the radiologic examination, a photogrammetric test was performed for each subject with the projection moire phenomenon.

RESULTS

The Pearson correlation found statistically significant associations concerning the length of lordosis (P < .001) and the Cobb angle (P < .001). Correlation of the depth of lordosis indicated a strong trend (P = .063).

CONCLUSIONS

This study found that the moire method of photogrammetric measurement produced similar findings to radiographic measurements in determining size of the Cobb angle and the length of lumbar lordosis.

Conversion coefficients for determining organ doses in paediatric pelvis and hip joint radiography

BACKGROUND

Knowledge of organ and effective doses achieved during paediatric X-ray examinations is an important prerequisite for assessment of radiation burden to the patient.

OBJECTIVE

Conversion coefficients for reconstruction of organ and effective doses from entrance doses for pelvis and hip joint radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients are provided regarding the Guidelines of Good Radiographic Technique of the European Commission.

MATERIALS AND METHODS

Using the personal computer program PCXMC developed by the Finnish Centre for Radiation and Nuclear Safety (Säteilyturvakeskus STUK), conversion coefficients for conventional pelvis and hip joint radiographs were calculated by performing Monte Carlo simulations in mathematical hermaphrodite phantom models representing patients of different ages. The clinical variation of radiation field settings was taken into consideration by defining optimal and suboptimal standard field settings.

RESULTS

Conversion coefficients for the reconstruction of organ doses in about 40 organs and tissues from measured entrance doses during pelvis and hip joint radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients were calculated for the standard sagittal beam projection and the standard focus detector distance of 115 cm.

CONCLUSION

The conversion coefficients presented can be used for organ dose assessments from entrance doses measured during pelvis and hip joint radiographs of children and young adults with all field settings within the optimal and suboptimal standard field settings.

Conversion coefficients for determining organ doses in paediatric spine radiography

BACKGROUND

Knowledge of organ and effective doses achieved during paediatric x-ray examinations is an important prerequisite for assessment of radiation burden to the patient.

OBJECTIVE

Conversion coefficients for reconstruction of organ and effective doses from entrance doses for segmental spine radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients are provided regarding the Guidelines of Good Radiographic Technique of the European Commission.

MATERIALS AND METHODS

Using the personal computer program PCXMC developed by the Finnish Centre for Radiation and Nuclear Safety (Säteilyturvakeskus STUK), conversion coefficients for conventional segmental spine radiographs were calculated performing Monte Carlo simulations in mathematical hermaphrodite phantom models describing patients of different ages. The clinical variation of beam collimation was taken into consideration by defining optimal and suboptimal radiation field settings.

RESULTS

Conversion coefficients for the reconstruction of organ doses in about 40 organs and tissues from measured entrance doses during cervical, thoracic and lumbar spine radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients were calculated for the standard sagittal and lateral beam projections and the standard focus detector distance of 115 cm.

CONCLUSION

The conversion coefficients presented may be used for organ dose assessments from entrance doses measured during spine radiographs of patients of all age groups and all field settings within the optimal and suboptimal standard field settings.

Assessing kyphosis with SpineScan: another attempt to reduce our dependence on radiography

BACKGROUND CONTEXT

Kyphosis management is mainly conservative, with annual examinations to assess angular progression. This includes physical examination and usually long spine X-rays, notorious for ionizing radiation. Several nonradiological instruments have been devised for this, but none have become popular. SpineScan, a programmed digital inclinometer, has been proved effective for screening kyphoscoliosis.

PURPOSE

The aim of this study was to assess the accuracy of SpineScan in monitoring kyphosis.

STUDY DESIGN/SETTING

Prospective, observational, diagnostic accuracy study.

PATIENT SAMPLE

Twenty-eight subjects examined for kyphosis, with recent full-length lateral spine X-rays.

METHODS

Each subject was examined by two examiners. The technique involved the subject standing with arms flexed to 90° and then sliding the SpineScan from just below C7 to L2. Maximum X-ray kyphotic Cobb angle was compared with the SpineScan result. The study was institutional review board approved, and all patients signed an informed consent.

RESULTS

The mean Cobb angle of the 28 subjects on radiography was 51° ± 15°. The mean SpineScan angle of all trials of all examiners was 54° ± 12°. The difference between the two measurements was significantly different from zero (3.2° ± 9.4°, p<.0001) and not normally distributed. The difference was significantly affected by the Cobb angle, examiner, and interaction between Cobb and examiner (statistical significance for all p<.0001). Ninety-five percent confidence intervals for all examiners ranged between -16° and 22° and for separate examiners between -25° and 32°, far above the 5° preplanned error level.

CONCLUSIONS

The results demonstrated that there is significant error in monitoring kyphosis with SpineScan. Even for a more modest indication including replacing radiography with SpineScan on alternate visits, the measurement was not accurate enough. Future research is necessary to find a nonradiographic method of kyphosis follow-up, possibly using a digitalized modification of one of the described instruments.

Development of a 3-Dimensional Back Contour Imaging System for Monitoring Scoliosis Progression in Children

STUDY DESIGN

Control study.

OBJECTIVES

To present a new surface topography system capable of taking 3-dimensional (3D) spine measurements, to establish baseline values for the measured parameters in a typically developing population, and to determine the intra-rater and inter-rater reproducibility of these parameters.

SUMMARY OF BACKGROUND DATA

Cumulative exposure to radiation from diagnostic radiographs increases patient risk for cancer development. There is a need for noninvasive and non-radiographic tools to accurately and reproducibly measure spine deformity and track scoliosis progression.

METHODS

We measured 10 typically developing subjects with the new Milwaukee Topography System, which is composed of 2 electromagnetic markers, an electronic processing unit, a handheld laser scanner, a software package, and a desktop computer. Two investigators separately scanned the same subjects multiple times, yielding a total of 4 scans per subject per investigator. We measured 17 3D back parameters in each scan. We performed a multivariate analysis of variances to test the hypothesis of no difference for all variables, measured intra-rater and inter-investigator reliability with intra-class correlation (ICC) coefficients, and calculated mean values.

RESULTS

There were highly reproducible ICC values between investigators for 6 parameters (ICC > 0.75), moderate ICC values for 8 parameters (0.75 > ICC > 0.4), and poor ICC values for 3 parameters (ICC < 0.4), all at p < .05. Intra-investigator ICCs were moderate to excellent for almost all parameters.

CONCLUSIONS

The Milwaukee Topography System can be used to monitor and measure 3D back contours in children. The 3D back parameters values measured in the typically developing population can be considered baseline values that can be compared with parameters measured in children with idiopathic scoliosis.

Inpatient radiation exposure in patients with spinal trauma

CONTEXT/OBJECTIVE

Radiation exposure from medical imaging is an important patient safety consideration; however, patient exposure guidelines and information on cumulative inpatient exposure are lacking.

DESIGN/SETTING

Trauma patients undergo numerous imaging studies, and spinal imaging confers a high effective dose; therefore, we examined cumulative effective radiation dose in patients hospitalized with spinal trauma. We hypothesized that people with spinal cord injury (SCI) would have higher exposures than those with spine fractures due to injury severity.

PARTICIPANTS/INTERVENTIONS

Retrospective data were compiled for all patients with spine injuries admitted to a level I trauma center over a 2-year period.

OUTCOME MEASURES

Injury severity score (ISS) and cumulative radiation exposure were then determined for these patients, including 406 patients with spinal fractures and 59 patients with SCI.

RESULTS

Cumulative effective dose was 45 millisieverts (mSv) in SCI patients, compared to 38 mSv in spinal fracture patients (P = 0.01). Exposure was higher in patients with an ISS over 16 (P = 0.001). Mean exposure in both groups far exceeded the European annual occupational exposure maximum of 20 mSv. More than one-third of patients with SCI exceeded the US occupational maximum of 50 mSv.

CONCLUSION

Patients with SCI had significantly higher radiation exposure and ISS than those with spine fracture, but the effective dose was globally high. Dose did not correlate with injury severity for patients with SCI. While the benefits of imaging are clear, radiation exposure does involve risk and we urge practitioners to consider cumulative exposure when ordering diagnostic tests.

The role of MRI in musculoskeletal practice: a clinical perspective

This clinical perspective presents an overview of current and potential uses for magnetic resonance imaging (MRI) in musculoskeletal practice. Clinical practice guidelines and current evidence for improved outcomes will help providers determine the situations when an MRI is indicated. The advanced competency standard of examination used by physical therapists will be helpful to prevent overuse of musculoskeletal imaging, reduce diagnostic errors, and provide the appropriate clinical context to pathology revealed on MRI. Physical therapists are diagnostically accurate and appropriately conservative in their use of MRI consistent with evidence-based principles of diagnosis and screening.

Reproducibility of newly developed spinal topography measurements for scoliosis

Objective:

In an effort to limit exposure to ionizing radiation and fully characterize three dimensional changes in the spine of patients with scoliosis reliable non-invasive methods of spinal back contour analysis (Milwaukee Topographic Scanner) (MTS) have been developed.

Study Design:

The current study compares spinal topography measurements among different subject positions and evaluates the reproducibility of the system for both inter-rater and intra-rater reliability.

Methods:

A dummy cast (plastic cast) of one patient with adolescent idiopathic scoliosis was created in order to test the reliability of the MTS. The dummy cast was positioned and rotated in 3D while scanned by two investigators using the MTS. A total of twelve parameters including Q-angle (an analog to X-ray’s Cobb angle) were extracted.

Results:

All measurements of intra-rater and inter-rater reliability were excellent (Intraclass Correlation Coefficients ranging from 0.89 to 0.99) with the exception of Pelvic Tilt (intra-rater ICC is 0.61) and lordosis angle (inter-rater ICC is 0.82). No significant variability among investigators was observed for all tested metrics. No significant variability due to position was observed for the majority of back contour measurements but there were significant changes in the T1-S1 angle, T1-S1 deviation, T1-NC angle, T1-NC deviation, and Back Height metric (p< 0.05).

Conclusions:

The MTS is a reliable method of raster stereography in the measurement of the back contour, which will help monitor the progression of children with idiopathic scoliosis and reduce the use of X-rays.

New method of scoliosis assessment: preliminary results using computerized photogrammetry

STUDY DESIGN

A new method for nonradiographic evaluation of scoliosis was independently compared with the Cobb radiographic method, for the quantification of scoliotic curvature.

OBJECTIVE

To develop a protocol for computerized photogrammetry, as a nonradiographic method, for the quantification of scoliosis, and to mathematically relate this proposed method with the Cobb radiographic method.

SUMMARY OF BACKGROUND DATA

Repeated exposure to radiation of children can be harmful to their health. Nevertheless, no nonradiographic method until now proposed has gained popularity as a routine method for evaluation, mainly due to a low correspondence to the Cobb radiographic method.

METHODS

Patients undergoing standing posteroanterior full-length spine radiographs, who were willing to participate in this study, were submitted to dorsal digital photography in the orthostatic position with special surface markers over the spinous process, specifically the vertebrae C7 to L5. The radiographic and photographic images were sent separately for independent analysis to two examiners, trained in quantification of scoliosis for the types of images received. The scoliosis curvature angles obtained through computerized photogrammetry (the new method) were compared to those obtained through the Cobb radiographic method.

RESULTS

Sixteen individuals were evaluated (14 female and 2 male). All presented idiopathic scoliosis, and were between 21.4 ± 6.1 years of age; 52.9 ± 5.8 kg in weight; 1.63 ± 0.05 m in height, with a body mass index of 19.8 ± 0.2. There was no statistically significant difference between the scoliosis angle measurements obtained in the comparative analysis of both methods, and a mathematical relationship was formulated between both methods.

CONCLUSION

The preliminary results presented demonstrate equivalence between the two methods. More studies are needed to firmly assess the potential of this new method as a coadjuvant tool in the routine following of scoliosis treatment.

Reproducibility of rasterstereography for kyphotic and lordotic angles, trunk length, and trunk inclination: a reliability study

STUDY DESIGN

Determination of reliability with 3 investigators using a collective of healthy volunteers.

OBJECTIVE

To determine the reliability of rasterstereography 3-dimensional back surface analysis and reconstruction of the spine in healthy test subjects.

SUMMARY OF BACKGROUND DATA

Rasterstereography has been in clinical use since 1989 for patients with scoliosis and other spinal deformities and it significantly reduces the need for otherwise indispensable radiographs. The validity of this device has previously been examined in other studies. This study was performed to evaluate the reliability of rasterstereography for clinical application in diagnostic and follow-up examinations.

METHODS

Fifty-one healthy volunteers were examined rasterstereographically by 3 investigators. Each investigator made a series of 3 measurements of each participant in which 8 spine parameters including kyphotic angle ICT-ITL (max.), kyphotic angle VP-ITL, kyphotic angle VP-T12, lordotic angle ITL-ILS (max.), lordotic angle ITL-DM, lordotic angle T12-DM, trunk length VP-DM and trunk inclination were measured. Cronbach alpha was calculated. The influence of high or low body mass index on the accuracy of the technique was evaluated as well.

RESULTS

Cronbach alpha for the intratester-reliability of the kyphotic angle ICT-ITL (max.) for the 3 investigators has values between 0.921 and 0.992. The intertester-reliability for the same parameter is 0.979 (95% CI). In this study group a meaningful association between body mass index and reliability of the device was not found.

CONCLUSION

The reliability revealed very good results, both for intratester and for intertester reliability. The technique is well suited for analysis of the back in standing position. The body mass index has no influence on the reproducibility.

The rasterstereographic-dynamic analysis of posture in adolescents using a modified Matthiass test

The Matthiass posture test is a clinical test to detect posture changes in children and adolescents. Aim of this study was to objectify this test using a dynamic rasterstereographic measuring device. We examined 31 healthy athletes during a modified Matthiass test with a dynamic rasterstereographic measuring system. Hereby the trunk inclination, kyphosis and lordosis angle were measured. The trunk inclination decreased by about 50% of the basic value just by raising the arms. Additional weight loads of only 5% body weight (bw) resulted in significant changes of the posture (lordosis and kyphosis angle) during this test. With this rasterstereographic measuring device it seems to be possible to determine spinal posture changes under dynamic conditions. The results suggest that additional weights of 5% bw during the Matthias-test are enough to create significant deviations in posture parameters, even in healthy subjects.

Risk factors for NSF: a literature review

Emerging evidence linking gadolinium-based contrast agents (GBCAs) to nephrogenic systemic fibrosis (NSF) has changed medical practice patterns toward forgoing GBCA-enhanced magnetic resonance imaging (MRI) or substituting other imaging methods, which are potentially less accurate and often radiation-based. This shift has been based on reports of high NSF incidence at sites where a confluence of risk factors occurred in patients with severe renal dysfunction. This review article explores the factors that affect NSF risk, compares risks of alternative imaging procedures, and demonstrates how risk can be managed by careful selection of GBCA dose, timing of injection with respect to dialysis, and other factors. Nearly half of NSF cases are a milder form that does not cause contractures or reduce mobility. It appears that eliminating even a single risk factor can reduce NSF incidence/risk at least 10-fold. Elimination of multiple risk factors by using single-dose GBCA, dialyzing dialysis patients quickly following GBCA administration, avoiding GBCA in acute renal failure while serum creatinine is rising, and avoiding nonionic linear GBCA in renal failure patients may reduce NSF risk more than a thousand-fold, thereby allowing safe GBCA-enhanced MRI in virtually all patients. J. Magn. Reson. Imaging 2009;30:1298-1308. (c) 2009 Wiley-Liss, Inc.

Raster stereography versus radiography in the long-term follow-up of idiopathic scoliosis

STUDY DESIGN

Raster-stereographic and radiographic evaluation of idiopathic scoliosis without braces in a retrospective longitudinal long-term follow-up study.

OBJECTIVE

To investigate the reliability and accuracy of raster stereography in comparison with radiography as the gold standard, using a longitudinal long-term study design in idiopathic scoliosis, to reduce the number of radiographs required during follow-up in scoliosis patients.

SUMMARY OF BACKGROUND DATA

It has been confirmed that raster stereography produces reliable data in patients with conservatively and surgically treated idiopathic scoliosis, up to a Cobb angle of 80 degrees. This means that the method can be used to replace radiography during the follow-up in these patients. However, no data have yet been published on the use of raster stereography in a longitudinal setting during a long-term follow-up period in comparison with radiography as the gold standard.

METHODS

Raster stereographs and digitized anterior-posterior radiographs of 16 patients with idiopathic scoliosis were studied retrospectively in a longitudinal study design, with a mean follow-up period of 8 years (range 3 to 10 y). Lateral vertebral deviation and vertebral rotation were measured between C7 and L4 using raster stereography and radiography, compared with Cobb angles, and correlated.

RESULTS

During the follow-up period, the Cobb angle increased on average by 13 degrees. The progression of lateral vertebral deviation measured using both techniques, and that of vertebral rotation measured with radiography, was greater than that of the Cobb angle, whereas that of raster-stereographic vertebral rotation was lower. However, there was an excellent correlation between the raster-stereographic and radiographic progression of these parameters (R2 >or=0.5). The mean difference between raster stereographs and radiographs was 3.21 mm for lateral vertebral deviation and 2.45 degrees for vertebral rotation.

CONCLUSIONS

Using the parameters of lateral vertebral deviation and vertebral rotation, raster stereography accurately reflects the radiographically measured progression of idiopathic scoliosis during the long-term follow-up, but these parameters are not directly comparable with the Cobb angle. In the follow-up of scoliosis patients, the authors would recommend a raster-stereographic examination every 3 to 6 months and a radiographic examination every 12 to 18 months only, provided that raster stereography does not show rapid deterioration of the scoliosis. The patient's radiation exposure can be reduced using this approach.

Reliability of a functional classification system in the monitoring of patients with idiopathic scoliosis

STUDY DESIGN

Patients with scoliosis from 1999 to 2001 were monitored using radiographs and the Quantec Spinal Imaging System (Quantec) to validate the Functional Classification System (FCS) developed at Children's Hospital of Wisconsin (CHW).

OBJECTIVE

To determine the accuracy of the FCS.

SUMMARY OF BACKGROUND DATA

The authors evaluated different noninvasive ways of evaluating the scoliotic spine. The FCS was developed as a means to predict the degree of scoliotic curve.

METHODS

Consecutive scoliosis visits (543) seen at CHW between 1999 and 2001 for initial or follow-up examination were investigated; of them, 157 had an radiograph within 6 months of Quantec. Subjects were placed into groups based on Cobb Angles. FCS classifications were compared to Cobb angle groupings and calculated sensitivity and specificity. Pearson's correlation coefficient was calculated for 39 subjects.

RESULTS

Sensitivity of the FCS for single curve groups ranged from 0.50 to 0.63 and specificity from 0.64 to 0.86. For double curve, both sensitivity and specificity ranged from 0.48 to 0.81. Pearson's correlation was statistically significant (r = 0.45, P < 0.05).

CONCLUSIONS

Sensitivity, specificity, and Pearson's correlation coefficient reflect the reliability of the Quantec method. Therefore, the FCS can be considered as a reliable tool for monitoring the progression of scoliosis with reduced need of radiographs.

Assessment of radiation dose awareness among pediatricians

BACKGROUND

There is increasing awareness among pediatric radiologists of the potential risks associated with ionizing radiation in medical imaging. However, it is not known whether there has been a corresponding increase in awareness among pediatricians.

OBJECTIVE

To establish the level of awareness among pediatricians of the recent publicity on radiation risks in children, knowledge of the relative doses of radiological investigations, current practice regarding parent/patient discussions, and the sources of educational input.

MATERIALS AND METHODS

Multiple-choice survey.

RESULTS

Of 220 respondents, 105 (48%) were aware of the 2001 American Journal of Roentgenology articles on pediatric CT and radiation, though only 6% were correct in their estimate of the quoted lifetime excess cancer risk associated with radiation doses equivalent to pediatric CT. A sustained or transient increase in parent questioning regarding radiation doses had been noticed by 31%. When estimating the effective doses of various pediatric radiological investigations in chest radiograph (CXR) equivalents, 87% of all responses (and 94% of CT estimates) were underestimates. Only 15% of respondents were familiar with the ALARA principle. Only 14% of pediatricians recalled any relevant formal teaching during their specialty training. The survey response rate was 40%.

CONCLUSION

Awareness of radiation protection issues among pediatricians is generally low, with widespread underestimation of relative doses and risks.

Radiation-free quantitative assessment of scoliosis: a multi center prospective study

Accurate quantitative measurements of the spine are essential for deformity diagnosis and assessment of curve progression. There is much concern related to the multiple exposures to ionizing radiation associated with the Cobb method of radiographic measurement, currently the standard procedure for diagnosis and follow-up of the progression of scoliosis. In addition, the Cobb method relies on 2-D analysis of a 3-D deformity. The aim of this prospective study was to investigate the clinical value of Ortelius800 that provides a radiation-free method for scoliosis assessment in three planes (coronal, sagittal, apical), with simultaneous automatic calculation of the Cobb angle in both coronal and sagittal views. Analysis of the clinical value of the device for assessing spinal deformities was performed on patients with adolescent idiopathic scoliosis, deformity angles ranging from 10 degrees to 48 degrees. Correlation between Cobb angles measured manually on standard erect posteroanterior radiographs and those calculated by Ortelius800 showed an absolute difference between the measurements to be significantly less than +/- 5 degrees for coronal measurements and significantly less than +/- 6 degrees for sagittal measurements indicating good correlation between the two methods. The measurements from four independent sites and six independent examiners were not significantly different. We found the novel clinical tool to be reliable for following mild and moderate idiopathic curves in both coronal and sagittal planes, without exposing the patient to ionizing radiation. Considering the need for further validation of this new method, any change in treatment protocol should still be based on radiographic control.

Musculoskeletal imaging in physical therapist practice

This article presents an overview of current concepts of evidence-based diagnosis using a variety of imaging modalities for a broad spectrum of musculoskeletal conditions and syndromes. There is limited but increasing evidence that physical therapists appropriately use diagnostic studies in clinical practice. Pathology revealed by diagnostic studies must be viewed in the context of the complete examination, as pathology is common in the asymptomatic population. Special diagnostic challenges are presented by patients with areas of referred pain, multiple injuries or multiple areas of pathology, neoplasms, and infections. Plain film radiographs have been overused in the clinical management of many conditions, including low back pain. Clinical decision rules provide simple evidence-based guidelines for the appropriate use of imaging studies.

Scoliosis: evidence-based diagnostic evaluation

This article summarizes the evidence behind the imaging evaluation of scoliosis, which is primarily performed with plain radiographs and MR imaging. Issues related to the radiographic evaluation of spinal curvature include interobserver variability of scoliosis measurements and the radiologist's detection of unexpected findings. The effects of radiation exposure during scoliosis evaluation and strategies to minimize radiation dose are summarized. The use of MR imaging in idiopathic scoliosis is discussed, with special attention to imaging groups at higher risk for underlying pathology of the neural axis.

Surface topography, Cobb angles, and cosmetic change in scoliosis

STUDY DESIGN

Preliminary analysis of the clinical value of surface topography in a spinal deformity clinic.

OBJECTIVES

The Cobb angle is the gold standard for the monitoring of scoliosis. This study was designed to determine whether surface topography would reflect Cobb angle status with sufficient reliability to permit its safe use as an alternative means of documentation in some circumstances.

SUMMARY OF BACKGROUND DATA

Surface topography offers the possibility of describing spinal deformity more fully than radiographic measures alone. To be useful, it must ignore changes due to varying posture and reliably detect differences that are clinically significant, while broadening the ability to assess deformity.

METHODS

Surface topography using Quantec () was obtained routinely in all patients attending a spinal deformity unit. Intrasubject variation was reduced by taking the mean for each parameter of four repositioned scans, which gives a smallest detectable change on all measures of approximately 10 U. Fifty-nine patients with two sets of radiographs and topography scans were studied to determine the ability of the different measurements to detect significant change.

RESULTS

There was a significant correlation between Cobb angle and Quantec spinal angle. A significant change in Cobb angle could be identified by associated change in at least one topographic measure in a significant proportion of cases.

CONCLUSIONS

It is unlikely that topography will supplant radiography for the ascertainment of Cobb angles, because the error margins of both are wide, and the two are not measuring the same aspect of the deformity. The Quantec system is useful in patient monitoring as an alternative to radiography, without diminishing the standard of care.

The association between cigarette smoking and back pain in adults

STUDY DESIGN

A retrospective cohort study of adolescent idiopathic scoliosis. A comparison group of persons without scoliosis was also selected randomly from the general population.

OBJECTIVES

To estimate the association between level of cigarette smoking and the prevalence and severity of back pain.

METHODS

A postal questionnaire was used to elicit information on smoking histories, a variety of indices of low back pain, and potential confounding factors. The association between smoking and back pain was estimated separately for men and women in the cohort and in the comparison group using ordinal regression models.

RESULTS

The questionnaire was completed by 1287 women and 184 men who had adolescent idiopathic scoliosis and by 1130 women and 621 men in the comparison population who did not have scoliosis. Statistically significant associations between back pain and current cigarette smoking were found in the two groups of women and men with scoliosis, but not among men selected from the general population. In the three former groups, proportional odds ratios comparing current smokers to persons who never smoked ranged from 1.4 to 1.9. Among current smokers, the prevalence of back pain increased with cigarette consumption, and the proportional odds ratios ranged from 1.2 to 1.8 per 10 pack-years (no. of cigarettes smoked per day x no. of years/20). In these three groups, intensity, frequency, and duration of episodes of back pain also were found to increase with smoking consumption.

CONCLUSION

The finding that smokers have more frequent episodes of back pain may imply that smoking exacerbates back pain, and the observation that stronger associations between back pain and smoking were found in the scoliosis cohort suggests that smoking may have a greater impact on persons with damaged spines.