Spine Computed Tomography Research Articles

Imaging incidence and type in primary care patients with low back pain: a cross-sectional study on new referrals to an Australian specialist spinal surgical centre.

Introduction Low back pain (LBP) is common and a significant cause of morbidity. Many patients receive inappropriate imaging for LBP in primary care. Aim To explore the incidence and type of spinal imaging conducted for LBP patients referred from general practice for specialist surgical opinion, and evaluate whether imaging conformed to clinical guidelines. Methods Audit of a sequential cohort (n = 100) of new LBP patients referred from primary care for specialist opinion at a suburban Australian capital city independent Spinal Centre. Results In the 6 months before referral, 90% (95% CI 83-95%) of patients underwent spinal imaging. Imaging was performed in 95% of those who did and 79% of those who did not meet guidelines for radiological investigation. 35% of patients were inappropriately imaged and 3% inappropriately not imaged. Spinal computed tomography (CT) imaging was used in 52% of patients, magnetic resonance imaging (MRI) in 42% and image-guided lumbar spinal interventional procedures in 28%. Discussion Most patients with LBP referred for surgical opinion have diagnostic radiological investigations whether or not it is indicated by clinical guidelines. The more frequent use of spinal CT compared to MRI may be due to idiosyncrasies of the Australian Medicare Benefits Schedule (MBS) rebate system. The findings of this pilot study provide support for the changes recommended by the 2016 MBS Review Taskforce on LBP that permit GP access to subsidised lumbar MRI, while constraining access to lumbar CT, and provide novel data about spinal imaging and practice in this cohort of patients.

Application of metal artifact reduction algorithm in reducing metal artifacts in post-surgery pediatric low radiation dose spine computed tomography (CT) images.

The commonly used methods for removing metal-induced beam hardening artifacts often rely on the use of high energy photons with either high tube voltage or high energy virtual monoenergetic images in dual-energy computed tomography (CT), the radiation dose was usually relatively high in order to generate adequate signals. This retrospective study is designed to evaluate the application of a metal artifact reduction (MAR) algorithm in reducing pedicle screw metal-caused beam hardening artifacts in post-surgery pediatric low radiation dose spine CT images. Seventy-seven children (3-15 years) who had undergone a low dose CT with 140 or 100 kV were enrolled. The radiation dose was 1.40 mGy for the 3-8 years old and 2.61 mGy for 9-15 years old children. There were 116 pedicle screws evaluated. The raw data were reconstructed with adaptive statistical iterative reconstruction-V (ASIR-V) at 50% strength, ASIR-V with MAR (AV-MAR), deep learning image reconstruction (DLIR) at high strength and DLIR with MAR (DL-MAR). The image quality concerning pedicle screws was evaluated objectively in terms of the length of beam-hardening artifact (LHA) and artifact index (AI), and subjectively using a 4-point scale (4 points: best, 3 points: acceptable). Both AV-MAR and DL-MAR significantly reduced metal-induced beam hardening artifacts with smaller LHA (15.76±10.12 mm, a reduction of 57.24% and 15.66±10.49 mm, a reduction of 57.40%, respectively), and AI value (62.50±33.51, a reduction of 64.65% and 61.03±32.61, a reduction of 65.01%, respectively) compared to ASIR-V and DLIR (all P<0.01), The subjective image quality scores concerning the screws were 3.37±0.49 and 3.47±0.50 with AV-MAR and DL-MAR, respectively, higher than the respective value of 1.73±0.44 and 1.76±0.43 without MAR (all P<0.01). MAR significantly reduces the low-density artifacts caused by metal screws in post-surgery pediatric low-dose spine CT images, across different tube voltages, radiation dose levels and reconstruction algorithms. Combining DL-MAR further improves the overall image quality under low radiation dose conditions.

A Dual-Selective Channel Attention Network for Osteoporosis Prediction in Computed Tomography Images of Lumbar Spine

Osteoporosis is a common systemic bone disease with insidious onset and low treatment efficiency. Once it occurs, it will increase bone fragility and lead to fractures. Computed tomography (CT) is a non-invasive medical examination method that can identify the bone condition of patients. In this paper, we propose a novel channel attention module, which is subsequently integrated into the supervised deep convolutional neural network (DCNN) termed DSNet, which can perform feature fusion from two different scales, and use the method of quadratic weight calculation to enhance the interconnection among feature map channels and improve the detection and classification performance for the bone condition in lumbar spine CT images. To train and test the proposed framework, we retrospectively collect 4805 CT images of 133 patients, using DXA as the gold standard. According to the T-value diagnostic criteria defined by WHO, the vertebral bodies of L1 - L4 in CT images are labeled and classified into osteoporosis, osteopenia and normal bone mineral density. Meanwhile, the training set and test set are constructed in the ratio of 4:1. As a result, the DSNet achieves a prediction accuracy of 83.4% and a recall rate of 90.0% on the test set, indicating that the proposed model has the potential to assist clinicians in diagnosing individuals with abnormal BMD and may alert patients at high risk of osteoporosis for timely treatment.

Thoracic Inlet in Cervical Spine CT of Blunt Trauma Patients: Prevalence of Pathologies and Importance of CT Interpretation.

The thoracic inlet of blunt trauma patients may have pathologies that can be diagnosed on cervical spine computed tomography (CT) but that are not evident on concurrent portable chest radiography (pCXR). This retrospective investigation aimed to identify the prevalence of thoracic inlet pathologies on cervical spine CT and their importance by measuring the diagnostic performance of pCXR and the predictive factors of such abnormalities. This investigation was performed at a level-1 trauma center and included CT and concurrent pCXR of 385 consecutive adult patients (280 men, mean age of 47.6 years) who presented with suspected cervical spine injury. CT and pCXR findings were independently re-reviewed, and CT was considered the reference standard. Traumatic, significant nontraumatic and nonsignificant pathologies were present at 23.4%, 23.6% and 58.2%, respectively. The most common traumatic diagnoses were pneumothorax (12.7%) and pulmonary contusion (10.4%). The most common significant nontraumatic findings were pulmonary nodules (8.1%), micronodules (6.8%) and septal thickening (4.2%). The prevalence of active tuberculosis was 3.4%. The sensitivity and positive predictive value of pCXR was 56.67% and 49.51% in diagnosing traumatic and 8.89% and 50% in significant nontraumatic pathologies. No demographic or pre-admission clinical factors could predict these abnormalities. Several significant pathologies of the thoracic inlet were visualized on trauma cervical spine CT. Since a concurrent pCXR was not sensitive and no demographic or clinical factors could predict these abnormalities, a liberal use of chest CT is suggested, particularly among those experiencing high-energy trauma with significant injuries of the thoracic inlet. If chest CT is not available, a meticulous evaluation of the thoracic inlet in the cervical spine CT of blunt trauma patients is important.

Usefulness of digital tomosynthesis in diagnosing cervical ossification of the posterior longitudinal ligament: a comparative study with other imaging modalities.

The diagnosis and classification of ossification of the posterior longitudinal ligament (OPLL) can be difficult with radiography alone; therefore, computed tomography (CT) is also usually performed. There are many reports on the usefulness of digital tomosynthesis (DTS) for image analysis in orthopedics. This study aimed to compare the accuracy of DTS with radiography and CT for the diagnosis and classification of cervical OPLL (C-OPLL). We included 31 patients with OPLL and 30 with cervical spondylotic myelopathy. The patients' cervical spine radiography, DTS, and CT images were each evaluated twice by three specialists and three residents. In the intra-observer reliability study, there was one observer with a fair level of kappa values for radiography and DTS among three residents. The kappa values for CT were the best for all observers. In the inter-observer reliability study, the interclass correlation coefficient (ICC) values were high for both diagnosis and classification by specialists at the almost perfect level for all three imaging modalities. On the other hand, the ICC values for both diagnosis and classification for radiography by the residents were lower than those for DTS and CT. This study revealed that DTS may be an alternative to CT for the diagnosis and classification of C-OPLL by specialists. Caution should be exercised in diagnosing and classifying C-OPLL using radiography and DTS by residents, and the use of CT is recommended.

Factors associated with the increased risk of atlantoaxial osteoarthritis: a retrospective study.

Purpose Atlantodens osteoarthritis and atlantoaxial osteoarthritis cause neck pain and suboccipital headaches. Currently, knowledge on the risk factors for atlantoaxial osteoarthritis is lacking. This study aimed to investigate the factors related to the increased risk of atlantoaxial osteoarthritis. Methods We analyzed computed tomography (CT) images of the upper cervical spine of 1266 adult trauma patients for whom upper cervical spine CT was performed at our hospital between 2014 and 2019. The degree of atlantoaxial osteoarthritis was quantified as none-to-mild (not having osteoarthritis) or moderate-to-severe (having osteoarthritis). Risk factors associated with atlantoaxial osteoarthritis were identified using univariate and multivariable logistic regression analyses. Results The study group included 69.4% men, and the overall average age of the study population was 54.9 ± 20.4years. The following factors were independently and significantly associated with atlantoaxial osteoarthritis in the multivariable logistic regression analysis: age in the sixth decade or older (odds ratio [OR], 20.5; 95% confidence interval [CI], 6.2‒67.2, p < 0.001), having calcific synovitis (OR, 4.9; 95% CI, 2.4‒9.9, p < 0.001), women sex (OR, 3.3; 95% CI, 1.9‒5.7, p = 0.002), and not having atlantodens osteoarthritis (OR, 2.1; 95% CI, 1.2‒3.8, p = 0.014). Conclusion In the multivariable logistic regression analysis, age in the sixth decade or older, calcification of the transverse ligament, being women, and not having atlantodens osteoarthritis were found to be significantly associated with atlantoaxial osteoarthritis. Delayed diagnosis and treatment can be avoided by focusing on these risk factors.

Prediction of osteoporosis and osteopenia by routine computed tomography of the lumbar spine in different regions of interest

BackgroundWe aimed to investigate the utility of Hounsfield units (HU) obtained from different regions of interest in opportunistic lumbar computed tomography (CT) to predict osteoporosis coupling with data of dual-energy X-ray absorptiometry (DXA).MethodsA total of 100 patients who attended a university hospital in Shanghai, China, and had undergone CT and DXA tests of the lumbar spine within 3 months were included in this retrospective review. Images were reviewed on axial sections, and regions of interest (ROI) markers were placed on the round, oval, anterior, left, and right of the L1–L4 vertebra to measure the HU. The mean values of CT HU were then compared to the bone mineral density (BMD) measured by DXA. Receiver operator characteristic curves were generated to determine the threshold for diagnosis and its sensitivity and specificity values.ResultsThe differences in CT HU of different ROI based on DXA definitions of osteoporosis, osteopenia, and normal individuals were statistically significant (p < 0.01). The HU values of the different ROI correlated well with the BMD values (Spearman coefficient all > 0.75, p < 0.01). The threshold for diagnosing osteoporosis varies from 87 to 111 HU in different ROIs, and the threshold for excluding osteoporosis or osteopenia is 99–125 HU.ConclusionThis is the first study on osteoporosis diagnosis of different ROI with routine CT lumbar scans. There is a strong correlation between CT HU of different ROI in the lumbar spine and BMD, and HU measurements can be used to predict osteoporosis.

Pharynx volume derived from three-dimensional computed tomography is associated with difficult intubation in spinal deformity surgery: A retrospective cohort study.

Spinal abnormality surgery, including surgery for ankylosing spondylitis and idiopathic scoliosis, can present significant challenges to anesthesiologists because of the potential difficult airway. The bedside screening tests routinely used to detect difficult airways are highly variable. Pharynx volume calculated using three-dimensional (3D) computed tomography (CT) may play a role in predicting difficult airways.We conducted a retrospective cohort study on patients (aged ≥14 years) who received orthopedic surgery for ankylosing spondylitis/idiopathic scoliosis under general anesthesia. Volume of the pharynx air space was calculated through volume rendering technique by 3D reconstruction of patients’ cervical spine CT. Patients were divided into 2 groups according to their pharynx volume, pharyngeal volume lower than 16 mL (n = 11) and equal or higher than 16 mL (n = 13).Pharynx volume in low volume group was 10.4 ± 3.6 mL (n = 11), and the counterpart in high volume group was 20.8 ± 5.5 mL (n = 13). The incidence of difficult intubation was significantly higher in low pharynx volume group than in high pharynx volume group (54.5% (6/11) vs 7.6% (1/13), P = .023). Bedside screening tests including modified Mallampati test, inter-incisor gap and thyromental distance, or radiological variables such as anterior neck soft tissue thickness to vocal cords were not different between the 2 groups.Smaller pharynx volume played an important role in difficult airways for patients undergoing orthopedic surgery for ankylosing spondylitis/idiopathic scoliosis.

Interpretation of computed tomography of the cervical spine by non-radiologists: a systematic review and meta-analysis.

After trauma, clearance of the cervical spine refers to the exclusion of underlying serious injuries. Accurate assessment of computed tomography (CT) is commonly required prior to clearance of the cervical spine. Delays to clearance can lead to prolonged immobilization with associated patient discomfort and adverse effects. This systematic review aimed to determine performance of non-radiologists to evaluate cervical spine CT. MEDLINE, EMBASE, Cochrane library with sources of grey literature and reference lists of selected articles were appraised from inception to April 2021. We included manuscripts that reported discordance in CT cervical spine interpretation between non-radiologists and radiologists. The Newcastle-Ottawa scale (NOS) was used to assess quality of included studies and statistical heterogeneity was assessed using the I2 statistic. There were 43 studies identified for eligibility and 4 manuscripts included in the final analysis. There were two studies that reported on the performance of radiology residents, one study on the performance of surgical residents and one on emergency physicians. The pooled discordance was 0.25 (95%CI 0.21-0.28) but was lower for radiology residents (range 0.007-0.05). There was significant statistical heterogeneity (I2 = 99.6%, P< 0.001) among studies. There is a paucity of evidence documenting the ability of non-radiologists in accurately interpreting CT of the cervical spine. A number of discordant findings suggest that studies with larger sample sizes are indicated to accurately ascertain the ability of non-radiologists in this area.

Intra-individual comparison of lumbar spine CT, abdomen-pelvis contrast enhanced CT, and low-dose chest CT for bone density measurement.

Dual-energy X-ray absorptiometry (DXA) is the reference standard for the measurement of bone mineral density (BMD) and subsequent diagnosis of osteoporosis. Since various computed tomography (CT) protocols are scanned for various indications, we can incidentally measure BMD using CT. Previous studies have revealed a correlation between BMD and Hounsfield unit (HU) values obtained with different CT protocols. To compare the diagnostic value of CT protocols (lumbar spine CT [LSCT], abdomen-pelvis contrast-enhanced CT [APCT], and low-dose chest CT [LDCT]) for osteoporosis. We retrospectively included 17 patients (6 men, 11 women; mean age=68 years) who had undergone all four imaging studies within six months, during 2011-2021. HU values were manually measured at the center of the L1 vertebra by a radiology resident. Pearson correlation test was performed between HU values and BMD of L1 vertebra. The diagnostic performance of each CT protocol was assessed with receiver operating characteristic (ROC) analysis. Intra-individual concordance of the four tests to diagnose osteoporosis was analyzed by tabulating. The mean HU values were 104.4 ± 47.2 HU with LSCT, 149.0 ± 56.9 HU with APCT, and 114.3 ± 60.0 HU with LDCT. HU values from each protocol were positively correlated (r = 0.676-0.735; P < 0.005) with BMD. LDCT had the highest diagnostic performance (area under the ROC curve [AUC] = 0.701) and APCT the lowest (AUC = 0.569). APCT was discordant with the other protocols for diagnosing osteoporosis. LDCT had the highest diagnostic performance for osteoporosis with predetermined cutoff value. APCT requires the increase of cutoff value for osteoporosis diagnosis.

Comparison of the Safety and Efficacy of Three-Dimensional Guiding Templates and Free Hand Technique for Cervical Pedicle Screw Fixation: A Retrospective Study

Aim. To compare the safety and efficacy of computed tomography (CT)-assisted three-dimensional guiding templates (3DGTs) and free-hand (FH) technique for posterior cervical pedicle screw fixation in cervical spondylotic myelopathy (CSM) treatment. Methods. Thirty-five patients (216 screws) with CSM and developmental cervical stenosis were randomly divided into groups A (FH) and B (3DGTs). All patients underwent modified posterior surgery with cervical pedicle screw insertion (C1-7). Preoperative, postoperative, and intergroup comparisons of efficacy were evaluated using the visual analog scale (VAS), Japanese Orthopaedic Association (JOA), and Short Form 12 (SF-12) scores and JOA score improvement rate. Incidence of intra- and postoperative complications was analyzed. Postoperative cervical spine CT was performed to evaluate (i) the pedicle screws' deviation angle from the optimal path (sagittal deviation, α; coronal deviation angle, β), screw insertion point's deviation distance (d), and screw accuracy and (ii) the deviation angle and distance of screw entrance point of pedicle screws from the optimal channel. Results. All patients successfully completed the procedures. Groups A and B did not significantly differ in age, sex ratio, body mass index, operative time, or intraoperative blood loss amount. Postoperative VAS, JOA, and SF-12 scores improved in both groups. VAS, JOA, or SF-12 scores did not significantly differ between the 2 groups. The α, β, and d scores were lower in group B, but accuracy was higher in group B. Conclusions. 3DGTs and FH technique show comparable outcomes with respect to neurological improvement and safety.

Contribution of an artificial intelligence deep-learning reconstruction algorithm for dose optimization in lumbar spine CT examination: A phantom study

PurposeThe purpose of this study was to assess the impact of the new artificial intelligence deep-learning reconstruction (AI-DLR) algorithm on image quality and radiation dose compared with iterative reconstruction algorithm in lumbar spine computed tomography (CT) examination. Materials and methodsAcquisitions on phantoms were performed using a tube current modulation system for four DoseRight Indexes (DRI) (i.e., 26/23/20/15). Raw data were reconstructed using the Level 4 of iDose4 (i4) and three levels of AI-DLR (Smoother/Smooth/Standard) with a bone reconstruction kernel. The Noise power spectrum (NPS), task-based transfer function (TTF) and detectability index (d’) were computed (d’ modeled detection of a lytic and a sclerotic bone lesions). Image quality was subjectively assessed on an anthropomorphic phantom by two radiologists. ResultsThe Noise magnitude was lower with AI-DLR than i4 and decreased from Standard to Smooth (-31 ± 0.1 [SD]%) and Smooth to Smoother (-48 ± 0.1 [SD]%). The average NPS spatial frequency was similar with i4 (0.43 ± 0.01 [SD] mm–1) and Standard (0.42 ± 0.01 [SD] mm–1) but decreased from Standard to Smoother (0.36 ± 0.01 [SD] mm–1). TTF values at 50% decreased as the dose decreased but were similar with i4 and all AI-DLR levels. For both simulated lesions, d’ values increased from Standard to Smoother levels. Higher detectabilities were found with a DRI at 15 and Smooth and Smoother levels than with a DRI at 26 and i4. The images obtained with these dose and AI-DLR levels were rated satisfactory for clinical use by the radiologists. ConclusionUsing Smooth and Smoother levels with CT allows a significant dose reduction (up to 72%) with a high detectability of lytic and sclerotic bone lesions and a clinical overall image quality.

Prevalence and neglected rate of sacroiliitis on lumbar spine CT in patients with low back pain.

The study aims to investigate the prevalence and neglected rate of sacroiliitis on lumbar spine computed tomography (CT) in patients with low back pain. From January 2016 to December 2020, a total of 4827 patients (mean age: 35.4 ± 9.5years) who underwent lumbar spine CT examinations were included in this retrospective study. The CT degree of sacroiliitis in all study population were retrospectively reviewed by two radiologists. The independent sample t-test was used to compare the continuous values and chi-squared or Fisher's exact test was used to compare the categorized values. Sacroiliitis was identified in 514 of 4827 patients (10.6%). Patients with sacroiliitis were significantly younger than those without sacroiliitis (32.1 ± 8.9 vs. 35.8 ± 9.5years, p < 0.001). Moreover, significantly more patients with sacroiliitis had HLA-B27 (p < 0.001) positivity and inflammatory back pain syndrome (p = 0.003) than those without sacroiliitis. Among the 514 patients, sacroiliitis was recognized on primary reading in 386 patients (75.1%) but was neglected in the remaining 128 patients (24.9%). Of the 386 patients, 371 patients were followed up, and finally, 295 patients of them (79.5%) were diagnosed with axSpA. Radiologists should pay careful and more attention to sacroiliac joint on lumbar spine CT for early diagnosis of sacroiliitis in young patients with low back pain, which could result in early diagnosis and treatment of axSpA.

Relationship between the Properties of Paraspinal Muscles and Bone Mineral Density in Osteoporotic Patients.

To investigate the properties of paraspinal muscle structures in osteoporotic patients, lumbar computed tomography (CT) and their relationship with lumbar and femoral neck bone mineral density (BMD). A Descriptive study. Department of Radiology and Physical Medicine, Istanbul Medeniyet University, Goztepe Prof Dr Suleyman Yalcin City Hospital, Istanbul, Turkey, between June 2020 and June 2021. Ninety patients with osteoporosis, who received lumbar spine CT and dual-energy X-ray absorptiometry (DEXA) examinations, were retrospectively included. Cross-sectional areas (CSA), densities, index values, and Hounsfield unit average calculation(HUAC) values were measured for psoas, multifidus, erector spinae, and quadratus lumborum muscles at the L3 level, and their associations with BMD were investigated. A total of 90 patients including 71 females were evaluated. The mean age was 63.31±11.90 years. A moderate correlation of lumbar spine (r=0.32, p<0.01) and femur neck BMD (r=0.28, p<0.05) with erector spinae CSA was defined. Small correlation between psoas CSA (r=0.28, p<0.05) and psoas muscle index (PMI, r=0.24, p<0.05) with lumbar spine BMD was found. The CSA of all the paraspinal muscles (p<0.01) and densities, except psoas muscle (p<0.05), were higher in males. In non-obese osteoporotic patients, the density and HUAC values of the paraspinal muscles, except the psoas muscle, were found to be significantly higher (p<0.05). The properties of the paraspinal muscles measured by the lumbar CT scan are found to be related to BMD. The psoas and erector spinae CSA and index values are the most significantly associated parameters with the lumbar spine BMD. Bone mineral density, Computed tomography, Osteoporosis, Paraspinal muscles, Psoas.

Appropriate Imaging for Geriatric Trauma.

Trauma is the leading cause of preventable death in the United States. Early detection of life-threatening injuries leads to improved survival. Computed tomography (CT) scanning has become the modality of choice for early detection of injuries in the stable patient. Some studies have associated selective imaging (Selective-CT) with equivalent outcomes compared to whole body imaging (Pan-CT) with lower costs and radiation exposure. Within the geriatric population, however, the utility of Pan-CT remains controversial. Therefore, the aim of this study was to determine if a difference exists between Selective-CT and Pan-CT imaging in the geriatric trauma patient. A retrospective analysis of Level 3 (G60) trauma activations presenting to our urban Level I trauma center between June 2016 and June 2019 was performed. Pan-CT was defined by ICD-10 codes indicating a head, cervical spine, chest, abdomen, and pelvis CT series. Patients with missing images and those who were transferred from other institutions were excluded. Logistic regression controlling for age, gender, injury type, severity, and Glasgow Coma Score was performed. A total of 1014 patients met inclusion criteria. Of these, 30.9% underwent Pan-CT (n = 314), 48.9% had Selective-CT (n = 497), and 20.2% received no CT imaging (n = 203). After logistic regression, no clinically significant variations in emergency department length of stay (LOS), hospital LOS, ICU LOS, ventilator days, discharge disposition, missed injury rate, or mortality rate were observed between imaging strategies. Pan-CT provides no clinically significant advantage over Selective-CT in the geriatric trauma patient.

Is It Possible to Replace Conventional Radiography (CR) with a Dose Neutral Computed Tomography (CT) of the Cervical Spine in Emergency Radiology-An Experimental Cadaver Study.

The purpose of this experimental study on recently deceased human cadavers was to investigate whether (I) the radiation exposure of the cervical spine CT can be reduced comparable to a dose level of conventional radiography (CR); and (II) whether and which human body parameters can be predictive for higher dose reduction potential (in this context). Materials and Methods: Seventy serial CT scans of the cervical spine of 10 human cadavers undergoing postmortem virtual autopsy were taken using stepwise decreasing upper limits of the tube current (300 mAs, 150 mAs, 110 mAs, 80 mAs, 60 mAs, 40 mAs, and 20 mAs) at 120 kVp. An additional scan acquired at a fixed tube current of 300 mAs served as a reference. Images were reconstructed with filtered back projection and the upper (C1-4) and lower (C4-7) cervical spine were evaluated by three blinded readers for image quality, regarding diagnostic value and resolution of anatomical structures according to a semiquantitative three-point-scale. Dose values and individual physical parameters were recorded. The relationship of diagnostic IQ, dose reduction level, and patients’ physical parameters were investigated. The high-contrast resolution of the applied CT protocols was tested in an additional phantom study. Results: The IQ of the upper cervical spine was diagnostic at 1.69 ± 0.58 mGy (CTDI) corresponding to 0.20 ± 0.07 mSv (effective dose) in all cadavers. IQ of the lower cervical spine was diagnostic at 4.77 ± 1.86 mGy corresponding to 0.560 ± 0.21 mSv (effective dose) in seven cadavers and at 2.60 ± 0.93 mGy corresponding to 0.31 ± 0.11 mSv in four cadavers. Significant correlation was detected for BMI (0.8366; p = 0.002548) and the anteroposterior (a.p.) chest diameter (0.8363; p = 0.002566), shoulder positioning (0.79799; p = 0.00995), and radiation exposure. Conclusions: Conventional radiography can be replaced with a nearly dose-neutral CT scan of the cervical spine.

Adjunct diagnostic value of radiological findings in mucopolysaccharidosis type IVa-related thoracic spinal abnormalities: a pilot study

BackgroundIn patients with mucopolysaccharidosis (MPS), systematic assessment and management of cervical instability, cervicomedullary and thoracolumbar junction spinal stenosis and spinal cord compression averts or arrests irreversible neurological damage, improving outcomes. However, few studies have assessed thoracic spinal involvement in MPS IVa patients. We aimed to evaluate thoracic spinal abnormalities in MPS IVa patients and identify associated image manifestations by CT and MRI study.ResultsData of patients diagnosed and/or treated for MPS IVa at MacKay Memorial Hospital from January 2010 to December 2020 were extracted from medical records and evaluated retrospectively. Computed tomography (CT), plain radiography and magnetic resonance imaging (MRI) findings of MPS IVa-related spinal abnormalities were reviewed. Spine CT and plain radiography findings of 12 patients (6 males and 6 females with median age 7.5 years, range 1–28 years) revealed two subtypes of spinal abnormalities: thoracic kyphosis apex around T2 (subtype 1, n = 8) and thoracic kyphosis apex around T5 (subtype 2, n = 4). Spine CT and plain radiography clearly identified various degrees of thoracic kyphosis with apex around T2 or T5 in MPS IVa patients. Square-shaped to mild central beaking in middle thoracic vertebral bodies was observed in subtype 1 patients, while greater degrees of central beaking in middle thoracic vertebral bodies was observed in subtype 2 patients.ConclusionsSpine CT findings clearly identify new radiological findings of thoracic kyphosis apex around T2 or T5 in MPS IVa patients. The degrees of central beaking at middle thoracic vertebral bodies may be a critical factor associated with different image presentations of thoracic kyphosis.

Adult Computed Tomography examinations in Uganda: Towards determining the National Diagnostic Reference Levels

IntroductionDiagnostic Reference Levels (DRLs), typically set at the 75th percentile of the dose distribution from surveys conducted across a broad user base using a specified dose-measurement protocol, are recommended for radiological examinations. There is a need to develop and implement DRLs as a standardisation and optimisation tool for the radiological protection of patients at Computed Tomography (CT) facilities.MethodsThis was a retrospective cross-sectional study conducted in seven (7) different CT scan facilities in which participants were recruited by systematic random sampling. The study variables were dose length product (DLP) and volume-weighted CTDI (CTDIvol) for the radiation doses for head, chest, abdomen and lumbar spine CT examinations. The DRLs for CTDIvol and DLP were obtained by calculating the 3rd quartiles of the radiation doses per study site by anatomical region. The national diagnostic reference levels were determined by computation of DRLs using the 75th centile of the median values.ResultsA total of 574 patients were examined with an average age of 47.1 years. For CTDIvol estimates; there was a strong positive significant relationship between the CTDIvol and examination mAs (rs = 0.9017, p-value < 0.001), and reference mAs (rs = 0.0.7708, p-value < 0.001). For DLP estimates; there was a moderate positive significant relationships between DLP and total mAs (rs = 0.6812, p-value < 0.001), reference mAs (rs = 0.5493, p-value < 0.001). The DRLs were as follows; for head CT scan – the average median CTDIvol was 56.02 mGy and the DLP was 1260.3 mGy.cm; for Chest CT, the CTDI volume was 7.82 mGy and the DLP was 377.0 mGy.cm; for the abdomen CT, the CTDI volume 12.54 mGy and DLP 1418.3 mGy.cm and for the lumbar spine 19.48 mGy and the DLP was 843 mGy.cm, respectively.ConclusionThis study confirmed the need to optimize the CT scan parameters in order to lower the national DRLs. This can be achieved by extensive training of all the CT scan radiographers on optimizing the CT scan acquisition parameters. Continuous dose audits are also advised with new equipment or after every three years to ensure that values out of range are either justified or further investigated.

A Radiological Assessment of the Prevalence of Osteoporosis in Male Patients Seen in a South African Hospital: A Retrospective Analysis.

Developing countries are predicted to bear the burden of osteoporosis in the coming decades. The prevalence of osteoporosis in South African men is unknown, but is thought to be rare. Opportunistic screening for osteoporosis can be performed using quantitative computed tomography (CT) obtained for various clinical indications. We assessed the frequency of osteoporosis in male patients using quantitative computed tomography (CT) obtained for various clinical indications. Data were collected from abdominal and spinal CT scans performed at the radiology department of a provincial tertiary hospital between January 2019 and January 2021. The CT examinations were derived from 507 male patients (mean age, 45±15 years; 83% Black, 0.8% Coloured, 4.1% Indian and 11.2% White). In the CT scans, the region of interest was placed manually at the axial cross-sections of L1 and L3 vertebrae. Using densitometry, we calculated average bone mass density and T and Z scores. We diagnosed osteoporosis in 18.5% (n = 94) of our patients. Only 7.9% of patients younger than 50 had osteoporosis, while 35.9% of patients older than 50 years showed signs of osteoporosis. Osteoporosis was more common amongst White male patients (45.6%) and least common in Black male patients (14.4%). Indian patients had the highest prevalence of osteopenia (42.9%). We successfully used CT scans, obtained for various conditions, to identify large numbers of patients with low bone mineral density (BMD). The prevalence of osteoporosis in this sample is similar to rates reported elsewhere in Africa. Asymptomatic patients at risk of developing insufficiency fractures can be diagnosed and managed early using CT scans, thus preventing unnecessary admissions and reducing osteoporosis-related morbidity and mortality.

The improved faster-RCNN for spinal fracture lesions detection

Purpose: Reading spinal CT (Computed Tomography) images is very important in the diagnosis of spondylosis, which is time-consuming and prones to make biases. In this paper, we propose a framework based on Faster-RCNN to improve detection performances of three spinal fracture lesions: cfracture (cervical fracture), tfracture (thoracic fracture) and lfracture (lumbar fracture). Methods: First, we use ResNet50 to replace VGG16 in backbone network in Faster-RCNN to increase depth of training network. Second, we utilize soft-NMS (Non-Maximum Suppression) instead of NMS to avoid missed detection of overlapped lesions. Third, we simplify RPN (Region Proposal Network) to accelerate training speed and reduce missed detection. Finally, we modify the classifier layer in Faster-RCNN and choose appropriate length-width ratio by changing anchor sizes in sliding window, then adopt multi-scale strategy in training to improve efficiency and accuracy. Results: The experimental results show that the proposed scheme has a good performance, mAP (mean average precision) is 90.6%, IOU (Intersection of Union) is 88.5 and detection time is 0.053 second per CT image, which means our proposed method can accurately detect spinal fracture lesions. Conclusion: Our proposed method can provide assistance and scientific references for both doctors and patients in clinically.