PURPOSE: This research aims at developing a PC-based spinal screw insertion simulation program and rapid prototyping spine models for correct placement of spinal screws. MATERIALS AND METHODS: We developed a surgical simulator on top of a 3-D medical imaging system V-worksTM (Cybermed, Inc.) and used Z-402 (Z Corporation) models made of hardened starch. RESULTS: The first phase is training surgeons using the simulation software. The trainees could simulate the insertion of spinal screws using the PC-based software. The second phase is a planning software to determine the ideal entry point and insertion angle using the multiplanar reconstruction images of spine CT. Finally, a rapid prototyping model of which the size is identical to the actual bone is produced for simulation surgery prior to the actual one. CONCLUSION: The system provides a tool for educating and training the beginners of spinal screw insertion, and also a pre-surgical simulation environment for planning the actual insertion surgery.
Diagnostic Imaging ; Spine ; Starch

A whole technical way of reconstructing 3D model of the scoliotic spine from two X-ray images was proposed. From the experimental results of 30 patients with mild to severe scoliosis, we can conclude that the accuracy of locating vertebrae is 0.5 mm, the orientation accuracy was 1.5. After comparing the results with those using the previous methods, we found that the method proposed in this paper can get higher resolution with less computational time, making it suitable for clinical routine use.
Humans ; Imaging, Three-Dimensional ; methods ; Models, Statistical ; Radiography ; Scoliosis ; diagnostic imaging ; Spine ; diagnostic imaging

In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests' results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.
Algorithms ; Calibration ; Humans ; Imaging, Three-Dimensional ; Scoliosis/diagnostic imaging* ; Spine/diagnostic imaging* ; Technology

BACKGROUND: Andersson lesions (ALs) are not uncommon in ankylosing spondylitis (AS). Plain radiography (PR) is widely used for the diagnosis of ALs. However, in our practice, there were some ALs in AS patients that could not be detected on plain radiographs. This study aimed to propose the concept of occult ALs and evaluate the prevalence and radiographic characteristics of the occult ALs in AS patients. METHODS: A total of 496 consecutive AS patients were admitted in the Affiliated Drum Tower Hospital, Medical School of Nanjing University between April 2003 and November 2019 and they were retrospectively reviewed. The AS patients with ALs who met the following criteria were included for the investigation of occult ALs: (1) with pre-operative plain radiographs of the whole-spine and (2) availability of pre-operative computed tomography (CT) and/or magnetic resonance imaging (MRI) of the whole-spine. The occult ALs were defined as the ALs which were undetectable on plain radiographs but could be detected by CT and/or MRI. The extensive ALs involved the whole discovertebral junction or manifested as destructive lesions throughout the vertebral body. Independent-samples t test was used to compare the age between the patients with only occult ALs and those with only detectable ALs. Chi-square or Fisher exact test was applied to compare the types, distribution, and radiographic characteristics between detectable and occult ALs as appropriate. RESULTS: Ninety-two AS patients with a mean age of 44.4 ± 10.1 years were included for the investigation of occult ALs. Twenty-three patients had occult ALs and the incidence was 25% (23/92). Fifteen extensive ALs were occult, and the proportion of extensive ALs was significantly higher in detectable ALs (97% vs. 44%, χ2 = 43.66, P < 0.001). As assessed by PR, the proportions of osteolytic destruction with reactive sclerosis (0 vs. 100%, χ2 = 111.00, P < 0.001), angular kyphosis of the affected discovertebral units or vertebral body (0 vs. 22%, χ2 = 8.86, P = 0.003), formation of an osseous bridge at the intervertebral space adjacent to ALs caused by the ossification of the anterior longitudinal ligament (38% vs. 86%, χ2 = 25.91, P < 0.001), and an abnormal height of the affected intervertebral space were all significantly lower in occult ALs (9% vs. 84%, χ2 = 60.41, P < 0.001). CONCLUSIONS Occult ALs presented with more subtle radiographic changes. Occult ALs should not be neglected, especially in the case of extensive occult ALs, because the stability of the spine might be severely impaired by these lesions.
Adult ; Humans ; Kyphosis/diagnostic imaging* ; Magnetic Resonance Imaging ; Middle Aged ; Radiography ; Retrospective Studies ; Spine/diagnostic imaging* ; Spondylitis, Ankylosing/diagnostic imaging*

OBJECTIVETo introduce a novel Cobb protractor and assess its reliability and rapidity for measuring Cobb angle in scoliosis patients.

METHODSThe novel Cobb protractor had two endplate markers. A measurement was performed just to align the two markers to each endplate of the curve. The Cobb angle on the posteroanterior radiographs of 24 patients clinically diagnosed with adolescent idiopathic scoliosis was measured by three orthopedic surgeons with both standard Cobb method and the new technique, and the time of measurement was recorded. Intraclass correlation coefficients (ICCs) were calculated to assess the reliability of the new method.

RESULTSThe time for a measurement with the new tool was approximately 10 seconds less than the time that used to finish a measurement with the standard method (P<0.05). The overall mean Cobb angle for the major curve of the 24 patients was 47.8°. The mean overall intraobserver and interobserver ICC was 0.971 and 0.971 for the Cobb method group, while the overall intraobserver ICC and the interobserver was 0.985 and 0.979 for the new tool group.

CONCLUSIONSThe novel Cobb protractor could perform quick measurement and measure almost all forms of radiographs. The Cobb protractor might be an ideal instrument to measure the Cobb angle.

Adolescent ; Child ; Equipment and Supplies ; Humans ; Radiography ; Reproducibility of Results ; Scoliosis ; diagnostic imaging ; Spine ; diagnostic imaging

OBJECTIVE: To analyze the correlation between Cobb angle and spinous process angle (SPA) on X-ray film and body surface in patients with mild to moderate adolescent idiopathic scoliosis(AIS). To explore the possibility of linear SPA to assess scoliosis. METHODS: Retrospective study for correlation of Cobb angle and linear SPA on X-ray film. AIS patients treated and taken full spine anteroposterior X-ray from January 2019 to December 2021 were analyzed correlation of Cobb angle and linear SPA on X-ray film. Prospective study for correlation of Cobb angle and body linear SPA. AIS patients treated and taken full spine anteroposterior X-ray from December 1 to December 9 this year were analyzed correlation of Cobb angle and body linear SPA. RESULTS: A total of 113 AIS patients with age an average of (14.02±2.16) years old(ranged from 10 to 18 years old) were recruited in retrospective study, involving 26 males and 87 females;there were 71 patients with mild AIS and 42 patients with moderate AIS. Cobb angle in AIS patients was significantly inversely associated with SPA(r=-0.564, P<0.001), the linear regression equation was:Cobb angle=169.444-0.878×SPA. Cobb angles in patients with mild scoliosis were significantly and inversely associated with SPA(r=-0.269, P=0.012), the linear regression equation was:Cobb angle=46.832-0.185×SPA. Cobb angles in patients with moderate scoliosis were also clearly correlated with SPA(r=-0.417, P=0.003), the linear regression equation was:Cobb angle=113.889-0.516×SPA. Thirty-eight patients were recruited in prospective study. The mean Cobb angle and body linear SPA were(18.70±6.98)°, ranged from 11.3° to 36.0° and (170.34±4.57)°, ranged from 162.1° to 177.7° respectively. There was significantly negative correlation(r=-0.651, P<0.001), the linear regression equation is:Cobb angle=187.91-0.99×SPA. CONCLUSION Linear SPA on X-ray film or on the body was significantly negatively correlated with Cobb angles, but the regression equation fits poorly, so it's not suitable for diagnosis of scoliosis;however, linear SPA is appropriate for self-controlled assessment of scoliotic therapy or for dynamic assessment of spinal flexibility.
Male ; Female ; Humans ; Adolescent ; Child ; Scoliosis/diagnostic imaging* ; Prospective Studies ; Retrospective Studies ; Spine/diagnostic imaging* ; Kyphosis

OBJECTIVETo investigate the clinical value of different magnetic resonance (MR) pulse sequences in diagnosis of spinal metastatic tumor.

METHODSFifteen patients with clinically suspected spinal metastatic tumor were included in this study. These patients were with documented primary tumors. Four MR pulse sequences, T1-weighted spin echo (T1WI SE), T2-weighted fast spin echo (T2WI FSE), short time inversion recovery (STIR), and gradient echo 2-D multi echo data imaging combination (GE Me-2D) were used to detect spinal metastasis.

RESULTSFifteen vertebral bodies were entire involvement, 38 vertebral bodies were section involvement, and totally 53 vertebral bodies were involved. There were 19 focal infections in pedicle of vertebral arch, 15 metastases in spinous process and transverse process. Fifty-three vertebral bodies were abnormal in T1 WI SE and GE Me-2D, 35 vertebral bodies were found abnormal in T2WI FSE, and 50 vertebral bodies were found abnormal in STIR. The verges of focal signal of involved vertebral bodies were comparatively clear in T1WI SE, comparatively clear or vague in T2WI FSE, vague in STIR, and clear in GE Me-2D.

CONCLUSIONSGE Me-2D may be the most sensitive technique to detect metastases. So three sequences (T1WI SE, T2WI FSE, GE Me-2D) can demonstrate the early changes of spinal metastasis roundly.

Cervical Vertebrae ; diagnostic imaging ; Coccyx ; diagnostic imaging ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; Magnetic Resonance Imaging ; methods ; Neoplasm Metastasis ; pathology ; Radiography ; Sacrum ; diagnostic imaging ; Sensitivity and Specificity ; Spinal Neoplasms ; pathology ; secondary ; Spine ; diagnostic imaging ; Thoracic Vertebrae ; diagnostic imaging

Objective To evaluate the value of bone marrow imaging by third-generation dual-source dual-energy CT(DSDECT) using virtual noncalcium(VNCa) technique for the assessment of diffuse infiltrative lesions of multiple myeloma(MM). Methods From December 2015 to June 2016,31 patients with plasma disorders at our center were prospectively recruited and received whole-body imaging with third-generation DSDECT and MRI. CT numbers of vertebrae were measured on VNCa images as well as regular CT images. Correlation between VNCa CT numbers and MRI signal intensities of the vertebrae was evaluated. The diagnostic ability of VNCa for MM infiltrative lesions was assessed by ROC analysis,using MRI as the reference standard. Results The mean VNCa CT numbers of vertebrae with MM diffuse infiltration (n=62) were (-13.27±18.96)HU,which were significantly higher than those of non-infiltrated vertebrae[(-63.31±26.75)HU,(n=117)] (Z=-9.731,P=0.000). VNCa CT numbers of vertebrae were negatively correlated with T1WI signal intensity normalized by non-degenerative vertebral discs (r=-0.592,P=0.000). ROC analysis showed the area under the curve of VNCa for the diagnosis of infiltrative lesions was 0.943. With the cut-off value of-37 HU,the sensitivity and specificity of VNCa were 90.32% and 87.18%,respectively. Conclusion Bone marrow imaging by third-generation DSDECT using VNCa technique is a valuable tool for assessing diffuse infiltrative lesions of MM.
Bone Marrow ; diagnostic imaging ; Humans ; Magnetic Resonance Imaging ; Multiple Myeloma ; diagnostic imaging ; ROC Curve ; Sensitivity and Specificity ; Spine ; diagnostic imaging ; Tomography, X-Ray Computed ; methods

Spinal biomechanics, especially the range of spine motion,has close connection with spinal surgery. The change of the range of motion (ROM) is an important indicator of diseases and injuries of spine, and the essential evaluating standards of effect of surgeries and therapies to spine. The analysis of ROM can be dated to the time of the invention of X-ray and even that before it. With the development of science and technology as well as the optimization of various types of calculation methods, diverse measuring methods have emerged, from imaging methods to non-imaging methods, from two-dimensional to three-dimensional, from measuring directly on the X-ray films to calculating automatically by computer. Analysis of ROM has made great progress, but there are some older methods cannot meet the needs of the times and disappear, some classical methods such as X-ray still have vitality. Combining different methods, three dimensions and more vivo spine research are the trend of analysis of ROM. And more and more researchers began to focus on vivo spine research. In this paper, the advantages and disadvantages of the methods utilized recently are presented through viewing recent literatures, providing reference and help for the movement analysis of spine.
Animals ; Humans ; Imaging, Three-Dimensional ; instrumentation ; methods ; trends ; Radiography ; Spine ; diagnostic imaging

AIMTo establish bone mineral density (BMD) reference database in healthy Chinese men of Han ethnicity, and to estimate the prevalence of osteoporosis in the population.

METHODSThe BMD in the lumbar spine 1-4 (L1-4) and proximal femur was measured using dual energy X-ray absorptiometry in a total of 1 385 healthy Chinese men of Han ethnicity aged 20-89 years old in Shanghai.

RESULTSThe highly significant negative correlation between age and BMD at any sites of proximal femur was found in the studied population, wheras no correlation between age and BMD at lumbar spine was observed. The peak BMD of the lumbar spine and any sites of hip in Chinese men was defined as the mean BMD for the subjects aged 20-89 years. According to World Health Organization (WHO) criteria, the BMD cut-off values for osteoporosis of the L1-4, total hip, femoral neck, trochanter and intertrochanter in Chinese men are 0.719, 0.638, 0.575, 0.437 and 0.725 g/cm(2), respectively. Using the current Chinese reference data, the prevalence of osteoporosis at the L1-4, total hip, femoral neck, trochanter and intertrochanter is 5.4%, 3.8%, 6.3%, 1.8% and 2.8% in 1 084 men aged 50 years or older, respectively. However, using a database for US non-Hispanic white men (NHANES III), the prevalence of osteoporosis or osteopenia at any sites of the hip was significantly higher than that while using the current Chinese reference data.

CONCLUSIONThe BMD reference database was established in healthy Chinese men of Han ethnicity, and will facilitate more accurate diagnosis of osteoporosis in Chinese men.

Absorptiometry, Photon ; Adult ; Aged ; Aged, 80 and over ; Bone Density ; China ; epidemiology ; Femur ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Osteoporosis ; diagnostic imaging ; epidemiology ; Prevalence ; Reference Values ; Spine ; diagnostic imaging