An Application of Artificial Intelligence to Diagnostic Imaging of Spine Disease: Estimating Spinal Alignment From Moiré Images

Kota Watanabe,Yoshimitsu Aoki,Morio Matsumoto 대한척추신경외과학회 2019 Neurospine Vol.16 No.4

The use of artificial intelligence (AI) as a tool supporting the diagnosis and treatment of spinal diseases is eagerly anticipated. In the field of diagnostic imaging, the possible application of AI includes diagnostic support for diseases requiring highly specialized expertise, such as trauma in children, scoliosis, symptomatic diseases, and spinal cord tumors. Moiré topography, which describes the 3-dimensional surface of the trunk with band patterns, has been used to screen students for scoliosis, but the interpretation of the band patterns can be ambiguous. Thus, we created a scoliosis screening system that estimates spinal alignment, the Cobb angle, and vertebral rotation from moiré images. In our system, a convolutional neural network (CNN) estimates the positions of 12 thoracic and 5 lumbar vertebrae, 17 spinous processes, and the vertebral rotation angle of each vertebra. We used this information to estimate the Cobb angle. The mean absolute error (MAE) of the estimated vertebral positions was 3.6 pixels (~5.4 mm) per person. T1 and L5 had smaller MAEs than the other levels. The MAE per person between the Cobb angle measured by doctors and the estimated Cobb angle was 3.42°. The MAE was 4.38° in normal spines, 3.13° in spines with a slight deformity, and 2.74° in spines with a mild to severe deformity. The MAE of the angle of vertebral rotation was 2.9°±1.4°, and was smaller when the deformity was milder. The proposed method of estimating the Cobb angle and AVR from moiré images using a CNN is expected to enhance the accuracy of scoliosis screening.

A Review of My Invention of Expansive Laminoplasty

Kiyoshi Hirabayashi,Kota Watanabe 대한척추신경외과학회 2019 Neurospine Vol.16 No.3

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Chin on Chest Deformity Caused by Upper Cervical Kyphosis Associated With Ankylosing Spondylitis: A Case Report

Ryosuke Maruiwa,Kota Watanabe,Satoshi Suzuki,Satoshi Nori,Osahiko Tsuji,Narihito Nagoshi,Eijiro Okada,Mitsuru Yagi,Nobuyuki Fujita,Masaya Nakamura,Morio Matumoto 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Chin on chest deformity caused by upper cervical kyphosis associated with ankylosing spondylitis is rare. A 66-year-old woman presented at our institute with chief complaints of difficulty in horizontal gaze and opening her mouth. Cervical radiographs showed a C0–2 angle of 1° on flexion and 7° on extension, and her chin-brow vertical angle was 49°. We planned fixation surgery at C0–5 posteriorly to prevent the progression of kyphosis, with slight correction of the kyphosis at C0–2. The correction was performed by pushing down the over lordotically contoured titanium rods connected to an occipital plate onto the C3–5 lateral mass screws, just like cantilever technique. No palpable cracking or loss of resistance was noticed during the correction. However, intraoperative radiographs revealed apparent anterior separation of the vertebral bodies between C3 and C4. Postoperative computed tomography images at the C3/4 level suggested hemorrhage from the fracture site. Tracheostomy was performed because of massive edema around the pharynx. To secure solid bone fusion, staged surgery to extend the fusion to T3 and to graft an additional iliac bone was performed. Fortunately, the C2–7 angle was corrected to 40°, and her chin-brow vertical angle was restored to 17° without any catastrophic complications. Although the patient finally obtained an ideal sagittal alignment, the surgeon should be aware that the technique had a higher perioperative risk for iatrogenic fracture, resulting in neurological and vascular injuries.

Abnormal Behavior in a Chromosome- Engineered Mouse Model for Human 15q11-13 Duplication Seen in Autism

Nakatani, Jin,Tamada, Kota,Hatanaka, Fumiyuki,Ise, Satoko,Ohta, Hisashi,Inoue, Kiyoshi,Tomonaga, Shozo,Watanabe, Yasuhito,Chung, Yeun Jun,Banerjee, Ruby,Iwamoto, Kazuya,Kato, Tadafumi,Okazawa, Makoto Cell Press 2009 Cell Vol.137 No.7

<P><B>Summary</B></P><P>Substantial evidence suggests that chromosomal abnormalities contribute to the risk of autism. The duplication of human chromosome 15q11-13 is known to be the most frequent cytogenetic abnormality in autism. We have modeled this genetic change in mice by using chromosome engineering to generate a 6.3 Mb duplication of the conserved linkage group on mouse chromosome 7. Mice with a paternal duplication display poor social interaction, behavioral inflexibility, abnormal ultrasonic vocalizations, and correlates of anxiety. An increased MBII52 snoRNA within the duplicated region, affecting the serotonin 2c receptor (5-HT2cR), correlates with altered intracellular Ca<SUP>2+</SUP> responses elicited by a 5-HT2cR agonist in neurons of mice with a paternal duplication. This chromosome-engineered mouse model for autism seems to replicate various aspects of human autistic phenotypes and validates the relevance of the human chromosome abnormality. This model will facilitate forward genetics of developmental brain disorders and serve as an invaluable tool for therapeutic development.</P>

The Variation in the Lumbar Facet Joint Orientation in an Adult Asian Population and Its Relationship with the Cross-Sectional Area of the Multifidus and Erector Spinae

Kazuhiro Sugawara,Masaki Katayose,Kota Watanabe 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Cross-sectional study of healthy volunteers. Purpose: We aimed to investigate the variation in the lumbar facet joint orientation in an adult Asian population. The relationship between the facet joint orientation and muscle cross-sectional area (CSA) of multifidus and erector spinae was also clarified. Overview of Literature: Several studies have reported that lumbar pathologies, such as lumbar spondylolysis and degenerative spondylolisthesis, were related to the horizontally shaped lumbar facet joint orientation at the lower lumbar level. However, data regarding variations in the facet joint orientation in asymptomatic subjects have not been well documented. Methods: In 31 healthy male adult Asian volunteers, the facet joint orientation and CSA of multifidus and erector spinae were measured using magnetic resonance imaging at the L4–5 and L5–S1 levels. Variation in the facet joint orientation was examined using coefficients of variation (CV). Pearson’s product-moment coefficient was used to investigate the relationship between the facet joint orientation and CSA of multifidus and erector spinae. Results: Lumbar facet joint orientation had a wider range of variation at L5–S1 (CV=0.30) than at L4–5 (CV=0.18). The L4–5 facet joint orientation had a weak but significant correlation with the CSA of erector spinae (r =0.40; p=0.031). The CSA of the multifidus had no relationship with the facet joint orientation at the L4–5 (r =0.19; p =0.314) and the L5–S1 level (r =0.19; p =0.312). Conclusions: The lumbar facet joint orientation was found to have a wide variation, particularly at the L5–S1 in the Asian adult population, and the facet joint orientation had a relationship with the CSA of the erector spinae at the L4–5.

Learner Error, Teacher Feedback and Learner Uptake in Small Groups: A Case Study in the Japanese University Context

( Kazuharu Owada ),( Akane Watanabe ),( Kota Kodachi ),( Michiko Nakano ) 범태평양응용언어학회 2004 범태평양응용언어학회지 Vol.8 No.1

Atlantoaxial Stabilization Using C1 Lateral Mass and C2 Pedicle/Translaminar Screw Fixation by Intraoperative C1- and C2-Direct-Captured Navigation with Preoperative Computed Tomography Images

Itoh Yasunobu,Kitagawa Ryo,Numazawa Shinichi,Yamakawa Kota,Yamada Osamu,Akasu Isao,Sakai Jun,Otomo Tomoko,Yoshida Hirotaka,Mori Kentaro,Watanabe Sadayoshi,Watanabe Kazuo 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.3

In C1–C2 posterior fixation, the C1 lateral mass and C2 pedicle/translaminar screw insertion under spine navigation have been used frequently. To avoid the risk of neurovascular damage in atlantoaxial stabilization, we assessed the safety and effectiveness of a preoperative computed tomography (CT) image-based navigation system with intraoperative independent C1 and C2 vertebral registration. It is ideal when a reference frame can be linked directly to the C1 posterior arch for C1-direct-captured navigation, but there is a mechanical challenge. A new spine clamp-tracker system was implemented recently, which allows reliable C1- and C2- direct-captured navigation in nine patients with traumatic C2 fractures. In this way, there was no misalignment of C1–C2 screws. C1 lateral mass screws were used except for one case, and translaminar screws were primarily used as an anchor for C2. The C1 lateral mass screw locations, which are 19 mm laterally from the C1 posterior arch’s center, are taken to be constant. However, there is one unusual circumstance in which using a C1 laminar hook instead of a C1 lateral mass screw appears to be a beneficial substitute. The increase of surgical accuracy for posterior C1–C2 screw fixation without cost constraints is significantly facilitated by intraoperative C1- and C2-direct-captured navigation with preoperative computed CT images.

Validation Study of Rajasekaran’s Kyphosis Classification System: Do We Clearly Understand Single- and Two-Column Deficiencies?

Ajoy Prasad Shetty,Rajesh Rajavelu,Vibhu Krishnan Viswanathan,Kota Watanabe,Harvinder Singh Chhabra,Rishi Mukesh Kanna,Jason Pui Yin Cheung,Yong Hai,Mun Keong Kwan,Gabriel Liu,Gabriel Liu,Saumajit Bas 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Study Design: Multicenter validation study.Purpose: To evaluate the inter-rater reliability of Rajasekaran’s kyphosis classification through a multicenter validation study.Overview of Literature: The classification of kyphosis, developed by Rajasekaran, incorporates factors related to curve characteristics, including column deficiency, disc mobility, curve magnitude, and osteotomy requirements. Although the classification offers significant benefits in determining prognosis and management decisions, it has not been subjected to multicenter validation.Methods: A total of 30 sets of images, including plain radiographs, computed tomography scans, and magnetic resonance imaging scans, were randomly selected from our hospital patient database. All patients had undergone deformity correction surgery for kyphosis. Twelve spine surgeons from the Asia-Pacific region (six different countries) independently evaluated and classified the deformity types and proposed their surgical recommendations. This information was then compared with standard deformity classification and surgical recommendations.Results: The kappa coefficients for the classification were as follows: 0.88 for type 1A, 0.78 for type 1B, 0.50 for type 2B, 0.40 for type 3A, 0.63 for type 3B, and 0.86 for type 3C deformities. The overall kappa coefficient for the classification was 0.68. Regarding the repeatability of osteotomy recommendations, kappa values were the highest for Ponte’s (Schwab type 2) osteotomy (kappa 0.8). Kappa values for other osteotomy recommendations were 0.52 for pedicle subtraction/disc-bone osteotomy (Schwab type 3/4), 0.42 for vertebral column resection (VCR, type 5), and 0.30 for multilevel VCRs (type 6).Conclusions: Excellent accuracy was found for types 1A, 1B, and 3C deformities (ends of spectrum). There was more variation among surgeons in differentiating between one-column (types 2A and 2B) and two-column (types 3A and 3B) deficiencies, as surgeons often failed to recognize the radiological signs of posterior column failure. This failure to identify column deficiencies can potentially alter kyphosis management. There was excellent consensus among surgeons in the recommendation of type 2 osteotomy; however, some variation was observed in their choice for other osteotomies.

Early Phase Functional Recovery after Spinal Intramedullary Tumor Resection Could Predict Ambulatory Capacity at 1 Year after Surgery

Suzuki Tetsuya,Tsuji Osahiko,Ichikawa Masahiko,Ishii Ryota,Nagoshi Narihito,Kawakami Michiyuki,Watanabe Kota,Matsumoto Morio,Tsuji Tetsuya,Fujiwara Toshiyuki,Nakamura Masaya 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.2

Study Design: This is a single-center retrospective cohort study with a university hospital setting.Purpose: This study aims to evaluate the short-term course of physical function and walking ability after intramedullary spinal cord tumor (ISCT) resection and predict walking independence 1 year after surgery.Overview of Literature: Although several reports have shown the postoperative functional prognosis of spinal intramedullary tumors with long-term follow-up, no reports have identified the predictors associated with the functional outcome at an early stage. Methods: A total of 79 individuals who underwent ISCT resection at our institute between 2014 and 2019 were enrolled in the study, whose preoperative walking state was independent ambulator regardless of cane support with the Functional Independence Measure Locomotor Scale (FIM-L) score of ≥6. The FIM-L, the American Spinal Injury Association (ASIA) motor and sensory scores in the lower extremities, and the Walking Index for Spinal Cord Injury II (WISCI II) were assessed for walking independence, lower-limb function, and walking ability, respectively. These evaluations were performed at 4 time points: preoperatively, 1 week (1W), 2 weeks (2W), and 1 year after surgery.Results: In the early phase after surgery, 71% and 43% of the participants were nonindependent ambulators at 1W and 2W, respectively. Histopathology indicated that patients with solid tumors (ependymoma, astrocytoma, or lipoma) showed significantly lower indices at 1W and 2W than those with vascular tumors (hemangioblastoma or cavernous hemangioma). Regarding tumor location, thoracic cases exhibited poorer lower-limb function at 1W and 2W and poorer walking ability at 2W than cervical cases. According to the receiver operating characteristic (ROC) analysis, 2 WISCI II points at 2W had the highest sensitivity (100%) and specificity (92.2%) in predicting the level of walking independence at 1 year postoperatively (the area under the ROC curve was 0.99 (95% confidence interval, 0.93–1.00).Conclusions: The higher the lower-limb function scores in the early phase, the better the improvement in walking ability is predicted 1 year after ISCT resection.

Surgical and Functional Outcomes of Expansive Open-Door Laminoplasty for Patients With Mild Kyphotic Cervical Alignment

Narihito Nagoshi,Satoshi Nori,Osahiko Tsuji,Satoshi Suzuki,Eijiro Okada,Mitsuru Yagi,Masaya Nakamura,Morio Matsumoto,Kota Watanabe 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Objective: To evaluate the cervical dynamics, neurological function, pain, and quality of life in patients with mild cervical kyphotic alignment who underwent expansive unilateral open-door laminoplasty (ELAP). Methods: In this retrospective single-center study, we reviewed the surgical outcomes of 80 patients with cervical spondylotic myelopathy who were followed for at least 2 years. The patients were categorized into the preoperative kyphotic group (C2–7 angle <0°) and nonkyphotic group (angle ≥0°). We compared clinical information, radiographic parameters, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) scores, and cervical Japanese Orthopaedic Association (JOA) scores between the groups. Results: The kyphotic and nonkyphotic groups comprised 17 and 63 patients, respectively. The preoperative C2–7 angles were -3.7° in the kyphotic group and 15.4° in the nonkyphotic group (p<0.01). In the kyphotic group, kyphotic alignment improved to lordosis at the final follow-up (2.6°, p=0.01). The preoperative (16.4° vs. 24.1°, p<0.01) and final-follow-up (17.8° vs. 24.5°, p<0.01) C7 slopes were significantly smaller in the kyphotic group. ELAP reduced pain in the arms or hands (p=0.02) and improved the JOA scores (p<0.01) in the kyphotic group. Patient-reported outcomes assessed using the JOACMEQ showed comparable effective rates in both groups. Conclusion: Patients with mild cervical kyphosis showed smaller C7 slopes as a compensatory mechanism. Kyphotic angles significantly improved to lordosis after ELAP, resulting in favorable clinical outcomes. ELAP is a useful surgical option for patients even if they present mild kyphotic cervical angles.