Deep Learning Super-Resolution Technique Based on Magnetic Resonance Imaging for Application of Image-Guided Diagnosis and Surgery of Trigeminal Neuralgia.

This study aimed to implement a deep learning-based super-resolution (SR) technique that can assist in the diagnosis and surgery of trigeminal neuralgia (TN) using magnetic resonance imaging (MRI). Experimental methods applied SR to MRI data examined using five techniques, including T2-weighted imaging (T2WI), T1-weighted imaging (T1WI), contrast-enhancement T1WI (CE-T1WI), T2WI turbo spin-echo series volume isotropic turbo spin-echo acquisition (VISTA), and proton density (PD), in patients diagnosed with TN. The image quality was evaluated using the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). High-quality reconstructed MRI images were assessed using the Leksell coordinate system in gamma knife radiosurgery (GKRS). The results showed that the PSNR and SSIM values achieved by SR were higher than those obtained by image postprocessing techniques, and the coordinates of the images reconstructed in the gamma plan showed no differences from those of the original images. Consequently, SR demonstrated remarkable effects in improving the image quality without discrepancies in the coordinate system, confirming its potential as a useful tool for the diagnosis and surgery of TN.

Direct C1 posterior arch screws for reduction and osteosynthesis in the treatment of Jefferson fracture.

The surgical treatment of Jefferson fractures generally involves solid fusion, which limits the range of motion of the upper cervical spine. Herein, we present a case of a Jefferson fracture that was surgically treated using direct C1 posterior arch screw reduction and osteosynthesis instead of fusion surgery. Postoperative computed tomography (CT) and plain radiography revealed that both C1 posterior arch screws were well positioned, and placing lag screws at the C1 level played a key role in fracture reduction. The present case highlights a surgical technique, which can preserve neck motion by using lag screws for reduction and osteosynthesis.

Massive Hyperostotic Meningioma En Plaque Mimicking Fibrous Dysplasia.

The authors report an extremely rare case of a massive hyperostotic meningioma en plaque, which had characteristics of unique bony growth. A 34-year-old man presented with a palpable solid mass in the left cranial region that had gradually grown in size with a broad base on the calvarium for 8 years. Radiologically, the area involved by the mass ranged from the sphenoid bone to the frontal, parietal, temporal, and occipital bones. Three-dimensional CT revealed multiple growing spiculate features on the inner and outer cranial surface. Even though the radiologic features resembled fibrous dysplasia, it was histologically found to be a type of meningioma.

Clinical Application of Botulinum Toxin for Hemifacial Spasm.

Hemifacial spasm is typically caused by contact between the facial nerve and blood vessels. Microvascular decompression, a treatment that directly addresses this pathogenesis, is often considered the most effective treatment method. However, surgery is not immediately performed for patients at risk from the surgical treatment, or for those with an unclear diagnosis. In these instances, Botulinum toxin injection can help manage the patient's symptoms. Numerous studies corroborate the effectiveness and safety of Botulinum toxin treatment, with large-scale studies indicating symptom control lasts, on average, around 15 weeks.

Impact fracture mechanism and heat deflection temperature of PLA/PEICT blends reinforced by glass fiber.

To enhance the crack propagation and initiation properties and heat deflection temperature of poly(lactic acid) (PLA), PLA/poly(1,4-cyclohexanedimethylene isosorbide terephthalate) (PEICT) blend systems were prepared and glass fibers (GF) were incorporated as reinforcements. Due to high shear force during extrusion and injection molding the length of GF was reduced and was oriented towards the flow direction. Although the reinforcing effect of the GF deviated from the theoretical values calculated by the Halpin-Tsai equation, both tensile and flexural properties were greatly enhanced with increasing GF content. Dynamic mechanical and thermal testing showed improved storage modulus throughout the entire temperature range showing outstanding reinforcing ability. By incorporating GF into the PLA/PEICT blend, the crack propagation and initiation properties were enhanced compared to pristine PLA. Such an increase in crack propagation properties was the result of enhanced modulus with the added GF. Moreover, because of the increased modulus, the heat deflection temperatures of the GF reinforced blends were drastically increased showing a value of 91.4 °C at 20 wt% GF loading. The high performance reached by the biomass-based composites developed in this research shows great possibility of replacing these conventional petroleum-based polymer systems.

Can Trigeminal Schwannoma-Related Symptoms be Controlled With Gamma Knife Radiosurgery?

OBJECTIVE: The effectiveness of gamma knife radiosurgery (GKRS) for the management of trigeminal schwannomas (TS) has been established. Although GKRS has been shown to inhibit tumor growth, the effect of GKRS on the symptoms caused by TS has not been sufficiently studied. In this study, symptomatic changes following GKRS for the management of symptomatic TS were investigated using long-term follow-up results. METHODS: A retrospective analysis was performed on 32 patients with TS who underwent GKRS between May 1994 and December 2016. Clinical charts, radiographic results, and surgical records were reviewed. To evaluate whether symptoms improved after GKRS, patient demographics, GKRS profile, radiological tumor size change, and tumor location were analyzed. RESULTS: Tumor control after GKRS for symptomatic TS was 87%. The improvement rates for facial pain at 6, 12, and 24 months after GKRS were 46%, 72%, and 86%, respectively. For the same time intervals, facial hypesthesia improved by 12%, 46%, and 52%, respectively. Of the patients with diplopia, 17% had improved symptoms 12 months after GKRS, and 50% of the patients improved after 24 months. CONCLUSIONS: GKRS can be an effective treatment modality for TS tumor control and shows favorable results in improving TS-related symptom, especially facial pain.

Clinical application of the optimized X-ray parameter model through analysis of disease risk and image quality when combining the ion chamber of automatic exposure control of digital radiography.

OBJECTIVE: To present an optimized examination model by analyzing the risk of disease and image quality according to the combination of the ion chamber of automatic exposure control (AEC) with digital radiography (DR). METHODS: The X-ray quality was analyzed by first calculating the percentage average error (PAE) of DR. After that, when using AEC, the combination of the ion chambers was the same as the left and centre and right, right and centre, left and centre, centre, right, and left, for a total of six. Accordingly, the entrance surface dose (ESD), risk of disease, and image quality were evaluated. ESD was obtained by attaching a semiconductor dosimeter to the L4 level of the lumbar spine, and then irradiating X-rays to dosimeter centre through average and standard deviation of radiation dose. The calculated ESD was input into the PCXMC 2.0 programme to evaluate disease risk caused by radiation. Meanwhile, image quality according to chamber combination was quantified as the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) through Image J. RESULTS: X-ray quality of DR used in the experiment was within the normal range of±10. ESD of six ion chamber combinations was 1.363mGy, 0.964mGy, 0.946mGy, 0.866mGy, 0.748mGy, 0.726mGy for lumbar anteroposterior (AP), and the lumbar lateral values were 1.126mGy, 0.209mGy, 0.830mGy, 0.662mGy, 0.111mGy, and 0.250mGy, respectively. Meanwhile, disease risk analyzed through PCXMC 2.0 was bone marrow, colon, liver, lung, stomach, urinary and other tissue cancer, and disease risk showed a tendency to increase in proportion to ESD. SNR and CNR recorded the lowest values when three chambers were combined and did not show proportionality with dose, while showed the highest values when two chambers were combined. CONCLUSION: In this study, combination of three ion chambers showed the highest disease risk and lowest image quality. Using one ion chamber showed the lowest disease risk, but lower image quality than two ion chambers. Therefore, if considering all above factors, combination of two ion chambers can optimally maintain the disease risk and image quality. Thus, it is considered an optimal X-ray examination parameter.

Early-onset adverse events after stereotactic radiosurgery for jugular foramen schwannoma: a mid-term follow-up single-center review of 46 cases.

BACKGROUND: Recently, stereotacitc radiosurgery (SRS) has been in the spotlight as an alternative therapeutic option for jugular foramen schwannomas (JFS). While most reported studies focus on the long-term efficacy and safety issues of SRS, none describe the early-onset adverse events (eAEs). We aimed to investigate the incidence, clinical characteristics, and mid-term outcomes of eAEs occurring within six months after SRS for JFS. METHODS: In this retrospective review, patients who underwent at least six months of follow-up were included among all patients with JFS who have performed SRS at our institution between July 2008 and November 2019. And eAEs were defined as a newly developed neurological deficit or aggravation of pre-existing symptoms during the first six months after SRS. RESULTS: Forty-six patients were included in the analysis. The median follow-up period was 50 months (range 9-136). The overall tumor control rate was 91.3%, and the actuarial 3-, 5-, and 10-year progression-free survival rates were 97.8%, 93.8%, and 76.9%, respectively. Of the 46 patients, 16 had eAEs, and the median time to onset of eAEs was one month (range 1-6 months), and the predominant symptoms were lower cranial nerve dysfunctions. Thirteen of 16 patients showed improved eAE symptoms during the follow-up period, and the median resolution time was six months (range 1-52). In 11 (68.8%) of 16 patients with eAEs, transient expansions were observed with a mean of 3.6 months after the onset of eAEs, and the mean difference between the initial tumor volume and the transient expansion volume was more prominent in the patients with eAEs (3.2 cm3 vs. 1.0 cm3; p = 0.057). In univariate analysis, dumbbell-shaped tumors (OR 10.56; p = 0.004) and initial tumor volume (OR 1.32; p = 0.033) were significantly associated with the occurrence of eAEs. CONCLUSIONS: Although acute adverse events after SRS for JFS are not rare, these acute effects were not permanent and mostly improved with the steroid treatment. Dumbell-shaped and large-volume tumors are significant predictive factors for the occurrence of eAEs. And the transient expansion also seems to be closely related to eAEs. Therefore, clinicians need to be more cautious when treating these patients and closely monitor the occurrence of eAEs.

Surgical Treatment for Trigeminal Neuralgia.

Various treatments for trigeminal neuralgia (TN) are known to yield initial satisfactory results; however, the surgical treatment has excellent long-term outcomes and a low recurrence rate. Surgical treatment addresses the challenge of vascular compression, which accounts for 85% of the causes of TN. As for surgical treatment for TN, microvascular decompression (MVD) has become the surgical treatment of choice after Peter J. Jannetta reported the results of MVD surgery in 1996. Since then, many studies have reported a success rate of over 90% for the initial surgical treatment. Most MVDs aim to separate (decompress) the culprit vessel from the trigeminal nerve. To increase the success rate of surgery, accurate indications for MVD and management of the offender vessels without complications are critical. In addition, if there is no vascular compression, partial sensory rhizotomy or internal neurolysis can be performed to improve surgical outcomes.

Is the pre-operative lateral spread response on facial electromyography a valid diagnostic tool for hemifacial spasm?

The lateral spread response (LSR) on preoperative facial electromyogram (EMG) is a useful tool in evaluating patients with hemifacial spasm (HFS). There may be some instances where the LSR does not appear on the preoperative EMG, thus disrupting the diagnosis and treatment of HFS. In this study, we evaluated the patients who did not exhibit LSR on preoperative EMG but underwent microvascular decompression (MVD) for hemifacial spasm. We searched for patients who underwent MVD for HFS but had an absence of LSR on preoperative EMG between January 2016 and June 2018. Surgical outcomes were evaluated at 1, 3, and 6 months after surgery. Follow-up facial EMG was performed 3 months after surgery. Results were divided into two categories: (1) spasm relief within 24 h of surgery and (2) spasm was observed immediately post-operation. The following parameters were analyzed when comparing between the two groups: age, sex, affected side, duration of symptoms, and offending vessel(s). A total of 306 patients underwent MVD for HFS during the study period. Among them, 13 (4.2%) patients had no LSR on preoperative EMG. Eight patients (61.5%) were female and five patients were male. The 13 patients had a mean age of 51 years. All patients exhibited probable offending vessels in the root exit zone (REZ) of the facial nerve on preoperative magnetic resonance (MR) imaging that was confirmed during surgery. Seven patients were free of HFS immediately after surgery, though six patients were not. Only one (7.7%) patient had persisted symptom 6 months after surgery. No patients experienced recurrence of spasm, nor exhibited abnormal waves on follow-up facial EMG. LSR on facial EMG is a valuable tool for evaluating hemifacial spasm. However, although LSR did not appear on preoperative EMG, if the patient presents with typical symptoms and the offending vessels are identified on MRI, we expect good results after MVD for HFS.

Clinical Outcome of Percutaneous Trigeminal Nerve Block in Elderly Patients in Outpatient Clinics.

OBJECTIVE: Trigeminal neuralgia (TN) is a severe neuropathic condition that affects several elderly patients. It is characterized by uncontrolled pain that significantly impacts the quality of life of patients. Therefore, the condition should be treated as an emergency. In the majority of patients, pain can be controlled with medication; however, other treatment modalities are being explored in those who become refractory to drug treatment. The use of the trigeminal nerve block with a local anesthetic serves as an excellent adjunct to drug treatment. This technique rapidly relieves the patient of pain while medications are being titrated to effective levels. We report the efficacy and safety of percutaneous trigeminal nerve block in elderly patients with TN at our outpatient clinic. METHODS: Twenty-one patients older than 65 years with TN received percutaneous nerve block at our outpatient clinic. We used bupivacaine (1 mL/injection site) to block the supraorbital, infraorbital, superior alveolar, mental, and inferior alveolar nerves according to pain sites of patients. RESULTS: All patients reported relief from pain, which decreased by approximately 78% after 2 weeks of nerve block. The effect lasted for more than 4 weeks in 12 patients and for 6 weeks in two patients. There were no complications. CONCLUSION: Percutaneous nerve block procedure performed at our outpatient clinic provided immediate relief from pain to elderly patients with TN. The procedure is simple, has no serious side effects, and is easy to apply.

Incidental Microaneurysms During Microvascular Surgery: Incidence, Treatment, and Significance.

BACKGROUND: Although new imaging tools have been developed for the detection of smaller aneurysms, angiographically negative microaneurysms are still encountered during cerebral microsurgery. Currently, only limited information regarding incidence and efficacy of treatment of these microaneurysms is available. METHODS: We investigated the incidence and treatment of incidental microaneurysms (IMAs) in the last 5 years. IMAs are unidentifiable and invisible on preoperative angiography, but are detected during microvascular surgery. The inclusion criteria were aneurysm cases treated with microsurgery via transsylvian approaches, and those undergoing preoperative digital subtraction angiography. RESULTS: This study enrolled 484 surgical cases (248 cases of subarachnoid hemorrhage and 236 cases of unruptured aneurysms) in 460 patients, and 33 tiny aneurysms were found in 31 operative cases (6.4% incidence per operation). The most typical type was located on another branching site of the middle cerebral artery found during neck clipping of the middle cerebral artery bifurcation aneurysm. A patient with multiple aneurysms presented a statistically significant risk (375/78 vs. 15/16; P < 0.001) of IMA identification. IMAs were treated by clipping and wrapping in 18 and 15 cases, respectively, without complications. CONCLUSIONS: This study revealed a 6.4% incidence of IMAs; however, this could be underestimated because of the limited range of inspection. Early detection of an IMA through careful inspection during microvascular surgery could be beneficial, especially in patients with multiple aneurysms.

Long-Term Outcomes of Gamma Knife Radiosurgery for Cystic Vestibular Schwannomas.

OBJECTIVE: Vestibular schwannomas (VSs) can either be solid or contain variable amounts of cystic components. It has been established that gamma knife radiosurgery (GKRS) is an effective treatment modality for solid VSs. However, in the case of cystic VS, given the somewhat unpredictable growth of the cystic portion of these tumors, microsurgery has often been preferred to GKRS in the management of cystic VS. However, to date, a relative paucity of data evaluating the outcomes after GKRS for cystic VS has been available. In the present study, we reviewed our experience treating cystic VSs with GKRS and evaluated the results. METHODS: The data from patients with a diagnosis of cystic VS who had undergone GKRS from 1999 to 2018 were analyzed. Only those patients who had undergone GKRS as the initial treatment of cystic VSs were included in the present study. Patients who had undergone previous surgical treatment were excluded. The cystic VSs were divided into intratumoral and peritumoral cysts. RESULTS: A total of 24 patients were enrolled in the present study. The mean age was 60.8 ± 2.4 years (range, 38-82 years). The mean follow-up period was 55.8 ± 8.1 months (range, 8-145 months). Of the 24 patients, 11 were men. The control rate after GKRS for cystic VSs was 75%. The 5-year progression-free rate was 70%. Six patients had presented with an increasing lesion size after GKS. Of these 6 patients, 2 underwent surgical treatment and 1 underwent repeat GKRS. No statistically significant differences were found between the control rate and cystic type (P = 0.093). CONCLUSION: The results from the present study have demonstrated that GKRS is an effective treatment modality for cystic VSs.

Gamma Knife Radiosurgery for Postoperative Remnant Meningioma: Analysis of Recurrence Factors According to World Health Organization Grade.

OBJECTIVE: The effectiveness of tumor control after Gamma Knife radiosurgery (GKS) for intracranial meningioma is well established. Moreover, GKS is an alternative to reduce surgical-remnant meningioma recurrence. Nevertheless, the tumor can recur even after GKS and is associated with its histologic malignancy. We here investigated the risk factors associated with recurrence from remnant lesions after GKS, assessing recurrence patterns according to histological grades. METHODS: From January 2007 to January 2017, 218 patients underwent GKS for surgical-remnant lesions. To evaluate post-GKS lesion recurrence, pre-GKS magnetic resonance images were compared with those at follow-up. We retrospectively analyzed the histologic classification of meningioma and patients' clinical characteristics (sex, age, tumor location, target volume, and prescription dose). RESULTS: Of the 218 patients, 13 (5.9%) developed post-GKS recurrence within a mean follow-up period of 37.4 months. The recurrence patterns were as follows: adjacent to the 50% marginal-dose field (9 patients); within the 50% marginal-dose field (2 patients); and outside the field (2 patients). Six of 196 World Health Organization grade I meningioma cases, 6 of 20 grade II cases, and 1 of 2 grade III cases developed recurrence. Thus 32% of high-grade meningioma cases (grades II and III) developed recurrence during the follow-up period. Histologic grade was significantly associated (P < 0.001) with recurrence. CONCLUSIONS: The study findings indicate that the post-GKS meningioma recurrence likelihood is high when the meningioma has malignant histologic features. In addition, considering the recurrence patterns, it is important to define a precise target for GKS.

Surgical Outcomes of Revision Microvascular Decompression for Persistent or Recurrent Hemifacial Spasm After Surgery: Analysis of Radiologic and Intraoperative Findings.

OBJECTIVES: Microvascular decompression (MVD) is the treatment of choice for hemifacial spasm (HFS), due to the high rate of complete resolution associated with MVD. However, some patients experience recurrent or persistent symptoms after surgery. In this study, we evaluated the causes of recurrence or failure based on our surgical experience with revision of MVD for HFS and analyzed the relationship between surgical outcomes and radiologic and intraoperative findings. METHODS: Among more than 2500 patients who underwent MVD surgery for HFS, 23 patients received a second MVD in our hospital from January 2002 to December 2017. Three-dimensional time-of-flight magnetic resonance angiography and reconstructed imaging were used to identify the culprit vessel and its conflict on the root exit zone (REZ) of the facial nerve. We reviewed patients' medical records and operation videos to identify the missing points of first surgery. RESULTS: In our experience with revision of MVD, 8 patients had incomplete decompression, such as single-vessel decompression of multiple offending vessels. Teflon was not detected at the REZ but was found in other locations in 12 patients. Three patients had severe adhesion with previous Teflon around the REZ. Nineteen patients had excellent surgical outcomes at immediate postoperative evaluation; 20 patients showed spasm disappearance at 1 year after surgery and 3 patients showed persistent symptoms. Neurovascular contacts around the REZ of the facial nerve were revealed on magnetic resonance imaging of incomplete decompression and Teflon malposition patient groups. There were no clear neurovascular contacts in the patients with severe Teflon adhesion. CONCLUSIONS: The decision regarding secondary MVD for persistent or recurrent spasm is troubling. However, if neurovascular contact was observed in the MRI of the patient and there were offending vessels, the surgical outcome might be favorable.

Late-onset neurological deficits induced by proximal adjacent segment degeneration related to severe post-tuberculous kyphotic deformities of the spine: a series of 7 cases and surgical correction concept.

OBJECTIVE: Late-onset neurological deficits are a rare complication of spinal tuberculosis that may be caused by proximal adjacent segment degeneration (ASD) above the kyphus. The objective of this study was to report several cases of neurological deficits due to proximal ASD in patients with post-tuberculous kyphotic deformity and discuss the characteristics of the authors' corrective surgical technique. METHODS: The inclusion criteria in this study were severe angular kyphosis due to a post-tuberculous kyphotic deformity and a late-onset neurological deficit. The cause of these deficits was related to a lesion in the proximal cephalad portion of the kyphotic deformity. Surgical intervention, including decompression and compromised restoration of the sagittal imbalance, was performed in all patients. Preoperative surgical planning with a radiological evaluation included CT, plain radiograph, and MRI studies. Clinical outcomes were evaluated using the American Spinal Injury Association Impairment Scale and the Oswestry Disability Index (ODI). RESULTS: The main goal of our surgical technique was the correction of sagittal malalignment by positioning the patient's head above the kyphotic deformity on the sagittal plane, excluding aggressive osteotomy. The neurological symptoms showed immediate improvements postoperatively, except in 1 patient. Compared to the preoperative value of 66.9, the mean ODI score improved to 42.6 at the final follow-up for all patients. Preoperatively, the mean values of the angles of deformity and the sagittal vertical axis were 99.7° and 157.7 mm, respectively, and decreased to 75.3° and 46.0 mm, respectively, at the final follow-up. No major complications were observed, and the patients' self-satisfaction was high with respect to both cosmetic and functional outcomes. CONCLUSIONS: Clinicians should be aware of the degeneration of the vertebrae above the kyphotic segment in patients with post-tuberculosis deformity. Successful neurological recovery and compromised sagittal balance could be obtained by using our "head on kyphus" surgical concept.

New mobile-bearing TKA with unique ball and socket post-cam mechanism offers similar function and stability with better prosthesis fit and gap balancing compared to an established fixed-bearing prosthesis.

PURPOSE: A mobile-bearing (MB) posterior-stabilized total knee arthroplasty (TKA) system with ball and socket post-cam mechanism has been developed with the aims of better prosthesis fit and enhanced stability. However, the data are limited to compare its clinical outcomes with an already established fixed-bearing (FB) implant design. METHODS: This is a prospective randomized study comparing 260 patients in the MB group and 133 patients in FB group with a minimum 2 years of follow-up. Intraoperative variables, post-operative functional outcomes and incidence of adverse events were compared. RESULTS: MB group showed better prosthesis fit as the incidence of over-hang of femoral component at junction (medial: 1% vs. 5% and lateral: 2% vs 4%, p < 0.001) and trochlea (medial: 2% vs 30%, p = 0.042 and lateral: 13% vs 21%, p = 0.015) was less than FB group. MB group also showed better gap balancing as the incidence of medio-lateral gap difference more than 2 mm was less in flexion (2.3% vs. 16%, p < 0.001) and extension (3.1% vs. 9.8%, p = 0.005). Post-operative functional outcomes and incidence of adverse events showed no difference between the two groups at 2 years. CONCLUSIONS: New MB design offers similar functional outcomes and stability along with better intraoperative prosthesis fit and gap balancing compared to an established fixed-bearing design. Hence, this new MB design could be an alternative prosthesis of choice for posterior-stabilized TKA. LEVEL OF EVIDENCE: I.

Gain determination of feedback force for an ultrasound scanning robot using genetic algorithm.

PURPOSE: The remote medical diagnosis system (RMDS) is for providing medical diagnosis to the patients located in remote sites. To apply to RMDS and medical automation, many master-slave type ultrasound scanning robots are being developed and researched. One of the important research issue of the master-slave type ultrasound scanning robot is to determine the gains of the feedback force. Therefore, in this study, we suggest a gain determination method of feedback force for a master-slave type ultrasound thyroid scanning robot using a genetic algorithm. METHOD: A master-slave type ultrasound thyroid scanning robot (NCCMSU) was constructed, and the optimal y and z direction feedback force gains were calculated for NCCMSU with genetic algorithm. The Hunt-Crossley model is used to model the elastic behavior of the thyroid phantom and the thyroid scanning procedure is embedded in genetic algorithm by modeling the procedure mathematically. The genetic algorithm solves the average feedback force-overall procedure time optimization problem to seek optimal y, z direction feedback gains candidates. RESULTS: The rating results show that although there are some deviations among the subjective ratings, the feedback force with the determined gain setting is within the appropriate range. By analyzing the subjective rating test, the optimal y, z direction feedback force gains were determined. The optimal gains were verified by thyroid phantom scanning test and the scanned ultrasound image analysis. CONCLUSION: With the proposed method, the y, z direction optimal feedback force gains of the master-slave type ultrasound scanning robots can be determined. The proposed methods were verified by thyroid phantom scanning test.