The Relationship between the Contouring Time of the Metal Artifacts Area and Metal Artifacts in Head and Neck Radiotherapy.

(1) Background: The impacts of metal artifacts (MAs) on the contouring workload for head and neck radiotherapy have not yet been clarified. Therefore, this study evaluated the relationship between the contouring time of the MAs area and MAs on head and neck radiotherapy treatment planning. (2) Methods: We used treatment planning computed tomography (CT) images for head and neck radiotherapy. MAs were classified into three severities by the percentage of CT images containing MAs: mild (<25%), moderate (25−75%), and severe (>75%). We randomly selected nine patients to evaluate the relationship between MAs and the contouring time of the MAs area. (3) Results: The contouring time of MAs showed moderate positive correlations with the MAs volume and the number of CT images containing MAs. Interobserver reliability of the extracted MAs volume and contouring time were excellent and poor, respectively. (4) Conclusions: Our study suggests that the contouring time of MAs areas is related to individual commitment rather than clinical experience. Therefore, the development of software combining metal artifact reduction methods with automatic contouring methods is necessary to reducing interobserver variability and contouring workload.

Comparing the Diagnostic Accuracy of Ultrasonography, CT, MRI, and PET/CT in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma.

(1) Background: In oral cancer staging, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) with positron emission tomography/computed tomography (PET/CT) are routinely used in clinical practice. The present study is a retrospective examination of the diagnostic accuracy of cervical lymph node metastasis using US, CT, MRI, and PET/CT, with histopathological diagnosis as a reference, to compare the different diagnostic imaging modalities. (2) Methods: The participants included 16 patients with oral squamous cell carcinoma who underwent US-, CT-, MRI-, and PET/CT-based preoperative diagnostic imaging and simultaneous primary lesion resection and neck dissection, including 82 level regions and 424 lymph nodes. We compared the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of each imaging modality based on the imaging results and the pathology results of metastasis. (3) Results: Of the four diagnostic imaging modalities, PET/CT exhibited the highest sensitivity but the lowest specificity and accuracy. US, CT, and MRI had high specificities. Comparing each level region and lymph node showed that differences were observed in PET/CT. (4) Conclusions: PET/CT to diagnose lymph node metastasis requires a comprehensive evaluation because it produces more false positives than other diagnostic imaging modalities. Using US, CT, and MRI, which have excellent spatial resolution, improves diagnostic accuracy at the lymph node level.

A comparative study between CT, MRI, and intraoral US for the evaluation of the depth of invasion in early stage (T1/T2) tongue squamous cell carcinoma.

OBJECTIVES: This study aimed to clarify the accuracy of intraoral ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in preoperative image depth of invasion (DOI) measurement of T1/T2 tongue cancer through comparison with histopathological measurements. METHODS: Imaging of the primary lesions was performed at our hospital; the lesions were classified into T1 and T2 based on the 8th edition of the AJCC/UICC, and surgery performed. There was histopathological confirmation of lesions as squamous cell carcinoma in 48 patients with tongue cancer. T3 and T4 cases, cases in which preoperative chemotherapy and radiation therapy were performed, and cases where biopsy was performed before imaging were excluded. The radiological DOI in US, CT, and MRI and the histopathological DOI as base were comparatively investigated and statistical analyses were performed by Bland-Altman analysis and Spearman's rank correlation coefficient. RESULTS: Bland-Altman analysis showed that the US radiological DOI was overestimated by an average of 0.2 mm compared to the histopathological DOI, while CT and MRI radiological DOI were overestimated by an average of 2-3 mm. The comparison of CT and MRI revealed that the difference between the MRI and histopathological DOI, as well as the 95% limit of agreement, were smaller than those of the CT radiological DOI. CONCLUSIONS: US is the most accurate preoperative diagnostic tool for T1 and T2 squamous cell carcinoma; CT and MRI tend to have an overestimation of about 2-3 mm and so caution is required.

Hallux valgus angle as a predictor of recurrence following proximal metatarsal osteotomy.

BACKGROUND: Postoperative recurrence of hallux valgus is a common complication. We hypothesized that patients who are at higher risk for recurrence of hallux valgus following a proximal metatarsal osteotomy could be recognized preoperatively and at the early follow-up on the basis of their radiographic evaluation. The purpose of this study was to clarify the relationship between the hallux valgus angle, intermetatarsal angle, and recurrence of hallux valgus. METHODS: We performed a case-control study of patients treated with a proximal metatarsal osteotomy for hallux valgus. Dorsoplantar weight-bearing radiographs of 72 feet were assessed preoperatively, at the early follow-up interval (mean 10 weeks), and at the most recent follow-up interval (mean 33 months). RESULTS: The rate of recurrence was 13.9% (ten feet). Risk factors for recurrence were preoperative hallux valgus angle >40° [odds ratio (OR) = 5.1; 95% confidence interval (CI) 1.3-20.8]. Decreased risks of hallux valgus recurrence were a hallux valgus angle ≤ 15° (OR = 0.036, 95% CI = 0.0056-0.24, p = 0.0005), and an intermetatarsal angle <10° (OR = 0.083, 95% CI = 0.015-0.46, p = 0.0075) at the time of the early follow-up with the numbers available. CONCLUSIONS: Our radiographic results indicated that a preoperative hallux valgus angle >40° can be a risk factor for hallux valgus recurrence. Decreased risk factors for recurrence included hallux valgus angle ≤ 15° and an intermetatarsal angle <10° at the early follow-up. These risk factors may be helpful for modifying surgical procedures, improving surgical outcome, and predicting hallux valgus recurrence.

Radiological imaging features of the salivary glands in xerostomia induced by an immune checkpoint inhibitor.

The clinical features of xerostomia induced by immune checkpoint inhibitors (ICI) are similar to those of Sjögren's syndrome (SS), whereas the immunohistological and serological features are known to differ from those of SS. However, the radiologic imaging features of salivary glands are not yet well known. We report a case of a 56-year-old male patient diagnosed with ICI-induced xerostomia. The patient underwent various imaging examinations to investigate the condition of the salivary glands, which indicated the following: (1) less specific findings on contrast-enhanced computed tomography, (2) mixed with intermediate and low signal intensity on both T1-weighted and fat-suppressed T2-weighted magnetic resonance imaging and poor "salt and pepper" appearance on magnetic resonance sialography, and (3) multiple ovoid hypoechoic areas with hyperechoic bands without acute sialadenitis on ultrasound. These radiologic imaging findings suggested remarkable lymphocyte infiltration, which could be a characteristic of ICI-induced xerostomia.

Quantitative evaluation of elasticity of lower orbicularis oris muscle during the lip closing measurement using sonographic elastography.

BACKGROUND: Lip closing functions have never been evaluated from the viewpoint of elastic properties. OBJECTIVES: The purpose of the present study was to investigate the behavior of the lower orbicularis oris muscle during a button-pull exercise to measure lip closing force and quantitatively evaluate its elastic properties using sonographic elastography. METHODS: Appropriate compression loads for elastography were randomly measured on one of three types of acoustic couplers on three examiners. Compression tests were performed on three types of acoustic couplers within the appropriate compression load. Using the acoustic coupler with the lowest elastic modulus, the strain ratio of the lower orbicularis oris muscle during lip closing was measured, and elastography was performed on six males under tension loads of 0-8 N. RESULTS: The intraclass correlation coefficient (1, 3) for the tension load of 0 N was 0.81. Elastography showed that the strain ratio values increased significantly (p < 0.05) as the tension load increased. CONCLUSIONS: Combining the data obtained from lip closing test devices and sonographic elastography enabled the muscle performance to be evaluated objectively and accurately.

The effect of platelet-rich plasma on Achilles tendon healing in a rabbit model.

OBJECTIVE: The aim of the present study was to evaluate the effects of PRP on Achilles tendon healing in rabbits during the inflammatory, proliferative, and remodeling phases by histological examination and quantitative assessments. METHODS: Fifty mature male Japanese albino rabbits with severed Achilles tendons were divided into two equal groups and treated with platelet-rich plasma (PRP) or left untreated. Tendon tissue was harvested at 1, 2, 3, 4, and 6 weeks after treatment, and sections were stained with hematoxylin-eosin and monoclonal antibodies against CD31 and type I collagen. RESULTS: Collagen fibers proliferated more densely early after severance, and subsequent remodeling of the collagen fibers and approximation of normal tendinous tissue occurred earlier in the PRP group than in the control group. The fibroblast number was significantly higher in the PRP group than in the control group at 1 and 2 weeks. Similarly, the area ratio of CD31-positive cells was significantly higher in the PRP group than in the control group at 1 and 2 weeks. Positive staining for type I collagen was more intense in the PRP group than in the control group after 3 weeks, indicating tendon maturation. CONCLUSION: Administration of PRP shortened the inflammatory phase and promoted tendon healing during the proliferative phase.

Sonographic measurement of transient synovitis in children: diagnostic value of joint effusion.

In an evaluation of the diagnostic criteria for ultrasonography (US) of transient synovitis in children, in a prospective study, 34 consecutive children with a painful hip underwent US. The ultrasonographic joint space (UJS) and the effusion space were measured in both hips, and the width of the UJS thickness in the asymptomatic hips was compared with that in the symptomatic hips. US showed the presence of a joint effusion in 31 of the 34 children and a bilateral effusion in 3. The US diagnostic criterion for hip effusion consists of a UJS thickness difference >2.0 mm between asymptomatic and symptomatic hips. However, we found that 8 of the 31 UJS measurements compared between symptomatic hips and asymptomatic hips exhibited differences of <2 mm. We suggest that effusion space measurements are possible for accurate visualization of synovitis, rather than the recording of differences in UJS measurements between hips.