UNASSIGNED: Therapeutic strategies for ankle osteoarthritis (OA) are determined based on OA staging, alignment, and articular cartilage conditions. However, it is difficult to evaluate the degeneration of the remaining cartilage using imaging modalities. Subchondral bone plays a crucial role in maintaining cartilage homeostasis. Measurement of local Hounsfield unit (HU) values allows for the quantitative assessment of small changes in the subchondral bone. This study aimed to evaluate a relationship between the HU values of the subchondral bone and the histologic findings of articular cartilage in ankle OA.
UNASSIGNED: The talar articular surface was harvested from 14 ankles during arthroplasty. The talus was divided into anterior, middle, and posterior parts, and histologic specimens were prepared. Safranin O staining was performed and histologic findings were evaluated using the modified Mankin score. The regions of interest (ROIs) were set in the medial, central, and lateral regions of the specimens and computed tomography (CT) images, and the relationship between the HU values and histologic findings was analyzed.
UNASSIGNED: As OA progressed, cartilage defects increased. In conjunction with cartilage degeneration, the subchondral bone plate thickened, and the HU values increased. The HU value significantly and positively correlated with the modified Mankin score (r = 0.756), subchondral bone thickness (r = 0.674, P < .01), and trabecular bone area (r = 0.637). The cutoff HU values were 594 (sensitivity, 0.813; specificity, 0.944) for 3 points and 727 (sensitivity, 0.929; specificity, 0.782) for 11 points on the modified Mankin score.
UNASSIGNED: Significant correlations between HU values and cartilage degeneration in ankle OA were noted. Measuring HU values on CT images can be useful for evaluating the joint surface condition, including histologic findings of the remaining cartilage.

OBJECTIVE: To optimize cervical vertebral bone quality (C-VBQ) score and explore its effectiveness in predicting cage subsidence in Anterior Cervical Corpectomy and Fusion (ACCF) and identify a new method for evaluating subsidence without different equipment and image scale interference.
METHODS: Collecting demographic, imaging, and surgical related information. Measuring Cage Subsidence with a new method. Multifactorial logistic regression was used to identify risk factors associated with subsidence. Pearson\'s correlation was used to determine the relationship between C-VBQ and computed tomography (CT) Hounsfield units (HU). The receiver operating characteristic (ROC) curve was used to assess C-VBQ predictive ability. Correlations between demographics and C-VBQ scores were analyzed using linear regression models.
RESULTS: 92 patients were included in this study, 36 (39.1%) showed subsidence with a C-VBQ value of 2.05 ± 0.45, in the no-subsidence group C-VBQ Value was 3.25 ± 0.76. The multifactorial logistic regression showed that C-VBQ is an independent predictor of cage subsidence with a predictive accuracy of 93.4%. Pearson\'s correlation analysis showed a negative correlation between C-VBQ and HU values. Linear regression analysis showed a positive correlation between C-VBQ and cage subsidence. Univariate analyses showed that only age was associated with C-VBQ.
CONCLUSIONS: The C-VBQ values obtained using the new measurements independently predicted postoperative cage subsidence after ACCF and showed a negative correlation with HU values. By adding the measurement of non-operated vertebral heights as a control standard, the results of cage subsidence measured by the ratio method are likely to be more robust, perhaps can exclude unavoidable errors caused by different equipment and proportional.

BACKGROUND: Adrenal incidentalomas (AI) are predominantly nonfunctional and benign, and their detection and differential diagnosis are aided by computed tomography (CT). A nonfunctioning adrenal incidentaloma (NFAI) usually requires regular follow-up; however, adrenalectomy may be necessary in certain patients. This study aimed to evaluate prognostic predictors to guide the treatment approach for AIs.
METHODS: This retrospective, single-center study involved patients diagnosed with NFAI from January 2000 to December 2020. Patients were divided into surgery and observation groups. A subgroup analysis compared malignant and benign adenoma within the surgery group.
RESULTS: A total of 307 patients were included, with 127 in the surgery group and 180 in the observation group. The surgery group displayed distinct morphological and malignant potential features in CT scans more frequently than the observational group did. The malignant subgroup exhibited more irregular borders on CT, and a higher number of patients with absolute washout under 60 % and relative washout under 40 % compared with the benign adenoma subgroup. Interestingly, within the surgery group, the mean tumor size was <4 cm for the both malignant and benign adenoma subgroups.
CONCLUSIONS: Characterizing NFAI is important for appropriate treatment, as not all AIs have a favorable prognosis. CT findings associated with malignant potential, such as Hounsfield unit and washout values, were useful in determining the need for surgical treatment. However, the conventional criterion of a 4-cm size threshold for surgery was not a reliable malignancy predictor. Surgical resection should be considered for specific patient groups to ensure proper treatment over mere observation.

UNASSIGNED: In cases where standardized maximum uptake (SUVmax) values in positron emission tomography (PET-CT) were not sufficient to differentiate mediastinal lymphadenopathy and masses from malignant or benign, the contribution of Hounsfield unit (HU) values in thorax computed tomography to the diagnosis was evaluated.
UNASSIGNED: The study was conducted by evaluating the data of 182 patients between 2019 and 2023. HU values on non-contrast thorax computed tomography and PET-CT SUVmax values of biopsied masses and lymph nodes were compared with histopathological diagnoses.
UNASSIGNED: Patients, 58 females (31.9%) and 124 males (68.1%), who underwent EBUS were included in the study. Biopsies were taken from 233 stations (199 lymph nodes, 34 masses) from 182 patients. A total of 135 of the biopsies taken from 233 stations were histopathologically malignant and 98 were benign. While PET-CT SUVmax values of cases with benign histopathology were 4.5 ± 3.5, it was 7.6 ± 4.2 in patients with malignant pathology (p<0.05). The HU value on non-contrast thorax tomography in patients with benign histopathology was 43.1 ± 15.7, and in patients with malignant histopathology it was 40.5 ± 13.7 (p>0.05). When HU was compared according to lung cancer type, it was found to be significantly higher in non-small cell lung cancer (p=0.035). A weak (r=0.182) positive and significant relationship (p<0.01) was found between PET-CT values and HU values in thorax computed tomography.
UNASSIGNED: While positron emission tomography maintains its importance in the differentiation of mediastinal lymphadenopathy and masses from malignant to non-malignant, it was concluded that HU values in computed tomography are not sufficient to distinguish malignant/non-malignant.

BACKGROUND: Cervical spine fracture-dislocations in patients with ankylosing spondylitis (AS) are mostly unstable and require surgery. However, osteoporosis, one of the comorbidities for AS, could lead to detrimental prognoses. There are few accurate assessments of bone mineral density in AS patients.
OBJECTIVE: To analyze Hounsfield units (HUs) for assessing bone mineral density in AS patients with cervical fracture-dislocation.
METHODS: The HUs from C2 to C7 of 51 patients obtained from computed tomography (CT) scans and three-dimensional reconstruction of the cervical spine were independently assessed by two trained spinal surgeons and statistically analyzed. Inter-reader reliability and agreement were assessed by interclass correlation coefficient.
RESULTS: The HUs decreased gradually from C2 to C7. The mean values of the left and right levels were significantly higher than those in the middle. Among the 51 patients, 25 patients (49.02%) may be diagnosed with osteoporosis, and 16 patients (31.37%) may be diagnosed with osteopenia.
CONCLUSIONS: The HUs obtained by cervical spine CT are feasible for assessing bone mineral density with excellent agreement in AS patients with cervical fracture-dislocation.

OBJECTIVE: Hounsfield unit (HU) values measured using CT have been increasingly recognized to stand as a reliable corollary to dual-energy x-ray absorptiometry (DEXA) scores in evaluating bone mineral density. The authors examined the correlation between cervical HU values and DEXA T- and Z-scores and determined novel cervical HU thresholds for determining bone quality classification.
METHODS: One hundred patients who underwent both cervical spine CT and DEXA, 85 patients who underwent both lumbar CT and DEXA, and 128 patients who underwent cervical and lumbar CT within 24 months at a single institution were included in this retrospective review. Two independent reviewers collected HU values from 3 cervical vertebral levels (C4-6) and 4 lumbar vertebral levels (L1-4), and the averaged values were used. Pearson\'s correlation coefficient analysis was performed to compare the association of cervical HU values with lumbar HU values and T- and Z-scores. The mean cervical HU values for each DEXA classification were calculated and compared. Receiver operating characteristic (ROC) curves were created to determine the threshold and its sensitivity and specificity for diagnosis.
RESULTS: Cervical (C4-6) HU values and average, lumbar, and femoral T- and Z-scores had significant correlations (0.436 > r > 0.274, all p < 0.01). A strong positive correlation between cervical and lumbar HU values was found (r = 0.79, p < 0.01). The average cervical HU value of healthy patients was 361.2 (95% CI 337.1-385.3); of osteopenic patients, 312.1 (95% CI 290.3-333.8); and of osteoporotic patients, 288.4 (95% CI 262.6-314.3). There was a significant difference between the cervical HU values of healthy and osteopenic patients (p = 0.0134) and between those of healthy and osteoporotic patients (p = 0.0304). The cervical HU value of 340.98 was 73.5% specific and 57.9% sensitive for diagnosing osteopenia with an area under the ROC (AUROC) curve of 0.655. The cervical HU value of 326.5 was 88.9% specific and 63.2% sensitive for diagnosing osteoporosis with an AUROC curve of 0.749.
CONCLUSIONS: This is the second large-scale study and first with a patient population from the United States to show that HU values obtained using cervical CT were significantly correlated with bone quality based on DEXA T- and Z-scores and to establish a cervical HU threshold for determining bone quality classification. These results show that cervical HU values can and should be used to predict poor bone quality in surgical cervical spine patients.

METHODS: Prospective cohort study.
OBJECTIVE: This study aimed to identify the optimal preoperative bone health assessment for adult spinal deformity (ASD) surgery through correlation analysis between intraoperative pedicle screw (PS) insertion torque and various bone quality measures, including bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DEXA), Hounsfield unit (HU) by computed tomography (CT), and vertebral bone quality (VBQ) score by magnetic resonance imaging.
BACKGROUND: Existing data on optimal assessment tools for ASD surgery are limited.
METHODS: The study included patients with ASD aged >60 years who underwent spinal corrective fusion surgery from the lower thoracic spine to the pelvis. The intraoperative PS insertion torque was measured using a torque meter. Pearson correlation coefficients were calculated between the PS insertion torque and the BMD, HU, and VBQ score. Preoperative bone quality was compared between the proximal junctional failure (PJF) and non-PJF groups.
RESULTS: Thirty-one patients with 177 PS at T10, T11, and T12 were analyzed. The PS insertion torque showed a moderate positive correlation with lumbar spine BMD (r=0.59-0.69, p<0.01), total hip BMD (0.58-0.62, p<0.01), and HU value (r=0.58-0.66, p<0.01). However, the VBQ score did not show significant correlation (r=-0.28 to -0.23, p >0.05). Notably, a strong correlation was found between the PS insertion torque and the HU value for screws of the same size (r=0.71 and 0.74, p<0.01). The HU value at T12 and the PS insertion torque at T10 were significantly lower in the PJF group than in the non-PJF group.
CONCLUSIONS: This study demonstrates a positive correlation between the PS insertion torque and HU value in the lower thoracic spine and a moderate correlation with BMD but not the VBQ score. Preoperative assessment using DEXA and CT is crucial for optimizing bone health management in ASD surgery.

BACKGROUND: In rhinoplasty, calcification around silicone implants is frequently observed in the tip dorsum (TD) area. Additionally, based on a review of various literature, it is presumed that calcification in silicone implants occurs due to both inflammatory chemical reactions and physical friction against the tissue. The calcification of nasal silicone implants not only results in the functional loss of the implants, but also leads to material deformation. However, there is a lack of research on calcification of nasal silicone implants in the current literature.
OBJECTIVE: To elucidate various clinical characteristics of calcification around nasal silicone implants, using histological and radiological analysis.
METHODS: This study analyzed data from 16 patients of calcified nasal implants, who underwent revision rhinoplasty for various reasons after undergoing augmentation rhinoplasty with silicone implants. The collected data included information on implant duration, implant types, location of calcification, presence of inflammatory reactions, and computed tomography (CT) scans.
RESULTS: The most common location of calcification, as visually analyzed, was in the TD area, accounting for 56%. Additionally, the analysis of CT scans revealed a trend of increasing Hounsfield Unit values for calcification with the duration of implantation, although this trend was not statistically significant (P = 0.139).
CONCLUSIONS: Our study shows that reducing the frequency of calcification may be achievable by using softer silicone implants and by minimizing the damage to perioperative tissues.

Pedicle screw loosening after posterior lumbar fusion is associated with poor bone quality, which often determines screw pull-out strength, insertion torque, and vertebral body loading characteristics. Magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score were associated with poor bone quality. Current evidence suggests that pedicle bone quality (PBQ) has a greater impact on screw stability. However, the correlation between MRI-based PBQ score and screw loosening has not been reported.
OBJECTIVE: To introduce and evaluate an MRI-based PBQ score to determine its effectiveness in predicting pedicle screw loosening following lumbar fusion surgery.
METHODS: The retrospective study analyzed 244 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screws between December 2017 and December 2021, with CT and MRI imaging before surgery. Data collected included patient demographics and preoperative radiological data. Radiographic screw loosening was measured at 12 months postoperatively. Clinical assessments included pain visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The PBQ score was measured using MRI scans. We use univariate analysis for preliminary screening of the risk factors of screw loosening. Subsequent analysis involved multivariate logistic regression to identify independent predictive factors for screw loosening. We constructed the receiver operating characteristic (ROC) curve to ascertain the discriminative capacity of the PBQ score. The area under the curve (AUC) quantified its predictive accuracy. Additionally, we evaluated the association between PBQ score and screw loosening using Spearman\'s correlation analysis.
RESULTS: Overall, 244 patients who underwent PLIF with pedicle screw fixation participated in this study, including 35 in the loosening group and 209 in the non-loosening group. PBQ score in the loosening group was significantly higher than that in the non-loosening group. On multivariate logistic regression, the higher PBQ score (OR = 8.481, 95% CI: 3.158-22.774; p < 0.001) and the lower mean Hounsfield unit (HU) value of L1-4 (OR = 0.967, 95% CI 0.951-0.984; p < 0.001) were the variables that significantly predicted screw loosening. The AUC for the PBQ score and HU value were 0.751 (95% CI: 0.673-0.828) and 0.702 (95% CI: 0.612-0.791). The PBQ score optimal cutoff to differentiate patients with loosening and with non-loosening was calculated as 3.045 with a sensitivity of 85.7% and specificity of 76.9%, while the optimal cutoff of the HU value was 151.5 with a sensitivity of 64.6% and specificity of 89.5%.
CONCLUSIONS: The association between the PBQ score and the propensity for lumbar pedicle screw loosening was found to be substantial. As a predictive measure, the PBQ score outperformed the HU value in forecasting the likelihood of screw loosening post-posterior lumbar fusion.

OBJECTIVE: The Hounsfield unit density value (HUDV) is a relative quantitative measurement of radio density used by radiologists in the interpretation of computed tomography (CT) images. Our aim is to investigate the role of HUDV in evaluating pre-epiglottic space (PES) involvement of laryngeal carcinoma.
METHODS: Seventy-four patients treated for laryngeal carcinoma in our clinic between 2014 and 2019 were included in the study. The invasion status of PES was determined radiologically and pathologically. HUDV was measured with a circular selected region of interest, with a constant size of 10 mm2 for PES. The relationship between patological PES invasion, radiological PES invasion, and HUDV was evaluated.
RESULTS: Measuring HUDV to determine PES invasion (74.3 %) was significantly higher than​​ conventional CT evaluation (59.5 %) (p = 0.001). The agreement coefficient (kappa value) of the conventional CT evaluation and the HUDV regarding PES involvement was 0.673, which was interpreted as \'good\'.
CONCLUSIONS: HUDV could be used as an additional tool in diagnosing pre-epiglottic space invasion in laryngeal cancer.