Hounsfield Units Research Articles

Development and validation of a nomogram to predict impacted ureteral stones via machine learning.

To develop and evaluate a nomogram for predicting impacted ureteral stones using some simple and easily available clinical features. From June 2019 to July 2022, 480 patients who underwent ureteroscopic lithotripsy (URSL) for ureteral calculi were enrolled in the study. From the eligible study population between June 2019 and December 2020, a training and validation set was randomly generated in a 7:3 ratio. To further evaluate the generalization performance of the nomogram, we performed an additional validation using the data from January 2021 to July 2022. Lasso regression analysis was used to identify the most useful predictive features. Subsequently, a multivariate logistic regression algorithm was applied to select independent predictive features. The predictive performance of the nomogram was assessed using Receiver Operating Characteristic (ROC) curves, calibration curves and decision Curve Analysis (DCA). The Hosmer-Lemeshow Test was utilized to evaluate the overall goodness of fit of the nomogram. Multivariate logistic regression analysis showed that flank pain, hydronephrosis, stone length/width, HU below (Hounsfield unit density of the ureter center below the stone), HU above/below (HU above divided by HU below) and UWT (ureteral wall thickness) were ascertained as independent predictors of impacted ureteral stones. The nomogram showed outstanding performance within the training dataset, with the area under the curve (AUC) of 0.907. Moreover, the AUC was 0.874 in the validation dataset. The ROC curve, calibration curve, DCA curve and Hosmer-Lemeshow Test suggested that the nomogram maintains excellent clinical applicability and demonstrates commendable performance. Similar results were achieved in the test dataset as well. We established a nomogram that can be effectively used for preoperative diagnosis of impacted ureteral stones, which is of great significance for the treatment of this disease.

The Significance of Hounsfield Unit and Tumor Diameter in the Differentiation of Malignant and Benign Adrenal Masses

The Significance of Hounsfield Unit and Tumor Diameter in the Differentiation of Malignant and Benign Adrenal Masses

Hounsfield units of vertebrae as a predictor of cervical deep paraspinal muscles atrophy and neck pain in degenerative cervical myelopathy.

This study investigated the correlation between Hounsfield units (HU) of the cervical vertebrae and atrophy of the cervical deep paraspinal muscles, namely the multifidus and semispinalis cervicis (SCer), in patients diagnosed with degenerative cervical myelopathy (DCM). The authors retrospectively analyzed data from 136 patients aged 50-79 years (81 males and 55 females) who underwent surgical intervention for DCM. HU measurements of the cancellous bone in the C4 vertebra were acquired through standardized techniques. The authors evaluated fatty infiltration (FI); analyzed functional and vertebral cross-sectional area (CSA) of the multifidus and SCer at the C4-5, C5-6, and C6-7 levels; and analyzed the presence of Modic changes (MCs) and the incidence of axial neck pain. Patients were categorized into group A (n = 56) with mean ± SD HU of 293.3 ± 15.6 and group B (n = 80) with mean ± SD HU of 389.5 ± 10.6. Both groups demonstrated significant improvements in postoperative clinical outcomes (p < 0.05); however, no statistically significant difference was observed (p > 0.05). Significant disparities in HU measurements and visual analog scale (VAS) scores for neck pain were observed between the groups (p < 0.05). The highest VAS score correlated with MCs-1 type (i.e., low signal on T1-weighted images and high signal on T2-weighted images). The functional CSA to vertebral CSA ratios of the multifidus and SCer in group A were markedly reduced compared to those of group B (p < 0.05). No significant difference was noted in functional CSA asymmetry between the groups for both muscles (p > 0.05). Lower HU measurements directly correlated with increased FI in the multifidus (p = 0.002) and SCer (p = 0.035). Furthermore, a strong positive association was found between the functional CSA to vertebral CSA ratio of the multifidus and HU values (p = 0.003), whereas HU measurements and VAS scores exhibited a negative correlation (p = 0.020). Among those patients older than 50 years with DCM, those with decreased HU values demonstrated elevated FI levels in the multifidus and SCer muscles. Moreover, these patients presented with pronounced muscle atrophy, which correlated with axial neck pain. A significant relationship was also identified between MCs and diminished HU values.

CBCT-based synthetic CT image generation using a diffusion model for CBCT-guided lung radiotherapy.

Although cone beam computed tomography (CBCT) has lower resolution compared to planning CTs (pCT), its lower dose, higher high-contrast resolution, and shorter scanning time support its widespread use in clinical applications, especially in ensuring accurate patient positioning during the image-guided radiation therapy (IGRT) process. While CBCT is critical to IGRT, CBCT image quality can be compromised by severe stripe and scattering artifacts. Tumor movement secondary to respiratory motion also decreases CBCT resolution. In order to improve the image quality of CBCT, we propose a Lung Diffusion Model (L-DM) framework. Our proposed algorithm is based on a conditional diffusion model trained on pCT and deformed CBCT (dCBCT) image pairs to synthesize lung CT images from dCBCT images and benefit CBCT-based radiotherapy. dCBCT images were used as the constraint for the L-DM. The image quality and Hounsfield unit (HU) values of the synthetic CTs (sCT) images generated by the proposed L-DM were compared to three selected mainstream generation models. We verified our model in both an institutional lung cancer dataset and a selected public dataset. Our L-DM showed significant improvement in the four metrics of mean absolute error (MAE), peak signal-to-noise ratio (PSNR), normalized cross-correlation (NCC), and structural similarity index measure (SSIM). In our institutional dataset, our proposed L-DM decreased the MAE from 101.47 to 37.87HU and increased the PSNR from 24.97 to 29.89 dB, the NCC from 0.81 to 0.97, and the SSIM from 0.80 to 0.93. In the public dataset, our proposed L-DM decreased the MAE from 173.65 to 58.95HU, while increasing the PSNR, NCC, and SSIM from 13.07 to 24.05 dB, 0.68 to 0.94, and 0.41 to 0.88, respectively. The proposed L-DM significantly improved sCT image quality compared to the pre-correction CBCT andthree mainstream generative models. Our model can benefit CBCT-based IGRT and other potential clinical applications as it increases the HU accuracy and decreases the artifacts from input CBCT images.

Nonquantitative CT scan Hounsfield unit as a determinant of cervical spine bone density.

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. 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. 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. 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.

Impact of osteoporosis on overall survival following endovascular repair for abdominal aortic aneurysms

ObjectiveTo evaluate the impact of osteoporosis on overall survival following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs). MethodsThis was a retrospective, single-center cohort study on 172 patients who had undergone primary EVAR for AAA between 2016 and 2018. Bone mineral density (BMD) was assessed by measuring the Hounsfield units (HUs) of the 11th thoracic vertebra on preoperative computed tomography; a BMD value of <110 HU was considered osteoporosis. All patients were divided into those with osteoporosis and those without osteoporosis, and long-term outcomes were compared. In addition, hazard ratios of each variable for all-cause mortality were evaluated using univariate and multivariate analysis. ResultsAll 172 patients were divided into two groups: 72 patients (41.9%) with osteoporosis and 100 patients (58.1%) without osteoporosis. The mean age was older and the mean BMD was lower in patients with osteoporosis than patients without osteoporosis (mean, 79.2 ± 7.2 years vs 75.0 ± 8.7 years, respectively; P < .05; 78.1 ± 26.7 HU vs 155.1 ± 36.3 HU, respectively; P < .05). During the median follow-up period of 68 months, overall survival was significantly lower in patients with osteoporosis than patients without osteoporosis (osteoporosis: 63.9% and 36.7% at 5 years and 7 years; nonosteoporosis: 83.8% and 74.6% at 5 years and 7 years, respectively; log-rank P < .05); freedom from aneurysm-related mortality did not differ significantly between groups (osteoporosis: 94.3% and 89.0% at 5 years and 7 years; nonosteoporosis: 100.0% and 96.7% at 5 years and 7 years, respectively; log-rank P = .078). In a multivariate analysis for overall survival after EVAR, coexistence of osteoporosis was found to be an independent risk factor for all-cause mortality (hazard ratio, 1.76; 95% confidence interval, 1.01-3.06; P < .05), as well as variables including age, statin use, sarcopenia, and aneurysm diameter. ConclusionsPatients with osteoporosis showed a higher all-cause mortality after EVAR than patients without osteoporosis. We believe that comorbidity of osteoporosis may be useful in estimating the life expectancy of patients with AAA.

Exploring the interplay between epicardial fat, coronary artery calcium score, and nonalcoholic fatty liver disease through non-ECG-gated chest computed tomography: A cross-sectional study.

This study examines the relationships between epicardial adipose tissue (EAT), nonalcoholic fatty liver disease (NAFLD), and coronary artery calcium score (CACS) using non-ECG-gated CT scans. It aims to determine the effectiveness of EAT measurements and NAFLD as predictors for coronary artery disease (CAD). This cross-sectional study was conducted at a specialized center, focusing on individuals who underwent non-ECG-gated chest CT scans without contrast. We evaluated EAT thickness and density in three areas: the right atrioventricular groove, the free wall of the right ventricle, and the central area of the right anterior interventricular groove. Additionally, we measured CACS and determined the presence of NAFLD by comparing liver-to-spleen density ratios. Statistical analyses, including regression models, were performed using SPSS (version 26). In this study, we enrolled 365 participants, including 203 males with an average age of 47 ± 17.93 years. EAT thickness was 6.28 ± 1.62 mm, and EAT density was -96.07 ± 12.47 Hounsfield units (HU). The mean CACS was 22.27 ± 79.01, and the mean liver density was 50.01 ± 10.76 HU. A significant positive correlation was observed between EAT thickness and CACS (r = 0.208, p < 0.001). EAT density showed a significant negative correlation with CACS (r = -0.155, p = 0.003). No correlation was found between NAFLD and CACS. Univariate logistic regression analysis identified significant predictors of increased CACS, including EAT thickness (OR: 1.803), EAT density (OR: 0.671), diabetes mellitus (DM) (OR: 5.921), and hypertension (HTN) (OR: 7.414). Multivariate analysis confirmed the significance of EAT thickness (OR: 0.682), DM (OR: 3.66), and HTN (OR: 2.79) as predictors of elevated CACS. Our findings demonstrate that increased EAT thickness and decreased density are associated with higher CACS. Also, both DM and HTN significantly contribute to increased CACS. These results support the inclusion of EAT measurements in cardiovascular risk assessment models to enhance diagnostic accuracy.

Synthetic Amphipathic Helical Peptide L-37pA Ameliorates the Development of Acute Respiratory Distress Syndrome (ARDS) and ARDS-Induced Pulmonary Fibrosis in Mice.

In this study, we evaluated the ability of the synthetic amphipathic helical peptide (SAHP), L-37pA, which mediates pathogen recognition and innate immune responses, to treat acute respiratory distress syndrome (ARDS) accompanied by diffuse alveolar damage (DAD) and chronic pulmonary fibrosis (PF). For the modeling of ARDS/DAD, male ICR mice were used. Intrabronchial instillation (IB) of 200 µL of inflammatory agents was performed by an intravenous catheter 20 G into the left lung lobe only, leaving the right lobe unaffected. Intravenous injections (IVs) of L-37pA, dexamethasone (DEX) and physiological saline (saline) were used as therapies for ARDS/DAD. L37pA inhibited the circulating levels of inflammatory cytokines, such as IL-8, TNFα, IL1α, IL4, IL5, IL6, IL9 and IL10, by 75-95%. In all cases, the computed tomography (CT) data indicate that L-37pA reduced lung density faster to -335 ± 23 Hounsfield units (HU) on day 7 than with DEX and saline, to -105 ± 29 HU and -23 ± 11 HU, respectively. The results of functional tests showed that L-37pA treatment 6 h after ARDS/DAD initiation resulted in a more rapid improvement in the physiological respiratory lung by 30-45% functions compared with the comparison drugs. Our data suggest that synthetic amphipathic helical peptide L-37pA blocked a cytokine storm, inhibited acute and chronic pulmonary inflammation, prevented fibrosis development and improved physiological respiratory lung function in the ARDS/DAD mouse model. We concluded that a therapeutic strategy using SAHPs targeting SR-B receptors is a potential novel effective treatment for inflammation-induced ARDS, DAD and lung fibrosis of various etiologies.

Optimizing preoperative bone health assessment for adult spinal deformity: a prospective correlation analysis of intraoperative pedicle screw insertion torque and imaging modalities in Japan.

Prospective cohort study. 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. Existing data on optimal assessment tools for ASD surgery are limited. 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. 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. 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.

Performance of Iterative Reconstruction in Image Space Algorithm in Combination with Automatic Tube Current Modulation Compared to Filtered Back Projection in Brain CT Scan.

High-quality images with minimum radiation dose are considered a challenge in Computed Tomography (CT) scans. The current study aimed to assess the efficacy of the Iterative Reconstruction in Image Space (IRIS) algorithm combined with Automatic Tube Current Modulation (ATCM) compared to Filtered Back Projection (FBP) in brain CT scans. In this cross-sectional study, 200 patients underwent to brain CT scan, and images were then reconstructed using both FBP and IRIS. The CT Number (CTN), noise, and Signal-to-Noise Ratio (SNR) were computed for different tissues from CT images. The performance of two algorithms under different exposure conditions was evaluated using a water phantom. Two experienced radiologists assessed the image quality. Volume CT Dose Index (CTDIvol) and Dose Length Product (DLP) were recorded for each scan. FBP reconstruction exhibited higher noise and lower SNR compared to IRIS, both with and without ATCM. Noise levels significantly increased for FBP combined with ATCM. Subjective analysis showed higher performance for IRIS without ATCM compared to other approaches. The mean CTDIvol with and without ATCM was 20.04±3.33 and 36.37±4.65 mGy, respectively. In the phantom study, the noise with IRIS remained lower than that with FBP even with a 42% dose reduction. IRIS algorithm can preserve the image quality when radiation dose is significantly reduced by ATCM in brain CT scan. Implementation of IRIS combined with ATCM is recommended for brain CT examinations.

Prediction of anemia with thoracic computed tomography findings.

This study explored the potential of non-contrast thoracic computed tomography (CT) to predict anemia by correlating CT parameters with hemoglobin (Hb) levels in patients who underwent non-contrast thoracic CT for various indications. This retrospective study included 150 patients who underwent non-contrast thoracic CT scans and complete blood counts within 24 hours at our center between January and June 2023. Exclusion criteria included acute bleeding, iron accumulation disorders, recent transfusions, pregnancy, and certain thoracic CT artifacts. Hounsfield Unit (HU) measurements were obtained from the ascending aorta, left ventricular cavity, and descending aorta, and compared with Hb and hematocrit (Htc) values. Anemia indicators such as the 'Aortic Ring Sign (ARS)' and the 'Hyperdense Septum Sign (HSS)' were also evaluated. Anemic patients (48%) exhibited significantly lower HU measurements at all three CT scan locations and higher instances of ARS and HSS compared to non-anemic patients. Notably, the presence of HSS and ARS was strongly associated with anemia. Thresholds for HU measurements corresponding to anemia were determined using receiver operating characteristic curve analysis, which also revealed strong positive correlations between HU measurements and Hb/Htc levels. The study concludes that non-contrast thoracic CT parameters, particularly HU measurements and the presence of ARS and HSS, are significantly associated with anemia. These CT indicators could serve as reliable, non-invasive markers for predicting anemia in patients, potentially aiding in the early diagnosis and management of the condition.

Zoledronate alleviates subchondral bone collapse and articular cartilage degeneration in a rat model of rotator cuff tear arthropathy

To evaluate the humeral head bone volume of patients with cuff tear arthropathy (CTA) and examine the therapeutic effect of zoledronate in a rat modified model of CTA (mCTA). The bone mass in patients with CTA was measured using Hounsfield units from CT images. The mCTA was induced by transecting the rotator cuff, biceps brachii tendon, and superior half of the joint capsule in adult rat shoulders. A single subcutaneous injection of zoledronate was followed by bone histomorphometry and immunohistochemistry of the humeral head, as well as the Murine Shoulder Arthritis Score (MSAS) assessment. The humeral head bone volume was decreased in patients with CTA. In the mCTA model, M1 macrophages were increased in the synovium and were decreased by zoledronate treatment. The increased expressions of TNF-α, IL-1β and IL-6 in mCTA synovium and articular cartilage were suppressed in the zoledronate-treated mCTA group. The expression of catabolic enzymes in the articular cartilage and MSAS showed similar results. The zoledronate-treated mCTA group showed a decreased subchondral bone collapse with a decreased RANKL/OPG expression ratio and a suppressed number of osteoclasts compared with the control mCTA group. The enhanced expressions of HMGB1 and S100A9 in the mCTA shoulders were eliminated in the zoledronate-treated mCTA group. The humeral head subchondral bone was decreased in patients with CTA. In the mCTA model, the collapse and osteoarthritic changes were prevented by zoledronate administration. Zoledronate seemed to suppress the number of M1 macrophages in the synovium and osteoclasts in the subchondral bone.

The Radiogenomic Landscape of Clear Cell Renal Cell Carcinoma: Insights into Lipid Metabolism through Evaluation of ADFP Expression.

This study aims to explore the relationship between radiological imaging and genomic characteristics in clear cell renal cell carcinoma (ccRCC), focusing on the expression of adipose differentiation-related protein (ADFP) detected through computed tomography (CT). The goal is to establish a radiogenomic lipid profile and understand its association with tumor characteristics. Data from The Cancer Genome Atlas (TCGA) and the Cancer Imaging Archive (TCIA) were utilized to correlate imaging features with adipose differentiation-related protein (ADFP) expression in ccRCC. CT scans assessed various tumor features, including size, composition, margin, necrosis, and growth pattern, alongside measurements of tumoral Hounsfield units (HU) and abdominal adipose tissue compartments. Statistical analyses compared demographics, clinical-pathological features, adipose tissue quantification, and tumoral HU between groups. Among 197 patients, 22.8% exhibited ADFP expression significantly associated with hydronephrosis. Low-grade ccRCC patients expressing ADFP had higher quantities of visceral and subcutaneous adipose tissue and lower tumoral HU values compared to their high-grade counterparts. Similar trends were observed in low-grade ccRCC patients without ADFP expression. ADFP expression in ccRCC correlates with specific imaging features such as hydronephrosis and altered adipose tissue distribution. Low-grade ccRCC patients with ADFP expression display a distinct lipid metabolic profile, emphasizing the relationship between radiological features, genomic expression, and tumor metabolism. These findings suggest potential for personalized diagnostic and therapeutic strategies targeting tumor lipid metabolism.

Elevated modiolus density on high-resolution computed tomography as an indicator of cochlear neurodysplasia: a retrospective case-control study.

Cochlear neurodysplasia (CND) is recognized as a contributing factor to sensorineural hearing loss in children. This study aimed to investigate the relationship between modiolus density on high-resolution computed tomography (HRCT) and CND, and to evaluate its performance in diagnosing CND. This retrospective study collected HRCT images of 34 patients diagnosed with unilateral neurological hearing loss in the Children's Hospital of Chongqing Medical University from March 2018 to December 2023, who were also diagnosed with unilateral CND by computed tomography (CT) and magnetic resonance imaging (MRI) hydroimaging. CT values of the modiolus and petrous bone were measured on the affected and healthy sides, in addition to determining the width of cochlear nerve foramina and the width of internal auditory tract. The receiver operator characteristic (ROC) curve was used to evaluate the diagnostic performance of these features. Simultaneously, comparisons were conducted with parameters obtained from normal children. A total of 29 patients without CND were randomly selected as a control group. The unilateral sensorineural hearing loss group had 34 patients, comprising 18 males and 16 females, with a median age of 4.5 years, ranging from 0.7 to 11 years. The normal children group consisted of 20 males and 9 females, with a median age of 5.9 years, ranging from 0.5 to 12.0 years. Statistically significant differences were observed in the CT values of the modiolus, modiolus/petrous bone CT value ratio, width of cochlear nerve foramina, and width of internal auditory tract between the affected and healthy sides in patients with unilateral sensorineural hearing loss (P<0.05). The area under the ROC curve (AUC) of the modiolus CT value and the width of cochlear nerve foramina for the diagnosis of unilateral sensorineural hearing loss was 0.98 [95% confidence interval (CI): 0.95-1.00] and 0.99 (95% CI: 0.98-1.00), respectively. the modiolus density was significantly elevated in the affected sides in patients with unilateral CND. The optimal cut-off value of modiolus CT values was 983 Hounsfield unit (HU). The elevated density of the modiolus on HRCT holds significant value in diagnosing CND.

Single-Slice Hounsfield Unit (HU) Value of the Chinese Proximal Humerus on Routine Chest CT: A Study on Opportunistically Screening for Low Bone Density

Single-Slice Hounsfield Unit (HU) Value of the Chinese Proximal Humerus on Routine Chest CT: A Study on Opportunistically Screening for Low Bone Density

Paraspinal Sarcopenia and Lower Hounsfield Units are Independent Predictors of Increased Risk for Proximal Junctional Complications Following Thoracolumbar Fusions Terminating in the Upper Thoracic Spine.

Retrospective cohort study. The impact of paraspinal sarcopenia following fusions that extend to the upper thoracic spine remain unknown. The purpose of the present study was to assess the impact of sarcopenia on the development of PJK and PJF following spine fusion surgery from the upper thoracic spine to the pelvis. We performed a retrospective review of patients who underwent spine fusion surgery that extended caudally to the pelvis and terminated cranially between T1-6. The cohort was divided into 2 groups: (1) patients without PJK or PJF and (2) patients with PJK and/or PJF. Univariate and multivariate analyses were performed to determine risk factors for the development of proximal junctional complications. We identified 81 patients for inclusion in this study. Mean HU at the UIV was 186.1 ± 47.5 in the cohort of patients without PJK or PJF, which was substantially higher than values recorded in the PJK/PJF subgroup (142.4 ± 40.2) (P < 0.001). Severe multifidus sarcopenia was identified at a higher rate in the subgroup of patients who developed proximal junction pathology (66.7%) than in the subgroup of patients who developed neither PJK nor PJF (7.4%; P < 0.001). Multivariate analysis demonstrated both low HU at the UIV and moderate-severe multifidus sarcopenia to be risk factors for the development of PJK and PJF. Severe paraspinal sarcopenia and diminished bone density at the UIV impart an increased risk of developing PJK and PJF in following thoracolumbar fusions from the upper thoracic spine to the pelvis.

Double low-dose computed tomography (CT) angiography of craniocervical arteries using a test bolus of diluted contrast medium and a personalized contrast protocol

To prospectively assess the value of a test bolus of diluted contrast medium (CM) combined with a personalized contrast protocol in craniocervical computed tomography angiography (cc-CTA) with low radiation and CM doses. Eighty-six consecutive subjects were divided into two groups at random (43 in each one): group A: 100/Sn140 kVp, filtered back-projection reconstruction, iopromide (370 mgI/ml) 50 ml; group B: 80/Sn140 kVp, iterative reconstruction, iodixanol (270 mgI/ml). In group B, the test bolus contained 27 ml of diluted CM, a personalized protocol with low-concentration CM was used for angiography, and the test bolus injection duration in angiography remained the same. Artery values over 200 Hounsfield units were considered significant. Image quality for all cases was found to be diagnostic. No significant differences were found in the arterial densities of the ascending aorta or basilar artery between the groups. The values of the common carotid artery, internal carotid artery, and middle cerebral artery in group B were significantly lower. The effective dose and average iodine uptake were significantly lower in group B. With double-low-dose cc-CTA, test bolus scanning based on diluted CM combined with a personalized contrast protocol can yield diagnostic-quality images and significantly reduce the radiation and CM doses.

Ureteroscopy vs laparoscopic ureterolithotomy for large proximal ureteric stone: a randomised trial.

To compare the outcomes of retrograde flexible ureteroscopy (fURS) with retroperitoneal laparoscopic ureterolithotomy (RLU) for large proximal ureteric stones. A prospective randomised trial was conducted from January 2018 through December 2022 including patients with impacted proximal ureteric stones of 15-25 mm. Patients underwent fURS or RLU. Primary outcome was the stone-free rate. Demographic data, stone features, and complications rates were also compared between groups. A total of 64 patients were enrolled, 32 in each group. The mean impacted stone time was similar between groups, as well as stone size (17 mm) and stone density (>1000 Hounsfield Units). The ureteric stone-free rates between the two groups (93.7% in fURS vs 96.8% in RLU; odds ratio [OR] 0.72, 95% confidence interval [CI] -1.72 to 3.17; P = 0.554), and overall success rates, which take into account residual fragments in the kidney (84.3% in fURS vs 93.7% in RLU; OR 1.02, 95% CI -0.69 to 2.74; P = 0.23), were similar. Operative time was also not statistically significantly different between groups (median 80 vs 82 min; P = 0.101). There was no difference in hospital length of stay. Retropulsion rate was higher with fURS (65.6% vs 3.1%; p < 0.001). Residual hydronephrosis (34.3% each group) and complication rates did no differ according to treatment. Flexible URS and RLU are both highly efficient and present low morbidity for large impacted proximal ureteric stone treatment. RLU is not superior to fURS.

Impact on Image Quality and Diagnostic Performance of Dual-Layer Detector Spectral CT for Pulmonary Subsolid Nodules: Comparison With Hybrid and Model-Based Iterative Reconstruction.

To evaluate the image quality and diagnostic performance of pulmonary subsolid nodules on conventional iterative algorithms, virtual monoenergetic images (VMIs), and electron density mapping (EDM) using a dual-layer detector spectral CT (DLSCT). This retrospective study recruited 270 patients who underwent DLSCT scan for lung nodule screening or follow-up. All CT examinations with subsolid nodules (pure ground-glass nodules [GGNs] or part-solid nodules) were reconstructed with hybrid and model-based iterative reconstruction, VMI at 40, 70, 100, and 130 keV levels, and EDM. The CT number, objective image noise, signal-to-noise ratio, contrast-to-noise ratio, diameter, and volume of subsolid nodules were measured for quantitative analysis. The overall image quality, image noise, visualization of nodules, artifact, and sharpness were subjectively rated by 2 thoracic radiologists on a 5-point scale (1 = unacceptable, 5 = excellent) in consensus. The objective image quality measurements, diameter, and volume were compared among the 7 groups with a repeated 1-way analysis of variance. The subjective scores were compared with Kruskal-Wallis test. A total of 198 subsolid nodules, including 179 pure GGNs, and 19 part-solid nodules were identified. Based on the objective analysis, EDM had the highest signal-to-noise ratio (164.71 ± 133.60; P < 0.001) and contrast-to-noise ratio (227.97 ± 161.96; P < 0.001) among all image sets. Furthermore, EDM had a superior mean subjective rating score (4.80 ± 0.42) for visualization of GGNs compared to other reconstructed images (all P < 0.001), although the model-based iterative reconstruction had superior subjective scores of overall image quality. For pure GGNs, the measured diameter and volume did not significantly differ among different reconstructions (both P > 0.05). EDM derived from DLSCT enabled improved image quality and lesion conspicuity for the evaluation of lung subsolid nodules compared to conventional iterative reconstruction algorithms and VMIs.

Osteoporosis Evaluation and Management in Spine Surgery.

Osteoporosis is a global health problem affecting over 200 million people worldwide and 54 million adults in the United States. Approximately half of all postmenopausal women will have an osteoporosis-related fracture during their lifetime. In the United States, the direct medical cost related to osteoporosis is expected to exceed $25 billion by 2025. Management of osteoporosis in vertebral fractures and elective spine surgery is of the utmost concern, given the high prevalence of osteoporosis in the general population and the increased risk of complication in this population. New pharmacologic treatment options such as anabolic medications and diagnostic tools including Hounsfield unit measurements on routine computed tomography scans are available to orthopaedic and spinal surgeons to help best manage this condition. This review serves as an update to diagnosis, management, and treatment of patients with osteoporosis undergoing spinal surgery.