1692 ANALYSIS OF STONE'S COMPOSITION AND CT DENSITY

Objectives Several authors hypothesized the usefulness of the non-contrast helical computed tomography (NCHCT) with the determination of stone Hounsfield Unit (HU) values in order to predict urinary stone compositions. Preoperative knowledge of stone composition might be interesting in pre-operative decision-making process. The aim of this study was to evaluate the possible correlation between stone chemical composition and correspondent stone HU value in an in-vivo experience. Methods Forty patients with urinary stones were preoperatively studied with abdominal NCHCT, where stone HU values were reported. Stone chemical composition was obtained in each patient, using the colorimetric method. The HU value of each stone was compared with the correspondent chemical analysis. Results The median HU values of calcium oxalate (n=10), mixed calcium oxalate and phosphate (n=19), calcium phosphate (n=2), uric acid (n=6) and mixed uric acid and calcium oxalate (n=3) stones were 1060 HU [interquartile range (IQR) 743.75–1222.5]; 900 HU (IQR 588.5–1108.5); 774 HU (range 720–828); 371 HU (IQR 361.25–436.25) and 532 HU (range 476–626), respectively. Conclusions Our results confirmed a statistically significant difference of the HU values between calcium and pure uric acid calculi, suggesting a correlation between stone chemical composition and CT-density. Hounsfield unit

Predicting Urinary Stone Composition Based on Single-energy Noncontrast Computed Tomography: The Challenge of Cystine

Predicting the stone composition of children preoperatively by Hounsfield unit detection on non-contrast computed tomography

Aim: Numerous studies have shown that urinary stone composition is directly associated with the effectiveness of extracorporeal shock wave lithotripsy and is significantly related to various factors, including stone-free rates and fragmentation time during endoscopic procedures.Therefore, this study aimed to predict stone composition using Hounsfield unit (HU) measurements obtained from non-contrast computed tomography (NCCT).Materials and Methods: Urinary stones were classified according to their predominant composition.HU measurements were compared with spectrophotometric analysis results to assess the accuracy of predicting stone composition.Additionally, patient demographic data, clinical characteristics, and stone-related parameters-including HU values, HU density, stone size, volume, and composition were recorded and analyzed.Results: A total of 571 patients' stone analysis data were retrospectively analyzed: mean core HU, peripheral HU, and average HU values.The calcium oxalate group had significantly higher values than those in the cystine, uric acid, and calcium oxalate + uric acid groups (all p<0.001).Furthermore, a statistically significant correlation was found between stone size and core HU values (r=0.291,p<0.001). Conclusion:NCCT may aid in selecting the most appropriate treatment by identifying stone composition.HU measurements (core, peripheral, and density) can be utilized to differentiate calcium-based stones from cystine-and uric acid-based stones.

Lithiasis is a disease with increasing incidence, may occur in the urinary tract, salivary glands and bile ducts. Genetic susceptibility, diet, low fluid intake, endocrine disorders, infections and other factors can influence the development of the disease and its recurrences. The aim of the study was to reveal the relationship between chemical composition of the stones, lifestyle and dietary habits and the results of laboratory analysis in patients with urinary tract and salivary gland lithiasis. The data of 258 patients with urinary tract and salivary gland lithiasis collected between September 2009 � May 2016 were studied. The subjects were from the Urology and Oral Surgery Hospital, and from the Marmed and Procardia medical units in Tirgu Mures. We evaluated the lifestyle habits using a questionnaire, microscopical examination, size measurement and chemical analysis of the stones were made and we processed the results of urinary strip analysis and sediment. In a subgroup of patients (48 samples) calciuria, phosphaturia, serum uric acid, calcium, phosphate, alkaline phosphatase and parathormone (PTH) levels were determined; in case of pathological values calcitonin measurement and endocrinology consultation were performed. The most frequent composition was the combination of calcium oxalate and phosphate in case of both urinary and salivary gland stones, in several uroliths we detected uric acid/xanthine crystals, rarely cystine and carbonate were found. The incidence of hematuria and leukocyturia exceeded 70%. Excessive calcium intake was observed in the diet of the several patients having calcium oxalate stones. In the subgroup tested for biochemical and hormonal analyses we found increased serum PTH concentration in 20.83% of the patients. Some of the subjects had pathological serum calcium, uric acid and alkaline phosphatase results, or the elimination of minerals in the urine was out of the normal range. We found pathological laboratory results in several patients suffering from lithiasis. Proper diet and medical treatment in many cases could prevent the recurrences of stone formation, but first a complex investigation of the patients is necessary to adapt the treatment plan to individual requirements.

This study aimed to fabricate a heterogeneous phantom replicating the commercial Rando phantom by mixing plaster powder and polylactic acid (PLA) powder. Producing a heterogeneous phantom using Plaster and PLA is cheaper because it can be easily obtained in the commercial market. Additionally, patient-specific Quality Assurance can be easily performed because the phantom can be produced based on the patient’s CT image. PLA has been well studied in the field of radiation therapy and was found to be safe and effective. To match the mean Hounsfield unit (HU) values of the Rando phantom, the bone tissue was changed using plaster and 0–35% PLA powder until an appropriate HU value was obtained, and soft tissue was changed using the PLA infill value until an appropriate HU value was obtained. Bone tissue (200 HU or higher), soft issue (− 500 to 200 HU), and air cavity (less than − 500 HU) were modeled based on the HU values on the computed tomography (CT) image. The bone tissue was modeled as a cavity, and after three-dimensional (3D) printing, a solution containing a mixture of plaster and PLA powder was poured. To evaluate the bone implementation of the phantom obtained by the mixture of plaster and PLA powder, the HU profile of the CT images of the 3D-printed phantom using only PLA and the Rando phantom printed using only PLA was evaluated. The mean HU value for soft tissue in the Rando phantom (− 22.5 HU) showed the greatest similarity to the result obtained with an infill value of 82% (− 20 HU). The mean HU value for bone tissue (669 HU) showed the greatest similarity to the value obtained with 15% PLA powder (680 HU). Thus, for the phantom composed of plaster mixed with PLA powder, soft tissue was fabricated using a 3D printer with an infill value of 82%, and bone tissue was fabricated with a mixture containing 15% PLA powder. In the HU profile, this phantom showed a mean difference of 61 HU for soft tissue and 109 HU for bone tissue in comparison with the Rando phantom. The ratio of PLA powder and plaster can be adjusted to achieve an HU value similar to bone tissue. A simple combination of PLA powder and plaster enabled the creation of a custom phantom that showed similarities to the Rando phantom in both soft tissue and bone tissue.

PurposeTo assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL).Materials and MethodsThis clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component.ResultsSignificant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p<0.001). All uric acid stones were red on color-coded DECT images, whereas 96.3% of the nonuric acid stones were blue. Patients with calcium oxalate stones were divided into two groups according to the amount of monohydrate (calcium oxalate monohydrate group: monohydrate≥90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001).ConclusionsDECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

A Study on Relationship between Single-Slice Hounsfield Unit(HU) value of the Chinese proximal humerus and Bone Mineral Density(BMD) Using Routine Chest CT and Dual-energy X-ray Absorptiometry(DEXA) was performed.Data were collected from 240 individuals who underwent DEXA and routine chest CT scans (including full images of the proximal humerus) on the same day at 967 Hospitals between January 2019 and December 2021.The method of measuring single-slice HU values of the proximal humerus on routine chest CT scans exhibited high reliability and repeatability (intraclass correlation coefficient > 0.961, P < 0.001).A strong positive correlation was observed between single-slice HU values of the proximal humerus and DEXA results, with the 20-mm HU value demonstrating the highest correlation.Across different BMI groups, the Area Under Curve (AUC) for the 20-mm HU value was consistently the largest (AUC=0.701-0.813,P< 0.05).Therefore, the 20-mm HU value can be considered a reliable reference for the opportunistic screening of low BMD, with reference values of -4HU for underweight individuals, -13HU for normal weight individuals, -7HU for overweight individuals, and -16HU for obese individuals.Values below these thresholds indicate a risk of low BMD.This study enriches the Chinese BMD data and offers a swift and effective approach for opportunistically screening low BMD.

BackgroundIntravenous thrombolysis (IVT) is a rapid and effective treatment in the early stage of ischemic stroke patients and the purpose of this work is to explore the significance of Hounsfield unit (HU) value in Alberta Stroke Program Early CT Score (ASPECTS) for predicting the clinical prognosis of stroke patients with middle cerebral artery occlusion (MCAO) treated by IVT.MethodsThe 84 stroke patients with MCAO treated by IVT were divided into good prognosis group (48 cases) and poor prognosis group (36 cases). HU ratio and HU difference calculated from non-contrast computed tomography between groups were analyzed.ResultsThe HU ratio of good prognosis group was higher than that in poor prognosis group and the HU difference of good prognosis group was lower than that in poor prognosis group (P < 0.05). The HU ratio and ASPECTS were negatively correlated with the infarct volume, and the HU difference was positively correlated with the infarct volume (P < 0.05). HU difference was an independent risk factor for prognosis of patients with MCAO treated by IVT. The area under the receiver operating characteristic curve of HU ratio and HU difference for prognosis was 0.743 and 0.833 respectively.ConclusionThe HU value changes are related to the clinical prognosis of stroke patients with MCAO treated by IVT, HU value may be a prognostic indicator for stroke patients with MCAO treated by IVT.

Retrospective observational study. This study aimed to determine the predictive utility of Hounsfield unit (HU) values, derived from single-slice computed tomography (CT) images, for identifying postoperative pedicle screw (PS) loosening in patients undergoing lumbar interbody fusion. The HU values were specifically measured along the planned PS trajectory. PS loosening is a frequent complication following spinal fusion surgery, particularly in individuals with compromised bone quality. Although prior research has explored the correlation between screw loosening and general vertebral HU values or bone mineral density, the specific predictive capability of a simple, single-slice measurement along the screw path remains a gap in the literature. We retrospectively reviewed data from 47 patients (212 screws) who underwent lumbar interbody fusion between November 2020 and September 2022. Preoperative CT images were used to measure HU values in both the vertebral body and along the PS trajectories. Patients were then stratified into two groups based on the presence (L group, n=9) or absence (no-loosening [NL] group, n=38) of screw loosening identified on 1-year follow-up CT. Comparative analyses were conducted, followed by a receiver operating characteristic curve analysis to establish the optimal predictive HU cutoff. The incidence of postoperative screw loosening was 11.8% (25/212). While no significant inter-group differences were observed regarding age, bone mineral density, or vertebral body HU values, the PS trajectory HU was significantly lower in the L group (111±40) compared to the NL group (157±74) (p <0.001). Receiver operating characteristic curve analysis identified an optimal HU cutoff of 123. The area under the curve was 0.7106, with an odds ratio of 3.18, sensitivity of 0.31, and specificity of 0.41. Lower HU values measured along the PS trajectory using single-slice CT images were significantly associated with a higher risk of screw loosening. This straightforward method may serve as a valuable tool for identifying high-risk patients during the preoperative planning phase of spinal fusion surgery.

Objective According to the infrared spectrum of renal stone composition analysis,discuss the relationship between gender,age and kidney stone.Methods Kidney stone composition analysis of 408 cases had been done in our hospital from the 2002 to 2011 by using Fourier transform infrared spectroscopy.There were 271 males (66.4％) and 137 females (33.6％).Results There were 359 cases with calcium stones,accounting for 88.0％ (359/408); 197 cases with calcium oxalate stones alone,accounting for 48.3％; 180 cases with phosphate stones,accounting for 44.1％; 211 cases with mixed composition stones,accounting for 51.7％.Main chemical composition of the stones were:calcium oxalate 48.3％,carbonate apatite 34.8％,urates 5.4％,ammonium magnesium phosphate 4.4％,ammonium carbonate eutectic 3.4％,brushite 1.5％,cystine 2.0％ and protein 0.3％.Male patients accounted for 66.4％ of all cases and the peak onset age was 30-59 years; Female patient accounted for 33.6％ of all cases and the peak onset age was 50-59 years.Conclusions Calcium oxalate and phosphate are the most common components of kidney stones.Males age between 30-59 years and females age between 50-59 years may suffer from of kidney stone formation. Key words: Infrared spectrum; Kidney stones; Composition

PurposeThis study compared Hounsfield unit (HU) values on computed tomography (CT) scans at fractured sites and each vertebral level of the whole spine among three groups: individuals with diffuse idiopathic skeletal hyperostosis (DISH), young individuals without DISH, and older individuals without DISH.MethodsA total of 71 patients with thoracolumbar fracture treated at our hospital from 2011 to 2022 were enrolled. Patients were divided into three groups: those with DISH (22 cases), young without DISH (Y non-DISH; age < 50 years, 24 cases), and older without DISH (O-non-DISH; age ≥ 50 years, 25 cases). The total spine HU values from C2 to S1 were measured from CT axial images, as follows: C2-C6, cervical spine; C7-T4, upper thoracic spine; T5-T9, lower thoracic spine; T10-L2, thoracolumbar spine; and L3-S1, lumbar spine. We compared (1) the HU values between fractured and non-fractured sites in each group (2) the HU values by site within each group, and (3) the HU values at each vertebral level of the whole spine between the three groups.ResultsIn all groups, the mean HU values were significantly higher in the cervical spine than in the other regions (p < .05) and HU values increase at the fracture site (p < .05). The mean HU values for the lower thoracic, thoracolumbar, and lumbar spine were not significantly different in each group. The mean HU values below T6 were significantly lower in the DISH and O-non-DISH groups than in the Y-non-DISH group (p < .05). The mean HU values, except at T3, did not differ significantly between the DISH and O-non-DISH groups.ConclusionAmong patients with thoracolumbar injuries, spinal HU values were lower in older patients with and without DISH than in younger patients.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12891-025-09382-5.

Rotational ankle instability (RAI) is associated with the faster onset of severe ankle osteoarthritis via dysfunction of the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament. No specific clinical examination is available for RAI, and diagnostic imaging has limitations in evaluating ligament degradation. This study investigated the deltoid ligament degeneration using Hounsfield unit (HU) values on computed tomography (CT) images. Patients were enrolled in this retrospective analysis if they had undergone magnetic resonance imaging (MRI) and CT scans of the ankle. The chronic ankle instability (CAI) group comprised 20 ankles with CAI (9 men, 11 women; mean age, 28.7 years) and the control group comprised 28 ankles (16 men, 12 women, mean age, 41.3 years). The average HU values of the deep posterior tibiotalar ligament (dPTL) that constitutes the deltoid ligament were measured on coronal CT images, and MRI results were used as a reference. All patients were subdivided based on the MRI findings of dPTL injury such as fascicular disruption, irregularity, and the loss of striation. A strong negative correlation was identified between age and HU values for all patients (Spearman ρ = -0.63; P < .001). The mean HU values of the dPTL for participants aged <60 years were 81.0 HU for the control group (21 ankles) and 69.5 HU for the CAI group (P = .0075). No significant differences in the HU values were observed for the dPTL among the MRI subgroups. In addition to the conventional imaging examination such as stress radiographs and MRI, HU measurements of CT images could be useful for quantitatively and noninvasively evaluating degenerative changes in the deltoid ligament for CAI patients to assist the diagnosis of RAI. Level III. case-control study.

Background: The use of CT-Scan is an examination of the urinary tract or what is usually called a non-contrast urography CT-Scan or CT-Scan Stonography. CT-Scan Stonography is a CT-Scan examination of the kidney tract which is usually used to detect the presence of stones in the kidneys. Stonography is used as an alternative to IVP (Intravenous Pyelography) examination because the IVP examination is limited in providing information to diagnose a disease, especially in cases of urolithiasis. In CT-Scan stonography examinations, the Hounsfield Unit (HU) value plays an important role in diagnosing abnormalities in the urinary system. The Hounsfield Unit (HU) value is the density level of various types of tissue which has 4,096 shades of gray, and has different density levels. differences found in CT-Scan. In establishing a diagnosis in patients with clinical urolithiasis or abnormalities in the presence of stones in the urinary system which are formed from crystals of Ca Oxalate, Ca Phosphate, Strufit stones, Cystine stones, and uric acid stones, the use of HU values helps in measuring the density value of the stones so that treatment can be estimated. that will be given to the patient. Objective: The aim of this study is to determine the Hounsfield Unit (HU) value in clinical urolithiasis using CT-Scan Stonography examination. Method: This research is a qualitative descriptive study, namely by carrying out CT-Scan stonography examinations on urolithiasis patients and analyzing the results of measuring Hounsfield Unit (HU) values. Results: Based on 10 research data results, the characteristics of stone composition based on Hounsfield Unit (HU) value analysis on 10 samples were categorized into 3 groups, namely, the calcium phosphate stone group consisting of 3 samples, cystine stone consisting of 5 samples, and 2 samples on uric acid stone group. Conclusion: Hounsfield Unit (HU) value to determine further medical action

In human CT imaging, opportunistic calculation of bone mineral density (BMD) is used to screen for osteoporosis, where BMD is estimated by Hounsfield Units (HU). There is potential to use HU for estimation of BMD in veterinary imaging. However, HU values can vary between different machines and over time. We undertook a serial measurements study to determine (1) the extent of the difference of the mean HU and noise (HU standard deviation) of eight regions of interest (ROI) of an electron density phantom scanned on two CT machines, a Siemens CT (conventional) machine and the Equina by Asto CT (standing) machine; and (2) to determine if the HU values obtained on each machine differed over time. The mean HU from 30 scans of an electron density phantom were generated from each of the two CT machines (N = 60; conventional and standing). Differences between machines were assessed using a linear mixed effects model. The mean HU of each positive value ROI from the conventional machine was decreased compared with the standing machine (P < 0.001) and the difference was greatest for the denser phantom inserts. A calibration curve equation utilising the four bone-equivalent insert plugs of the phantom, with known calcium hydroxyapatite (CaHA) concentration, was generated using linear regression to represent CaHA, and therefore BMD, for the conventional machine (CaHA = -29.58 + 0.98xROImean) and the standing machine (CaHA = -54.53 + 0.95xROImean). For opportunistic calculation of BMD from HU in horses, the differences in HU observed between different CT machines warrants calibration of HU using a bone equivalent phantom.