29 research outputs found
Clinical Significance of DXA and HR-pQCT in Autosomal Dominant Osteopetrosis (ADO II)
No full textThe main hallmark of high bone mass (HBM) disorders is increased bone mineral density, potentially visible in conventional radiographs and quantifiable by other radiographic methods. While one of the most common forms of HBM is CLCN7-related autosomal dominant osteopetrosis type II (ADO II), there is no consensus on diagnostic thresholds. We therefore wanted to assess whether CLCN7-osteopetrosis patients differ from benign HBM cases in terms of (1) bone mineral density, (2) bone structure, and (3) microarchitectural abnormalities. 16 patients meeting the criteria of HBM (DXA T/Z-score ≥ 2.5 at all sites) were included in this retrospective study. Osteologic assessment using dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and serum analyses was performed. The presence of CLCN7 and/or other HBM gene mutations affecting bone mass were tested using a custom designed bone panel. While a DXA threshold for ADO II could be implemented (DXA Z-score ≥ + 6.0), the differences in bone microarchitecture were of lesser extent compared to the benign HBM group. All adult patients with ADO II suffered from elevated fracture rates independent from Z-score. In HR-pQCT, structural alterations, such as bone islets were found only inconsistently. In cases of HBM, a DXA Z-score ≥ 6 may be indicative for an inheritable HBM disorder, such as ADO II. Microarchitectural bone alterations might represent local microfracture repair or accumulation of cartilage remnants due to impaired osteoclast function, but seem not to be correlated with fracture risk
Relevant genetic variants are common in women with pregnancy and lactation-associated osteoporosis (PLO) and predispose to more severe clinical manifestations
No full textPregnancy and lactation-associated osteoporosis (PLO) is a rare skeletal disorder characterized by early-onset osteoporosis typically manifestating with vertebral compression fractures or transient osteoporosis of the hip. We hypothesized that genetic variants may play a role in the development of PLO. This study aimed to analyze the presence of genetic variants and a potential association with the clinical presentation in PLO. 42 women with PLO were included from 2013 to 2019 in a multicenter study in Germany. All cases underwent comprehensive genetic analysis based on a custom-designed gene panel including genes relevant for skeletal disorders. The skeletal status was assessed using dual-energy X-ray absorptiometry (DXA). Subgroups were further analyzed by serum bone turnover markers (n = 31) and high-resolution peripheral computed tomography (HR-pQCT; n = 23). We detected relevant genetic variants in 21 women (50%), with LRP5, WNT1 and COL1A1/A2 being the most commonly involved genes. The mean number of vertebral compression fractures was 3.3 ± 3.4 per case with a significantly higher occurrence in the subgroup with genetic variants (4.8 ± 3.7 vs. 1.8 ± 2.3, p = 0.02). Among the total cohort, DXA Z-scores were significantly lower at the lumbar spine compared to the femoral neck (p = 0.002). HR-pQCT revealed a pronounced reduction of trabecular and cortical thickness, while trabecular number was within the reference range. Eighteen women (43%) received a bone-specific therapy (primarily teriparatide). Overall, a steep increase in bone mass (+37.7%) was observed after 3 years. In conclusion, pregnancy and lactation represent skeletal risk factors, which may unmask hereditary bone disorders leading to PLO. These cases were affected more severely. Nevertheless, a timely diagnosis and adequate treatment can ensure a substantial recovery potential even without specific therapy. Patients with genetically induced low bone turnover (e.g.; LRP5, WNT1) may especially benefit from osteo-anabolic medication
Cartilage calcification of the ankle joint is associated with osteoarthritis in the general population
No full textAbstract Background Cartilage calcification (CC) is associated with osteoarthritis (OA) in weight-bearing joints, such as the hip and the knee. However, little is known about the impact of CC and degeneration on other weight-bearing joints, especially as it relates to the occurrence of OA in the ankles. The goal of this study is to analyse the prevalence of ankle joint cartilage calcification (AJ CC) and to determine its correlation with factors such as histological OA grade, age and BMI in the general population. Methods CC of the distal tibia and talus in 160 ankle joints obtained from 80 donors (mean age 62.4 years, 34 females, 46 males) was qualitatively and quantitatively analysed using high-resolution digital contact radiography (DCR). Correlations with factors, such as the joint’s histological OA grade (OARSI score), donor’s age and BMI, were investigated. Results The prevalence of AJ CC was 51.3% (95% CI [0.40, 0.63]), independent of gender (p = 0.18) and/or the joint’s side (p = 0.82). CC of the distal tibia was detected in 35.0% (28/80) (95% CI [0.25, 0.47]) and talar CC in 47.5% (38/80) (95% CI [0.36, 0.59]) of all cases. Significant correlations were noted between the mean amount of tibial and talar CC (r = 0.59, p = 0.002), as well as between the mean amount of CC observed in one ankle joint with that of the contralateral side (r = 0.52, p = 0.02). Furthermore, although the amount of AJ CC observed in the distal tibia and talus correlated with the histological OA-grade of the joint (r = 0.70, p < 0.001 and r = 0.72, p < 0.001, respectively), no such correlation was seen in the general population with relation to age (p = 0.32 and p = 0.49) or BMI (p = 0.51 and p = 0.87). Conclusion The prevalence of AJ CC in the general population is much higher than expected. The relationship between the amount of AJ CC and OA, independent of the donors’ age and BMI, indicates that CC may play a causative role in the development of OA in ankles
Effect of the new iterative reconstruction technique "Iterative Model Reconstruction" (IMR) on the visibility of normal and abnormal lung structures in low dose chest CTs in comparison to iDose4TM and the conventional filtered back projection (FBP)
No full textIn dieser Arbeit wurde der neuartige iterative Bildrekonstruktionsalgorithmus „Iterative Model Reconstruction“ (IMR) hinsichtlich seines Einflusses auf Bildrauschen, Bildeindruck sowie Abgrenzbarkeit normaler und pathologischer Lungenstrukturen in Niedrigdosis-CTs der Lunge untersucht und mit dem Vorgängermodell iDose4TM und der herkömmlichen gefilterten Rückprojektion (FBP) verglichen. Die Rohdatensätze von 81 computertomographischen Untersuchungen des Thorax wurden mit FBP sowie verschiedenen Iterationsstufen von iDose4TM und IMR rekonstruiert. Die mittlere effektive Dosis der Niedrigdosis CT Untersuchungen betrug 0,86 ± 0,2 mSv. Für die objektive Analyse wurden in allen Rekonstruktionen Messungen der Rausch- und Dichtewerte durchgeführt. Zwei Radiologen, die über 7- und 12-jährige klinische Erfahrung in der Beurteilung von Lungen-CT-Untersuchungen verfügen, bewerteten alle Rekonstruktionen unabhängig voneinander hinsichtlich der subjektiven Bildqualität anhand einer 5-Punkte-Skala. Zusätzlich wurde die Abgrenzbarkeit normaler Strukturen (1. große Bronchien und Gefäße, 2. kleine Bronchien, Bronchiolen und kleine Gefäße, 3. pleurale und subpleurale Strukturen, 4. interlobuläre Septen, 5. intralobuläres Interstitium) und pathologischer Strukturen (1. retikuläre Zeichnung, 2. kleine Rundherde, 3. Areale mit reduzierter Lungendichte 4. Areale mit erhöhter Lungendichte) untersucht. Unsere Ergebnisse konnten zeigen, dass IMR das Bildrauschen um bis zu 88% gegenüber FBP und um bis zu 72% im Vergleich zu iDose4TM reduziert (p<0,001). Hinsichtlich des Einflusses von IMR für die Bildqualität muss zwischen anatomischen und pathologischen Strukturen differenziert werden. Die Abgrenzbarkeit kleiner anatomischer Strukturen ist in den IMR-Rekonstruktionen den iDose4TM-Rekonstruktionen unterlegen. Im Gegensatz dazu war die Abgrenzbarkeit pathologischer Lungengenveränderungen in den IMR-Rekonstruktionen den FBP und iDose4TM -Rekonstruktionen überlegen. Lediglich die retikuläre Zeichnungsvermehrung ist in den iDose-Rekonstruktionen besser als in IMR darzustellen. Ursächlich für die schlechtere Bewertung der IMR-Rekonstruktionen hinsichtlich der kleineren anatomischen Strukturen sind ein weichgezeichneter Bildeindruck, eine zunehmende Unschärfe und die Reduktion des räumlichen Auflösungsvermögens. Diese nehmen mit zunehmender IMR-Iterationsstufe zu und können die diagnostische Sicherheit einschränken. Aufgrund dieser heterogenen Ergebnisse ist IMR in seiner jetzigen Fassung nicht das bevorzugte Bildrekonstruktionsverfahren von Niedrigdosis-CT-Untersuchung des Thorax. Dem gegenüber lieferte iDose4TM mit der Iterationsstufe L6 sowohl ein niedriges Bildrauschen als auch eine befriedigende Bildqualität und ermöglichte so die suffiziente Abgrenzbarkeit von sowohl anatomischen als auch pathologischen Lungenstrukturen. Das iterative Bildrekonstruktionsverfahren iDose4TM stellt eine geeignete Methode zur Rekonstruktion von Niedrigdosis-CT-Untersuchungen des Thorax dar und sollte in dir klinischen Routine etabliert werden.In this study we analysed the impact of the new iterative reconstruction technique Iterative Model Reconstruction (IMR, Philips Healthcare) on the subjective image quality of low dose chest CTs and compared it with the iDose4TM and Filtered Back Projection (FBP). Therefore we saved the raw data of 81 submillisievert chest CT studies (Brilliance iCT, Philips Healthcare), which are carried out during the clinical assessment and being reconstructed with FBP and multiple iteration levels of iDose4TM and IMR. The effective dose (E) was 0,86 ± 0,2 mSV. For the objective analysis we measured the parameters attenuation and objective image noise (OIN) in all reconstructed images. In addition, we compiled clinical data and dose information of the patients included in this study. For the subjective Analysis we assessed the effect of these diverse techniques on the image quality using a 5-Point-Scale, in order to objectify this subjective impressions. Two radiologists, with 7 and 12 years of clinical experience with chest CT, rated the visualisation of normal structures (1: intralobular interstitium, 2: interlobular septa, 3: small bronchi, bronchioles and vessels, 4: pleural and subpleural structures, 5: large bronchi and vessels) and abnormal structures (1: decreased lung attenuation, 2: increased lung attenuation, 3: reticular pattern, 4: small nodules) in all reconstructed images. They were blinded regarding the reconstruction techniques. Our results show that IMR is capable in reducing image noise up to 88 % compared to FBP. In comparison to iDose4TM the results show a noise reduction up to 72 % (p<0,001). Regarding the results of the subjective image quality and visualisation we have to differentiate between normal and abnormal findings. IMR is inferior compared to iDose4TM when it comes to normal structures. Nevertheless, it shows a superior performance in the graphic representation of abnormal structures apart from the reticular pattern. Its visualisation showed the best results using iDoseL6-reconstructions. The reasons for the poor rating of IMR compared to iDoseL6-reconstructions in visualisation of normal findings are a blotchy appearance and a loss of anatomical details, which result in a compromised diagnostic confidence. These negative effects increased with higher iteration levels of IMR. The iDose4TM-reconstructions showed a range of satisfying up to good results in normal, aswell as in abnormal findings
Comparison of Bone Microarchitecture Between Adult Osteogenesis Imperfecta and Early-Onset Osteoporosis
No full textDiagnosis and management of adult individuals with low bone mass and increased bone fragility before the age of 50 can be challenging. A number of these patients are diagnosed with mild osteogenesis imperfecta (OI) through detection of COL1A1 or COL1A2 mutations; however, a clinical differentiation from early-onset osteoporosis (EOOP) may be difficult. The purpose of this study was to determine the bone microstructural differences between mild OI and EOOP patients. 29 patients showed mutations in COL1A1 or COL1A2 and were classified as OI. Skeletal assessment included dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and bone turnover serum analyses. Bone microstructure of 21/29 OI patients was assessed and compared to 23 age- and sex-matched patients clinically classified EOOP but without mutations in the known disease genes as well as to 20 healthy controls. In the OI patients, we did not observe an age-dependent decrease in DXA Z-scores. HR-pQCT revealed a significant reduction in volumetric BMD and microstructural parameters in the distal radius and tibia in both the OI and EOOP cohorts compared to the healthy controls. When comparing the bone microstructure of OI patients with the EOOP cohort, significant differences were found in terms of bone geometry in the radius, while no significant changes were detected in all other HR-pQCT parameters at the radius and tibia. Taken together, adult mild OI patients demonstrate a predominantly high bone turnover trabecular bone loss syndrome that shows minor microstructural differences compared to EOOP without mutation detection
