Two Postprocessing CT Techniques for Determining the Composition of Trabecular Bone

Goodsitt, Mitchell M.; Rosenthal, Daniel I.; Reinus, William R.; Coumas, James M.

doi:10.1097/00004424-198703000-00005

Cited by 47 publications

(42 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eighty KvP scans were used for calculation of single energy QCT, as previously described (19). The data from the 80-and 140-KvP scans were combined to yield corrected dual energy measurements and a value for intraosseous fat, as previously described, in 18 AN patients and all normal women (20). A greater than 95% likelihood existed that a duplicate average would fall within 5 CT units for 1 subject (19).…”

Section: Bone Densitometrymentioning

confidence: 99%

Mechanisms of Osteoporosis in Adult and Adolescent Women with Anorexia Nervosa*

Biller

Saxe

Herzog

et al. 1989

The Journal of Clinical Endocrinology & Metabolism

Self Cite

402

229

View full text Add to dashboard Cite

Osteoporosis is a known consequence of anorexia nervosa (AN) in adults, but the mechanism of bone loss is not established, and there have been no studies of bone mass in women developing AN before attaining peak bone mass. To investigate the causes of bone loss in AN and to determine the consequences of developing AN during adolescence on bone mass, we compared the effects of AN on cortical and trabecular bone in 26 women with AN (19 adults, 18-42 yr old, and 7 adolescents, 14.9-17.0 yr old) using direct radial photon absorptiometry and both single and dual energy spinal computed tomography. The adult AN patients had marked spinal osteopenia [mean bone density, 120 +/- 28 (+/- SD) mg K2HPO4/cm3] compared with age-matched normal women (mean, 176 +/- 26 mg K2HPO4/cm3; P = 0.0001), which was severe (greater than 2 SD below the normal mean) in 50% of patients. Adult AN patients with the onset of amenorrhea before age 18 yr had significantly (P = 0.04) lower spinal bone density than those developing amenorrhea later (mean, 103 +/- 25 vs. 129 +/- 25 mg K2HPO4/cm3) independent of other variables correlated with bone density (duration of amenorrhea or urinary cortisol excretion). We found a negative correlation between spinal bone density and duration of amenorrhea (P = 0.006; r = -0.53). To determine the contribution of endogenous cortisol excess to the pathogenesis of the osteoporosis, urinary cortisol was measured. Urinary cortisol/creatinine clearance was significantly (P = 0.001) higher in AN patients than in normal women (mean, 2.7 +/- 1.2 vs. 1.0 +/- 0.3 nmol/L) and was negatively correlated (P = 0.03; r = -0.43) with bone mass. We conclude that AN affects trabecular bone and that both the onset of AN before attainment of peak bone mass and prolonged duration of amenorrhea result in more severe osteopenia. In addition to the significant contribution of hypogonadism, the cortisol excess that occurs in AN patients may contribute to the development of osteoporosis in these patients.

show abstract

Section: Bone Densitometrymentioning

confidence: 99%

Mechanisms of Osteoporosis in Adult and Adolescent Women with Anorexia Nervosa*

Biller

Saxe

Herzog

et al. 1989

The Journal of Clinical Endocrinology & Metabolism

Self Cite

402

229

View full text Add to dashboard Cite

show abstract

“…Image analysis was based on a threematerial decomposition algorithm for the bone mineral, yellow marrow and red marrow. [18][19][20][21] For our evaluation of the vertebral bodies, the relative contrast material ratio was set to a value of 1.75, and the range of the filter was set to 3 based on the experience from previous studies. 5,11,22,23 Non-calcium images were displayed in greyscale.…”

Section: Dual-source Ct Protocolmentioning

confidence: 99%

The feasibility of dual-energy CT in differentiation of vertebral compression fractures

Karaca

Yuceler

Kantarcı

et al. 2016

BJR

View full text Add to dashboard Cite

Objective: To prospectively evaluate the ability of dual-energy CT (DECT), compared with MRI, to identify vertebral compression fractures in acute trauma patients. Methods: This institutional review board-approved study included 23 consecutive patients with 32 vertebral fractures who underwent both DECT and MRI of the spine between February 2014 and September 2014. A total of 209 vertebrae were evaluated for the presence of abnormal bone marrow attenuation on DECT and signal on MRI by five experienced radiologists. The specificity, sensitivity, predictive values and intraobserver and interobserver agreements were calculated. Results: MRI revealed a total of 47 vertebrae (22.4% of all vertebrae) and DECT revealed 44 vertebrae (21.0% of all vertebrae) with oedema. Using MRI as the reference standard, DECT had sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of 89.3, 98.7, 95.4, 96.9 and 96.6%, respectively. With respect to establishing the presence of oedema, the interobserver agreement was almost perfect (k 5 0.82), and the intraobserver agreement was substantial (k 5 0.80). Conclusion: Compared with MRI, DECT can provide an accurate demonstration of acute vertebral fractures and can be used as an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI. Advances in knowledge: Distinguishing of acute and chronic vertebral compression fracture is important for treatment choices. DECT is very fast compared with MRI and is an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI.

show abstract

“…This is consistent with membership values being interpreted as the volume-fraction composition of the tissue types. 24,39 The Hounsfield values of pure air, fat, fluid, brain, and cortical bone were set to −1000, −98, 13, 40, and 1524 HU, respectively. …”

Section: R2mentioning

confidence: 99%

Generation of brain pseudo‐CTs using an undersampled, single‐acquisition UTE‐mDixon pulse sequence and unsupervised clustering

Stehning

et al. 2015

Medical Physics

View full text Add to dashboard Cite

Purpose: MR-based pseudo-CT has an important role in MR-based radiation therapy planning and PET attenuation correction. The purpose of this study is to establish a clinically feasible approach, including image acquisition, correction, and CT formation, for pseudo-CT generation of the brain using a single-acquisition, undersampled ultrashort echo time (UTE)-mDixon pulse sequence. Methods: Nine patients were recruited for this study. For each patient, a 190-s, undersampled, single acquisition UTE-mDixon sequence of the brain was acquired (TE = 0.1, 1.5, and 2.8 ms). A novel method of retrospective trajectory correction of the free induction decay (FID) signal was performed based on point-spread functions of three external MR markers. Two-point Dixon images were reconstructed using the first and second echo data (TE = 1.5 and 2.8 ms). R2 * images (1/T2 * ) were then estimated and were used to provide bone information. Three image features, i.e., Dixon-fat, Dixon-water, and R2 * , were used for unsupervised clustering. Five tissue clusters, i.e., air, brain, fat, fluid, and bone, were estimated using the fuzzy c-means (FCM) algorithm. A two-step, automatic tissue-assignment approach was proposed and designed according to the prior information of the given feature space. Pseudo-CTs were generated by a voxelwise linear combination of the membership functions of the FCM. A low-dose CT was acquired for each patient and was used as the gold standard for comparison. Results: The contrast and sharpness of the FID images were improved after trajectory correction was applied. The mean of the estimated trajectory delay was 0.774 µs (max: 1.350 µs; min: 0.180 µs). The FCM-estimated centroids of different tissue types showed a distinguishable pattern for different tissues, and significant differences were found between the centroid locations of different tissue types. Pseudo-CT can provide additional skull detail and has low bias and absolute error of estimated CT numbers of voxels (−22 ± 29 HU and 130 ± 16 HU) when compared to low-dose CT. Conclusions: The MR features generated by the proposed acquisition, correction, and processing methods may provide representative clustering information and could thus be used for clinical pseudo-CT generation. C 2015 American Association of Physicists in Medicine.

show abstract

Two Postprocessing CT Techniques for Determining the Composition of Trabecular Bone

Cited by 47 publications

References 0 publications

Mechanisms of Osteoporosis in Adult and Adolescent Women with Anorexia Nervosa*

Mechanisms of Osteoporosis in Adult and Adolescent Women with Anorexia Nervosa*

The feasibility of dual-energy CT in differentiation of vertebral compression fractures

Generation of brain pseudo‐CTs using an undersampled, single‐acquisition UTE‐mDixon pulse sequence and unsupervised clustering

Contact Info

Product

Resources

About