ABSTRACT
OBJECTIVE@#To explore the clinical significance of magnetic resonance imaging water-fat separation (Dixon) technique in patients with multiple myeloma.@*METHODS@#A total of 41 newly diagnosed patients with multiple myeloma who underwent Dixon in The Affiliated Hospital of Qingdao University from April 2019 to April 2021 were included in this study. Patients were divided into observation group and control group according to whether Dixon performance was normal or not. The differences of clinical data and fat fraction (FF) between the two groups were compared. The correlation between FF and clinical data, disease stages and differences before and after treatment were also compared. The receiver operator characteristic curve of patients was drawn to analyze the diagnostic value of FF combined with serum alkaline phosphatase for bone destruction in patients with multiple myeloma.@*RESULTS@#Among the 41 patients, there were 12 cases in the control group and 29 cases in the observation group. There was no significant difference in age and sex between the two groups. In the observation group, β2-microglobulin concentration and M protein were significantly higher than those in the control group, while serum alkaline phosphatase and FF were lower (P<0.05). In all 41 patients included in the study, there was a significant negative correlation between FF value and β2-microglobulin concentration (r=-0.57), and a significant positive correlation between FF value and serum alkaline phosphatase (r=0.31). After treatment, FF value increased, while myeloma cell percentage, β2-microglobulin concentration and M protein decreased in 11 patients who completed 4 cycles of chemotherapy, and the differences before and after treatment were statistically significant (P<0.05). The value of serum alkaline phosphatase combined with FF value in predicting bone destruction is higher than that of FF value or serum alkaline phosphatase alone.@*CONCLUSION@#Dixon's different imaging manifestations can reflect the severity of the disease. FF value is correlated with clinical examination results and R-ISS staging, and there is a significant difference before and after treatment. Serum alkaline phosphatase combined with FF value is better than two indicators alone in predicting bone destruction.
Subject(s)
Humans , Magnetic Resonance Imaging , Multiple Myeloma/diagnostic imaging , Technology , WaterABSTRACT
Objective To validate a chemical shift-encoded MRI(CSE-MRI)water-fat imaging for quantifying vertebral marrow fat content using MRS as the reference standard.Methods MRS and CSE-MRI were performed to calculate proton density fat fraction(PDFF) in 83 subjects,including 41 normal bone mass,26 osteopenia and 16 osteoporosis.Eight participants were scanned three times with repositioning to assess the repeatability of CSE-MRI PDFF measurements.Agreements of intra-observer and inter-observer were evaluated by intraclass correlation coefficient(ICC).Linear regression,Bland-Altman 95% limit of agreement and Lin's concordance correlation coefficient were calculated.Results The repeatability for CSE-MRI PDFF measurements expressed as absolute precision error was 1.45%.PDFF was 62.1%±11.1% by MRS and 60.4%±10.1% by CSE-MRI in 83 subjects.There were significant differences in PDFF among the normal bone mass,osteopenia and osteoporosis groups after adjusting for age,years since menopause and body mass index (all P<0.001).The intra-and inter-rater reliability for duplicate measurements at CSE-MRI PDFF were more than 0.993.Pearson correlation coefficient was 0.979 and Lin's concordance correlation coefficient was 0.962.All data points calculated using the Bland-Altman method were within the limits of agreement.Inverse associations were observed between BMD (r=-0.560--0.710)and CSE-MRI-based PDFF,and between BMD (r=-0.539--0.706)and MRS-based PDFF in various groups.Conclusion CSE-MRI with multiple lipids peak model and T2?-correction is equally accurate in characterizing marrow fat content as MRS.
ABSTRACT
Objective To detect the changes in vertebral marrow fat fraction (MFF) using T2 *-corrected water-fat MRI and to analyze the relationships between MFF with bone biomarkers of non-dialysis chronic kidney disease (CKD).Methods 78 CKD patients were divided into five groups according to the eGFR and underwent water/fat MRI to obtain MFF.The reliability of MFF measurements by two radiologists was assessed with intra-class correlation coefficient (ICC).Serum calcium,phosphorus,alkaline phosphatase,osteocalcin,intact parathyroid hormone and 25(OH)D3 were determined.Results Mean CV for MFF measurements reproducibility was 2.37％.The inter-observer agreement for MFF was excellent (ICC=0.901).The ICC for each intra-observer agreement was excellent (ICC=0.959 and 0.948,respectively).There were statistical differences in MFF among five groups of CKD.Changes of MFF were earlier than those of serum calcium,phosphorus,parathyroid hormone,alkaline phosphatase and osteocalcin.MFF was positively correlated with serum phosphorus (r =3.011,P =0.003),parathyroid hormone (r=3.852,P＜0.001),and negatively associated with calcium (r=-2.767,P=0.017),25(OH)D3 (r=6.032,P＜0.001),eGFR (r=-5.104,P＜0.001),respectively.Multivariable regression analysis showed MFF was negatively correlated with 25(OH)D3(Sβ=-0.343)and eGFR(S(S=-0.284,P＜0.001).Conclusion CKD patients had higher marrow fat.T2 *-corrected water fat MRI could serve as a useful tool to quantify marrow fat content for CKD patients.
ABSTRACT
Objective To study the effects of 17β-estradiol (E2)on marrow adiposity in ovariectomized (OVX)rats using water/fat MRI.Methods Twenty-seven female SD rats were divided equally into SHAM,OVX and OVX+E2 groups.BMD and marrow fat fraction (MFF)were measured at baseline and 6,12 weeks postoperation.Marrow adipocyte were evaluated by HE.Results OVX rats showed a significant increase in MFF over time,with an increase in MFF (by 40.0%)at week 6 from baseline ,and maintained until week 12 (by 69.4%).Compared with SHAM group,MFF in OVX group was markedly increased at week 6 but a reduction in BMD first detected at week 12.OVX rats had substantially higher adipocyte size (by 29.5%),density (by 57.3%)and volume (by 163%)than that in SHAM rats.E2 treatment prevented OVX-induced bone loss and rescued marrow adiposity to the levels of SHAM rats.MFF was inversely related to vertebral BMD(r=-0.668)and femoral BMD (r=-0.735)but positively associated with percent adipocyte volume(r=0.819),size(r=0.598)and density(r=0.743,allP<0.01).Conclusion Water/fat MRI may be an useful technique to quantify marrow fat content.By regulating the amount of marrow fat,this effect may contribute to the beneficial effect of E2 on bone mass.
ABSTRACT
Objective To analyze quantitatively the multiple parameters of iterative Dixon water-fat separation with echo asymmetric and least-squares estimation (IDEAL) MR imaging sequence, in order to realize safe, noninvasive and accurate observation of intervertebral disc degeneration, and to predict early degeneration in time, improve image quality, and to realize precision medical treatment by providing personalized examinations and optimized imaging protocols.Methods A total of 40 volunteers, 23 males and 17 females, with 20-84 years of age (mean (53.4±16.5) years), were participated in our study to accept lumbar spine MRI examination, including sequences of OSAG T2 FSE, OSAG T1 FSE, OAX T2 FSE, OSAG T2 FSE FS and OSAG IDEAL T2.Lumbar intervertebral disc degeneration was evaluated by Pfirrmann classification.The water signal fraction (WSF) of each disc was measured and calculated accurately with IDEAL in phase and IDEAL out phase images.The differences between Pfirrmann grade and WSF were analyzed statistically.The signal-to-noise ratio (SNR) measurements were carried out on equal size region of interest (ROI) from the same levels of vertebral body (L3) and background zone of T2 FSE FS and T2 IDEAL water image mid-sagittal planes, respectively, and the average value of vertebral body signal strength and the standard deviation of background signal were measured.SNRs of the two sequences were calculated, and the image qualities were compared statistically.Results Of all 200 lumbar discs that measured using Pfirrmann classification, 39 discs were classified as Pfirrmann grade Ⅰ, 42 as grade Ⅱ, 27 as grade Ⅲ, 53 as grade Ⅳ, and 39 as grade Ⅴ.The SNR of T2 FSE FS images was (11.42±6.17) dB, while that of the IDEAL water images was (20.63±9.44) dB, and there was a statistically significant difference between them (P＜0.05).The WSF decreased along with the increase of Pfirrmann grade.The significant differences of WSF were found in all grades (P＜0.05) except for the grade Ⅳ and Ⅴ (P＞0.05).Conclusions The SNR of the IDEAL water images is significantly higher than that of T2 FSE FS images, which bring about better image quality.The WSF calculated based on the IDEAL in phase and IDEAL out phase images will make possible the quantitative, noninvasive and accurate analysis of lumbar disc degeneration, especially on the early stage of disc degeneration.
ABSTRACT
OBJECTIVE: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. MATERIALS AND METHODS: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student's t test and Wilcoxon's signed rank test. RESULTS: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. CONCLUSION: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging/methods , Signal-To-Noise Ratio , Spinal Diseases/diagnosis , Statistics, NonparametricABSTRACT
Water-fat separation is a particularly important problem for magnetic resonance imaging. Although many methods have been proposed, the reliability is still challenging. In this work, we have presented a method based on the combination of the branch-cut method and multigrid algorithm to get a more robust performance of water-fat separation. First, the branch-cut method is applied to identify residues, which violates the requirement that the interacting phase gradient around a closed path be zero. Residues and branches are marked to be zeros and filled to the weighting factor array. Then, the unwrapped phase array can be given by the multigrid algorithm. Finally, the Dixon method for water-fat separation is applied to the unwrapped phase array. Experiments for brain scanning on the 0.3T low field MRI system demonstrate the successful application of the proposed method.
ABSTRACT
Water-fat separation is a particularly important problem for magnetic resonance imaging. Although many methods have been proposed, the reliability is still challenging. In this work, we have presented a method based on the combination of the branch-cut method and multigrid algorithm to get a more robust performance of water-fat separation. First, the branch-cut method is applied to identify residues, which violates the requirement that the interacting phase gradient around a closed path be zero. Residues and branches are marked to be zeros and filled to the weighting factor array. Then, the unwrapped phase array can be given by the multigrid algorithm. Finally, the Dixon method for water-fat separation is applied to the unwrapped phase array. Experiments for brain scanning on the 0.3T low field MRI system demonstrate the successful application of the proposed method.