T2 Fat Research Articles

Three-dimensional ultrashort echo time imaging with tricomponent analysis for human cortical bone.

To investigate tricomponent analysis of human cortical bone using a multipeak fat signal model with 3D ultrashort TE Cones sequences on a clinical 3T scanner. Tricomponent fitting of bound water, pore water, and fat content using a multipeak fat spectra model was proposed for 3D ultrashort TE imaging of cortical bone. Three-dimensional ultrashort TE Cones acquisitions combined with tricomponent analysis were used to investigate bound and pore water and fractions, as well as fat and fraction in cortical bone. Feasibility studies were performed on 9 human cortical bone specimens with regions of interest selected from the endosteum to the periosteum in 4 circumferential regions. Microcomputed tomography studies were performed to measure bone porosity and bone mineral density for comparison and validation of the bound and pore water analyses. The oscillation of the signal decay was well-fitted with the proposed tricomponent model. The sum of the pore water and fat fractions from tricomponent analysis showed a high correlation with microcomputed tomography porosity (R = 0.74, P < 0.01). Estimated bound-water fraction also demonstrated a high correlation with bone mineral density (R = 0.70, P < 0.01). Tricomponent analysis significantly improves the estimation of bound-water and pore-water fractions in human cortical bone.

MRI prognostic factors of tongue cancer: potential predictors of cervical lymph nodes metastases.

BackgroundThis study aimed to evaluate the efficacy of three MR imaging parameters, which are tumour thickness, para-lingual distance and apparent diffusion coefficient (ADC) value for prediction of cervical lymph nodes metastasis in cancer tongue patients.Patients and methodsFifty patients with proved cancer tongue by histopathological examination underwent MRI examination. T1 and T2- weighted MRI, diffusion-weighted images and post-contrast T1 fat suppression sequences were used.ResultsThe patients were classified according to lymph nodes involvement as seen by MRI into two groups. Significant differences between positive and negative nodes groups were observed regarding tumour thickness and para-lingual distance (p-values = 0.008 and 0.003 respectively). ROC curve analyses revealed cut-off values >13.8 mm and ≤ 3.3 mm for tumour thickness and para-lingual distance respectively for prediction of nodes involvement. No significant differences between patients with and without cervical lymph nodes metastasis were found regarding corresponding ADC value of the tumour (p-value = 0.518).ConclusionsPara-lingual distance and tumour thickness are factors that could influence pre-operative judgment and prognosis of tongue cancer patients. ADC value of the tumour itself seem not to be a reliable index of cancer progression to regional lymph nodes.

Role of Magnetic Resonance Imaging in the Diagnosis of Different Pancreatic Lesions

AbstractBackground: Pancreatic cancer is one of the most lethal human cancers that requires early diagnosis. Ultrasound, CT and MRI are different imaging modalities used for diagnosis of pancreatic masses. Diffusion-Weighted Imaging (DWI) and Time-signal Intensity Curve (TIC) can add to the diagnosis of pancreatic masses.Aim of Study: The aim of this study was to evaluate the role of magnetic resonance imaging in the diagnosis of different pancreatic lesions.Patients and Methods: Twenty-three patients were divided into 4 groups, group A (Acute Pancreatitis) (AP), group B (pancreatic cysts) which subdivided into malignant and benign cysts, group C (adenocarcinoma) and group D (Focal Pancre-atitis) (FP), all patients groups were compared to the control group. MRI protocol included MRI-c (T1WI, T1 Fat Suppres-sion (FS), T2WI, T2FS and IV dynamic contrast study) and DWI which performed on (1.5 Tesla) Magnet Unit General Electric (GE). TIC was obtained from the dynamic study and the results were divided into three patterns of curves.Results: Control group demonstrated type-I TIC, group (A & D) demonstrated type-II and group C demonstrated type-III.The mean Apparent Diffusion Coefficient (ADC) values were significant lower (p<0.001) in (A & C) groups, statically different (p<0.02) between benign and malignant cysts. Stat-ically different (p<0.001) between control and patients' groups. The sensitivity, specificity, accuracy, positive and negative predictive values of DWI and MRI-c were 92.3%, 90%, 91.3%, 92.3%, 90% and 100%, 90%, 95.7%, 92.9%, 100%, respec-tively.Conclusion: DWI and TIC were useful tools in diagnosis, characterization and differentiation between pancreatic lesions.

23 Na MRI depicts early changes in ion homeostasis in skeletal muscle tissue of patients with duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disease leading to progressive muscle wasting. Since there is a need for MRI variables that serve as early sensitive indicators of response to treatment, several quantitative MRI methods have been suggested for disease monitoring. To evaluate the potential of sodium (23 Na) and proton (1 H) MRI methods to assess early pathological changes in skeletal muscle of DMD. Prospective clinical study. 23 Na and 1 H MRI of the right leg were performed in 13 patients with DMD (age 7.8 ± 2.4) and 14 healthy boys (age 9.5 ± 2.2). 3 T including a multiecho-spin-echo sequence, diffusion-weighted sequences, 1 H spectroscopy, 3-pt Dixon, and 23 Na ultrashort echo time sequences. We obtained water T2 maps, fat fraction (FF), pH, and diffusion properties of the skeletal muscle tissue. Moreover, total tissue sodium concentration (TSC) was calculated from the 23 Na sequence. Intracellular-weighted 23 Na signal (ICwS) was derived from 23 Na inversion-recovery imaging. Results from DMD patients and controls were compared using Wilcoxon rank-sum tests and repeated analysis of variance (ANOVA). Spearman-rank correlations and area under the curve (AUC) were calculated to assess the performance of the different MRI methods to distinguish dystrophic from healthy muscle tissue. FF, water T2 , and pH were higher in DMD patients (0.07 ± 0.03, 39.4 ± 0.8 msec, 7.06 ± 0.03, all P < 0.05) than in controls (0.02 ± 0.01, 36.0 ± 0.4 msec, 7.03 ± 0.02). No difference was observed in diffusion properties. TSC (26.0 ± 1.3 mM, P < 0.05) and ICwS (0.69 ± 0.05 a.u., P < 0.05) were elevated in DMD (controls: 16.5 ± 1.3 mM and 0.47 ± 0.04 a.u.). The ICwS was frequently abnormal in DMD even when water T2 , FF, and pH were in the normal range. 23 Na MRI showed higher AUC values in comparison to the 1 H methods. Sodium anomalies were regularly observed in patients with DMD compared with controls, and were present even in absence of fatty degenerative changes and water T2 increases. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1103-1113.

T2 Mapping and Fat Quantification of Thigh Muscles in Children with Duchenne Muscular Dystrophy.

Quantitative magnetic resonance image (MRI) in individual muscles may be useful for monitoring disease progression in Duchenne muscular dystrophy (DMD). The purpose of this study was to measure T2 relaxation time of thigh muscles in children with DMD and healthy boys, and to correlate the T2 relaxation time of muscles with the fat fraction (FF) at quantitative magnetic resonance and results of clinical assessment. Thirty-two boys with DMD and 18 healthy boys were evaluated with T2 mapping and three-point Dixon MRI. Age, body mass index (BMI), muscle strength assessment, timed functional tests (time to walk or run 10 metres, rise from the floor and ascend four stairs), and the North Star Ambulatory Assessment (NSAA) were evaluated. Spearman's correlation was used to assess the relationships between FF and clinical assessments and T2 relaxation time. The mean T2 relaxation time of thigh muscles in DMD was significantly longer than that in the control group (P<0.05), except for the gracilis (P=0.952). The gracilis, sartorius and adductor longus were relatively spared by fatty infiltration in DMD patients. The T2 relaxation time was correlated significantly with the mean FF in all muscles. Age, BMI, total muscle strength score, timed functional tests and NSAA were significantly correlated with the overall mean T2 relaxation time. T2 mapping may prove clinically useful in monitoring muscle changes as a result of the disease process and in predicting the outcome of DMD patients.

Magnetic resonance fingerprinting with dictionary-based fat and water separation (DBFW MRF): A multi-component approach.

PurposeTo obtain a fast and robust fat‐water separation with simultaneous estimation of water T1, fat T1, and fat fraction maps.MethodsWe modified an MR fingerprinting (MRF) framework to use a single dictionary combination of a water and fat dictionary. A variable TE acquisition pattern with maximum TE = 4.8 ms was used to increase the fat–water separability. Radiofrequency (RF) spoiling was used to reduce the size of the dictionary by reducing T2 sensitivity. The technique was compared both in vitro and in vivo to an MRF method that incorporated 3‐point Dixon (DIXON MRF), as well as Cartesian IDEAL with different acquisition parameters.ResultsThe proposed dictionary‐based fat–water separation technique (DBFW MRF) successfully provided fat fraction, water, and fat T1, B0, and B1+ maps both in vitro and in vivo. The fat fraction and water T1 values obtained with DBFW MRF show excellent agreement with DIXON MRF as well as with the reference values obtained using a Cartesian IDEAL with a long TR (concordance correlation coefficient: 0.97/0.99 for fat fraction–water T1). Whereas fat fraction values with Cartesian IDEAL were degraded in the presence of T1 saturation, MRF methods successfully estimated and accounted for T1 in the fat fraction estimates.ConclusionThe DBFW MRF technique can successfully provide T1 and fat fraction quantification in under 20 s per slice, intrinsically correcting T1 biases typical of fast Dixon techniques. These features could improve the diagnostic quality and use of images in presence of fat.

MRI assessment of changes in adipose tissue parameters after bariatric surgery.

Bariatric surgery and other therapeutic options for obese patients are often evaluated by the loss of weight, reduction of comorbidities or improved quality of life. However, little is currently known about potential therapy-related changes in the adipose tissue of obese patients. The aim of this study was therefore to quantify fat fraction (FF) and T1 relaxation time by magnetic resonance imaging (MRI) after Roux-en-Y gastric bypass surgery and compare the resulting values with the preoperative ones. Corresponding MRI data were available from 23 patients (16 females and 7 males) that had undergone MRI before (M0) and one month after (M1) bariatric surgery. Patients were 22–59 years old (mean age 44.3 years) and their BMI ranged from 35.7–54.6 kg/m2 (mean BMI 44.6 kg/m2) at M0. Total visceral AT volumes (VVAT-T, in L) were measured by semi-automatic segmentation of axial MRI images acquired between diaphragm and femoral heads. MRI FF and T1 relaxation times were measured in well-defined regions of visceral (VAT) and subcutaneous (SAT) adipose tissue using two custom-made analysis tools. Average BMI values were 45.4 kg/m2 at time point M0 and 42.4 kg/m2 at M1. Corresponding VVAT-T values were 5.94 L and 5.33 L. Intraindividual differences in both BMI and VVAT-T were highly significant (p<0.001). Average relaxation times T1VAT were 303.7 ms at M0 and 316.9 ms at M1 (p<0.001). Corresponding T1SAT times were 283.2 ms and 280.7 ms (p = 0.137). Similarly, FFVAT differences (M0: 85.7%, M1: 83.4%) were significant (p <0.01) whereas FFSAT differences (M0: 86.1, M1: 85.9%) were not significant (p = 0.517). In conclusion, bariatric surgery is apparently not only related to a significant reduction in common parameters of adipose tissue distribution, here BMI and total visceral fat volume, but also significant changes in T1 relaxation time and fat fraction of visceral adipose tissue. Such quantitative MRI measures may potentially serve as independent biomarkers for longitudinal and cross-sectional measurements in obese patients.

Imaging sequence for joint myocardial T1 mapping and fat/water separation.

PurposeTo develop and evaluate an imaging sequence to simultaneously quantify the epicardial fat volume and myocardial T1 relaxation time.MethodsWe introduced a novel simultaneous myocardial T1 mapping and fat/water separation sequence (joint T1‐fat/water separation). Dixon reconstruction is performed on a dual‐echo data set to generate water/fat images. T1 maps are computed using the water images, whereas the epicardial fat volume is calculated from the fat images. A phantom experiment using vials with different T1/T2 values and a bottle of oil was performed. Additional phantom experiment using vials of mixed fat/water was performed to show the potential of this sequence to mitigate the effect of intravoxel fat on estimated T1 maps. In vivo evaluation was performed in 17 subjects. Epicardial fat volume, native myocardial T1 measurements and precision were compared among slice‐interleaved T1 mapping, Dixon, and the proposed sequence.ResultsIn the first phantom, the proposed sequence separated oil from water vials and there were no differences in T1 of the fat‐free vials (P = .1). In the second phantom, the T1 error decreased from 22%, 36%, 57%, and 73% to 8%, 9%, 16%, and 26%, respectively. In vivo there was no difference between myocardial T1 values (1067 ± 17 ms versus 1077 ± 24 ms, P = .6). The epicardial fat volume was similar for both sequences (54.3 ± 33 cm3 versus 52.4 ± 32 cm3, P = .8).ConclusionThe proposed sequence provides simultaneous quantification of native myocardial T1 and epicardial fat volume. This will eliminate the need for an additional sequence in the cardiac imaging protocol if both measurements are clinically indicated.

THE VALUE OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF PERI-ANAL FISTULA

Background: Perianal fistula accounts for 0.01% of general population and is frequently managed inadequately resulting in a significant morbidity. Magnetic resonance imaging (MRI) plays an essential role in the preoperative assessment of the disease, therefore improving post-operative surgical outcome. Objective: To study the role of MRI in the evaluation of perianal fistula and to show the value of using contrast enhanced MR study in the determination of the precise tract pathway, extensions and other associated pathologies. Methods: A cross sectional analytic study was conducted on a total of 32 patients with perianal fistulas in the MRI Department of Al-Imamein Al-Kadhimein Medical City, Baghdad, Iraq during the period from November 2015 to December 2016. Patients underwent MRI examination using axial and coronal T2 weighted images with and without fat suppression and T1 fat suppressed sequences before and after contrast administration. The type of fistula, location of the internal opening, associated abscesses and/or sinus tracts and horseshoe extension were evaluated using different MR sequences. Results: The most common type of fistula encountered was the inter-sphincteric type, which was seen in 21 patients (66%), of those patients 16 fistulas (50%) were grade I and 5 fistulas (16%) were grade II. Trans-sphincteric fistulas were seen in 9 patients (28%), 2 of them (6%) were grade III and 7 fistulas (22%) were grade IV. Two patients (6%) had extra-sphincteric type. T2 weighted TSE, T2 TSE with fat suppression and T1 weighted fat suppressed post contrast sequences all show significant correlation with surgical results (with p-value less than 0.05) and the highest significance was obtained by the post contrast sequence (p-value of 0.00001). The highest accuracy in the diagnosis of fistula in ano was with the use of T1 enhanced fat suppressed sequence (98.8%) followed by 87% for the T2 fat suppression sequence and only 57% for the T2 weighted TSE sequence. Conclusion: MRI is an essential, noninvasive tool in the preoperative assessment of perianal fistulous tracks, with the axial and coronal post contrast fat suppression T1 providing the highest accuracy and clinical significance with surgical data and therefore giving a highly promising decrement in the incidence of post-operative complications. Keywords: MRI, perianal fistula Citation: Jawad AM, kadhim MA, Al-Jobouri ZK, Hussain MAA. The value of magnetic resonance imaging in the evaluation of peri-anal fistula. Iraqi JMS. 2018; 16(2): 166-176. doi: 10.22578/IJMS.16.2.8

Multiparameter estimation using multi-echo spoiled gradient echo with variable flip angles and multicontrast compressed sensing.

To develop multiparameter mapping including T1 , R2*, and proton density fat fraction with a single breath-hold to evaluate liver disease and liver function. A 6-echo spoiled gradient-echo sequence with dual flip angles was used to acquire a 12-set MRI volume data set. To shorten the scan time, undersampling and multicontrast compressed-sensing reconstruction were used. The scan time was 18 seconds. R2* and proton density fat fraction mapping were achieved by using the iterative least-squares method. T1 mapping was estimated using driven equilibrium single-pulse observation of T1 . Quantitative values were validated by performing phantom and volunteer studies. Statistical analysis showed that the quantitative values measured using the proposed methods agreed with those measured using conventional methods. T1 values of water proton measured by the proposed method in phantom and volunteer studies were in good agreement with those by MRS. The results showed that accurate quantitative mapping of T1 , R2*, and proton density fat fraction with a single breath-hold was achieved using our approach.

Small C7–T1 lordotic angle and muscle degeneration at C7 level were independent radiological characteristics of patients with cervical imbalance: a propensity score-matched analysis

Background contextCervical sagittal vertical axis (cSVA) of ≥40 mm is recognized as the key factor of poor health-related quality of life, poor surgical outcomes, and correction loss after surgery for cervical deformity. However, little is known about the radiological characteristics of patients with cSVA≥40 mm. PurposeThe purpose of this study was to identify the radiological characteristics of patients with cervical imbalance. DesignRetrospective analysis of weight-bearing cervical magnetic resonance (MR) images. Patient sampleConsecutive 1,500 MR images of symptomatic patients in weight-bearing position. Outcome measuresCervical sagittal vertical axis, cervical alignment, cervical balance parameters (T1 slope, Co–C2 angle, C2–C7 angle, C7–T1 angle, neck tilt, and thoracic inlet angle), disc degeneration (Pfirmann and Suzuki classification), end plate degeneration (Modic change), spondylolisthesis (antero- and retrolisthesis), anteroposterior (AP) diameter of dural sac, cross-sectional area (CSA), and fat infiltration ratio of the transversospinalis muscles at C4 and C7 levels. MethodsPatients were divided into two groups: cSVA≥40 mm and cSVA<40 mm. Gender, age, and cervical alignment were analyzed. Subsequently, matched imbalance (cSVA≥40 mm) and control (<40 mm) groups were created using the propensity score to adjust for age, gender, and cervical alignment. Cervicothoracic angular parameters, disc degeneration, Modic change, spondylolisthesis, and degeneration of the transversospinalis muscles at C4 and C7 were compared. Variables with p<.05 were included in the multinomial logistic regression model to identify factors that relate to the cervical balance grouping. ResultsThe incidence of patients with cervical imbalance was 2.5% (37 patients). Those patients had a higher incidence of kyphosis, were older, and there were more male patients. In the matched imbalance group, the T1 slope was greater (p=.028), C7–T1 lordotic angle was smaller (p<.001), the number of anterolisthesis was greater (p=.012), and the fat infiltration ratio at C4 and C7 was higher (p=.023, 0.030) compared with the control. Logistic regression analysis showed that the C7–T1 angle (adjusted odds ratio [aOR]=0.592, p=.001) and fat infiltration ratio at C7 level (aOR=1.178, p=.030) were significant independent variables. ConclusionsSmaller C7–T1 lordotic angle and severe muscle degeneration at C7 level were independent characteristics of patients with cervical imbalance.

Developmental patterns of fetal fat and corresponding signal on T1-weighted magnetic resonance imaging.

Evaluation of subcutaneous fetal fat layer thickness on T1-weighted sequences can be used to predict birth weight. Little is known about normal MR signal patterns of subcutaneous tissue throughout pregnancy. To establish developmental patterns of subcutaneous fetal fat signal on T1-weighted sequences during the 2nd and 3rd trimesters. We retrospectively examined T1-weighted images of 110 fetal MRI scans. We measured signal intensity of subcutaneous fat on thighs, buttocks, trunk, nuchal region, chin and scalp. We then calculated the ratios of the obtained values with fetal muscle, amnios and maternal fat signal, and compared the results with those of immunohistochemical examination of adipose tissue extracted from the abdominal wall of fetuses as part of standard autopsy protocol. We included 60 MRI scans in fetuses without intra-uterine growth restriction or macrosomia of non-diabetic mothers (range 23-37weeks of gestation). Fat T1 intensity of all anatomical regions was low in all fetuses before 26weeks of gestation. It became more hyperintense with increasing gestational age, in the following order: chin and nuchal region, then buttocks, thighs and trunk, and eventually the scalp at 33weeks of gestation. After 33weeks of gestation, all fetal subcutaneous tissues demonstrated overall hyperintense signal. This progression followed the conversion at immunohistochemistry of fetal adipose tissue composition from predominant brown to white adipose cells in 19 fetuses (19-41weeks of gestation). Between 26weeks and 33weeks of gestation, subcutaneous fetal fat signal changed in an orderly pattern from chin to buttocks and scalp. This may reflect the conversion from predominant brown to white adipose tissues in subcutaneous fetal fat.

Variability of T1-weighted signal intensity of pericallosal lipomas in the fetus.

Pericallosal lipomas are often associated with corpus callosum dysgenesis. The diagnosis of lipoma, suggested on ultrasonography, relies on the classic T1 hyperintensity on magnetic resonance imaging (MRI). However, this feature may be absent prenatally. Our objective was to study the changes of T1 intensity in fetal lipomas with comparison to postnatal/postmortem data and to assess the factors influencing the signal variations of pericallosal lipomas on prenatal MRI. Patients with callosum dysgenesis and interhemispheric hyperechogenicity suggestive of a pericallosal lipoma with available postnatal or postmortem data were included. Gestational age, lipoma size and pattern, corpus callosum size and changes in fetal fat T1 intensity were recorded. Comparison with postmortem neuropathology was available for one fetus. Eleven patients with callosum dysgenesis and pericallosal lipomas (seven curvilinear and four tubulonodular) were included. All MRI scans were performed in the third trimester. Curvilinear lipomas were thinner and six cases were associated with prenatal T1 iso-intensity. Typical T1 hyperintensity appeared on postnatal MRI only. All tubulonodular lipomas were much larger and showed prenatal T1 hyperintensity. In two patients, the lipoma increased in size on postnatal MRI. The type and size of a lipoma influence T1 prenatal intensity. Absence of T1 intensity was observed in curvilinear lipomas only. Curvilinear lipomas are much thinner. Changes in T1 intensity may also be related to fat maturation within the lipoma and, subsequently, to gestational age. In the case of callosum dysgenesis, absence of prenatal T1 pericallosal hyperintensity should not exclude the diagnosis of pericallosal lipoma.

Qualitative and semi-quantitative assessment of temporomandibular joint MRI protocols for juvenile idiopathic arthritis at 1.5 and 3.0 T

ObjectiveTemporomandibular joints (TMJs) frequently develop silent inflammatory and osteochondral changes in children with juvenile idiopathic arthritis. Data-driven recommendations for TMJ imaging protocol are needed to reduce measurement error and scanning time. This study compares the impact of different protocols, imaging coils, and magnet strength on the reliability of image assessment and the subjective quality of images. Materials and methodsThree groups of bilateral TMJ MR studies were retrospectively collected from two institutions, including 24 1.5T and 19 3.0T studies using dedicated TMJ surface coils, and 23 1.5T studies with head coil. Post-contrast sequences were re-compiled from the full protocol to create minimum protocol studies for the three groups. Two radiologists and two non-radiologists first scored the three minimum protocol images according to pre-specified definitions, then scored the full protocol images. Minimum-to-full protocol agreement, inter-reader agreement, and subjective item visibility scores were assessed. ResultsWith dedicated TMJ dual surface coils, minimum-vs-full protocol agreement was moderate to good (0.5–0.8 intraclass correlation coefficients or kappa) for most items, and was not influenced by the magnet strength. Inter-reader reliability was more significantly influenced by the imaging coil and reader’s training background than by protocol length or magnet strength differences. Sagittal and coronal planes weighted on PD, T2 Fat Suppressed and T1 Fat Suppressed -postcontrast adequately visualized all the different features, whereas the axial plane was more limited to visualizing synovium. ConclusionInter-reader reliability and qualitative measure of image quality improved more consistently with the coil offering the higher resolution, rather than increased magnet strength.

Values of fat saturation sequence in MRI for juvenile arthritis

To explore the values of fat saturation sequence in MRI for juvenile arthritis. Methods: A total of 1 131 cases with juvenile arthritis and 1 601 with symptomatic arthritis were examined by MRI normal T1 weighted imaging (T1WI) and T2 weighted imaging (T2WI) sequence and spectral presaturation attenuatedinversion recovery (SPAIR) T2 fat saturation sequence. All the images were independently evaluated by two senior doctors from the Department of Radiology and the Department of Pediatric Rheumatology and Immunology respectively to confirm the types and degree of pathological changes of joint tissues. Results: Among the subjects, 847 patients demonstrated positive in MRI, accounting for 52.9%; 409 patients showed positive in normal sequence, accounting for 48.3%; 816 patients showed positive in fat saturation sequence, accounting for 96.3%. Joint hydrops accounted for 59.5%. Bone marrow edema accounted for 39.7%. The relevant ratio of bone marrow edema, joint hydrops, thickening of synovium and cartilage injuries in fat saturation sequence were higher than that in normal sequence (P<0.05). The relevant ratio of bone erosion in normal sequence was higher than that in fat saturation sequence (P<0.05). However, no significant difference of joint cysts was found between the fat saturation sequence and normal sequence (P<0.05). Conclusion: Application of fat saturation sequence by MRI to check juvenile arthritis could obviously improve the positive MRI relevant ratio. In addition, the relevant ratio of the early pathological changes of juvenile arthritis (such as bone marrow edema and joint hydrops) was high, which might provide references for the early diagnosis of juvenile arthritis.

Tissue oxygenation mapping by combined chemical shift and T1 magnetic resonance imaging.

To propose a method for determining tissue oxygenation via the measurement of fat T1 . The method is based on a 2D fat/water chemical shift-encoded and T1 -weighted acquisition. A 2D data set was acquired with a fast spin echo sequence with several echo asymmetries and repetition times, wherein one dimension is related to the fat/water phase modulation and the other to the T1 saturation recovery. A joint magnitude-based process of phase modulation and T1 evolution allowed for the collection of the fat fraction and T1 maps with resolved fat or water dominance ambiguity while avoiding the phased error problem. In vitro imaging allowed for the attribution of fat content for different water/oil emulsions that demonstrated longitudinal relaxation rate (R1 ) sensitivity to the oxygenated emulsion environment. The fat R1 values were subsequently compared to reference values, which were measured using low receiver bandwidth acquisition to enhance water and fat signal separations. In vivo feasibility of tissue oxygenation assessment was demonstrated by investigating interscapular brown adipose tissue modifications during an air/carbogen challenge in rats. The proposed method offers a precise and robust estimate of tissue oxygenation illustrated by the method's ability to detect-brown adipose tissue oxygenation modifications. Magn Reson Med 79:1981-1991, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Midterm CT and MRI Appearance of Osteobiologic Plugs in the Knee

Objectives:The objective of this study is to evaluate the bony integration and cartilage morphology of Trufit Plugs (Smith & Nephew) placed to fill chondral defects in the knee.Methods:17 patients underwent osteobiologic plug implantation for chondral defects of the knee. 13 plugs in 7 patients (mean age 38 years, range 21-49) were available for radiographic review. The mean follow up was 36.4 months (range 20-57 months). Each patient underwent CT for evaluation of bony integration as judged by a percentage of integration. The Hounsfield units (HU) of the plug and the native bone were recorded. A percentage of HU implant and HU native cancellous bone (HU implant/HU native bone) was calculated. MRI was used to evaluate the amount and quality of articular cartilage.Results:CT results showed percentage of bony integration to be mean 37.7% (range 0-100, SD ±30.1). HU implant/HU native bone was mean 32.2%, range 11.8-64.9. MRI showed articular cartilage fill to be: 38.5% filled 0-25% of the defect, 15.3% filled 25-50%, 23.1% filled 50-75%, and 23.1% filled 75-100%. T2 fat saturated signals were isointense in 26.9%, hyperintense in 34.6%, intermediate in 23.1%, hypointense in 23.1%, and cancellous bone in 7.7%.Conclusion:In this study bony integration of the TruFit Plug was poor. The amount of articular cartilage fill was significantly incomplete. The quality of resulting cartilage was inconsistent.

The role of MRI in evaluation of recto-sigmoid junction wall endometriosis. A case report

Endometriosis is a condition that occurs due to the presence of endometrial glandular tissue outside the uterine cavity, more frequently at pelvic level affecting ovaries, uterosacral ligament, recto-vaginal septum, sigma or urinary bladder. The diagnosis of endometriosis involves a detailed anamnesis, gynecological examination, imagistic examinations, biochemical investigations, laparoscopy, and histological confirmation. We present herein the case of a 30-year-old patient with severe dysmenorrhea and infertility, diagnosed with profound endometriosis. The patient undergone a magnetic resonance imaging (MRI) pelvic examination with a specific protocol which includes endovaginal and endorectal instillation of gel and involves a scan of the pelvis in three planes (axial, coronal and sagittal) T2-weighted; T2 sequences with inclinations at the level of the uterus, urinary bladder and uterosacral ligaments; T1, T1 Fat Sat sequence unenhanced and post-contrast and T2 sequences post vaginal and rectal instillation of sterile gel. The MRI examination with endovaginal and endorectal instillation of sterile gel has a high specificity and sensitivity in establishing the diagnosis, allowing an accurate evaluation of the various modifications caused by endometriosis and its extent in the wall of pelvic organs. Such an investigation allows an exact preoperative mapping of lesions.

MRI for Assessment of Anal Fistula

Abstract: A fistula-in-ano is the passage between the skin around the anus and anal canal that usually caused by a previous anorectal abscess and an obvious sign of that is continuous discharge. Although its not the common disease in GI tract but it has caused considerable morbidity. The outbreaks have almost 11 per 111, 111, and 2 - 4 times more frequent in men and if its not diagnosed and treated on time, it can be a high risk of recurrence and fecal incontinence and associated risk of sepsis and abscesses. Objectives: The purpose of the study was to evaluate the role of Magnetic Resonance Imaging in detection and characterization of perianal fistulae and correlating it with surgical findings. Methods: In this study, 14 patients with clinical and physical examination of perianal fistulas were prospectively selected for MRI evaluation, with specific MRI sequence T1W, T2W, T1 Fat Sat or T2 Fat Sat, T1 + contrast, etc,and with special coils plans axial, coronal, sagittal . MRI findings were recorded. The surgery was performed and the results were also recorded and eventually the consistency and effectiveness of MRI were compared with the results after surgery. Results: Amongst the total of 14 patients,in 1 patient (7117) Transsphincteric fistula, 11 patients (78167) Intersphincteric fistula and 2 patients (14137) Suprasphincteric fistula were diagnosed and in surgery findings, 1 (7117) Transsphincteric fistula, 11 (71147) Intersphincteric fistula and 2 (14137) Suprasphincteric fistulas were detected and in one case no fistula was observed. An agreement between two detection methods was 82177 and sensitivity of MRI in the diagnosis of intersphincteric, transsphincteric and suprasphincteric fistulas were 1117 and the specificity was 757 in the detection and diagnosis of intersphincteric fistulas and 1117 for transsphincteric and suprasphincteric fistulas1 Conclusions: Based on the results of this study and according to the 1117 sensitivity of MRI, its useful to locate the perianal fistulas, reduce the chance of recurrence and postoperative complications and can contribute the healing process better than other diagnostic methods.

Muscle MRI at the time of questionable disease flares in Juvenile Dermatomyositis (JDM)

BackgroundThe course of JDM has improved substantially over the last 70 years with early and aggressive treatments. Yet it remains difficult to detect disease flares as symptoms may be mild; signs of rash and muscle weakness vary widely and are often equivocal; laboratory tests of muscle enzyme levels are often normal; electromyography and muscle biopsy are invasive. Alternative tools are needed to help decide if more aggressive treatment is needed. Our objective is to determine the effectiveness of muscle Magnetic Resonance Imaging (MRI) in detecting JDM flares, and how an MRI affects physician’s decision-making regarding treatment.MethodsThis study was approved by the Institutional Review Board of Nationwide Children’s Hospital. JDM patients were consulted between 1/2005 and 6/2015. MRIs were performed on both lower extremities without contrast sequentially: axial T1, axial T2 fat saturation, axial and coronal inversion recovery, and axial diffusion weighted. The physician decision that a JDM patient was in a flare was considered the gold standard. MRI results were compared with physician’s decisions on whether a relapse had occurred, and if there was a concordance between the assessment methods.ResultsForty-five JDM patients were studied. Eighty percent had weakness at diagnosis, 100% typical rash, and 73% typical nail-fold capillary changes. At diagnosis, muscle enzymes were compatible with JDM generally (CK 52%, LDH 62%, aldolase 72%, AST 54% abnormal). EMG was abnormal in 3/8, muscle biopsy typical of JDM in 10/11, and MRI abnormal demonstrating myositis in 31/40. Thirteen patients had a repeat MRI for possible flares with differing indications. Three repeat MRI’s were abnormal, demonstrating myositis. There was moderate agreement about flares between MRI findings and physician’s treatment decisions (kappa = 0.59). In each abnormal MRI case the physician decided to increase treatment (100% probability for flares). MRI was negative for myositis in 10 patients, by which 7/10 the physicians chose to continue or to taper the medications (70% probability for non-flares).ConclusionA muscle MRI would facilitate objective assessments of JDM flares. When an MRI shows myositis, physicians tend to treat 100% of the time. When an MRI shows no myositis, physicians continued the same medications or tapered medications 70% of the time. Further studies would help confirm the utility and cost-effectiveness of MRI to determine JDM flares.