Diffusion Weighted Imaging in the Assessment of Tumor Grade in Endometrial Cancer Based on Intravoxel Incoherent Motion MRI.

The aim of this study is to investigate the possibility of predicting histological grade in patients with endometrial cancer on the basis of intravoxel incoherent motion (IVIM)-related histogram analysis parameters. This prospective study included 52 women with endometrial cancer (EC) who underwent MR imaging as initial staging in our hospital, allocated into low-grade (G1 and G2) and high-grade (G3) tumors according to the pathology reports. Regions of interest (ROIs) were drawn on the diffusion weighted images and apparent diffusion coefficient (ADC), true diffusivity (D), and perfusion fraction (f) using diffusion models were computed. Mean, median, skewness, kurtosis, and interquartile range (IQR) were calculated from the whole-tumor histogram. The IQR of the diffusion coefficient (D) was significantly lower in the low-grade tumors from that of the high-grade group with an adjusted p-value of less than 5% (0.048). The ROC curve analysis results of the statistically significant IQR of the D yielded an accuracy, sensitivity, and specificity of 74.5%, 70.1%, and 76.5% respectively, for discriminating low from high-grade tumors, with an optimal cutoff of 0.206 (×10-3 mm2/s) and an AUC of 75.4% (95% CI: 62.1 to 88.8). The IVIM modeling coupled with histogram analysis techniques is promising for preoperative differentiation between low- and high-grade EC tumors.

Extraocular Muscle Volumetry for Assessment of Thyroid Eye Disease.

BACKGROUND: In this study we evaluate the diagnostic accuracy of extraocular muscle volumetry in detecting thyroid eye disease and to compare the results with simple measurements of maximal medial rectus (MR) diameter. METHODS: Cross-sectional study that included 47 eyes of 47 patients with thyroid eye disease and 47 healthy controls. Patients underwent slitlamp examination and imaging consisting of computed tomography scans. Image segmentation and volume measurements were performed by 2 independent researchers. Intraobserver and interobserver reliability testing was also conducted. RESULTS: Total extraocular muscle volume was 7.31 ± 1.88 cm3 and medial volume was 2.38 ± 0.73 cm3 in the study group. In this group, the maximum measured diameter of the MR was 6.67 ± 0.35 mm. MR volume was statistically associated with maximum MR diameter (r = 9.78; P < 0.001). Both MR volume and maximum MR diameter measurements showed good predictive efficacy as shown using receiver operator characteristic curve analysis. CONCLUSIONS: Complications of thyroid eye disease are often sight threatening, and timely diagnosis is crucial for the management of the entity and its sequelae. The results of this study imply that simple measurements of maximum MR diameter are sensitive enough to establish diagnosis.

Dynamic CT perfusion imaging for type 2 endoleak assessment after endograft placement.

Endovascular repair of abdominal aortic aneurysm is a widely performed treatment method due to its minimal invasiveness, reduced need for intensive care unit (ICU), shorter hospitalization and lower 30-day morbidity and mortality compared to open surgery. Endoleak is the drawback of this procedure and is considered the main culprit for re-interventions due to the risk of late aneurysm sac growth and rupture. Type 2 endoleak (T2EL) is the most common type of endoleak which is also the most controversial regarding its management. The aim of this paper is to investigate the potential of dynamic contrast-enhanced CT for the assessment of T2EL after endovascular aneurysm repair using qualitative and quantitative image analysis of the aneurysmal sac.

An update on the assessment of osteoporosis using radiologic techniques.

In this article, the currently available radiologic techniques for assessing osteoporosis are reviewed. Density measurements of the skeleton using dual X-ray absorptiometry (DXA) are clinically indicated for the assessment of osteoporosis and for the evaluation of therapies. DXA is the most widely used technique for identifying patients with osteoporosis. Quantitative computed tomography (QCT) is the only method, which provides a volumetric density. Unlike DXA, QCT allows for selective trabecular measurement and is less sensitive to degenerative diseases of the spine. The analysis of bone structure in conjunction with bone density is an exciting new field in the assessment of osteoporosis. High-resolution multi-slice CT and micro-CT are useful tools for the assessment of bone microarchitecture. A growing literature indicates that quantitative ultrasound (QUS) techniques are capable of assessing fracture risk. Although the ease of use and the absence of ionizing radiation make QUS attractive, the specific role of QUS techniques in clinical practice needs further determination. Considerable progress has been made in the development of MR techniques for assessing osteoporosis during the last few years. In addition to relaxometry techniques, high-resolution MR imaging, diffusion MR imaging and in-vivo MR spectroscopy may be used to quantify trabecular bone architecture and mineral composition.

Assessment of the skeletal status by MR relaxometry techniques of the lumbar spine: comparison with dual X-ray absorptiometry.

PURPOSE: To measure lumbar spine T2*, T2, T2' and T1 MR relaxometry parameters and compare them with lumbar spine bone mineral density (BMD) in a group of postmenopausal women. MATERIALS AND METHODS: Lumbar spine T2*, T2, T2' and T1 MR relaxometry parameters and BMD values were assessed in 101 postmenopausal women (mean age: 61.8 +/- 7.1 (1 S.D.) years); of them 63 referred to as control subjects (group A, BMD T-scores > or = -2.5 S.D.) and 38 as osteoporotic (group B, BMD T-scores < -2.5 S.D.). All magnetic resonance imaging (MRI) examinations were performed on an 1.5 T imaging system using: (a) a 2D single slice multi echo (32 echoes) gradient echo (MEGRE) sequence (TR/TE1/TE32/FA: 160/2.7/74.93 ms/25 degrees for the T2* measurement, (b) a respiratory gated 2D single slice Multi Echo (16 echoes) Spin Echo (MESE) sequence (TR/TE1/TE16/FA: 2000-2500/22.5/360 ms/90 degrees) for the T2 measurement and (c) a 2D single slice multi TI (18 repeats) turbo Fast Low Angle Shot (turbo FLASH) sequence (TR/TE/TI1/TI16/FA: 11/4.2/10/5000 ms/10 degrees) for the T1 measurement. T2' was calculated from its definition equation: (1/T2' = 1/T2* - 1/T2). Lumbar spine BMD was assessed using DXA. RESULTS: All measured parameters showed statistically significant differences between groups A and B (from P < 0.05 to <0.001). All parameters showed significant associations with subject's age ranging from r = 0.245 (P < 0.05) for the T2 up to r = 0.377 (P < 0.001) for the T2*. All parameters showed significant associations with subject's BMD measurements ranging from r = -0.184 (P < 0.05) for the R1 = (1/T1) up to r = -0.345 (P < 0.0005) for the T2. CONCLUSION: Among the MR relaxometry parameters studied, T2* and T2 showed better discrimination of patients with osteoporosis from control subjects.