Fatty transformation of angiomyolipoma in TSC patients after initiation of mTOR inhibitor therapy.

<p><b>A</b>: Example of a large AML at the central part of the right kidney in a 33 year-old female TSC patient. <b>A1</b>: At baseline a heterogeneous AML with a mixed-signal on the T2 fat saturated MR sequence (solid arrows) could be visualized. Slow flowing blood in a small vessel (dotted arrows) appears hyperintense on the fat saturated sequence. The unaffected “healthy” kidney tissue is also visualized with a hyperintense signal (*). <b>A2</b>: 2.5 months following the initiation of the mTOR inhibitor therapy a reduction in the overall signal of the AML on the T2 fat saturated sequence can be visualized. The vessel, which was visible at baseline (A1: dotted line) cannot be delineated anymore. Additionally, a reduction of size of the AML can be visualized. This case represents a good example of how difficult it can be to clearly quantify a size reduction in a heterogenous AML following the initiation of mTOR therapy. <b>B</b>: Example of a AML at the caudal part of the right kidney in a 45 year-old male TSC patient. <b>B1</b>: At baseline a heterogeneous relatively bright angiomyolipoma could be visualized on the T2 fat saturated sequence (arrows). The unaffected “healthy” kidney tissue is visualized with a homogenous hyperintense signal on the T2 fat saturated sequence (*). <b>B2</b>: 3 to 6 months following the initiation of the mTOR inhibitor therapy, a clear reduction in the signal on the T2 fat saturated sequence as well as in the size of the angiomyolipoma is visualized. The signal of the healthy kidney tissue does not change following the initiation of the therapy (*). MRI: Magnetic Resonance Imaging. Fatsat: Fat saturated. Scale bar: 1.5 cm.</p

Characteristics of the investigated TSC patient cohort.

<p>Characteristics of the investigated TSC patient cohort.</p

Trough levels and dosing of everolimus.

<p>Trough levels and dosing of everolimus.</p

Signal changes in magnetic resonance imaging with selective fat suppression in TSC patients following the initiation of mTOR inhibitor therapy.

<p>Patients were investigated at baseline and after 0–3 months, 3–6 months and 18–24 months of mTOR inhibitor therapy. Additionally, a control collective of TSC patients without mTOR inhibitor therapy was investigated. A pronounced and significant reduction of the mean contrast to noise ratio (CNR) was already observed in the early group within the first three months. In the control group, no reduction of the mean CNR value was observed. Error bars indicate the standard deviation. P-values generated from linear mixed model statistical analysis (* p<0.01, *** p<0.0001); CNR: Contrast to noise ratio.</p

Size changes in magnetic resonance imaging in TSC patients following the initiation of mTOR inhibitor therapy.

<p>Patients were investigated at baseline and after 0–3 months, 3–6 months and 18–24 months of mTOR inhibitor therapy. Additionally, a control collective of TSC patients without mTOR inhibitor therapy was investigated. A significant (p ≤ 0.05) reduction of the size of angiomyolipomas (in mm²) was already observed in the early group within the first three months. In the control group, no reduction of the size was observed. Error bars indicate the standard deviation. P-values generated from linear mixed model statistical analysis (* p<0.01, ** p<0.001, *** p<0.0001).</p

Best percentage reduction of contrast to noise ratio as well as size of angiomyolipomas in each individual patient reported at any time point.

<p>In all analyzed patients a reduction in CNR could be observed whereas 2 patients did not show a size reduction of AML under everolimus treatment. AML size is given in mm², results are sorted by value.</p

High-Field Open versus Short-Bore Magnetic Resonance Imaging of the Spine: A Randomized Controlled Comparison of Image Quality

<div><p>Background</p><p>The purpose of the present study was to compare the image quality of spinal magnetic resonance (MR) imaging performed on a high-field horizontal open versus a short-bore MR scanner in a randomized controlled study setup.</p><p>Methods</p><p>Altogether, 93 (80% women, mean age 53) consecutive patients underwent spine imaging after random assignement to a 1-T horizontal open MR scanner with a vertical magnetic field or a 1.5-T short-bore MR scanner. This patient subset was part of a larger cohort. Image quality was assessed by determining qualitative parameters, signal-to-noise (SNR) and contrast-to-noise ratios (CNR), and quantitative contour sharpness.</p><p>Results</p><p>The image quality parameters were higher for short-bore MR imaging. Regarding all sequences, the relative differences were 39% for the mean overall qualitative image quality, 53% for the mean SNR values, and 34–37% for the quantitative contour sharpness (<i>P</i><0.0001). The CNR values were also higher for images obtained with the short-bore MR scanner. No sequence was of very poor (nondiagnostic) image quality. Scanning times were significantly longer for examinations performed on the open MR scanner (mean: 32±22 min versus 20±9 min; <i>P</i><0.0001).</p><p>Conclusions</p><p>In this randomized controlled comparison of spinal MR imaging with an open versus a short-bore scanner, short-bore MR imaging revealed considerably higher image quality with shorter scanning times.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00715806" target="_blank">NCT00715806</a></p></div

Diagnostic accuracy of susceptibility-weighted magnetic resonance imaging for the evaluation of pineal gland calcification - Fig 5

<p><b>Linear regression and Bland-Altman plot of the difference between diameter measurements of calcifications in CT and SWMR (A) and of the difference between diameter measurements of calcifications in CT and MRI T1 and T2 weighted images (B).</b> Diameter measurements show a strong correlation (R² = 0.85) between SWMR magnitude images and the reference standard CT with a mean difference of 1.13 (CI: 0.73 to 1.53). In comparison, correlation between MRI T1 and T2 weighted images and CT is only moderate (R² = 0.49) with a mean difference of 0.92 (CI: 0.53 to 1.30). The mean difference of the data is illustrated by the central horizontal line. Upper and lower reference lines show the upper and lower limits of agreement (95% confidence intervals).</p

Imaging findings of a 55-year-old woman with a calcified pineal gland.

<p>(A), CT shows a sharply defined oval-shaped pineal calcification with a diameter of 11 mm. In axial T1-weighted MRI (B) and in axial T2-weighted MRI (C) it is hardly possible to demarcate the calcified area against the surrounding tissue. In conventional MRI, it is not possible to reliably identify the hypointense foci as calcifications. The inverted SWMR magnitude image (D) and the phase image (E) show well-defined focal hyperintensities in the pineal region area. While the image information solely derived from the magnitude image is not superior to conventional MRI sequences, the combination of SWMR magnitude and phase image allows for a clear and reliable identification of diamagnetic calcifications. Magnified images are provided for (B), (C), (D) and (E). As CT and MRI of the brain have diverged reference lines with the bicommissural line used as a convenience standard for MRI and the orbitomeatal line used for CT, the slice angles vary accordingly.</p

Linear regression and Bland–Altman plot for the assessment of interobserver variability for diameter measurements of calcifications in meningiomas in SWMR.

<p>Diameter measurements show an excellent correlation (R² = 0.91) with a mean ratio of 1.00 (CI: 0.72 to 1.29) between calcification measurements of the two readers in SWMR magnitude images. The mean ratio of diameter measurements of readers 1 and 2 is illustrated by the central horizontal line. Upper and lower reference lines show the upper and lower limits of agreement (95% confidence intervals).</p