Improved diagnostic accuracy in differentiating malignant and benign lesions using single-voxel proton MRS of the breast at 3 T MRI

AIM: To investigate the diagnostic accuracy of single-voxel proton magnetic resonance spectroscopy (SV (1)H MRS) by quantifying total choline-containing compounds (tCho) in differentiating malignant from benign lesions, and subsequently, to analyse the relationship of tCho levels in malignant breast lesions with their histopathological subtypes. MATERIALS AND METHODS: A prospective study of SV 1H MRS was performed following dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in 61 women using a 3 T MR system. All lesions (n = 57) were analysed for characteristics of morphology, contrast-enhancement kinetics, and tCho peak heights at SV (1)H MRS that were two-times above baseline. Subsequently, the tCho in selected lesions (n = 32) was quantified by calculating the area under the curve, and a tCho concentration equal to or greater than the cut-off value was considered to represent malignancy. The relationship between tCho in invasive ductal carcinomas (IDCs) and their Bloom & Richardson grading of malignancy was assessed. RESULTS: Fifty-two patients (57 lesions; 42 malignant and 15 benign) were analysed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), of predicting malignancy were 100, 73.3, 91.3, and 100%, respectively, using DCE-MRI and 95.2, 93.3, 97.6, and 87.5%, respectively, using SV (1)H MRS. The tCho cut-off for receiver operating characteristic (ROC) curve was 0.33 mmol/l. The relationship between tCho levels in malignant breast lesions with their histopathological subtypes was not statistically significant (p = 0.3). CONCLUSION: Good correlation between tCho peaks and malignancy, enables SV (1)H MRS to be used as a clinically applicable, simple, yet non-invasive tool for improved specificity and diagnostic accuracy in detecting breast cancer

Left ventricular flow propagation velocity measurement: is it cast in stone?

This study aims to investigate the measurement of left ventricular flow propagation velocity, V, using phase contrast magnetic resonance imaging and to assess the discrepancies resulting from inflow jet direction and individual left ventricular size. Three V measuring techniques, namely non-adaptive (NA), adaptive positions (AP) and adaptive vectors (AV) method, were suggested and compared. We performed the comparison on nine healthy volunteers and nine post-infarct patients at four measurement positions, respectively, at one-third, one-half, two-thirds and the conventional 4\ua0cm distances from the mitral valve leaflet into the left ventricle. We found that the V measurement was affected by both the inflow jet direction and measurement positions. Both NA and AP methods overestimated V, especially in dilated left ventricles, while the AV method showed the strongest correlation with the isovolumic relaxation myocardial strain rate (r\ua0=\ua00.53, p\ua

Left ventricular diastolic function in CMR using transmitral velocity in Thalassemia patients: correlations with echocardiography

Objectives: We sought to compare diastolic values in cardiac magnetic resonance imaging (CMR) compared with echocardiography in assessing left ventricular diastolic function in patients with thalassemia. Background: Left ventricular assessment by CMR is mainly limited to the evaluation of the systolic function of the heart and is widely used in clinical practice. On the other hand, the gold standard for diastolic function assessment is echocardiography. The role of CMR in diastolic function assessment is less well-established clinically, despite the importance of the early diagnosis of diastolic dysfunction, which precedes systolic dysfunction. Methods: Forty-five subjects (mean age =27.8±10.9 y) who underwent CMR and echocardiography on the same day were evaluated. Diastolic function parameters using the technique of the transmitral flow (the E wave, the A wave, the E/A ratio, and the deceleration time) of the left ventricle were evaluated via both CMR and echocardiography. Results: The E/A ratio of the transmitral flow to assess diastolic parameters in CMR correlated well with echocardiography (r=0.745*, P<0.001), while the E and A values had weak correlations between the 2 modalities (r=0.301, P<0.05 and r=0.343, P<0.05). The measurement of the deceleration time in CMR had no statistically significant correlation with that of echocardiography (r=0.219, P=0.152). A weak correlation existed between the diastolic index measured using the technique of the fractional area change of the left ventricle and the E/A ratio measured in echocardiography (r=0.325, P[removed

Mammographic compression in Asian women

<div><p>Objectives</p><p>To investigate: (1) the variability of mammographic compression parameters amongst Asian women; and (2) the effects of reducing compression force on image quality and mean glandular dose (MGD) in Asian women based on phantom study.</p><p>Methods</p><p>We retrospectively collected 15818 raw digital mammograms from 3772 Asian women aged 35–80 years who underwent screening or diagnostic mammography between Jan 2012 and Dec 2014 at our center. The mammograms were processed using a volumetric breast density (VBD) measurement software (Volpara) to assess compression force, compression pressure, compressed breast thickness (CBT), breast volume, VBD and MGD against breast contact area. The effects of reducing compression force on image quality and MGD were also evaluated based on measurement obtained from 105 Asian women, as well as using the RMI156 Mammographic Accreditation Phantom and polymethyl methacrylate (PMMA) slabs.</p><p>Results</p><p>Compression force, compression pressure, CBT, breast volume, VBD and MGD correlated significantly with breast contact area (p<0.0001). Compression parameters including compression force, compression pressure, CBT and breast contact area were widely variable between [relative standard deviation (RSD)≥21.0%] and within (p<0.0001) Asian women. The median compression force should be about 8.1 daN compared to the current 12.0 daN. Decreasing compression force from 12.0 daN to 9.0 daN increased CBT by 3.3±1.4 mm, MGD by 6.2–11.0%, and caused no significant effects on image quality (p>0.05).</p><p>Conclusions</p><p>Force-standardized protocol led to widely variable compression parameters in Asian women. Based on phantom study, it is feasible to reduce compression force up to 32.5% with minimal effects on image quality and MGD.</p></div