Diagnostic potential of ultrafast contrast-enhanced MRI of the breast in hypervascularized lesions: are there advantages in comparison with standard dynamic MRI?

PURPOSE: Our goal was to evaluate possible diagnostic advantages of ultrafast MRI of the breast in comparison with dynamic MRI. METHOD: Thirty patients with 35 hypervascularized lesions were selected prospectively after undergoing standard dynamic MRI (temporal resolution 87 s). Patients underwent additional ultrafast imaging (temporal resolution 2 s). Onset, rate, and pattern of enhancement were analyzed. RESULTS: Histopathology revealed 15 malignant and 20 benign lesions (3-40 mm). Enhancement pattern was centripetal in 2 benign and 4 malignant lesions, centrifugal in 5 and 3, and homogeneous in 13 and 8. The onset of lesion enhancement ranged from 3 to 13 s (parenchymal enhancement 4-14 s) and the rate of enhancement from 3 to 70%/s, both without any correlation to the histologic diagnosis. There was no significant difference between ultrafast and standard dynamic MRI. CONCLUSION: Ultrafast MRI does not provide additional information in comparison with standard dynamic MRI.     

Does dynamic post contrast MRI of the breast have a role in screening of high risk patients?

Purpose

The aim of this work is to assess the role of dynamic post contrast MRI of the breast as an adjunct to mammography in screening high risk women especially those with dense breast parenchyma.

Patients and methods

A prospective study of 70 high risk cases of breast cancer who are examined by mammography and MRM to evaluate the results.

Results

MRM proved higher sensitivity, specificity, positive and negative predictive values.

Conclusion

MRM proved to be of high importance in diagnosis and management of breast cancer.     

Are there differences in postural regulation according to the level of competition in judoists?

The aim of this work was to study the posturokinetic capacities and use of visual information by judoists according to their level of competition. Twenty male judoists aged between 16 and 19 took part. They were separated into two groups: those that competed at regional level and those that competed at national and international level. Static balance was measured on a force platform. No difference was seen between the two groups. However, it seems that visual information is more important to the higher level judoists. Perhaps the level of competition influences the sensory canals involved in balance.     

Clinical application of bilateral high temporal and spatial resolution dynamic contrast-enhanced magnetic resonance imaging of the breast at 7 T

Objective

The objective of our study was to evaluate the clinical application of bilateral high spatial and temporal resolution dynamic contrast-enhanced magnetic resonance imaging (HR DCE-MRI) of the breast at 7 T.

Methods

Following institutional review board approval 23 patients with a breast lesion (BIRADS 0, 4–5) were included in our prospective study. All patients underwent bilateral HR DCE-MRI of the breast at 7 T (spatial resolution of 0.7 mm³ voxel size, temporal resolution of 14 s). Two experienced readers (r1, r2) and one less experienced reader (r3) independently assessed lesions according to BI-RADS®. Image quality, lesion conspicuity and artefacts were graded from 1 to 5. Sensitivity, specificity and diagnostic accuracy were assessed using histopathology as the standard of reference.

Results

HR DCE-MRI at 7 T revealed 29 lesions in 23 patients (sensitivity 100 % (19/19); specificity of 90 % (9/10)) resulting in a diagnostic accuracy of 96.6 % (28/29) with an AUC of 0.95. Overall image quality was excellent in the majority of cases (27/29) and examinations were not hampered by artefacts. There was excellent inter-reader agreement for diagnosis and image quality parameters (κ?=?0.89–1).

Conclusion

Bilateral HR DCE-MRI of the breast at 7 T is feasible with excellent image quality in clinical practice and allows accurate breast cancer diagnosis.

Key points

? Dynamic contrast-enhanced 7-T MRI is being developed in several centres. ? Bilateral high resolution DCE-MRI of the breast at 7 T is clinically applicable. ? 7-T HR DCE-MRI of the breast provides excellent image quality. ? 7-T HR DCE-MRI should detect breast cancer with high diagnostic accuracy.     

Breast MRI: Are T2 IR sequences useful in the evaluation of breast lesions?

Aim

To evaluate the potential role of signal intensities calculated in T2 images as an adjunctive parameter in the analysis of mass-like enhancements classified as BIRADS (Breast Imaging Reporting and Data System) assessment categories 2, 3, 4 or 5 with the standard T1 criteria.

Materials and methods

After a retrospective review of 338-breast Magnetic Resonance Imaging (MRI) performed for the evaluation of a suspicious lesion we selected a group of 65 mass-like enhancements ranging from 5 to 20 mm, classified as BIRADS assessment categories 2, 3, 4 or 5, histologically proved. In all cases we calculated the ratio between the signal intensity (SI) of the nodule and the pectoralis major muscle (LMSIR, lesion to muscle signal intensity ratio) with a multiROIs (region of interest) analysis on T2 images. A ROC analysis was performed to test the ability of the two diagnostic parameters separately considered (BIRADS and LMSIR) and combined in a new mono-dimensional variable obtained by a computerized discriminant function.

Results

Histological examination assessed 34 malignant lesions (52.3%) and 31 benign lesions (47.7%). The evaluation of ROC curves gave the following results: BIRADS area under the curve (AUC) 0.913, S.E. 0.0368, LMSIR AUC 0.854, S.E. 0.0487, combined BIRADS-LMSIR AUC 0.965, S.E. 0.0191 with a definitive increase in the AUC between the overall ROC area and those of the two diagnostic modalities separately considered.

Discussion

T2-weighted SI assessment with LMSIR measurement improves the diagnostic information content of standard breast MRI and can be considered a promising potential tool in the differential diagnosis of mass-like enhancements judged as borderline lesions (BIRADS 3 and 4).     

Does MRI help in the assessment of inflammatory breast disorders?

Objective

The aim of work is to evaluate the role of magnetic resonance imaging in the assessment of different entities of inflammatory breast disorders.

Materials and methods

Eighty-one non-lactating patients with mastitis had been evaluated by post contrast MR imaging; their ages ranged from 22 to 70 years (Average age: 41.6 years). MRI data analysis was performed regarding qualitative criteria and parametric color maps for image post processing. Diagnosis was made up regarding resolution in follow up sessions for simple mastitis and biopsy were done for cases with suspicious imaging findings.

Results

Mammary interstitial edema with no masses or abnormal enhancement was elicited in 28.4% (n = 23/81). T2-weighed and post contrast series were the sequences of choice to rely upon in evaluation. T2 had demonstrated lesions in 64.2% (n = 52/81) and contrast uptake was detected in 68% (n = 55/81). Quantitative analysis was overlapping.MR imaging had displayed sensitivity, specificity and accuracy of 87.5%, 72.3%, and 75.4% respectively in differentiating benign forms of mastitis from malignant ones.

Conclusion

In inflammatory breast disorders, MR imaging can precisely delineate disease extent and monitor response to therapy. Immediate distinction between infectious/non-infectious and malignant mastitis is difficult to be obtained.     

Does the degree of background enhancement in breast MRI affect the detection and staging of breast cancer?

Objective  

The purpose of this study was to assess the influence of background enhancement on the detection and staging of breast cancer using MRI as an adjunct to mammography or ultrasound.     

Do T2-weighted pulse sequences help with the differential diagnosis of enhancing lesions in dynamic breast MRI?

In this study, our purpose was to determine whether T2-weighted images are a useful diagnostic adjunct for lesion characterization in dynamic breast MRI. On a 1.5-T system, 205 enhancing benign and malignant breast tumors were examined. The standardized protocol consisted of a T2-weighted turbo spin echo (TSE) pulse sequence with and without spectral fat suppression (SPIR), followed by a two-dimensional dynamic series with subtraction postprocessing. In 59 cases, T2*-weighted gradient-echo images also were obtained. Two independent radiologists visually rated the lesions (101 malignant, 104 benign) as having either a low or a high signal with respect to the adjacent glandular tissue. To assess age dependency of lesion enhancement velocities and T2-TSE signal intensities, we compared the results for patients at or below the age of 50 (group A), between 40 and 50 (group B), and beyond the age of 50 (group C). In T2-weighted TSE images, breast cancers were iso- or hypointense with respect to breast parenchyma in 87% of cases, whereas fibroadenomas were hyperintense in 71%. Visual assessment of lesion appearance in T2-weighted TSE images allowed to distinguish between fibroadenomas and breast cancers, with a respective sensitivity, specificity, positive predictive value, and negative predictive value of 72%, 75%, 46%, and 90% for young patients; 94%, 66%, 78%, and 89% for the patients between 40 and 50; and 89%, 62%, 85%, and 68% for the patients over 50 years of age. No significant difference was found for the distribution of signal intensities of lesions in T2*-weighted images or in fat-suppressed images. In a contrast-enhancing breast lesion, careful analysis of T2-weighted TSE images can improve differential diagnosis. The accuracy of this criterion varies with age.     

Are there limits to respect for autonomy in bioethics?

I discuss the significance of respect for personal autonomy in bioethics with reference to its practical expression: rational informed patient choice. The question is whether, given the apparent practical limitations to this notion, bioethical autonomy should be seen as an absolute. After a historical review of informed consent and its development, I discuss the requirements for informed consent. Some inherent tensions are evaluated, as is the applicability of the notion that in order to be legitimate, autonomy should do some ethical work. Limits to the notion of informed consent are explored with reference to six examples: the right of women to reproductive autonomy; the autonomy of legally minor Jehovah's Witnesses; autonomy in cosmetic surgery; inappropriate treatment; autonomy and human medical research, and euthanasia and other end-of-life options. The discussion is within a South African framework with reference to other jurisdictions and decisions where appropriate. I conclude that whilst some unusual instances of limitation of bioethical informed consent might be ethically justifiable, the arguments presented point to the opposite: the unfounded limitation of informed consent.     

Contrast-enhanced ultrasonography (CEUS) vs. MRI of the small bowel in the evaluation of Crohn’s disease activity

Purpose

The presence of disease activity in Crohn??s disease (CD) is one of the main parameters used to establish whether optimal therapy should be drug therapy or surgery. However, a major problem in monitoring CD is the common mismatch between the patient??s symptoms and imaging objective signs of disease activity. Bowel ultrasonography (US) has emerged as a low-cost, noninvasive technique in the diagnosis and follow-up of patients with CD. Accordingly, the use of contrastenhanced US (CEUS) has made possible an evaluation of the vascular enhancement pattern, similar to the use of magnetic resonance imaging (MRI). The aim of our study was to evaluate the role of CEUS in comparison with small-bowel MRI for assessing Crohn??s disease activity.

Materials and methods

We prospectively enrolled 30 consecutive patients with known CD. Clinical and laboratory data were compared with imaging findings obtained from MRI and CEUS of the small bowel. MRI was performed with a 1.5-T system using phased-array coils and biphasic orally administered contrast agent prior to and after gadolinium chelate administration. We performed US with a 7.5-MHz linear-array probe and a second-generation contrast agent. The parameters analysed in both techniques were the following: lesion length, wall thickness, layered wall appearance, comb sign, fibroadipose proliferation, presence of enlarged lymph nodes and stenosis. We classified parietal enhancement curves into two types in relation to the contrast pattern obtained with the time-intensity curves at MRI and CEUS: (1) quick washin, quick washout, (2) slow washin, plateau with a slow washout.

Results

Comparison between Crohn??s disease activity index (CDAI) and MRI showed a low correlation, with an rho=0.398; correlation between CDAI-laboratory data and CEUS activity was low, with rho=0.354; correlation between MRI activity and CEUS activity was good, with rho = 0.791; high correlation was found between CEUS and MRI of the small bowel when assessing wallthickness, lymph nodes and comb sign; good correlation was fund when assessing layered wall appearance, disease extension and fibroadipose proliferation. At MRI, timeintensity curves for 12/30 patients were active, compared with for 14/30 patients at CEUS; therefore there was a poor correlation between curve on CEUS and curve on MRI (r=0.167; p=0.36).

Conclusions

The use of CEUS can be recommended if there is a discrepancy between MRI and clinical/laboratory parameters. MRI of the small bowel remains the most accurate method for evaluating disease activity.     

High field MRI in the diagnosis of multiple sclerosis: high field–high yield?

Following the approval of the U.S. Food and Drug Administration (FDA), high field magnetic resonance imaging (MRI) has been increasingly incorporated into the clinical setting. Especially in the field of neuroimaging, the number of high field MRI applications has been increased dramatically. Taking advantage on increased signal-to-noise ratio (SNR) and chemical shift, higher magnetic field strengths offer new perspectives particularly in brain imaging and also challenges in terms of several technical and physical consequences. Over the past few years, many applications of high field MRI in patients with suspected and definite multiple sclerosis (MS) have been reported including conventional and quantitative MRI methods. Conventional pulse sequences at 3 T offers higher lesion detection rates when compared to 1.5 T, particularly in anatomic regions which are important for the diagnosis of patients with MS. MR spectroscopy at 3 T is characterized by an improved spectral resolution due to increased chemical shift allowing a better quantification of metabolites. It detects significant axonal damage already in patients presenting with clinically isolated syndromes and can quantify metabolites of special interest such as glutamate which is technically difficult to quantify at lower field strengths. Furthermore, the higher susceptibility and SNR offer advantages in the field of functional MRI and diffusion tensor imaging. The recently introduced new generation of ultra-high field systems beyond 3 T allows scanning in submillimeter resolution and gives new insights into in vivo MS pathology on MRI. The objectives of this article are to review the current knowledge and level of evidence concerning the application of high field MRI in MS and to give some ideas of research perspectives in the future.     

Is there a role for dynamic swallowing MRI in the assessment of gastroesophageal reflux disease and oesophageal motility disorders?

Objectives  

To evaluate the diagnostic value of dynamic MRI swallowing in patients with symptoms of Gastroesophageal Reflux Disease (GERD).     

Ultrafast Dynamic Contrast-enhanced MRI of the Breast: How Is It Used?

Ultrafast dynamic contrast-enhanced (UF-DCE) MRI is a new approach to capture kinetic information in the very early post-contrast period with high temporal resolution while keeping reasonable spatial resolution. The detailed timing and shape of the upslope in the time–intensity curve are analyzed. New kinetic parameters obtained from UF-DCE MRI are useful in differentiating malignant from benign lesions and in evaluating prognostic markers of the breast cancers. Clinically, UF-DCE MRI contributes in identifying hypervascular lesions when the background parenchymal enhancement (BPE) is marked on conventional dynamic MRI. This review starts with the technical aspect of accelerated acquisition. Practical aspects of UF-DCE MRI include identification of target hypervascular lesions from marked BPE and diagnosis of malignant and benign lesions based on new kinetic parameters derived from UF-DCE MRI: maximum slope (MS), time to enhance (TTE), bolus arrival time (BAT), time interval between arterial and venous visualization (AVI), and empirical mathematical model (EMM). The parameters derived from UF-DCE MRI are compared in terms of their diagnostic performance and association with prognostic markers. Pitfalls of UF-DCE MRI in the clinical situation are also covered. Since UF-DCE MRI is an evolving technique, future prospects of UF-DCE MRI are discussed in detail by citing recent evidence. The topic covers prediction of treatment response, multiparametric approach using DWI-derived parameters, evaluation of tumor-related vessels, and application of artificial intelligence for UF-DCE MRI. Along with comprehensive literature review, illustrative clinical cases are used to understand the value of UF-DCE MRI.     

Cluster analysis of signal-intensity time course in dynamic breast MRI: does unsupervised vector quantization help to evaluate small mammographic lesions?

We examined whether neural network clustering could support the characterization of diagnostically challenging breast lesions in dynamic magnetic resonance imaging (MRI). We examined 88 patients with 92 breast lesions (51 malignant, 41 benign). Lesions were detected by mammography and classified Breast Imaging and Reporting Data System (BIRADS) III (median diameter 14 mm). MRI was performed with a dynamic T1-weighted gradient echo sequence (one precontrast and five postcontrast series). Lesions with an initial contrast enhancement >or=50% were selected with semiautomatic segmentation. For conventional analysis, we calculated the mean initial signal increase and postinitial course of all voxels included in a lesion. Secondly, all voxels within the lesions were divided into four clusters using minimal-free-energy vector quantization (VQ). With conventional analysis, maximum accuracy in detecting breast cancer was 71%. With VQ, a maximum accuracy of 75% was observed. The slight improvement using VQ was mainly achieved by an increase of sensitivity, especially in invasive lobular carcinoma and ductal carcinoma in situ (DCIS). For lesion size, a high correlation between different observers was found (R(2) = 0.98). VQ slightly improved the discrimination between malignant and benign indeterminate lesions (BIRADS III) in comparison with a standard evaluation method.     

Is there any correlation between model-based perfusion parameters and model-free parameters of time-signal intensity curve on dynamic contrast enhanced MRI in breast cancer patients?

Objective

To find out any correlation between dynamic contrast-enhanced (DCE) model-based parameters and model-free parameters, and evaluate correlations between perfusion parameters with histologic prognostic factors.

Methods

Model-based parameters (Ktrans, Kep and Ve) of 102 invasive ductal carcinomas were obtained using DCE-MRI and post-processing software. Correlations between model-based and model-free parameters and between perfusion parameters and histologic prognostic factors were analysed.

Results

Mean Kep was significantly higher in cancers showing initial rapid enhancement (P?=?0.002) and a delayed washout pattern (P?=?0.001). Ve was significantly lower in cancers showing a delayed washout pattern (P?=?0.015). Kep significantly correlated with time to peak enhancement (TTP) (ρ?=??0.33, P?<?0.001) and washout slope (ρ?=?0.39, P?=?0.002). Ve was significantly correlated with TTP (ρ?=?0.33, P?=?0.002). Mean Kep was higher in tumours with high nuclear grade (P?=?0.017). Mean Ve was lower in tumours with high histologic grade (P?=?0.005) and in tumours with negative oestrogen receptor status (P?=?0.047). TTP was shorter in tumours with negative oestrogen receptor status (P?=?0.037).

Conclusions

We could acquire general information about the tumour vascular physiology, interstitial space volume and pathologic prognostic factors by analyzing time-signal intensity curve without a complicated acquisition process for the model-based parameters.

Key points

? Kep mainly affected the initial and delayed curve pattern in time–signal intensity curve. ? There is significant correlation between model-based and model-free parameters. ? We acquired information about tumour vascular physiology, interstitial space volume and prognostic factors.