Myra Shapiro-Feinberg

CT findings of the chest in adults with aspirated foreign bodies.

Abstract The aim of this study was to assess the imaging findings in adult patients with tracheobronchial foreign body aspiration. Nineteen patients (11 men and 8 women; age range 26–89 years) with foreign-body aspiration were retrospectively reviewed. Nine

Parametric diffusion tensor imaging of the breast

Objectives:To investigate the ability of parametric diffusion tensor imaging (DTI), applied at 3 Tesla, to dissect breast tissue architecture and evaluate breast lesions. Materials and Methods:All protocols were approved and a signed informed consent was obtained from all subjects. The study included 21 healthy women, 26 women with 33 malignant lesions, and 14 women with 20 benign lesions. Images were recorded at 3 Tesla with a protocol optimized for breast DTI at a spatial resolution of 1.9 × 1.9 × (2–2.5) mm3. Image processing algorithms and software, applied at pixel resolution, yielded vector maps of prime diffusion direction and parametric maps of the 3 orthogonal diffusion coefficients and of the fractional anisotropy and maximal anisotropy. Results:The DTI-derived vector maps and parametric maps revealed the architecture of the entire mammary fibroglandular tissue and allowed a reliable detection of malignant lesions. Cancer lesions exhibited significantly lower values of the orthogonal diffusion coefficients, &lgr;1, &lgr;2, &lgr;3, and of the maximal anisotropy index &lgr;1-&lgr;3 as compared with normal breast tissue (P < 0.0001) and to benign breast lesions (P < 0.0009 and 0.004, respectively). Maps of &lgr;1 exhibited the highest contrast-to-noise ratio enabling delineation of the cancer lesions. These maps also provided high sensitivity/specificity of 95.6%/97.7% for differentiating cancers from benign lesions, which were similar to the sensitivity/specificity of dynamic contrast-enhanced magnetic resonance imaging of 94.8%/92.9%. Maps of &lgr;1-&lgr;3 provided a secondary independent diagnostic parameter with high sensitivity of 92.3%, but low specificity of 69.5% for differentiating cancers from benign lesions. Conclusion:Mapping the diffusion tensor parameters at high spatial resolution provides a potential novel means for dissecting breast architecture. Parametric maps of &lgr;1 and &lgr;1-&lgr;3 facilitate the detection and diagnosis of breast cancer.

Diffusion-Tensor MR Imaging of the Breast: Hormonal Regulation

PURPOSE To investigate the parameters obtained with magnetic resonance (MR) diffusion-tensor imaging (DTI) of the breast throughout the menstrual cycle phases, during lactation, and after menopause, with and without hormone replacement therapy (HRT). MATERIALS AND METHODS All protocols were approved by the internal review board, and signed informed consent was obtained from all participants. Forty-five healthy volunteers underwent imaging by using T2-weighted and DTI MR sequences at 3 T. Premenopausal volunteers (n = 16) underwent imaging weekly, four times during one menstrual cycle. Postmenopausal volunteers (n = 19) and lactating volunteers (n = 10) underwent imaging once. The principal diffusion coefficients (λ1, λ2, and λ3), apparent diffusion coefficient (ADC), fractional anisotropy (FA), and maximal anisotropy (λ1-λ3) were calculated pixel by pixel for the fibroglandular tissue in the entire breast. RESULTS In all premenopausal volunteers, the DTI parameters exhibited high repeatability, remaining almost equal along the menstrual cycle, with a low mean within-subject coefficient of variance of λ1, λ2, λ3, and ADC (1%-2% for all) and FA (5%), as well as a high intraclass correlation of 0.92-0.98. The diffusion coefficients were significantly lower (a) in the group without HRT use as compared with the group with HRT use (P < .01) and premenopausal volunteers (P < .01) and (b) in the lactating volunteers as compared with the premenopausal volunteers (P < .005). No significant differences in DTI parameters were found between premenopausal volunteers free of oral contraceptives and those who used oral contraceptives (P = .28-0.82) and between premenopausal volunteers and postmenopausal volunteers who used HRT (P = .31-0.93). CONCLUSION DTI parameters are not sensitive to menstrual cycle changes, while menopause, long-term HRT, and presence of milk in lactating women affected the DTI parameters. Therefore, the timing for performing breast DTI is not restricted throughout the menstrual cycle, whereas the modulations in diffusion parameters due to HRT and lactation should be taken into account in DTI evaluation.

Overcoming limitations in diffusion‐weighted MRI of breast by spatio‐temporal encoding

Evaluating the usefulness of diffusion‐weighted spatio‐temporal encoding (SPEN) methods to provide quantitative apparent diffusion coefficient (ADC)‐based characterizations of healthy and malignant human breast tissues, in comparison with results obtained using techniques based on spin‐echo echo planar imaging (SE‐EPI).

Can diffusion tensor anisotropy indices assist in breast cancer detection

To evaluate whether the various anisotropy indices derived from breast diffusion tensor imaging (DTI) can characterize the healthy breast structure and differentiate cancer from normal breast tissue.

Advantages and drawbacks of breast DTI

In 1965, Stejskal and Tanner developed the pulsed gradient spin echo (PGSE) technique for measuring the diffusion coefficient in solution [1]. The discovery of MRI led to the development of diffusion imaging sequences particularly sequences based on echo planar imaging – EPI that facilitate fast clinical diffusion measurements. As a result of gradient strength limitations in most human scanners, it is necessary to use long finite-width gradient pulses in order to achieve high b values and hence, the short gradient pulse approximation breaks down. Nevertheless, it was shown by Zielinski and Sen [2] that diffusion experiments with long diffusion gradient pulses still measure a physical parameter reflecting self diffusion in systems that have open geometry and large amount of restriction as is the case in most tissues. Water diffusion in tissues presents a highly complex process as the system is composed of several different compartments with partial restriction processes within the compartments. Water diffusion coefficients of tissues are not merely affected by Brownian motion, but also by additional contributions of flow, restriction by cell membrane, extracellular tortuosity and exchange between tissue compartments. Water diffusion in tissues is often anisotropic due to restriction by membranes and walls of various micro-structures. Namely, anisotropic diffusion leads to variable diffusion coefficients for various directions and hence the diffusion coefficients are described by a diffusion tensor. The diffusion of water molecules in the mammary tissue presents a particular example of restricted movement in well defined microstructures composed of the ductal/ glandular trees. The, diffusion in parallel to the walls of the ducts is free; however, it is restricted in the directions perpendicular to the walls. The extent of restriction will depend on the experimental diffusion time versus the size of the ductal and glandular regions. Blockage of the ducts by cancer cells predominantly affects the free diffusion in parallel to the walls, reducing the diffusion coefficient in all directions, and consequently the extent of anisotropy. We have applied an experimental protocol to track this anisotropic motion using diffusion gradients in 30 to 60 directions and two b-values with a relatively high diffusion time [3]. In voxels with anisotropic water diffusion the distribution of the fraction of change in signal intensity in all directions of the field gradients assumed an anisotropic ellipsoid form, whereas in voxels with isotropic

Incisional endometriomas: CT findings

We report a woman with two painful abdominal-wall masses within the scar of a previous cesarian section. The CT findings and the differential diagnosis are presented.

Monitoring In-Vivo the Mammary Gland Microstructure during Morphogenesis from Lactation to Post-Weaning Using Diffusion Tensor MRI

Lactation and the return to the pre-conception state during post-weaning are regulated by hormonal induced processes that modify the microstructure of the mammary gland, leading to changes in the features of the ductal / glandular tissue, the stroma and the fat tissue. These changes create a challenge in the radiological workup of breast disorder during lactation and early post-weaning. Here we present non-invasive MRI protocols designed to record in vivo high spatial resolution, T2-weighted images and diffusion tensor images of the entire mammary gland. Advanced imaging processing tools enabled tracking the changes in the anatomical and microstructural features of the mammary gland from the time of lactation to post-weaning. Specifically, by using diffusion tensor imaging (DTI) it was possible to quantitatively distinguish between the ductal / glandular tissue distention during lactation and the post-weaning involution. The application of the T2-weighted imaging and DTI is completely safe, non-invasive and uses intrinsic contrast based on differences in transverse relaxation rates and water diffusion rates in various directions, respectively. This study provides a basis for further in-vivo monitoring of changes during the mammary developmental stages, as well as identifying changes due to malignant transformation in patients with pregnancy associated breast cancer (PABC).

Fasting hypoglycemia in solitary fibrous tumor of the peritoneum: a diagnostic clue for an emergent situation

Solitary fibrous tumors are rare fibrous tumors found in various anatomic sites. Extrathoracic neoplasms are often symptomatic at presentation, with paraneoplastic hypoglycemia being reported as one of the associated clinical features of such slow-growing tumors. As hypoglycemia can be an emergent clinical situation, we describe a patient with a giant abdominal tumor who presented with a symptomatic hypoglycemia, which might be regarded as a diagnostic clue.