Fast Magnetic Resonance Imaging on Regions of Interest: From Sensing to Reconstruction

Background/Aim. Bone scintigraphy is well-known method for the detection of neoplastic lesions with a high sensitivity and, at the same time, a lower specificity. On the other hand magnetic resonance imaging (MRI) is previously established noninvasive imaging method regarding its diagnostic specificity. The aim of this study was to determine the possibilities and to correlate two different diagnostic methods - bone scintigraphy and MRI in the detection of bone metastasis in the spine and pelvic bones. Methods. A total of 123 patients who underwent both bone scintigraphy and spine and pelvic MRI on 1.5 T MR imager were enrolled in this study. Scans were subsequently analyzed in total and divided in regions of interest (cervical, upper, middle and lower thoracic, upper and lower lumbar and pelvic region, which includes sacral spinal segment); afterwards the total number of 585 matching regions were compared and statistically analyzed. Results. The statistical analysis demonstrated significant correlation between the findings of both methods in total. Divided by regions of interest, significant degrees of correlation were demonstrated in all of them, except in the cervical spine region where the r-value was in the range of low correlation. Conclusion. Having a high mutual correlation, bone scintigraphy and MRI are to be considered as the complementary diagnostic methods in the detection of bone metastases. Still, increased diagnostic potential of MRI may highlights negative bone scintigraphy findings in the patients with solitary metastatic lesions or diffuse vertebral infiltration. Advances in the bone scintigraphy (single photon emission tomography - SPECT, SPECTcomputed tomography - SPECT-CT) and MRI (whole body MRI, diffusion MRI), make it possible the diagnostic potential of both methods will result in a further improvement in bone metastasis detection.

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Resting-State Functional Magnetic Resonance Imaging Connectivity Between Semantic and Phonological Regions of Interest May Inform Language Targets in Aphasia

Journal of Speech Language and Hearing Research ◽

10.1044/2020_jslhr-19-00117 ◽

2020 ◽

Vol 63 (9) ◽

pp. 3051-3067

Author(s):

Amy E. Ramage ◽

Semra Aytur ◽

Kirrie J. Ballard

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Magnetic Resonance Imaging ◽

Resting State ◽

Brain Regions ◽

Regions Of Interest ◽

Healthy Controls ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Language Performance

Purpose Brain imaging has provided puzzle pieces in the understanding of language. In neurologically healthy populations, the structure of certain brain regions is associated with particular language functions (e.g., semantics, phonology). In studies on focal brain damage, certain brain regions or connections are considered sufficient or necessary for a given language function. However, few of these account for the effects of lesioned tissue on the “functional” dynamics of the brain for language processing. Here, functional connectivity (FC) among semantic–phonological regions of interest (ROIs) is assessed to fill a gap in our understanding about the neural substrates of impaired language and whether connectivity strength can predict language performance on a clinical tool in individuals with aphasia. Method Clinical assessment of language, using the Western Aphasia Battery–Revised, and resting-state functional magnetic resonance imaging data were obtained for 30 individuals with chronic aphasia secondary to left-hemisphere stroke and 18 age-matched healthy controls. FC between bilateral ROIs was contrasted by group and used to predict Western Aphasia Battery–Revised scores. Results Network coherence was observed in healthy controls and participants with stroke. The left–right premotor cortex connection was stronger in healthy controls, as reported by New et al. (2015) in the same data set. FC of (a) connections between temporal regions, in the left hemisphere and bilaterally, predicted lexical–semantic processing for auditory comprehension and (b) ipsilateral connections between temporal and frontal regions in both hemispheres predicted access to semantic–phonological representations and processing for verbal production. Conclusions Network connectivity of brain regions associated with semantic–phonological processing is predictive of language performance in poststroke aphasia. The most predictive connections involved right-hemisphere ROIs—particularly those for which structural adaptions are known to associate with recovered word retrieval performance. Predictions may be made, based on these findings, about which connections have potential as targets for neuroplastic functional changes with intervention in aphasia. Supplemental Material https://doi.org/10.23641/asha.12735785

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