Faculty Bibliography

Purpose: To determine the impact of DWI and T2WI acquisition parameters on first-order hepatic texture measures at 3T MRI.
Material(s) and Method(s): Five healthy volunteers (3 M/2F, mean 40 years old) were prospectively imaged at 3T using baseline liver free-breathing DWI and T2WI acquisition twice to assess scan-rescan repeatability. Three modifications to acquisition parameters were also performed individually: decreased averages (2 vs. 4); lower resolution (DWI: 128x96 vs. 192x144 and T2WI: 192x192 vs. 320x320); and increased slice thickness (8 vs. 4 mm). A single reader placed four co-registered hepatic ROIs using 3D Slicer v4.8.1 (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.slicer.org&d=DwIFAg&c=j5oPpO0eBH1iio48DtsedeElZfc04rx3ExJHeIIZuCs&r=EQR3KLkQ5UWCWWT7EfebH2P_dJeKQhvwk7yvrJe5GJY&m=VVljDEDjGLS_4z5jZ0uX9AVqXkAPM24hpGmZl06It_E&s=TQM-Y7ippXB-a-cXGwkMg-DnVAXTLHOB9hyiAIzdwXQ&e= ). 10 first-order histogram texture features (average of the four ROI) were compared to baseline acquisition. Percent difference (%diff) and coefficient of variance (CV) were computed using MedCalc.
Result(s): For ADC, 8 out of 10 parameters were repeat-able with <10% scan-rescan %diff; Skewness and Minimum were least repeatable with >10% scan-rescan %diff. Entropy was the only parameter that had < 10% CV and %diff for all acquisition schemes; all other parameters had >10% CV for at least one modified acquisition scheme. Skewness, Minimum, and Variance had the largest average CV. Change in slice thickness had the largest impact on most texture features. For T2WI, 9 out of 10 parameters were repeatable with <10% scan-rescan %diff; Skewness had >10% scan-rescan %diff. Entropy and Uniformity were the only two parameters that had <15% CV and %diff for all acquisition schemes. Change in slice thickness had the largest impact on most texture features.
Conclusion(s): ADC and T2WI first-order hepatic texture features, except for entropy, depend on acquisition parameters. Care must be taken to maintain identical acquisition schemes to compare changes in these features, such as after treatment

PURPOSE/OBJECTIVE:To determine the need for a standardized renal mass reporting template by analyzing reports of indeterminate renal masses and comparing their contents to stated preferences of radiologists and urologists. METHODS:The host IRB waived regulatory oversight for this multi-institutional HIPAA-compliant quality improvement effort. CT and MRI reports created to characterize an indeterminate renal mass were analyzed from 6 community (median: 17 reports/site) and 6 academic (median: 23 reports/site) United States practices. Report contents were compared to a published national survey of stated preferences by academic radiologists and urologists from 9 institutions. Descriptive statistics and Chi-square tests were calculated. RESULTS:Of 319 reports, 85% (271; 192 CT, 79 MRI) reported a possibly malignant mass (236 solid, 35 cystic). Some essential elements were commonly described: size (99% [269/271]), mass type (solid vs. cystic; 99% [268/271]), enhancement (presence vs. absence; 92% [248/271]). Other essential elements had incomplete penetrance: the presence or absence of fat in solid masses (14% [34/236]), size comparisons when available (79% [111/140]), Bosniak classification for cystic masses (54% [19/35]). Preferred but non-essential elements generally were described in less than half of reports. Nephrometry scores usually were not included for local therapy candidates (12% [30/257]). Academic practices were significantly more likely than community practices to include mass characterization details, probability of malignancy, and staging. Community practices were significantly more likely to include management recommendations. CONCLUSIONS:Renal mass reporting elements considered essential or preferred often are omitted in radiology reports. Variation exists across radiologists and practice settings. A standardized template may mitigate these inconsistencies.

Advances in multimodality imaging, providing accurate information of the irradiated target volume and the adjacent critical structures or organs at risk (OAR), has made significant improvements in delivery of the external beam radiation dose. Radiation therapy conventionally has used computed tomography (CT) imaging for treatment planning and dose delivery. However, magnetic resonance imaging (MRI) provides unique advantages: added contrast information that can improve segmentation of the areas of interest, motion information that can help to better target and deliver radiation therapy, and posttreatment outcome analysis to better understand the biologic effect of radiation. To take advantage of these and other potential advantages of MRI in radiation therapy, radiologists and MRI physicists will need to understand the current radiation therapy workflow and speak the same language as our radiation therapy colleagues. This review article highlights the emerging role of MRI in radiation dose planning and delivery, but more so for MR-only treatment planning and delivery. Some of the areas of interest and challenges in implementing MRI in radiation therapy workflow are also briefly discussed.

The original version of this article contained an error in author name. The co-author's name was published as Ivan M. Pedrosa, instead it should be Ivan Pedrosa. The original article has been corrected.

PURPOSE/OBJECTIVE:-weighted images from a single scan and allows for free-breathing acquisition. THEORY AND METHODS/UNASSIGNED:-weighted gradient-echo (GRE) data. Improved robustness is achieved by extracting a respiratory signal from the GRE data and using it for motion-weighted reconstruction. RESULTS:-weighted Dixon acquisition is possible. CONCLUSION/CONCLUSIONS:-weighted imaging in a single scan. In addition to free-breathing abdominal examination, it promises value for clinical applications that are frequently affected by motion artifacts.

INTRODUCTION/BACKGROUND:-weighted DCE-MRI. MATERIALS AND METHODS/METHODS:) and arterial input function (AIF). In addition, the effect of the conversion method on the diagnostic accuracy was evaluated with 36 breast lesions (19 benign and 17 malignant). RESULTS:. CONCLUSION/CONCLUSIONS:measurement is not available and a low FA is used for DCE-MRI, the uncertainty in the contrast kinetic parameter estimation can be reduced by using the LC method with pAIF, without compromising the diagnostic accuracy.

The disease-focused panel (DFP) program was created by the Society of Abdominal Radiology (SAR) as a mechanism to "improve patient care, education, and research" in a "particular disease or a particular aspect of a disease". The DFP on renal cell carcinoma (RCC) was proposed in 2014 and has been functional for 4 years. Although nominally focused on RCC, the scope of the DFP has included indeterminate renal masses because many cannot be assigned a specific diagnosis when detected. Since its founding, the DFP has been active in a variety of clinical, research, and educational projects to optimize the care of patients with known or suspected RCC. The DFP is utilizing multi-institutional and cross-disciplinary collaboration to differentiate benign from malignant disease, optimize the management of early stage RCC, and ultimately to differentiate indolent from aggressive cancers. Several additional projects have worked to develop a quantitative biomarker that predicts metastatic RCC response to anti-angiogenic therapy. While disease focus is the premise by which all DFPs are created, it is likely that in the future the RCC DFP will need to expand or create new panels that will focus on other specific aspects of RCC-a result that the program's founders envisioned. New knowledge creates a need for more focus.

PET imaging (PET/CT) is routinely used in evaluation of patients with various malignancies including lymphoma. Many of these patients also undergo a separate MRI examination as a problem solving tool. These PET (PET/CT) and MRI examinations are usually performed with temporal delay (at a different time and date). Introduction of hybrid PET/MR systems over the last 5 to 10 years now enables simultaneous or near simultaneous acquisition of PET and MRI information. The role of hybrid PET/MRI is being investigated by many groups in various oncologic applications such as cancer detection, staging, and assessment of treatment response. These hybrid PET/MR systems provide not only metabolic PET information but multi-parametric MRI information (such as diffusion and perfusion weighted imaging) which is temporally and spatially correlated. To test, validate, and clinically implement these systems and to take advantage of all of its various capabilities and functionalities we need to understand: - different components of the system and how they have been modified from conventional PET and M