Medical Specialties Commons^™

Harmonization Of Multi-Site Diffusion Tensor Imaging Data For Cervical And Thoracic Spinal Cord At 1.5 T And 3 T Using Longitudinal Combat, Devon M. Middleton, Yutong Li, Andrew Chen, Russell Shinohara, Joshua Fisher, Laura Krisa, Mark Elliot, Scott H. Faro, John H. Woo, Adam E. Flanders, Feroze B. Mohamed

Department of Radiology Faculty Papers

MRI scanner hardware, field strengths, and sequence parameters are major variables in diffusion studies of the spinal cord. Reliability between scanners is not well known, particularly for the thoracic cord. DTI data was collected for the entire cervical and thoracic spinal cord in thirty healthy adult subjects with different MR vendors and field strengths. DTI metrics were extracted and averaged for all slices within each vertebral level. Metrics were examined for variability and then harmonized using longitudinal ComBat (longComBat). Four scanners were used: Siemens 3 T Prisma, Siemens 1.5 T Avanto, Philips 3 T Ingenia, Philips 1.5 T Achieva. Average …

Characterization Of Adnexal Masses Using Contrast-Enhanced Subharmonic Imaging: A Pilot Study., Lauren J. Delaney, Priscilla Machado, Mehnoosh Torkzaban, Andrej Lyshchik, Corinne Wessner, Christine H. Kim, Md, Norman G Rosenblum, Scott D. Richard, Kirk Wallace, Flemming Forsberg

Department of Radiology Faculty Papers

OBJECTIVES: This pilot study evaluated whether contrast-enhanced subharmonic imaging (SHI) could be used to characterize adnexal masses before surgical intervention.

METHODS: Ten women (with 12 lesions) scheduled for surgery of an ovarian mass underwent an SHI examination of their adnexal region using a modified LOGIQ E9 scanner (GE Healthcare, Waukesha, WI) with an endocavitary transducer, in which digital clips were acquired by pulse destruction-replenishment SHI across the lesions. Time-intensity curves were created offline to quantitatively evaluate SHI parameters (fractional tumor perfusion, peak contrast intensity, time to peak contrast enhancement, and area under the time-intensity curve), which were compared to pathologic …

Subharmonic And Endoscopic Contrast Imaging Of Pancreatic Masses: A Pilot Study., Flemming Forsberg, Maria Stanczak, Andrej Lyshchik, David E. Loren, Patrick O'Kane, Ali Siddiqui, Thomas E. Kowalski, Cynthia Miller, Traci Fox, Ji-Bin Liu, John R. Eisenbrey

Department of Radiology Faculty Papers

OBJECTIVES: To use subharmonic imaging (SHI) to depict the vascularity of pancreatic masses compared to contrast-enhanced endoscopic ultrasound (EUS) and pathologic results.

METHODS: Sixteen patients scheduled for biopsy of a pancreatic mass were enrolled in an Institutional Review Board-approved study. Pulse-inversion SHI (transmitting/receiving at 2.5/1.25 MHz) was performed on a LOGIQ 9 system (GE Healthcare, Milwaukee, WI) with a 4C transducer, whereas contrast harmonic EUS (transmitting/receiving at 4.7/9.4 MHz) was performed with a radial endoscope (GF-UTC180; Olympus Corporation, Tokyo, Japan) connected to a ProSound SSD α-10 scanner (Hitachi Aloka, Tokyo, Japan). Two injections of the contrast agent Definity (Lantheus Medical …

Sonoelastography Of The Common Flexor Tendon Of The Elbow With Histologic Agreement: A Cadaveric Study., Andrea S Klauser, Mathias J Pamminger, Ethan J. Halpern, Mohamed M H Abd Ellah, Bernhard Moriggl, Mihra S Taljanovic, Christian Deml, Judith Sztankay, Guenter Klima, Leonhard Gruber, Werner R Jaschke

Department of Radiology Faculty Papers

Purpose To determine the correlation of the results of conventional B-mode ultrasonography (US) and compression sonoelastography with histologic results in common flexor tendons of the elbow in human cadavers. Materials and Methods Twenty-five common flexor tendons were evaluated in 16 fresh, unembalmed cadavers of 11 women with a median age of 85 years (range, 71-101 years) and five men with a median age of 78 years (range, 70-88 years). Informed consent was provided according to the last will of the donors. B-mode US results were classified as grade 1, normal tendon with homogeneous fibrillar pattern; grade 2, tendon thickening or …

Effect Of Pulse Shaping On Subharmonic Aided Pressure Estimation In Vitro And In Vivo., Ipshita Gupta, John R. Eisenbrey, Maria Stanczak, Anush Sridharan, Jaydev K. Dave, Ji-Bin Liu, Christopher Hazard, Xinghua Wang, Ping Wang, Huiwen Li, Kirk Wallace, Flemming Forsberg

Department of Radiology Faculty Papers

OBJECTIVES: Subharmonic imaging (SHI) is a technique that uses the nonlinear oscillations of microbubbles when exposed to ultrasound at high pressures transmitting at the fundamental frequency ie, f

METHODS: Eight waveforms with different envelopes were optimized with respect to acoustic power at which the SHAPE study is most sensitive. The study was run with four input transmit cycles, first in vitro and then in vivo in three canines to select the waveform that achieved the best sensitivity for detecting changes in portal pressures using SHAPE. A Logiq 9 scanner with a 4C curvi-linear array was used to acquire 2.5 MHz …

Parametric Mapping Of Contrasted Ovarian Transvaginal Sonography., Katrina Korhonen, Ryan Moore, Andrej Lyshchik, Arthur C. Fleischer

Department of Radiology Faculty Papers

The purpose of this study was to assess the accuracy of parametric analysis of transvaginal contrast-enhanced ultrasound (TV-CEUS) for distinguishing benign versus malignant ovarian masses. A total of 48 ovarian masses (37 benign and 11 borderline/malignant) were examined with TV-CEUS (Definity; Lantheus, North Billerica, MA; Philips iU22; Philips Medical Systems, Bothell, WA). Parametric images were created offline with a quantification software (Bracco Suisse SA, Geneva, Switzerland) with map color scales adjusted such that abnormal hemodynamics were represented by the color red and the presence of any red color could be used to differentiate benign and malignant tumors. Using these map …

Body Mri Artifacts In Clinical Practice: A Physicist's And Radiologist's Perspective., Martin J Graves, Donald Mitchell

Department of Radiology Faculty Papers

The high information content of MRI exams brings with it unintended effects, which we call artifacts. The purpose of this review is to promote understanding of these artifacts, so they can be prevented or properly interpreted to optimize diagnostic effectiveness. We begin by addressing static magnetic field uniformity, which is essential for many techniques, such as fat saturation. Eddy currents, resulting from imperfect gradient pulses, are especially problematic for new techniques that depend on high performance gradient switching. Nonuniformity of the transmit radiofrequency system constitutes another source of artifacts, which are increasingly important as magnetic field strength increases. Defects in …

Potentials And Limitations Of Real-Time Elastography For Prostate Cancer Detection: A Whole-Mount Step Section Analysis., Daniel Junker, Georg Schäfer, Friedrich Aigner, Peter Schullian, Leo Pallwein-Prettner, Jasmin Bektic, Wolfgang Horninger, Ethan J Halpern, Ferdinand Frauscher

Department of Radiology Faculty Papers

OBJECTIVES: To evaluate prostate cancer (PCa) detection rates of real-time elastography (RTE) in dependence of tumor size, tumor volume, localization and histological type.

MATERIALS AND METHODS: Thirdy-nine patients with biopsy proven PCa underwent RTE before radical prostatectomy (RPE) to assess prostate tissue elasticity, and hard lesions were considered suspicious for PCa. After RPE, the prostates were prepared as whole-mount step sections and were compared with imaging findings for analyzing PCa detection rates.

RESULTS: RTE detected 6/62 cancer lesions with a maximum diameter of 0-5 mm (9.7%), 10/37 with a maximum diameter of 6-10 mm (27%), 24/34 with a maximum diameter …