Prostate gland volume estimation: anteroposterior diameters measured on axial versus sagittal ultrasonography and magnetic resonance images

윤서연,최문형,이영준,Robert Grimm,Heinrich von Busch,Han Dongyeob,Yohan Son,Bin Lou,Ali Kamen 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.1

Purpose: The aim of this study was to evaluate the accuracy of prostate volume estimates calculated from the ellipsoid formula using the anteroposterior (AP) diameter measured on axial and sagittal images obtained through ultrasonography (US) and magnetic resonance imaging (MRI).Methods: This retrospective study included 456 patients with transrectal US and MRI from two university hospitals. Two radiologists independently measured the prostate gland diameters on US and MRI: AP diameters on axial and sagittal images, transverse, and longitudinal diameters on midsagittal images. The volume estimates, volumeax and volumesag, were calculated from the ellipsoid formula by using the AP diameter on axial and sagittal images, respectively. The prostate volume extracted from MRI-based whole-gland segmentation was considered the gold standard. The intraclass correlation coefficient (ICC) was used to evaluate the inter-method agreement between volumeax and volumesag, and agreement with the gold standard. The Wilcoxon signedrank test was used to analyze the differences between the volume estimates and the gold standard.Results: The prostate gland volume estimates showed excellent inter-method agreement, and excellent agreement with the gold standard (ICCs >0.9). Compared with the gold standard, the volume estimates were significantly larger on MRI and significantly smaller on US (P<0.001). The volume difference (segmented volume–volume estimate) was greater in patients with larger prostate glands, especially on US.Conclusion: Volumeax and volumesag showed excellent inter-method agreement and excellent agreement with the gold standard on both US and MRI. However, prostate volume was overestimated on MRI and underestimated on US.

A rapid non-destructive DNA extraction method for insects and other arthropods

Mark A. Castalanelli,Dustin L. Severtson,Cameron J. Brumley,Andras Szito,Mike Grimm,Kylie Munyard,David M. Groth,Robert G. Foottit 한국응용곤충학회 2010 Journal of Asia-Pacific Entomology Vol.13 No.3

Preparation of arthropods for morphological identification often damages or destroys DNA within the specimen. Conversely, DNA extraction methods often destroy the external physical characteristics essential for morphological identification. We have developed a rapid, simple and non-destructive DNA extraction technique for arthropod specimens. This technique was tested on four arthropod orders, using specimens that were fresh, preserved by air drying, stored in ethanol, or collected with sticky or propylene glycol traps. The technique could be completed in 20 min for Coleoptera, Diptera and Hemiptera, and 2 min for the subclass Acarina, without significant distortion, discolouration, or other damage to the specimens.

Evaluation of Transient Motion During Gadoxetic Acid–Enhanced Multiphasic Liver Magnetic Resonance Imaging Using Free-Breathing Golden-Angle Radial Sparse Parallel Magnetic Resonance Imaging

Yoon, Jeong Hee,Lee, Jeong Min,Yu, Mi Hye,Hur, Bo Yun,Grimm, Robert,Block, Kai Tobias,Chandarana, Hersh,Kiefer, Berthold,Son, Yohan Wolters Kluwer Health, Inc. All rights reserved. 2018 Investigative radiology Vol.53 No.1

<P>Objectives: The aims of this study were to observe the pattern of transient motion after gadoxetic acid administration including incidence, onset, and duration, and to evaluate the clinical feasibility of free-breathing gadoxetic acid-enhanced liver magnetic resonance imaging using golden-angle radial sparse parallel (GRASP) imaging with respiratory gating.& para;& para;Materials and Methods: In this institutional review board-approved prospective study, 59 patients who provided informed consents were analyzed. Free-breathing dynamic T1-weighted images (T1WIs) were obtained using GRASP at 3 T after a standard dose of gadoxetic acid (0.025 mmol/kg) administration at a rate of 1 mL/s, and development of transient motion was monitored, which is defined as a distinctive respiratory frequency alteration of the self-gating MR signals. Early arterial, late arterial, and portal venous phases retrospectively reconstructed with and without respiratory gating and with different temporal resolutions (nongated 13.3-second, gated 13.3-second, gated 6-second T1WI) were evaluated for image equality and motion artifacts. Diagnostic performance in detecting focal liver lesions was compared among the 3 data sets.& para;& para;Results: Transient motion (mean duration, 21.5 +/- 13.0 seconds) was observed in 40.0% (23/59) of patients, 73.9% (17/23) of which developed within 15 seconds after gadoxetic acid administration. On late arterial phase, motion artifacts were significantly reduced on gated 13.3-second and 6-second T1WI (3.64 +/- 0.34, 3.61 +/- 0.36, respectively), compared with nongated 13.3-second T1WI (3.12 +/- 0.51, P < 0.0001). Overall, image quality was the highest on gated 13.3-second T1WI (3.76 +/- 0.39) followed by gated 6-second and nongated 13.3-second T1WI (339 +/- 0.55, 2.57 +/- 0.57, P < 0.0001). Only gated 6-second T1WI showed significantly higher detection performance than nongated 13.3-second TIWI (figure of merit, 0.69 [0.63-0.76]) vs 0.60 [0.56-0.65], P = 0.004).& para;& para;Conclusions: Transient motion developed in 40% (23/59) of patients shortly after gadoxetic acid administration, and gated free-breathing T1WI using GRASP was able to consistently provide acceptable arterial phase imaging in patients who exhibited transient motion.</P>

Towards Routine Clinical Use of Radial Stack-of-Stars 3D Gradient-Echo Sequences for Reducing Motion Sensitivity

kai tobias block,Hersh Chandarana1,Sarah Milla,Mary Bruno,Tom Mulholland,Girish Fatterpekar,Mari Hagiwara,Robert Grimm,Christian Geppert,Berthold Kiefer 대한자기공명의과학회 2014 Investigative Magnetic Resonance Imaging Vol.18 No.2

Purpose : To describe how a robust implementation of a radial 3D gradient-echo sequence with stack-of-stars samplingcan be achieved, to review the imaging properties of radial acquisitions, and to share the experience from more than5000 clinical patient scans. Materials and Methods: A radial stack-of-stars sequence was implemented and installed on 9 clinical MR systems operatingat 1.5 and 3 Tesla. Protocols were designed for various applications in which motion artifacts frequently pose a problemwith conventional Cartesian techniques. Radial scans were added to routine examinations without selection of specificpatient cohorts. Results: Radial acquisitions show significantly lower sensitivity to motion and allow examinations during free breathing. Elimination of breath-holding reduces failure rates for non-compliant patients and enables imaging at higher resolution. Residual artifacts appear as streaks, which are easy to identify and rarely obscure diagnostic information. The improvedrobustness comes at the expense of longer scan durations, the requirement for fat suppression, and the nonexistence of atime-to-center value. Care needs to be taken during the configuration of receive coils. Conclusion: Routine clinical use of radial stack-of-stars sequences is feasible with current MR systems and may serve assubstitute for conventional fat-suppressed T1-weighted protocols in applications where motion is likely to degrade theimage quality

Towards Routine Clinical Use of Radial Stack-of-Stars 3D Gradient-Echo Sequences for Reducing Motion Sensitivity

Block, Kai Tobias,Chandarana, Hersh,Milla, Sarah,Bruno, Mary,Mulholland, Tom,Fatterpekar, Girish,Hagiwara, Mari,Grimm, Robert,Geppert, Christian,Kiefer, Berthold,Sodickson, Daniel K. Korean Society of Magnetic Resonance in Medicine 2014 Investigative Magnetic Resonance Imaging Vol.18 No.2

Purpose : To describe how a robust implementation of a radial 3D gradient-echo sequence with stack-of-stars sampling can be achieved, to review the imaging properties of radial acquisitions, and to share the experience from more than 5000 clinical patient scans. Materials and Methods: A radial stack-of-stars sequence was implemented and installed on 9 clinical MR systems operating at 1.5 and 3 Tesla. Protocols were designed for various applications in which motion artifacts frequently pose a problem with conventional Cartesian techniques. Radial scans were added to routine examinations without selection of specific patient cohorts. Results: Radial acquisitions show significantly lower sensitivity to motion and allow examinations during free breathing. Elimination of breath-holding reduces failure rates for non-compliant patients and enables imaging at higher resolution. Residual artifacts appear as streaks, which are easy to identify and rarely obscure diagnostic information. The improved robustness comes at the expense of longer scan durations, the requirement for fat suppression, and the nonexistence of a time-to-center value. Care needs to be taken during the configuration of receive coils. Conclusion: Routine clinical use of radial stack-of-stars sequences is feasible with current MR systems and may serve as substitute for conventional fat-suppressed T1-weighted protocols in applications where motion is likely to degrade the image quality.