Browsing by Author "Blomgren, Philip M."

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    Comparison of Tissue Injury from Focused Ultrasonic Propulsion of Kidney Stones Versus Extracorporeal Shock Wave Lithotripsy
    (Elsevier, 2014-01) Connors, Bret A.; Evan, Andrew P.; Blomgren, Philip M.; Hsi, Ryan S.; Harper, Jonathan D.; Sorensen, Mathew D.; Wang, Yak-Nam; Simon, Julianna C.; Paun, Marla; Starr, Frank; Cunitz, Bryan W.; Bailey, Michael R.; Lingeman, James E.; Department of Anatomy & Cell Biology, IU School of Medicine
    Purpose Focused ultrasonic propulsion is a new non-invasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, the extent of tissue injury associated with this technique is not known. As such, we quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions, and under conditions of higher power or continuous duty cycles, and compared those results to SWL injury. Materials and Methods A human calcium oxalate monohydrate stone and/or nickel beads were implanted (with ureteroscopy) into 3 kidneys of live pigs (45–55 kg) and repositioned using focused ultrasonic propulsion. Additional pig kidneys were exposed to SWL level pulse intensities or continuous ultrasound exposure of 10 minutes duration (ultrasound probe either transcutaneous or on the kidney). These kidneys were compared to 6 kidneys treated with an unmodified Dornier HM3 Lithotripter (2400 shocks, 120 SWs/min and 24 kV). Histological analysis was performed to assess the volume of hemorrhagic tissue injury created by each technique (% functional renal volume, FRV). Results SWL produced a lesion of 1.56±0.45% FRV. Ultrasonic propulsion produced no detectable lesion with the simulated clinical treatment. A lesion of 0.46±0.37% FRV or 1.15±0.49% FRV could be produced if excessive treatment parameters were used while the ultrasound probe was placed on the kidney. Conclusions Focused ultrasonic propulsion produced no detectable morphological injury to the renal parenchyma when using clinical treatment parameters and produced injury comparable in size to SWL when using excessive treatment parameters.
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    Development of a Novel Magnetic Resonance Imaging Acquisition and Analysis Workflow for the Quantification of Shock Wave Lithotripsy-Induced Renal Hemorrhagic Injury
    (Springer, 2017-10) Handa, Rajash K.; Territo, Paul R.; Blomgren, Philip M.; Persohn, Scott A.; Lin, Chen; Johnson, Cynthia D.; Jiang, Lei; Connors, Bret A.; Hutchins, Gary D.; Anatomy and Cell Biology, School of Medicine
    Introduction The current accepted standard for quantifying shock wave lithotripsy (SWL)-induced tissue damage is based on morphometric detection of renal hemorrhage in serial tissue sections from fixed kidneys. This methodology is time and labor intensive and is tissue destructive. We have developed a non-destructive magnetic resonance imaging (MRI) method that permits rapid assessment of SWL-induced hemorrhagic lesion volumes in post-mortem kidneys using native tissue contrast to reduce cycle time. Methods Kidneys of anesthetized pigs were targeted with shock waves using the Dornier Compact S lithotripter. Harvested kidneys were then prepared for tissue injury quantification. T1 weighted (T1W) and T2 weighted (T2W) images were acquired on a Siemens 3T Tim Trio MRI scanner. Images were co-registered, normalized, difference (T1W–T2W) images generated, and volumes classified and segmented using a Multi-Spectral Neural Network (MSNN) classifier. Kidneys were then subjected to standard morphometric analysis for measurement of lesion volumes. Results Classifications of T1W, T2W and difference image volumes were correlated with morphometric measurements of whole kidney and parenchymal lesion volumes. From these relationships, a mathematical model was developed that allowed predictions of the morphological parenchymal lesion volume from MRI whole kidney lesion volumes. Predictions and morphology were highly correlated (R=0.9691, n=20) and described by the relationship y=0.84x+0.09, and highly accurate with a sum of squares difference error of 0.79%. Conclusions MRI and the MSNN classifier provide a semi-automated segmentation approach, which provide a rapid and reliable means to quantify renal injury lesion volumes due to SWL.
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    Using 300 Pretreatment Shock Waves in a Voltage Ramping Protocol Can Significantly Reduce Tissue Injury During Extracorporeal Shock Wave Lithotripsy
    (Mary Ann Leibert, 2016-09-01) Connors, Bret A.; Evan, Andrew P.; Handa, Rajash K.; Blomgren, Philip M.; Johnson, Cynthia D.; Liu, Ziyue; Lingeman, James E.; Anatomy and Cell Biology, School of Medicine
    Purpose: Pretreating a pig kidney with 500 low-energy shock waves (SWs) before delivering a clinical dose of SWs (2000 SWs, 24 kV, 120 SWs/min) has been shown to significantly reduce the size of the hemorrhagic lesion produced in that treated kidney, compared with a protocol without pretreatment. However, since the time available for patient care is limited, we wanted to determine if fewer pretreatment SWs could be used in this protocol. As such, we tested if pretreating with 300 SWs can initiate the same reduction in renal lesion size as has been observed with 500 SWs., Materials and Methods: Fifteen female farm pigs were placed in an unmodified Dornier HM-3 lithotripter, where the left kidney of each animal was targeted for lithotripsy treatment. The kidneys received 300 SWs at 12 kV (120 SWs/min) followed immediately by 2000 SWs at 24 kV (120 SWs/min) focused on the lower pole. These kidneys were compared with kidneys given a clinical dose of SWs with 500 SW pretreatment, and without pretreatment. Renal function was measured both before and after SW exposure, and lesion size analysis was performed to assess the volume of hemorrhagic tissue injury (% functional renal volume, FRV) created by the 300 SW pretreatment regimen., Results: Glomerular filtration rate fell significantly in the 300 SW pretreatment group by 1 hour after lithotripsy treatment. For most animals, low-energy pretreatment with 300 SWs significantly reduced the size of the hemorrhagic injury (to 0.8% ± 0.4%FRV) compared with the injury produced by a typical clinical dose of SWs., Conclusions: The results suggest that 300 pretreatment SWs in a voltage ramping treatment regimen can initiate a protective response in the majority of treated kidneys and significantly reduce tissue injury in our model of lithotripsy injury.