Lasers in Surgery and Medicine, 2014, Vol.46(7), p.558(5)
To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1002/lsm.22262/abstract Byline: Stefan Vallo, Katrin Eichler, Kathrin Kelly, Boris Schulz, Georg Bartsch, Axel Haferkamp, Thomas J Vogl, Stephan Zangos Purpose To evaluate the clinical value of different magnetic resonance imaging (MRI) sequences for a real-time thermo-monitoring during laser-induced thermotherapy (LITT) in kidneys. Methods Twenty-eight ex vivo pig kidneys were treated with laser ablation under MR guidance in a high-field MR scanner (Magnetom Espree or Avanto Fit, Siemens, Germany). For the thermal ablation of the kidney, a neodymium yttrium-aluminum-garnet (Nd:YAG) laser was used in combination with a special protective catheter (length 43cm, 4 French) which is sealed at the distal end. First, ablation was performed for 7, 10, and 13minutes using FLASH sequences for investigation of time-dependent growth of lesion size. In the second step, we evaluated the optimal imaging sequence during a 7minutes ablation of the kidney and after cooling using four different MR sequences (Haste, FLASH, radial VIBE, and Caipirinha DIXON). Results Macroscopic lesion volume increased from 3,784[+ or -]1,525mm.sub.3 to 7,683[+ or -]5,756mm.sub.3 after the ablation from 7 to 13minutes and MR volume ranged from 2,107[+ or -]1,674mm.sub.3 to 2,934[+ or -]1,549mm.sub.3 after the ablation from 7 to 13minutes. During ablation, FLASH (132[+ or -]34%) and radial VIBE (120[+ or -]43%) sequences displayed lesion volumes most efficiently with a trend to overestimation. The Caipirinha DIXON (323[+ or -]24%) sequence overestimated the volumes significantly during real-time monitoring. The volumes measured by MRI with FLASH (61[+ or -]30%), Haste (67[+ or -]28%), or radial VIBE (48[+ or -]14%) sequences after cooling of the kidney after ablation were always underestimated. The Caipirinha DIXON (142[+ or -]2%) sequence still overestimated the lesion volume after cooling of the kidney. Conclusion LITT is a feasible ablation modality in kidney tissue. Moreover, macroscopic and MR lesion volume increases time-dependently. For online monitoring, radial VIBE and FLASH sequences seem to be most efficient. Lasers Surg. Med. 46:558-562, 2014. [c] 2014 Wiley Periodicals, Inc. Article Note: Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Magnetic Alloys – Evaluation ; Magnetic Alloys – Comparative Analysis ; Rare Earth Metals – Evaluation ; Rare Earth Metals – Comparative Analysis ; Ablation (Surgery) – Comparative Analysis ; Rare Earth Metal Compounds – Evaluation ; Rare Earth Metal Compounds – Comparative Analysis ; Diagnostic Imaging – Comparative Analysis ; Lasers – Evaluation ; Lasers – Comparative Analysis