High‐dose Gd‐DTPA vs. Bis‐Gd‐mesoporphyrin for monitoring laser‐induced tissue necrosis

Abstract

Purpose:To compare Bis-Gd-mesoporphyrin (Bis-Gd-MP), a contrast agent with a reported high affinity to necrotic tissue, with high-dose gadopentate dimeglumin (Gd-DTPA) for defining laser-induced muscle and liver necrosis by contrast-enhanced (CE) MRI. Materials and Methods:Laser-induced interstitial thermotherapy (LITT) was performed in the muscle and liver tissue of New Zealand White rabbits (1500 J and 2100 J; n ϭ 80 lesions). The animals were randomly assigned to a group that received 0.3 mmol/kg bw Gd-DTPA or a group that received 0.05 mmol/kg bw Bis-Gd-MP. Following contrast injection, dynamic MRI was performed on muscle lesions with a T1-weighted, two-dimensional, fast low-angle shot (FLASH) sequence. The liver and muscle lesions were then repeatedly imaged for six hours after contrast injection using a T1-weighted spin-echo (SE) sequence. Central and peripheral lesion enhancement was determined and correlated with gross pathology and microscopy findings.Results: Both contrast agents allowed precise determination of lesion diameters with an average accuracy of 6.8% Ϯ 1.3%. Rim enhancement during dynamic MRI was superior for Gd-DTPA (P Ͻ 0.001) and revealed slightly higher lesion diameters compared to the results of follow-up MR studies. A persistent enhancement of necrotic liver and muscle tissue was observed for both contrast agents throughout the observation period, suggesting that simple diffusion-type processes may underlie the supposed affinity of Bis-Gd-MP for tissue necrosis. Conclusion:Bis-Gd-MP and Gd-DTPA are equally well suited for postinterventional lesion assessment in LITT.

Comparison of Fenestra VC Contrast-Enhanced Computed Tomography Imaging With Gadopentetate Dimeglumine and Ferucarbotran Magnetic Resonance Imaging for the In Vivo Evaluation of Murine Liver Damage After Ischemia and Reperfusion

“…From the kinetic of delayed hyperenhancement, reaching peak intensity values after approximately 15 minutes, one might speculate that gadopentetate dimeglumine follows a diffusion gradient between the vascular space and the damaged/necrotic tissue. This is also supported by data by Bremer et al, 29 who investigated laser-induced tissue necrosis and showed that this effect of delayed enhancement is still apparent even after longer postinjection observation periods, and no washout phenomenon was observed in these histologically verified necrotic areas for up to 12 hours. Moreover, the MRI data showed that the regions of delayed hyperenhancement expand as a function of duration of ischemia from focal areas (45 minutes ischemia, 24 hours reperfusion, Fig.…”

“…15,26,27 Moreover, gadopentetate dimeglumine has been considered to be a valuable tool for the determination of tissue necrosis in vivo, eg, by laser-induced interstitial tissue ablation. 28,29 It was also shown that gadopentetate dimeglumine accumulates in necrotic liver tissue and therefore might be a suitable contrast medium to visualize the consequences of hepatic ischemia and reperfusion. In an experimental setting similar to that used for CT imaging, we confirmed that short periods of LLL ischemia (30 minutes, Fig.…”

Tumor models and specific contrast agents for small animal imaging in oncology

“…This development in clinical oncology has posed an urgent need for early therapeutic assessment that can noninvasively to differentiate residual tumor tissue and benign periablational reactive tissues after the minimally invasive ablations. While virtually impossible to achieve with nonspecific CAs including macromolecular blood pool CAs or commercial ECF CAs [77][78][79][80], the use of NACAs in this regard may fundamentally solve the problems raised by two recent articles [79,80]. Thus, functioning as a virtual biopsy technique, the resultant NACA-enhanced MRI would provide unconditional and unambiguous visual outcomes (Fig.…”

Molekulare Bildgebung von Apoptose und Nekrose - Zellbiologische Grundlagen und Einsatz in der Onkologie

“…Der Einsatz von Metalloporphyrinen zur Detektion von Nekrose sollte kritisch beurteilt werden, da kürzlich anhand eines Tierexperiments gezeigt werden konnte, dass sich Bis-Gd-Mesoporphyrin und Gd-DTPA gleichermaßen in LITT-induzierter Nekrose anreicherten [25].…”

“…Wie bereits dargelegt, sollte das Anreicherungsverhalten von Metalloporphyrinen kritisch beurteilt werden, da in nekrotischem Gewebe bereits mithilfe von Gd-DTPA eine entsprechende Akkumulation erzielt werden kann [25].…”