TY - JOUR
T1 - Jeannette wilkins award
T2 - Can locally delivered gadolinium be visualized on MRI? a pilot study infection
AU - Giers, Morgan B.
AU - Estes, Chris S.
AU - McLaren, Alex C.
AU - Caplan, Michael
AU - McLemore, Ryan
N1 - Funding Information:
One of the authors (MBG) receives funding from the Ira A. Fulton Schools of Engineering, and one or more of the authors (ACM, MBG, RM, MRC) receive funding from the Arizona Biomedical Research Commission (Grant 1116). One or more of the authors (RM, ACM) receive funding from Banner Good Samaritan Medical Center, and the authors received seed funding for this project from the Herbert Louis fund at OREF. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research. This work was performed at St Joseph’s Hospital, Banner Good Samaritan Medical Center, Phoenix, AZ, USA, and Arizona State University, Tempe, AZ, USA.
PY - 2012/10
Y1 - 2012/10
N2 - Background: Management of orthopaedic infections relies on débridement and local delivery of antimicrobials; however, the distribution and concentration of locally delivered antimicrobials in postdébridement surgical sites is unknown. Gadolinium-DTPA (Gd-DTPA) has been proposed as an imaging surrogate for antimicrobials because it is similar in size and diffusion coefficient to gentamicin. Questions/purposes: Is in vivo distribution of locally delivered Gd-DTPA (1) visible on MRI; (2) reliably visualized by different observers; (3) affected by the anatomic delivery site; and (4) affected by the in vitro release rate from the delivery vehicle? Methods: Twenty-four local delivery depots were imaged in nine rabbits using two anatomic sites (intramedullary canal, quadriceps) with Gd-DTPA in intermediate-porosity polymethylmethacrylate (PMMA) or high-porosity PMMA; six of the nine rabbits also had Gd-DTPA delivered in collagen at a third site (hamstring). A total of 45,000 fat-suppressed T1-weighted RARE scans were acquired using a 7-T Bruker Biospec MRI: nine rabbits, 2-mm slices over 10 cm, four TR values, 25 time periods (pre, every 15 minutes for 6 hours). T1 maps were constructed at every time period. Gd-DTPA distribution was observed qualitatively on the T1 maps. Interobserver reliability was determined. Results: Locally delivered Gd-DTPA was visible. Interobserver agreement was excellent. Intramuscular delivery followed intermuscular planes; intramedullary delivery was contained within the canal by bone. Distribution from collagen decreased after 1 hour but from PMMA increased over 6 hours. Conclusions: Locally delivered Gd-DTPA can be visualized on MRI; distribution is affected by anatomical location and delivery vehicle. Clinical Relevance: Contrast-based imaging using locally delivered Gd-DTPA may be useful as an antibiotic surrogate to determine antibiotic distribution in surgical sites.
AB - Background: Management of orthopaedic infections relies on débridement and local delivery of antimicrobials; however, the distribution and concentration of locally delivered antimicrobials in postdébridement surgical sites is unknown. Gadolinium-DTPA (Gd-DTPA) has been proposed as an imaging surrogate for antimicrobials because it is similar in size and diffusion coefficient to gentamicin. Questions/purposes: Is in vivo distribution of locally delivered Gd-DTPA (1) visible on MRI; (2) reliably visualized by different observers; (3) affected by the anatomic delivery site; and (4) affected by the in vitro release rate from the delivery vehicle? Methods: Twenty-four local delivery depots were imaged in nine rabbits using two anatomic sites (intramedullary canal, quadriceps) with Gd-DTPA in intermediate-porosity polymethylmethacrylate (PMMA) or high-porosity PMMA; six of the nine rabbits also had Gd-DTPA delivered in collagen at a third site (hamstring). A total of 45,000 fat-suppressed T1-weighted RARE scans were acquired using a 7-T Bruker Biospec MRI: nine rabbits, 2-mm slices over 10 cm, four TR values, 25 time periods (pre, every 15 minutes for 6 hours). T1 maps were constructed at every time period. Gd-DTPA distribution was observed qualitatively on the T1 maps. Interobserver reliability was determined. Results: Locally delivered Gd-DTPA was visible. Interobserver agreement was excellent. Intramuscular delivery followed intermuscular planes; intramedullary delivery was contained within the canal by bone. Distribution from collagen decreased after 1 hour but from PMMA increased over 6 hours. Conclusions: Locally delivered Gd-DTPA can be visualized on MRI; distribution is affected by anatomical location and delivery vehicle. Clinical Relevance: Contrast-based imaging using locally delivered Gd-DTPA may be useful as an antibiotic surrogate to determine antibiotic distribution in surgical sites.
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U2 - 10.1007/s11999-012-2315-6
DO - 10.1007/s11999-012-2315-6
M3 - Article
C2 - 22441993
AN - SCOPUS:84866366968
SN - 0009-921X
VL - 470
SP - 2654
EP - 2662
JO - Clinical Orthopaedics and Related Research
JF - Clinical Orthopaedics and Related Research
IS - 10
ER -