Efficacy of Methylene Blue Photodynamic Therapy for Treatment of Deep Tissue Abscesses

Inclusion Criteria: * Adults 18 years or older * All patients with clinical symptoms (ex: fever, chills, pain, tachycardia, hypotension), laboratory (leukocytosis) and radiologic findings (thick walled, rim-enhancing collection with gas bubbles or air-fluid levels) compatible with an abscess that requires image- guided percutaneous drainage * Approval by the primary care team to pursue PDT and discuss enrollment with the patient Exclusion Criteria: * Pregnancy * Lactation * Allergy to contrast media, narcotics, sedatives, atropine or eggs * Necrotic tissue that requires surgical debridement * Severely compromised cardiopulmonary function or hemodynamic instability * Thrombocytopenia (\<50,000/mm3) * Uncorrectable coagulopathy * Poor kidney function (serum creatinine \>3mg/dl) * Lack of a safe pathway to the abscess or fluid collection * Unable or unwilling to understand or to provide informed consent * Unable or unwilling to undergo study procedures * Patient unable to cooperate with, or to be positioned for the procedure * Unable to comply with necessary follow up * Patients with pancreatic abscesses * Patients with known fistulous communication with their abscess * Abscess greater than 13 cm in diameter