Assessment of [18F]-Fluorocellobiose ([18F]FCB) Pharmacokinetics in Healthy Volunteers and Subjects With Invasive Mold Infections

* INCLUSION CRITERIA: Inclusion Criteria for healthy volunteers (Groups 1 and 2) 1. Male or female \>=18 years of age at the time of consent and imaging. 2. Provision of signed and dated informed consent form. 3. Subjects must have the ability to read, understand and provide written informed consent for the initiation of any study related procedures. Adults lacking capacity will not be enrolled in this study. 4. Stated willingness to comply with all study procedures and availability for the duration of the study. 5. Generally healthy subjects based on medical history, physical examination, and laboratory testing, as determined by the PI. 6. Female participants of childbearing potential must be using a medically acceptable means of contraception. Inclusion Criteria for Patients with PROVEN or PROBABLE Aspergillosis or Mucormycosis Infections (Groups 3a and 3b) 1. Male or female \>=18 years of age at the time of consent and imaging. 2. Provision of signed and dated informed consent form. 3. Subjects must have the ability to read, understand and provide written informed consent for the initiation of any study related procedures. Adults lacking capacity will not be enrolled in this study. 4. Stated willingness to comply with all study procedures and availability for the duration of the study. 5. PROVEN or PROBABLE Invasive fungal disease (IFI), defined by the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) \[18\]. 6. Female participants of childbearing potential must be using a medically acceptable means of contraception. For inpatients, they should be determined by the attending of record to be stable to participate in the study (will be documented in the research records). Inclusion Criteria for Participants with Non-Aspergillus/Non-Mucorales Mold Infections (Group 4a) and Participants with Dimorphic Fungal Infections (Group 4b). 1. Male or female \>=18 years of age at the time of consent and imaging. 2. Provision of signed and dated informed consent form. 3. Subjects must have the ability to read, understand and provide written informed consent for the initiation of any study related procedures. Adults lacking capacity will not be enrolled in this study. 4. Stated willingness to comply with all study procedures and availability for the duration of the study. 5. Non-Aspergillus/non-Mucorales mold infections including, but not limited to Cladophialophora spp., Dematiaceous molds (such as Curvularia, Scedosporium spp.) or dimorphic fungi (including, but not limited to Blastomyces spp., Coccidioides spp., Histoplasma spp. and Exophiala spp.). 6. Female participants of childbearing potential must be using a medically acceptable means of contraception. For inpatients, they should be determined by the attending of record to be stable to participate in the study (will be documented in the research records). Acceptable effective method of contraception (birth control) will include: * Partner vasectomy (making sterile) * Bilateral tubal ligation * Intrauterine devices (IUDs) * Hormonal implants (such as Implanon) * Other hormonal methods (birth control pills, injections, patches, vaginal rings) EXCLUSION CRITERIA: Exclusion Criteria for healthy subjects (Groups 1 and 2) Complete medical records will be reviewed, and within 1-3 months prior to the planned imaging, EKG, blood, and urine laboratory studies will be performed. Subjects will be excluded from enrollment if any of the following apply: 1. Clinically significant abnormalities on EKG or laboratory testing (blood and urine tests) as judged by the principal investigator. 2. Reported pregnancy or pregnancy as determined by positive or indeterminate serum human Chorionic Gonadotrophin (hCG) or urine pregnancy tests prior to radiopharmaceutical dosing. 3. Lactating females. 4. History of uncontrolled diabetes mellitus. 5. Lack of adequate venous access. 6. Previous nuclear imaging or therapy administered within 5 physical half-lives of the used radioisotope prior to study enrollment. 7. Inability to lie flat on the PET/CT bed for the planned duration of scan, including claustrophobia and weight greater than the maximum for the scanner (500 lbs). 8. NIH employee who is a subordinate/relative/co-worker of the investigators. Exclusion Criteria for with PROVEN or PROBABLE Aspergillosis or Mucormycosis infections (Groups 3a and 3b) and non-Aspergillus/non-Mucorales mold (Group 4a) or dimorphic fungal infections (Group 4b) Complete medical records will be reviewed, and within 28 days prior to imaging, EKG, blood and urine laboratory studies will be performed (unless already performed by the referring team as part of clinical evaluation). Subjects will be excluded from enrollment if any of the following apply: 1. Abnormalities on laboratory testing judged by the principal investigator to affect the reliability or safe performance of the scan. 2. Participants with severe hepatic and/or renal failure as determined by the primary clinical team 3. Reported pregnancy or pregnancy as determined by positive or indeterminate serum (hCG) or urine pregnancy tests prior to radiopharmaceutical dosing. 4. Lactating females. 5. History of uncontrolled diabetes mellitus. 6. Lack of adequate venous access. 7. Previous administration of a radioisotope within 5 physical half-lives prior to study enrollment. 8. Inability to lie flat on the PET/CT bed for the planned duration of scan, including claustrophobia and weight greater than the maximum for the scanner (500 lbs).