Please assess the completion status of the following clinical trial:

Trial Title: Microvascular Blood Flow in Sickle Cell Anemia

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: SEQUENTIAL
- Observational Model: None
- Primary Purpose: DIAGNOSTIC
- Time Perspective: None
- Masking: NONE
- Phase: None
- Number of Arms: 5.0

Eligibility Criteria:
Inclusion Criteria:~Regadenoson ARM Inclusion Criteria:~* Diagnosis of sickle cell anemia confirmed by hemoglobin analysis~* Ages 18 to 70 years~* Subjects must have laboratory indices as outlined by the protocol~* Reliable IV access as determined by physician~Sickle Cell Controls ARM Inclusion Criteria:~* Diagnosis of sickle cell anemia confirmed by hemoglobin analysis~* Ages 18 to 70 years~Sickle Cell CEU ARM Inclusion Criteria:~* Diagnosis of sickle cell anemia, confirmed by hemoglobin analysis~* Males and females age 18-70 years~Healthy Control ARM Inclusion Criteria:~* African American~* Ages 18 to 70 years~Technique Optimization Control ARM Inclusion Criteria:~-Ages 18 to 70 years~Exclusion Criteria:~Regadenoson ARM Exclusion Criteria~* Hospitalization, emergency department visit or self-reported crisis within last 2 weeks for any reason or 4 weeks from acute chest syndrome~* Current physician diagnosis of active asthma (within last 12 months) or current use of asthma medications~* Second or third degree AV block or sinus node dysfunction~* Known or suspected right to left sided cardiac shunts~* History of a bleeding diathesis~* History of clinically overt stroke~* History of severe hypertension not adequately controlled with anti-hypertensive medications~* Receiving chronic anti-coagulation or anti-platelet therapy~* History of metastatic cancer~* Receiving other investigational study agents, or have received a study agent in the last 30 days~* Uncontrolled intercurrent illness~* Pregnant or breastfeeding women~* Subjects who have a HIV infection~* Subjects who have had a hematopoietic stem cell transplant~* Subjects who are taking medications that may interact with the investigational agent~* Prior hypersensitivity reactions to either regadenoson or ultrasound contrast agents~Sickle Cell Controls Exclusion Criteria:~* Hospitalization, emergency department visit or self-reported crisis within last 2 weeks for any reason or 4 weeks from acute chest syndrome~* Known pregnancy~* Known history of HIV~* Known or suspected right to left sided cardiac shunts~* Receiving other investigational study agents, or have received a study agent within the last 30 days~* Subjects who have had a hematopoietic stem cell transplant~* Prior hypersensitivity reactions to ultrasound contrast agents~* History of severe hypertension not adequately controlled with anti-hypertensive medications~* Uncontrolled intercurrent illness~Sickle Cell CEU ARM Exclusion Criteria:~* Pregnant women~* Subjects who have a HIV infection~* History of stem cell transplant~* Current involvement in a therapeutic clinical trial~* Known or suspected right to left sided cardiac shunts~* Prior hypersensitivity reactions to ultrasound contrast agents~* History of severe hypertension not adequately controlled with anti-hypertensive medications~* Uncontrolled intercurrent illness~Healthy Control ARM Exclusion Criteria:~* Sickle cell disease or sickle cell trait~* Known or suspected right to left sided cardiac shunts~* Diagnosis of type 1 or type 2 diabetes mellitus~* Hypertension~* History or current diagnosis of dyslipidemia or taking lipid lowering drugs~* Diagnosis of coronary artery disease or peripheral vascular disease~* Body weight greater than 10% of ideal weight~* Uncontrolled intercurrent illness~* Pregnant or breastfeeding women~* Subjects who have a HIV infection~* Prior hypersensitivity reactions to ultrasound contrast agents~Technique Optimization Control ARM Exclusion Criteria:~* Known sickle cell disease or sickle cell trait~* Known or suspected right to left sided cardiac shunts~* Uncontrolled intercurrent illness~* Known pregnant or breastfeeding women~* Prior hypersensitivity reactions to ultrasound contrast agents

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 70 Years
- Healthy Volunteers: t

Study Arms:
- Regadenoson ARM (Type: EXPERIMENTAL): Adult subjects with sickle cell anemia will receive a regadenoson infusion with contrast-enhanced ultrasound
- Sickle Cell Controls ARM (Type: OTHER): Adult subjects with sickle cell anemia will receive contrast-enhanced ultrasound
- Sickle Cell CEU ARM (Type: OTHER): Adults subjects with sickle cell anemia will receive contrast-enhanced ultrasound
- Healthy Control ARM (Type: OTHER): Healthy African American control subjects without sickle cell anemia will receive contrast-enhanced ultrasound
- Technique Optimization Controls (Type: OTHER): Healthy volunteers will undergo contrast-enhanced ultrasound.

Based on this trial design, predict the completion outcome and termination type (if applicable).

Answer: outcome: complete