Purpose or Case Report: Review the time course of early and late complications of hematopoietic cell transplant (HCT).
Assess and compare the infectious and non-infectious complications of HCT secondary to immunosuppression and treatment-related toxicity.
Review the imaging pearls in diagnosing non-infectious complications post HCT pediatric patients with case examples.
Methods & Materials: A head-to-toe comprehensive review of the diagnostic pearls of infectious and non-infectious post-HCT complications among pediatric patients through literature search and case based learning utilizing multimodal imaging examples including radiograph, ultrasound, CT and MRI. Diagrams and flow charts are employed to facilitate review of the time-wise complications of HCT secondary to immunosuppression and treatment-related toxicity.
Results: CNS/Head and neck:
Infectious (I): meningitis/encephalitis , dental abscess, sinusitis
Sterile (S): CVA, subdural hemorrhage, PTLD, autoimmune (i.e. Sicca)

Lung:
I: sino-pulmonary infection, bacterial, viral (HSV, CMV, PCP, RSV) and fungal pneumonia
S: acute/chronic graft versus host disease, idiopathic pneumonia syndrome, pulmonary edema, diffuse alveolar hemorrhage, engraftment syndrome, pulmonary cytolytic thrombi, air-leak syndrome, pleuroparenchymal fibroelastosis, venoocclusive disease, PTLD

Cardiovascular:
I: endocarditis
S: CHF, cardiomyopathy, pericardial effusion

GI:
I: infectious colitis (bacterial/fungal/viral), bacterial or fungal abscesses of liver
S: neutropenic colitis, venooclusive disease of the liver/spleen (aute, chronic, medication toxicity), PTLD

GU:
I: bacterial/fungal renal abscess
S: hemolytic uremic syndrome, papillary necrosis, renal vein thrombosis, hemorrhagic cystitis, renal papillary necrosis, nephrolithiasis
Conclusions: As hematopoietic stem cell transplantation becomes widely available in both large academic centers and smaller community hospitals, radiologists must be familiar with both its infectious and non-infectious complications. While most infectious etiologies may be clinically identified with culture and exam, the non-infectious causes can be confusing and complex. Imaging findings are essential in identifying the cause in combination with the appropriate clinical context. A working knowledge of the time course of these complications, clinical context in which they occur, and characteristic appearance on imaging will aid the radiologist in the diagnosis of these conditions.