43cyclophosphamide and shows up on CT as focal or diffuse bladder wall thickening,
intraluminal clots, and sloughed mucosa. Renal abscesses will show up as hypoat-
tenuating collections, with wall enhancement on contrast-enhanced CT (Fig. 3.7).
Renal parenchymal loss can be seen in patients who have received radiation therapy
and manifest on CT as atrophy of the kidney [ 2 ].
Although HSCT is performed for both malignant and non-malignant diseases,
there is always a chance that patients may develop secondary malignancies following
the preparative regimens. These include post-transplantation lymphoproliferative dis-
order (PTLD), lymphoma, leukemia, myelodysplasia, or various solid tumors. For
PTLD, it is recommended that chest, abdomen, and pelvis CT be utilized for staging
purposes. Findings on imaging may include lymphadenopathy, hepatosplenomegaly,
focal parenchymal masses and nodules, and diffuse organ infiltration without a focal
mass [ 2 ]. CT with contrast material enhancement is the preferred radiologic procedure
for assessing the degree of lymphadenopathy and/or organ involvement in patients in
whom there is post-transplantation lymphoproliferative disorder (PTLD) or lym-
phoma [ 1 ]. It is also important to note that patients under that age of 10 have the
greatest overall risk of having post-transplantation development of malignancy [ 4 ].
Although cerebrovascular events are rare post-stem cell transplantation, early
assessment via head CT to differentiate between hemorrhage and infarction is clini-
Fig. 3.7 Hepatic micro abscesses (top) and left renal abscess in two different patients following
HSCT. Axial post contrast T2 W fat sat images through the liver (Top Left) and post contrast T1 W
images (right) show multiple T2 hyperintense liver lesions that show ring like enhancement on
post contrast images (arrows). Axial post contrast CT image shows a hypodense non enhancing
lesion near the superior pole of the left kidney compatible with renal abscess (black arrow, bottom
image)
3 Radiologic Procedures Used in Pediatric Stem Cell Transplantation