Distinguishing soft-tissue hemangiomas from vascular malformations using technetium-labeled red blood cell scintigraphy.

Soft-tissue vascular lesions in children can be classified as either hemangiomas or vascular malformations. The distinction between the two has important prognostic and therapeutic implications. Over the past 8 years, we have evaluated 64 vascular lesions with the technetium-labeled red blood cell (Tc-RBC) scan. Twenty-eight lesions imaged as hemangiomas with intense focal uniform uptake. This diagnosis was confirmed in 27 lesions, or 96 percent. Thirty-six lesions imaged as vascular malformations with abnormal vessels or diffusely increased activity. This diagnosis was confirmed in 35 lesions, or 97 percent. Overall, the Tc-RBC scan was 97 percent accurate in distinguishing hemangiomas from vascular malformations. It is particularly useful when the clinical diagnosis of the lesion may not be evident. Not only can biopsy be avoided, but parents can be reassured at an earlier age and given accurate information regarding prognosis.

Trochanteric bursitis: bone scan appearance.

Trochanteric bursitis is one of the most common soft tissue abnormalities in the hip region, yet it is frequently underdiagnosed. There is a characteristic pattern of uptake seen on the bone scan in patients with this condition. Its recognition is important to avoid misinterpretation of increased trochanteric uptake, particularly in patients with malignant disease, and to aid in the diagnosis and effective management of this treatable condition.

Cutaneous gallium uptake in patients with AIDS with mycobacterium avium-intracellulare septicemia.

Gallium imaging is increasingly being used for the early detection of complications in patients with AIDS. A 26-year-old homosexual man who was HIV antibody positive underwent gallium imaging for investigation of possible Pneumocystis carinii pneumonia. Widespread cutaneous focal uptake was seen, which was subsequently shown to be due to mycobacterium avium-intracellulare (MAI) septicemia. This case demonstrates the importance of whole body imaging rather than imaging target areas only, the utility of gallium imaging in aiding the early detection of clinically unsuspected disease, and shows a new pattern of gallium uptake in disseminated MAI infection.

Subperiosteal abscess in children: scintigraphic appearance.

A subperiosteal abscess is an uncommon complication of osteomyelitis in childhood. Bone scanning is very sensitive for the detection of early skeletal infection; however, a subperiosteal abscess has a different and distinctive scintigraphic appearance. The usual increased tracer uptake of osteomyelitis is overshadowed by the presence of a "cold" lesion on the delayed views, probably due to interruption of the vascular supply of the bone. Early recognition of the condition is important, as surgery is indicated to prevent extensive bone necrosis and chronic osteomyelitis. In suspected osteomyelitis, a central photopenic area is highly suggestive of subperiosteal abscess; when such an area is seen, a computed tomographic (CT) scan can be helpful in planning the surgical approach for drainage. Plain radiographs may be unremarkable even when the bone scan and CT findings are dramatic. Five such cases are presented, and a recommended diagnostic approach is discussed that views the two procedures as complementary.

Percutaneous fine needle aspiration biopsy of canine pancreas allograft provides diagnosis of treatable rejection.

Despite improved pancreas transplant graft survival, early diagnosis of rejection remains a clinical challenge. Using a canine model of whole pancreas transplantation with bladder exocrine drainage we have shown fine needle aspiration biopsy (FNAB) to provide an earlier diagnosis of rejection than fall in urinary amylase (UA). The aim of this study was to assess the ability of anti-rejection therapy to reverse rejection when the diagnosis was based on either FNAB findings or a fall of UA. Sixteen dogs received a total pancreas allograft with an inadequate dose of oral cyclosporine (5 mg/kg/day). Fasting UA levels were measured daily and percutaneous FNAB with ultrasound guidance was performed three times weekly on all dogs. The diagnosis of rejection was made in alternate dogs with either a fall of UA to a level of less than 5000 IU/liter (median 7 days) or when the total corrected increment (TCI) of aspirated infiltrating cells was greater than 2.6 (median 5 days). Anti-rejection therapy consisted of methylprednisolone 10 mg/kg/day iv for 5 days and an increase of oral cyclosporine dosage to 25 mg/kg/day. Early vascular thrombosis (Day 2) occurred in three allografts. Diagnosis of rejection based on a low level of UA permitted the successful reversal of rejection in only one of six grafts, whereas five of seven grafts were successfully treated when rejection diagnosis was based on FNAB. Median allograft survivals were 9 days (range 8-19) and 32 days (range 11-63), respectively (P less than 0.01). The earlier diagnosis of allograft rejection made by FNAB improved the ability of conventional anti-rejection therapy to reverse pancreas allograft rejection and significantly improved allograft survival.