Solubilized xenon 133 lung scintigraphy.

Lung scanning using solubilized xenon 133 can provide important information concerning both pulmonary perfusion and ventilation. This technique proved valuable in establishing the diagnosis of congenital lobar emphysema in a 7-month-old baby.

Indium-111-labeled leukocyte scintigraphy: diagnosis of subperiosteal abscesses complicating osteomyelitis in a child.

Preoperative 111In-labeled leukocyte scintigraphy demonstrated extensive subperiosteal abscesses complicating acute bilateral tibial osteomyelitis in a child. Plain radiographs showed only marked soft-tissue swelling; three-phase bone scintigraphy depicted both "hot" and "cold" areas consistent with acute osteomyelitis.

Detection of a prosthetic aortic valvular abscess with indium-111-labeled leukocytes.

An unsuspected annular abscess at the base of a prosthetic aortic valve in a patient with endocarditis was identified by indium-111-labeled leukocyte scintigraphy alone. This highly sensitive and specific technique expediently demonstrated the surgically proven inflammatory focus.

Detection of bacterial endocarditis with indium-111 labeled leukocytes.

Bacterial endocarditis in a patient with dense mitral annular calcification secondary to renal failure and hyperparathyroidism was detected by indium-111 labeled leukocyte imaging. Although the gallium-67 image was negative, echocardiography subsequently confirmed the diagnosis.

Gallium-67 breast uptake in a patient with hypothalamic granuloma (sarcoid).

An unusual case is presented of bilateral breast uptake of [67Ga]citrate in a patient with a hypothalamic granuloma in the absence of galactorrhea is presented. A possible mechanism for this incidental finding is elevated prolactin levels, as other causes of gallium breast uptake such as drug therapy, and intrinsic breast disease, were not present.

Arthroscopic treatment of medial meniscal avulsion fractures.

The meniscal ossicle is an infrequent radiographic finding in humans. It has long been recognized in relation to trauma to the meniscus. Previous theories as to the etiology of these ossicles have been that they are vestigial or result from metaplastic change in an area of injury. We present four patients with meniscal ossicles associated with a longitudinal tear of the medial meniscus. The origin of the ossicle was an avulsion of the insertion of the posterior horn of the medial meniscus. Arthroscopic resection in these patients resolved their symptoms.

A case of biliary atresia and polysplenia. Evaluation by hepatobiliary scintigraphy.

A 5-week old jaundiced female underwent hepatobiliary scintigraphy using technetium-99m disofenin. Early images suggested right-sided cardiac activity. A nearly symmetric, bilobed liver with left-sided predominance was discovered. No biliary ducts, gallbladder, or small bowel activity were demonstrated up to 24 hours post-injection. Laparotomy confirmed situs inversus, polysplenia, and extrahepatic biliary atresia.

Imaging of pelvic rhabdomyosarcoma by bone scintigraphy.

Urinary tract distortion caused by pelvic rhabdomyosarcoma was imaged during 99mTc-oxidronate bone scintigraphy for suspected metastatic disease. This appearance correlated well with the anatomy defined on other imaging modalities. Bone scanning also proved valuable in detecting an otherwise occult osseous metastasis from this unusual tumor.

CT detection of necrotising enterocolitis.

Necrotising enterocolitis may occur as a complication of granulocytopenia of any aetiology. The clinical presentation may be non-specific and the diagnosis therefore depends heavily on radiographic findings, particularly changes seen by CT. In immune-compromised patients being investigated for possible abdominal sources of fever, CT may be particularly helpful in elucidating bowel sources of infection. Two cases of necrotising enterocolitis demonstrated by CT are presented. The two cases were in immune-compromised patients with malignant disorders who presented with fever. The CT findings of this disorder are presented.

Bullous change by CT heralding metastatic sarcoma.

The association of spontaneous pneumothorax with metastatic osteosarcoma is well known. Small blebs and bullous change can be easily detected in the lungs by computed tomography. In patients with known sarcomas, blebs and bullae may appear as the first or early manifestation of metastatic disease (or concurrent with the disease) as illustrated by the three patients presented here with three different types of sarcomas. The literature has been reviewed as to the etiology of spontaneous pneumothoraces occurring in metastatic sarcomas and the relationship of bleb and bullae formation to these spontaneous pneumothoraces is discussed.

Computed tomography in tarsal coalition.

The limitations of routine radiography of the feet in demonstrating tarsal coalitions are well known. Even with the use of multiple projections of the foot, tarsal coalitions may escape detection. Computed tomographic examinations of the feet were performed in persons suspected of having tarsal coalitions. The CT images were obtained in both the longitudinal and axial axes of the foot. Results of these examinations suggest the longitudinal projection to be most helpful in demonstrating talonavicular coalitions and the axial projection in demonstrating talocalcaneal coalitions. The history, pathology, and other imaging modalities of tarsal coalitions are reviewed.

Computed tomographic findings in renal angiomyolipoma: an histologic correlation.

Accurate preoperative diagnosis of renal angiomyolipomas is essential if conservative resection or angiographic embolization is to be used. Computed tomographic (CT) scanning failed to diagnose angiomyolipoma preoperatively in 2 patients, and this led to a retrospective review of 6 patients to define the limits of CT scanning in preoperative diagnosis. The CT findings were correlated with the histology of the tumors. Two tumors with positive attenuation coefficients suggestive of renal adenocarcinoma had significant amounts of immature "fetal" fat, and one of these had a virtual absence of mature fat. The relative inability of CT scanning to identify immature "fetal" fat, especially in the presence of abundant vessel and muscle elements, is a limitation to its use in the preoperative diagnosis of angiomyolipoma. A negative attenuation coefficient is highly characteristic of renal angiomyolipoma with mature fat elements. A positive attenuation coefficient, although suggestive of renal cell carcinoma, may be found in angiomyolipomas with paucity of mature fat or high proportions of immature fat.

Computed tomography differentiation of pyelonephritis and renal infarction.

Acute renal infarction and acute pyelonephritis can have identical clinical presentations. Most of the computed tomography findings seen in acute renal infarction are similar to those in acute pyelonephritis, except for the characteristic cortical rim sign seen in acute infarction. This finding differentiates these two disorders. This sign may be subtle and not appreciated unless searched for diligently with appropriate computed tomography imaging at varying window settings with particular attention to the subcapsular region.