Hemangioendothelioma of the temporal bone with radiologic findings resembling hemangioma.

SUMMARY: Hemangioendotheliomas are rare vascular tumors that can affect bone. They account for 0.5% to 1.0% of malignant primary bone tumors. Only four cases have been reported involving the temporal bone. A 5-year-old child with grade II hemangioendothelioma of the right temporal bone is presented, and the radiologic findings on different imaging studies are described. The patient was treated with preoperative endovascular embolization followed by wide surgical resection. The imaging patterns of this malignant tumor may be similar to those of a benign lesion.

Role of MR imaging in the diagnosis of complicated arachnoid cyst.

BACKGROUND: Arachnoid cysts are intra-arachnoidal cerebrospinal fluid collections that are usually asymptomatic, however, they may become acutely symptomatic due to enlargement of the cyst or the presence of hemorrhage. MATERIALS AND METHODS: We report a case of a child presenting with a 3-week history of headaches, nausea, and vision problems. There was no history of trauma. MRI clearly demonstrated a left middle cranial fossa arachnoid cyst with associated subacute intracystic and subdural hematoma that was causing mass effect and required surgery. RESULTS: This lesion was isodense to the brain on CT. CONCLUSION: We focus on the importance of MR imaging in the differentiation of these subacute/early chronic hemorrhagic collections that may be overlooked with CT.

Imaging of nonlaryngeal neuroendocrine carcinoma.

The imaging and pathologic features of three cases of nonlaryngeal neuroendocrine carcinoma of the head and neck are described. Neuroendocrine carcinomas represent malignant epithelial neuroendocrine neoplasms and are classified as three types: typical carcinoid (well differentiated), atypical carcinoid (moderately differentiated), and small cell neuroendocrine (poorly differentiated) carcinomas. The CT and MR imaging features of these tumors are nonspecific. Paranasal sinus neuroendocrine carcinomas showed expansion and destruction of the sinus, whereas metastatic neuroendocrine carcinomas to an intraparotid lymph node presented as a circumscribed parotid mass on CT scans.

MR angiography of vascular malformations.

Magnetic resonance angiography (MRA) plays an important role in the evaluation of cerebrovascular disease. This is especially true in the diagnosis and management of cerebral vascular malformations. Both time-of-flight and phase contrast MRA techniques have proved useful for the imaging of all types of cerebral vascular malformations including AVMs, dural fistulas, cavernous malformations, and venous angiomas. The role of MRA in the evaluation of these lesions is discussed.

Selective intraarterial gene delivery into a canine meningioma.

OBJECT: The goal of this study was to evaluate gene delivery to a benign brain tumor. METHODS: A recombinant adenovirus vector bearing the Escherichia coli beta-galactosidase reporter gene was selectively injected into the vascular supply of a spontaneously occurring canine olfactory groove meningioma. The tumor and a small amount of peritumoral brain tissue were removed 5 days after viral injection and stained with X-Gal to assess gene delivery. The authors noted significant beta-galactosidase gene expression by the tumor, but not by surrounding brain tissue. No obvious viral-related cytotoxicity was noted. CONCLUSIONS: The authors found that meningiomas can be successfully transduced by adenovirus vectors by using endovascular techniques.

Endovascular occlusion of the carotid or vertebral artery with temporary proximal flow arrest and microcoils: clinical results.

PURPOSE: To determine the clinical effectiveness of parent artery occlusion of the carotid or vertebral artery by means of temporary proximal flow arrest and microcoils. METHODS: Nineteen parent artery occlusions (15 carotid, four vertebral) were performed in 19 patients who successfully passed a balloon test occlusion. In these patients, endovascular occlusion of the carotid or vertebral artery was accomplished with the use of temporary proximal flow arrest and microcoils. RESULTS: All 19 parent arteries were occluded. Eighteen patients (95%) had good outcomes and one (5%) had a poor outcome. Fourteen patients (74%) had no complications and five (26%) had complications, of whom only one was left with a permanent neurologic deficit. Three (60%) of the complications were the result of delayed ischemic events after parent artery occlusion and were not predicted by balloon test occlusion. CONCLUSION: Endovascular occlusion with temporary proximal flow arrest and microcoils can be done effectively and successfully. The predictive value of the balloon test occlusion is the major complicating factor, as it is with balloon occlusion. This technique offers an additional tool that can be used for endovascular occlusion of the carotid or vertebral artery and seems to be less difficult technically. It is our primary technique for parent artery occlusion.

Intraarterial thrombolysis in a pig model: a preliminary note.

PURPOSE: To develop a pig model of arterial thrombosis suitable for assessing different methods of thrombolysis and to use this model to compare the efficacy of intraarterial thrombolysis performed by continuous proximal urokinase infusion versus mechanical clot disruption combined with intrathrombic urokinase injection. METHODS: In a control group of five pigs, a thrombus was made in a short segment of femoral artery and observed for 2 hours to assess its stability. In a treatment group of six pigs, intraarterial thrombolysis was performed immediately after thrombus formation. Thrombolysis was accomplished by continuously infusing urokinase into the proximal leading edge of the thrombus in three pigs and by mechanical clot disruption combined with intrathrombic urokinase injection in the remaining three pigs. RESULTS: There was no spontaneous reestablishment of flow in the control group during the 2-hour observation period. In the first treatment group, no flow was observed after a 1-hour treatment period when urokinase was infused continuously into the proximal edge of the thrombus. In the second treatment group, with mechanical clot disruption and intrathrombic urokinase injection, some degree of flow was observed in all three pigs. Reestablishment of flow was more sustained and of a greater degree with the addition of systemic heparinization. CONCLUSION: This animal model could provide a useful way to evaluate and compare different methods of thrombolysis. Our results suggest that mechanical clot disruption combined with intrathrombic urokinase injection is more effective in achieving reestablishment of flow than is continuous infusion of urokinase into the proximal edge of the thrombus.

Recanalization of the falcine sinus after venous sinus thrombosis.

Thrombosis of the straight and transverse sinuses associated with a large hemorrhagic venous infarct developed in an infant with large chronic subdural fluid collections after drainage of the subdurals. CT and MR studies obtained before and after the onset of venous sinus thrombosis showed interval widening of a segment of the posterior falx between the vein of Galen and the superior sagittal sinus. MR angiography confirmed a recanalized falcine sinus.

The effect of flow arrest on distal embolic events during arterial occlusion with detachable coils: a canine study.

PURPOSE: To determine the effect of proximal flow arrest on the frequency and timing of distal embolic events during occlusion of the common femoral artery with detachable coils. METHODS: Twenty-three complex fibered platinum coils were delivered into 10 common femoral arteries without proximal flow arrest. The arteries were continuously monitored for flow and embolic events by Doppler sonography during delivery and for at least 10 minutes after delivery of each coil. Thirty-four coils were delivered into 6 arteries after proximal flow arrest by inflation of a nondetachable balloon. After balloon deflation, each artery was monitored by Doppler sonography for 10 minutes. RESULTS: In the 10 arteries occluded without flow arrest, 87 events (8.7 per artery) occurred, of which 47 were embolic and 40 were indeterminate. In the 6 arteries with flow arrest, the number of emboli detected was 3 (0.5 per artery). Embolic events occurred only if there was residual flow. In those arteries that were occluded when the flow-arrest balloon was deflated, no emboli were detected. CONCLUSIONS: Proximal flow arrest virtually eliminates the risk of distal emboli during arterial occlusion with detachable fibered coils. The use of fibered coils, in conjunction with proximal flow arrest, allows for safe arterial occlusion when detachable balloons are not available or their use is not feasible.

Intrathoracic stomach. Another cause of IVC pseudothrombosis.

We report the case of a patient with a large hiatal hernia accompanied by partial gastric volvulus in whom the computed tomography (CT) findings mimic the appearances of thrombus in the inferior vena cava (IVC). To our knowledge, this has not been previously reported as a cause of "pseudothrombosis" of the IVC on CT.