Mansour Mirfakhraee

MR Imaging of Transverse/Sigmoid Dural Sinus and Jugular Vein Thrombosis

Magnetic resonance (MR) imaging was performed on six patients with thrombosis involving the transverse/sigmoid sinus and jugular bulb/vein. Venographic confirmation was obtained in five cases. Thrombi were characterized by increased intraluminal signal on all planes of section and pulse sequences. The change in signal intensity from first to second echo for thrombi was qualitatively less than that found with slow flow. Partial thrombosis in one case was seen as a ring pattern of central intermediate intensity corresponding to the thrombus, surrounded by a peripheral ring of signal void related to flowing blood. The MR findings closely correlated with venography in predicting thrombosis. Evidence of thrombi was not available from CT. Magnetic resonance is well suited for the diagnosis of occlusive disease of the dural venous sinus and jugular bulb.

Computed tomography of traumatic atlantooccipital dislocation.

Although atlantooccipital dislocation is a well-recognized radiological entity, its computed tomographic (CT) recognition has not been previously described. It is the purpose of this report to show the complementary role of CT in precisely defining the abnormalities in both the coronal and the sagittal reconstruction planes. A case is presented and the literature is reviewed.

Retrieval of intravascular foreign bodies.

The use of intravascular catheters for diagnostic and therapeutic purposes has resulted in an increased number of foreign body embolizations. The retained foreign body is a potential source of morbidity and mortality. In this communication we describe the different techniques that are used to remove foreign bodies from various locations within the heart or vascular tree. A brief review of the literature concerning the reported complications from retained foreign bodies is made to underline the importance of early percutaneous removal of these fragments.

MR imaging of orbital blow-out fractures.

We report on a case of orbital blow-out fractures involving the medial and inferior walls. In this case conventional multiplanar 8 mm thick sections with magnetic resonance (MR) imaging proved to be more helpful than 1.5 mm axial thin sections with CT in demonstrating the extent of orbital floor herniation of fat. Entrapment of muscle was excluded. Oblique sagittal views were most helpful in evaluating the orbital floor, since the full course of the inferior rectus muscle is seen. Additionally, the optic nerve is seen along its entire length. Masking of intraorbital contents by isodense hemorrhage on CT studies apparently is not a problem with MR imaging if hemorrhage is small or nonacute.

Trauma of occult hydronephrotic kidney

The occult unilateral hydronephrotic kidney is often discovered during the genitourinary evaluation of patients sustaining blunt abdominal trauma. Few cases have been reported documenting the angiographic, computerized tomography (CT), and ultrasound appearances. Two cases are described which demonstrate that relatively minor trauma can precipitate hematuria and hypovolemic shock. Angiography demonstrated the bleeding site in both cases and was utilized in conjunction with other parameters of clinical assessment to plan initial management. CT and ultrasound proved to be useful noninvasive diagnostic parameters for baseline and follow-up studies in patients undergoing conservative management. They accurately demonstrated the degree of hydronephrosis, residual renal parenchymal, and resolving hematoma.

Computed tomography of internal jugular vein thrombosis

Thrombosis of the internal jugular vein was diagnosed by computed tomography in two cases. On contrast computed tomography, the thrombosed vein appeared as an enlarged vein containing a low density lumen surrounded by a sharply defined wall. This entity should be looked for whenever a patient is examined by computed tomography for acute cervical swelling or inflammatory ear disease.

Combined CT metrizamide syringography and needle aspiration of cystic intramedullary spinal cord lesions

A modified spinal cord puncture technique that was combined with CT metrizamide syringography for the evaluation of potentially cystic spinal cord lesions has been used in 5 patients. This procedure proved to be safe and efficacious in the preoperative differentiation of cystic neoplasms from syringohydromyelia. It also aided in planning a surgical approach by revealing details of the tumor location and/or syrinx dynamics. Spinal cord puncture associated with CT metrizamide syringography has a role in the diagnosis and therapy of patients with cystic spinal cord lesions.

Unusual subclavian steal: bidirectional and antegrade blood flow in the vertebral artery

We present an unusual radiographic manifestation of subclavian steal seen in six patients. These cases differ from the classic form of subclavian steal in that antegrade and bidirectional blood flow in the vertebral-subclavian antery system in seen, resulting in the steal phenomenon.

Membranous obstruction of the inferior vena cava: an ultrasound, computed tomography, and inferior vena cavogram image correlation

The purpose of this paper is to present the computed tomography (CT) and ultrasound findings in one case of membranous obstruction of the inferior vena cava (IVC). Although the incidence of membranous obstruction of the IVC is rare in the United States, the diagnosis is essential because of the association of this lesion with portal fibrosis and hepatocellular carcinoma. Membranous obstruction of the IVC is suggested by the findings of a filling defect within the IVC at the level of either the diaphragm or right atrium. Until more specific CT and ultrasound features are described, an inferior vena cavogram will remain the definitive diagnostic procedure for membranous obstruction of the IVC.