CT angiography using electron-beam computed tomography (EBCT): a phantom study

The purpose of this study was to evaluate the accuracy of CT angiography in small vessels using electron-beam computed tomography (EBCT). Vessel phantoms with inner diameters of 8 mm, 6 mm, and 4 mm were prepared with segments of 75%, 50%, and 25% stenosis in each vessel. The vessels were filled with contrast medium (Iopamidol 300 at 1/24 dilution, approximately 380 HU). The EBCT apparatus used was an Imatron C- 150. The step volume scan mode was used with slice thicknesses of 1.5 mm and 3.0 mm, scan time of 0.3 sec, and 210 mm field of view. Images with a slice thickness of 1.5 mm were definitely better than those with a slice thickness of 3.0 mm. The quality of maximum intensity projection (MIP) images was quite similar to that of three-dimensional (3D) images. Using the 8 mm vessel phantom, all stenotic segments were accurately visualized on CT angiography. The 50% stenotic segments were accurately estimated in all vessels. However, the 75% stenotic segments were slightly overestimated in smaller vessels, and the 25% stenotic segments were slightly underestimated in smaller vessels. We consider CT angiography using EBCT to be a useful, less invasive diagnostic modality for stenoocclusive lesions.

Superficial siderosis of the central nervous system. Its MRI manifestations

Three cases of superficial siderosis of the central nervous system are reported here. Using a 1.0-T magnetic resonance (MR) unit, typical hypointense rims were observed under the brain surface on T2-weighted images. In one patient, marked atrophy of the superior cerebellar vermis and cerebellar parenchymal hyperintensity were also detected. The spinal cord was involved in two of the three patients. On T1-weighted images, hyperintense rims were demonstrated over the brain surface in two of the three patients. This finding has not been previously reported.

Computed radiography angiography using storage phosphor imaging plates: eight year's experience

We reviewed the indications, modalities, and quality of angiographic examinations performed in our department from 1987 to 1994 and compared the image characteristics and technical convenience of three modalities: conventional film-screen angiography, fluorographic digital subtraction angiography (F-DSA), and computed radiography angiography using biplane rapid changers of storage phosphor imaging plates (IP-CRA). IP-CRA has practically eclipsed conventional film-screen angiography in our radiology department. Sixty-percent of the total 700 examinations carried out in 1994 were performed using a combination of IP-CRA and fluorographic digital subtraction angiography (F-DSA). The remainder were performed with F-DSA alone. The post-processing functions of IP-CRA like subtraction and change of contrast or density were useful especially in such regions as pulmonary, bronchial, or external carotid arterial territories, where high natural contrast made image processing difficult with both F-DSA and film-screen angiography. The spatial resolution of IP-CRA was superior to that of F-DSA and comparable to the film-screen method. It was concluded that angiography using imaging plates was a useful part of the digital radiography system.

Dural ectasia of the optic nerve sheath in neurofibromatosis type 1: MRI manifestations

Patients with neurofibromatosis type 1 (NF-1) have an increased incidence of optic glioma. Although spinal dural ectasia or meningocele is well represented in the NF-1 literature, radiologists are not as familiar with dural ectasia of the optic nerve sheath as spinal dural ectasia. This is a report of a pediatric patient with NF-1 with dural ectasia of the optic nerve sheath. This is the second reported case of dural ectasia of the optic nerve sheath demonstrated by magnetic resonance imaging.

Intraorbital wooden and bamboo foreign bodies: CT

We describe the CT findings of intraorbital wooden and bamboo foreign bodies in the acute, subacute, and chronic stages. We examined four patients using CT a total of seven times. The CT findings were reviewed. There were three dry wooden foreign bodies. CT within a day of the accident demonstrated wooden foreign bodies as low density relative to surrounding orbital fat, while CT 8-29 days after the accident showed them as denser than the extraocular muscles. In the acute stage, dry wooden foreign bodies mimic air bubbles. Wooden foreign bodies in the subacute and chronic stages should be included in the differential diagnosis of intraorbital lesions of soft tissue density or above on CT of traumatised orbits. There was one dry bamboo foreign body. Within a day of the accident it was recognised as linear lesion isodense with fat. Therefore, such foreign bodies may be missed on CT when located in the orbital fat.

Spinal cord herniation: report of two cases and review of the literature

Idiopathic herniation of the spinal cord is an extremely rare disorder which may cause progressive myelopathy. Two cases of this entity reported herein were both examined using MRI and CT myelography. The typical appearance of this disease with or without a dorsal intradural arachnoid cyst is focal ventral displacement of the mid-thoracic spinal cord, mimicking an isolated intradural spinal arachnoid cyst on MRI. CT myelography using thin slice sections is useful in the diagnosis of this disease.

Pontine venous congestion caused by dural carotid-cavernous fistula: report of two cases

This is a report of two patients in whom a pontine venous congestion occurred with a dural carotid-cavernous fistula (CCF), an extremely rare complication. This is the first such report. We underscore the importance of early diagnosis and treatment of dural CCFs.

CT and MRI of sellar spine with upward extension of the pituitary gland: case report

This is a report of CT and MRI findings in a patient with a sellar spine which caused deformity of the pituitary gland. The sellar spine is an infrequent anatomical variant characterized by an osseous spine which arises in the midline from the anterior aspect of the dorsum sellae and extends into the pituitary fossa. The CT and MRI findings of sellar spine have been described in previous reports; however, only one investigator reported deformity of the pituitary gland as revealed by CT. This is the first report of the MRI finding of the sellar spine associated with a deformity and superior extension of the pituitary gland, mimicking pituitary hypertrophy.

MR imaging and MR angiography of persistent trigeminal artery and its variant

Six patients with persistent trigeminal artery (PTA) and one patient with its variant (PTAV) were studied using a 1.0-T magnetic resonance unit. With both magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), four of the six PTAs were detected as abnormal connecting arteries between the cavernous internal carotids and the basilar arteries. The remaining two PTAs and one PTAV were not detected using MRI, but were imaged by MRA. It was concluded that relatively large PTAs can be detected using MRI, but small PTAs and PTAVs may be missed using MRI.

Giant cell reparative granuloma of the cranial vault

We describe a case of giant cell reparative granuloma in the cranial vault, which is an extremely rare location for this entity. CT scans showed an enhancing skull tumor with no surrounding sclerosis in the frontal bone. MR images showed a mass isointense with gray matter on both T1- and T2-weighted images.

Intra-arterial digital subtraction angiography with extra-large fields using a computed radiography system in evaluating peripheral vascular disease

The authors evaluated the usefulness of intra-arterial digital subtraction angiography (DSA) with extra-large field sizes using a computed radiography (CR) system in evaluating peripheral vascular disease (PVD). Intra-arterial DSA using CR was performed in 55 patients with suspected PVD. A 4 F catheter was advanced into the abdominal aorta via the transbrachial approach and 90 ml of contrast medium was injected during six exposures using a long leg changer mounting a total of 18 imaging plates on six surfaces. Visualization of the superficial femoral and popliteal arteries was judged as diagnostic in all cases. The abdominal aorta, iliac arteries, and subtrifurcation were also visualized in most cases, but visualization was suboptimal in some cases. As a complication, median nerve palsy occurred in one case. This technique is thought to be a useful method for evaluating PVD because of the advantages of a large field of view and wide exposure latitude, in spite of its relatively long processing time.

Cerebral venous angiomas associated with hemorrhagic lesions. Their MRI manifestations

Using two 1.5-T magnetic resonance (MR) scanners, 82 venous angiomas (VAs) were imaged. There were 13 (16%) VAs associated with hemorrhagic lesions. Ten of the 13 hemorrhagic lesions were considered hematomas in the subacute or chronic stage, caused by VAs or coexisting cavernous hemangiomas. Two of the 13 were subacute intracerebral hematomas; the remaining one was a sequela of a hemorrhagic venous infarct. After analysis of our data, it was concluded that infratentorial VAs and deeply draining supratentorial VAs in relatively young adults, especially females, are relatively frequently associated with intracerebral hemorrhagic lesions. MR imaging proved useful for diagnosing VAs and associated hemorrhagic lesions.

Type D dural carotid-cavernous fistula. Results of combined treatment with irradiation and particulate embolization

PURPOSE

To assess the efficacy of irradiation combined with particulate embolization for treating type D dural carotid-cavernous fistulas, supplied by the meningeal branches of both external (ECA) and internal carotid arteries.

MATERIAL AND METHODS

Nine patients were treated by particulate embolization via the ECA branches, followed by radiation therapy with doses of 30 Gy. One of these patients with recurrent symptoms received an additional 30 Gy one year after initial treatment, making a total dose of 60 Gy.

RESULTS

In all cases, symptoms were improved immediately after the particulate embolizations. In 8 cases, complete resolution of symptoms were obtained in 4-19 months and an average of 8 months after treatment. In one case, chemosis was markedly improved and persisted minimally 41 months later.

CONCLUSION

Particulate embolization is effective for immediate symptomatic improvement, and complete resolution of symptoms can usually be achieved by subsequent radiation therapy.

Intracranial metastasis of renal cell carcinoma: MR imaging

The purpose of this study was to evaluate the magnetic resonance (MR) findings of intracranial metastatic tumors of renal cell carcinomas (RCCs). MR images of seven patients with intracranial metastases of RCCs were retrospectively reviewed. Each of the seven patients had a single lesion, including five supratentorial intraparenchymal lesions, one 4th ventricular lesion, and one pituitary lesion. Intra- and/or peritumoral flow voids were observed in five of the seven lesions. The signal intensities of the tumors were not specific. All lesions showed gadolinium enhancement, including solid (3), nearly solid (2), and ring enhancement (2). We concluded that intra- and/or peritumoral flow void is a relatively characteristic MR finding of intracranial metastases of RCCs.

[High flow priapism following a straddle-injury-induced arteriocavernosal fistula: a case report]

A 26-year-old man with high flow priapism after blunt perineal trauma, is described herein. Patient evaluation included intracavernal blood-gasometry, cavernography, color flow Doppler sonography. The blood-gasometry showed pH 7.413, pO2 77.9 mmHg, pCO2 41.0 mmHg, HCO2- 26.1 mmol/L, BE 2.0 mmol/L. By direct cavernosography, pooling of contrast agent was seen at the root of the penis. Color flow Doppler sonography revealed pulsatile, turbulent flow within left corpus cavernosum. Our case was diagnosed as high flow priapism from these findings. Detumescence was not achieved by an alpha-adrenergic agent. Superselective embolization of the deep artery of the penis with autologous blood clot was performed with good results. Our case demonstrates that this procedure is a safe and effective therapy for high flow priapism and that erectile function can return to normal.

Postcontrast 3D-TOF-MR angiography of intracranial venous angiomas

The clinical value of three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) was assessed in 15 patients with intracranial venous angiomas (VAs), by comparing results thereof with those of postcontrast T1-weighted MR images (MRIs). All 15 VAs were identified both on the postcontrast MRIs and MRAs. The MRAs surpassed the MRIs in imaging entire structures, including the draining veins of the supratentorial VAs. For the infratentorial VAs, the MRAs and the MRIs were of equal value. Although the addition of MRA to the MRI procedure incurs more time and expense, the complete structure of the VA can thereby be identified three-dimensionally on MRA. Conventional angiography is apparently not required for the confirmation of a VA. Thus, it is concluded that MRA is very useful for diagnosing VAs.

Intracranial epidermoid carcinoma: CT and MRI

We report a patient with an epidermoid carcinoma an extremely rare brain tumour, in the right cerebellopontine angle cistern. Contrast enhancement is the most important feature for differential diagnosis of epidermoid carcinomas from atypical benign epidermoid cysts.

Double cerebral venous angiomas: MRI

Using a 1.5 Tesla MR imager, we examined 58 patients with venous angiomas (VA); images were also obtained following contrast medium in 33. Of the 58 patients 29 underwent selective cerebral angiography. We found in all 63 VA, including two with arterial components; 5 of the 58 patients thus each had two VA. The VA were supratentorial and bilateral in 4 cases; the remaining patient had supra- and infratentorial VA. Of these 5 patients, 4 received intravenous contrast medium and in 2 of them, the second VA was so small that it was detectable only on the contrast-enhanced images. The incidence of double VA in patients receiving contrast medium was 12% (4/33).

Varix occurring with cerebral venous angioma: a case report and review of the literature

We report a patient in whom a varix occurred with a venous angioma, a rare combination of cerebral vascular malformations. During our review of the 7 previously reported cases, we discovered that all 8 venous angiomas were relatively large and supratentorial, and that the varices involved the veins draining then.

MRI of the brain in chronic carbon monoxide poisoning

We examined 13 patients with chronic carbon monoxide (CO) poisoning by magnetic resonance imaging (MRI); all of them had been in an explosion in a coal mine 25 years previously. Symmetrical globus pallidus lesions were observed in 12, as was degeneration of the white matter, with focal cortical atrophy. The temporal parietal and occipital lobes were usually affected, the parietooccipital region being the most frequently and extensively damaged. Of the 12 patients with white matter degeneration 7 had definitely asymmetrical cortical and subcortical lesions. There were 6 patients with dilated temporal horns, probably due to atrophy of the hippocampal gyri. A history of CO inhalation and an awareness of the typical distributions of lesions are important for recognition of the effects of CO poisoning, especially when patients are in the chronic stage.