Pyeong Ho Yoon

MRI of germinomas arising from the basal ganglia and thalamus.

Abstract We reviewed the MRI findings of germinomas originating from the basal ganglia, thalamus or deep white matter in 13 patients with 14 germinomas, excluding those in the suprasellar or pineal regions. Ten cases were confirmed as germinomas by stereotaxic biopsy, three by partial and one by total removal of the tumour. Analysis was focussed on the location and the signal characteristic of the tumour, haemorrhage, cysts within the tumour and any other associated findings. Thirteen of the tumours were in the basal ganglia and one in the thalamus. Haemorrhage was observed in seven patients, while twelve showed multiple cysts. Associated ipsilateral cerebral hemiatrophy was seen in three patients. The signal intensity of the parenchymal germinomas was heterogeneous on T1- and T2-weighted images due to haemorrhage, cysts and solid portions. We also report the MRI findings of germinomas in an early stage in two patients.

Rescue treatment with abciximab in acute ischemic stroke

In acute ischemic stroke, reocclusion after an initially successful thrombolysis treatment can occur and is associated with increased morbidity and mortality. The authors present the successful use of abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, in a patient with a thrombotic occlusion of the proximal middle cerebral artery, which was refractory to combined IV and intra-arterial thrombolysis and percutaneous intracranial balloon angioplasty.

Treatment of spontaneous arterial dissections with stent placement for preservation of the parent artery.

SummaryBackground. A wide variety of treatment regimens have been advocated for dissections involving the intracranial arteries. Recently, the stent can be used to exclude the aneurysm from the circulation and preserve the parent artery. We evaluated the safety and efficacy of stent angioplasty for intracranial arterial dissections.Methods. Ten patients with spontaneous dissections, nine vertebral artery and one internal carotid artery lesions underwent endovascular treatment using stent placement as primary treatment modality. One stent placement was attempted in five patients initially. Three patients were intentionally treated with two overlapping stents which completely covered the aneurysm orifice. Two tandem stents were used in one patient to allow spanning the entire length of the dissection. Stent-assisted coil embolization was performed in one patient.Results. Of the 10 patients in whom stenting was tried, the overall success in reaching the target lesion with stents was 90%. Of the 9 patients treated with stents, stent release and positioning were considered optimal in 7 patients (77.8%) and suboptimal in two. Lesions of 8 patients were improved or stable in angiographic follow-up. However, one pseudo-aneurysm was enlarged, and subsequently, was treated by proximal occlusion using coils. There were no instances of postprocedural ischaemic attacks, new neurological deficits, and no new minor or major strokes prior to patient discharge. All parent arteries of the patient who underwent the successful procedure were preserved. On the modified Rankin scale used for the follow up, all patients were assessed as functionally improved or of stable clinical status.Conclusions. The success in reducing dissection-induced stenosis or pseudo-aneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischaemic or haemorrhagic) suggest that stent placement offers a viable alternative to complex surgical procedures or deconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remains to be determined in a large series.

Treatment of Intra- and Extracranial Arterial Dissections Using Stents and Embolization

PurposeTo evaluate the safety and efficacy of stent placement for extracranial and intracranial arterial dissections.MethodsEighteen patients underwent endovascular treatment of carotid and vertebral dissections using intraluminal stent placement. Five patients with arterial dissection were treated, 2 using one insertion of a single stent and 3 using placement of two stents. Patients with a dissecting aneurysm were treated as follows: 7 patients with insertion of one stent, 4 with placement of two stents, and 2 by stent-assisted Guglielmi detachable coil embolization. In the 18 patients in whom stenting was attempted, the overall success in reaching the target lesion was 94.4%. Of the 17 patients treated with stents, stent release and positioning were considered optimal in 16 (94%) and suboptimal in one (6%). In patients who underwent a successful procedure, all parent arteries were preserved. There were no instances of postprocedural ischemic attacks, new neurologic deficits, or new minor or major strokes prior to patient discharge. In follow up, all patients were assessed, using the modified Rankin scale, as functionally improved or of stable clinical status. The reduction in dissection-induced stenosis or pseudoaneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischemic or hemorrhagic) suggest that stent placement offers a viable alternative to complex surgical bypass or reconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remain to be determined in a larger series.

The Usefulness of the New “Double-Catheter Technique” in the Treatment of Parent Artery Incorporated Wide-Necked Aneurysm with Guglielmi Detachable Coils Technical Notes

We describe a technique used to treat a wide-necked aneurysm in which the neck is incorporated with the parent artery. The patient was a 54-year-old woman who had suffered a grade III subarachnoid haemorrhage. Angiogram and three-dimensional CT showed a large, wide-necked aneurysm of the basilar bifurcation area with the right posterior cerebral artery incorporated in the aneurysm sac. A microcatheter was placed in the right posterior cerebral artery (PCA). Another catheter was placed within the aneurysm lumen. When making a first frame with a GDC, we made sure that the frame of the coil did not overlap the PCA positioned microcatheter. Then, with the microcatheter positioned at the PCA, the angiogram was done. The flow pattern and dye-disappearance time were checked. Subsequent coils were introduced, but not beyond the frame of the first coil to maintain PCA flow. This new “double-catheter technique” represents a viable option for treating wide-necked aneurysms, especially when the parent artery is incorporated in a wide-necked aneurysm and the delineation of the parent artery is impossible.

Perirolandic hypoperfusion on single-photon emission computed tomography in term infants with perinatal asphyxia: comparison with MRI and clinical findings

Abstract We describe the findings on single-photon emission computed tomography (SPECT) in patients with perinatal asphyxia at term, with perirolandic cortico-subcortical changes on MRI, and to correlate them with clinical features. SPECT of 7 patients was obtained after injection of 185–370 MBq of Tc-99m-ECD (ethyl cysteinate dimer). The patients had spastic quadriplegia (7/7) with perinatal asphyxia (6/7) at term (7/7). The results were correlated with the MRI findings. Hypoperfusion of the perirolandic cortex was clearly seen on SPECT in all patients, even in two with subtle changes on MRI. SPECT demonstrated a more extensive area of involvement than MRI, notably in the cerebellum (in 4), the thalamus (in 7) and basal ganglia (in 5), where MRI failed to show any abnormalities.

Comparison of Orbital Pseudotumor and Lymphoma: Clinical and Radiological Findings

Purpose: To compare the clinical and radiological findings of orbital pseudotumor with those of orbital lymphoma. Materials and Methods: The clinical and radiological features of 12 orbital pseudotumors were compared with those of 17 orbital lymphomas, the nature of all lesions being confirmed by tissue biopsy. Twenty-four CT scans and nine MR images were retrospectively reviewed and compared, with special focus on the location of a tumor in the orbit, the invasion of periorbital structures, tumor margin, bilaterality, and signal intensity. The initial symptoms at admission were also classified and compared. Results: In 50% of cases, orbital pseudotumors were located in both extraconal and intraconal space; 75% involved two or more extraocular muscles, and 33% involved the optic nerve. Margins were either infiltrative (75%) or ill-defined (92%). As for orbital lymphomas, 64% occupied extraconal space, invading one or less extraocular muscle (76%) and conjunctiva (29%). Seventy-one percent had a sharp margin, and 65% were lobulated or round. In pseudotumors, orbital pain and visual loss were major symptoms, while in lymphomas a painless orbital mass was the initial symptom. Conclusion: CT or MR image analysis of lesion location, margin, and the involvement of adjacent extra-ocular muscle or optic nerves may help differentiate between orbital lymphoma and orbital pseudo tumor

Emboilzation of Dural Arteriovenous Fistulas Involving the Cavernous Sinus

Purpose : To compare the results of endovascular treatment by using transarterial, transvenous, or a combinedapproach in cavernous dural arteriovenous fistulars(CDAVF). Materials and Methods : Twenty-nine angiographicallyconfirmed CDAVF patients underwent endovascular treatment. Initial presenting symptoms and the characteristics ofCDAVF, as seen on angiograms, were investigated. Patients were divided according to Barrow ’s classification.Using embolic materials, endovascular treatment was performed transarterially or transvenously, and the clinicalresults were retrospectively evaluated during follow up ranging from 5 to 122(mean 48.8) months. Results : Allpatients complained of ocular symptoms. Twenty six (90%) showed congestive symptoms related to superior ophthalmicvein drainage, but three presented with only opthalmoplegia without congestion. According to Barrow ’sclassification, patients were classified as follows : type B(n=2), type C(n=1), or type D(n=26). Twenty-fourpatients had a unilateral CDAVF, and five a bilateral CDAVF. The results of angiographic treatment were as follows: completely treated in 8 cases(28%), partially treated in 21(72%). Clinical symptoms completely disappeared in 19patients, for eight of these treatment was entirely angiographic, while for 11 it was partially angiographic.Clinical improvements were noted in eight patients, but in two, visual acuity progressively decreased. In 12patients who underwent transarterial treatment, the clinical results were as follows : complete cure in five(42%),improvement in five(42%), and progressively decreasing visual acuity in two(16%). Among 17 patients who underwenttransvenous or transvenous with transarterial treatment, complete cure was seen in 14(82%), and improvement inthree(18%). Conclusion : Twenty-seven of 29 CDAVF patients were completely cured or improved after endovasculartreatment. For type-D patients, transvenous with transarterial treatment led to a higher cure rate than thetransarterial approach alone.