Basilar impression complicating osteogenesis imperfecta type IV: the clinical and neuroradiological findings in four cases.
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OBJECTIVES: To describe the clinical and neuroradiological features of basilar impression in patients with osteogenesis imperfecta type IV. METHODS: Four patients with basilar impression were ascertained in a population study of osteogenesis imperfecta. All four had detailed clinical and neuroradiological examination with both CT and MRI of the craniocervical junction and posterior fossa structures. RESULTS: All four showed significant compression of the posterior fossa structures and surgical decompression was performed with relief of symptoms. CONCLUSION: Symptoms of cough headache and trigeminal neuralgia occurring in patients with osteogenesis imperfecta are indications for detailed clinical and neuroradiological investigation to document basilar impression. (+info)
Automatic three-dimensional multimodality registration using radionuclide transmission CT attenuation maps: a phantom study.
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Coregistration of images from a single subject, acquired by different modalities, is important in clinical diagnosis, surgery and therapy planning. The purpose of this study was to evaluate, using a physical torso phantom, a novel, fully automated method for three-dimensional image registration of CT and SPECT, using radionuclide transmission (RNT) attenuation maps. METHODS: We obtained CT scans and SPECT scans paired with RNT maps of an anthropomorphic cardiac phantom. RNT attenuation maps were acquired using an uncollimated 99mTc-filled flood source. RNT and SPECT scans were acquired in the same spatial orientation (usual clinical practice in nonuniform attenuation correction). In addition, CT attenuation maps (CTMAPs) for 99mTc SPECT were generated from CT by linear energy scaling. RNT maps were registered to CT and CTMAPs by iterative simplex minimization of count difference and uniformity index (sum of RNT map intensity variances corresponding to each intensity level in the CT volume). In each iteration, three shifts and three angles were adjusted. To register SPECT to CT, we applied the RNT transformation parameters to SPECT. RESULTS: RNT maps could be registered to CT and CTMAP images using both criteria. The average three-dimensional distance between landmark and automated registration was 2.5 +/- 1.2 mm for count difference and 3.3 +/- 1.3 mm for uniformity index. The three-dimensional reproducibility errors were 1.2 +/- 0.7 mm for count difference, 2.1 +/- 0.5 mm for uniformity index and 2.3 +/- 1.0 mm for manual marker registration. The minimization of uniformity index was robust when up to 50% CT or RNT slices were missing and was not affected significantly (<2 mm) by realistic variation in CT values (+/- 12 Hounsfield units). CONCLUSION: In addition to typical use in nonuniform attenuation correction, RNT maps can be used for fully automated three-dimensional registration of SPECT to CT. Such registration is not affected by features and quality of SPECT images and avoids difficulties associated with fiducial markers. Our method can be applied to SPECT-CT registration of various organs, such as brain, heart, lungs, breasts and abdomen, including oncological scans. (+info)
Endovascular abdominal aortic aneurysm repair with percutaneous transfemoral prostheses deployment under local anaesthesia. Initial experience with a new, simple-to-use tubular and bifurcated device in the first 27 cases.
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BACKGROUND: Modification of endografts are required to simplify and improve the safety of the endovascular management of abdominal aortic aneurysms (AAA). OBJECTIVES: The aim of this study is to evaluate the efficacy of a new custom-made, tubular and bifurcated device. MATERIALS AND METHODS: The graft consisted of a continuous, self-expanding, stainless steel, Z-stent structure, covered with a thin wall PTFE tube. Bifurcated grafts were constructed in vivo from three PTFE tubes with a continuous Z-stent structure. Twenty-seven high risk patients with a mean age of 74 (62-86) years and AAA, mean diameter 5.9 cm, were treated in the last 26 months. Tube grafts were deployed in 13 aortic and one iliac cases, bifurcated grafts in nine cases and aorto-uni-iliac grafts with femorofemoral bypass in four cases. Grafts were deployed percutaneously under local anaesthesia. Patients were followed with contrast CT periodically. RESULTS: All grafts were deployed. There were no open conversions or other major complications. There were nine proximal and one distal postoperative endoleak. Four sealed spontaneously, three were treated successfully with endovascular techniques and three are under surveillance. In the 7 (2-23) months follow-up, one patient died due to heart failure 3 months post-procedure. CONCLUSIONS: Local anaesthesia and percutaneous graft introduction simplify and improve the efficacy of the procedure. Continuous aortic graft support provides stability and reduces the risk of migration. PTFE is a flexible, low-profile material for use in endovascular stent-grafts. The bifurcation concept used offers a simple technique for bifurcated grafts. (+info)
Complications in carotid endarterectomy are predicted by qualifying symptoms and preoperative CT findings.
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OBJECTIVES: To relate the 30-day perioperative rate of stroke or death in carotid endarterectomy (CEA) to preoperative qualifying symptoms and to the presence of cerebral infarction (CI) demonstrated on computed tomography (CT). DESIGN: Retrospective clinical study. MATERIAL AND METHODS: Two hundred and seventy-two consecutive CEAs for symptomatic stenosis in 262 patients were analysed. RESULTS: The total complication rate was 5.9%. Patients with retinal symptoms (n = 81) had no complications, TIA patients (n = 76) had 6.6% (p < 0.001). Patients qualifying with minor stroke (n = 113) had complications in 9.7% (N.S. compared to TIA patients). Patients qualifying with cortical symptoms had a significantly higher complication rate compared to those with retinal (8.4% vs. 0%, p = 0.004). The presence of a preoperative CT-verified infarction resulted in a higher risk for stroke or death (9.8% vs 2.8%, p = 0.008). Within the subgroup presenting with minor stroke, the presence of CI resulted in stroke or death in 13.9%. In patients without CI the corresponding figure was 2.4% (p = 0.017). CONCLUSION: The qualifying symptoms and the presence of CI visualized by CT influence the complication rate in CEA. When evaluating risk and comparing outcome, these parameters should be included in reporting standards. (+info)
Bilateral vertebral artery occlusion following cervical spine trauma--case report.
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A 41-year-old female presented with a rare case of bilateral vertebral artery occlusion following C5-6 cervical spine subluxation after a fall of 30 feet. Digital subtraction angiography showed occlusion of the bilateral vertebral arteries. Unlocking of the facet joint, posterior wiring with iliac crest grafting, and anterior fusion were performed. The patient died on the 3rd day after the operation. This type of injury has a grim prognosis with less than a third of the patients achieving a good outcome. (+info)
Abrupt exacerbation of acute subdural hematoma mimicking benign acute epidural hematoma on computed tomography--case report.
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A 75-year-old male was hit by a car, when riding a bicycle. The diagnosis of acute epidural hematoma was made based on computed tomography (CT) findings of lentiform hematoma in the left temporal region. On admission he had only moderate occipitalgia and amnesia of the accident, so conservative therapy was administered. Thirty-three hours later, he suddenly developed severe headache, vomiting, and anisocoria just after a positional change. CT revealed typical acute subdural hematoma (ASDH), which was confirmed by emergent decompressive craniectomy. He was vegetative postoperatively and died of pneumonia one month later. Emergent surgical exploration is recommended for this type of ASDH even if the symptoms are mild due to aged atrophic brain. (+info)
Surgical treatment of internal carotid artery anterior wall aneurysm with extravasation during angiography--case report.
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A 54-year-old female presented subarachnoid hemorrhage from an aneurysm arising from the anterior (dorsal) wall of the internal carotid artery (ICA). During four-vessel angiography, an extravasated saccular pooling of contrast medium emerged in the suprasellar area unrelated to any arterial branch. The saccular pooling was visualized in the arterial phase and cleared in the venophase during every contrast medium injection. We suspected that the extravasated pooling was surrounded by hard clot but communicated with the artery. Direct surgery was performed but major premature bleeding occurred during the microsurgical procedure. After temporary clipping, an opening of the anterior (dorsal) wall of the ICA was found without apparent aneurysm wall. The vessel wall was sutured with nylon thread. The total occlusion time of the ICA was about 50 minutes. Follow-up angiography demonstrated good patency of the ICA. About 2 years after the operation, the patient was able to walk with a stick and to communicate freely through speech, although left hemiparesis and left homonymous hemianopsia persisted. The outcome suggests our treatment strategy was not optimal, but suture of the ICA wall is one of the therapeutic choices when premature rupture occurs in the operation. (+info)
Fractures of the posteromedial process of the talus. A report of two cases.
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The authors present two cases of fractures of posteromedial process of talus. One was treated conservatively and the other by excision. The appearances of the CT scans, the therapeutic options and the mechanisms of injury are discussed. (+info)