Biomedical subjects
Publications and source records attributed to P T Vieco.
We describe a CT-guided percutaneous technique for aspiration of an anterior intraspinal fluid collection through a cervical disk. The approach is identical to that of cervical diskography or percutaneous cervical diskectomy, with intentional placement of the needle tip in the spinal canal. This procedure had no adverse effects and avoided an open operation to exclude spinal cord compression.
Rapidly acquired, anatomically accurate depictions of intracranial vascular anatomy can be obtained with helical CT. This article discusses data acquisition, reconstruction techniques, normal anatomy, pitfalls, aneurysms, and a number of other vascular pathologies that have been successfully imaged with CT angiography.
CT angiography shows promise as a noninvasive method to display carotid vascular pathology. This article discusses technique, stenosis measurements, pitfalls, strengths, and weaknesses of CT imaging of the carotid artery.
MRI of the brain of a 3-year-old boy performed 3 days after the onset of hemichorea (Sydenham Chorea) revealed abnormal signal and enlargement of the contralateral caudate and putamen. Follow-up imaging 40 months later showed a persistent cystic appearance of the caudate and putamen. This case is the first report of permanent MRI abnormalities after Sydenham Chorea.
Two patients with subarachnoid hemorrhage underwent CT angiography and conventional angiography at presentation. In each patient, both studies were repeated after the onset of intracranial vasospasm. In both cases, CT angiograms were able to demonstrate convincingly the conventional angiographic findings. CT angiography may prove useful in the evaluation of vasospasm in patients with subarachnoid hemorrhage.
We present three patients who were admitted to our institution with vertebrobasilar dolichoectasia diagnosed at CT angiography. Two patients had associated intraarterial thrombi and one patient had basilar artery dissection. Shaded surface display images were useful in showing arterial anatomy relative to the skull base. Source images and curved-reformatted images were helpful in diagnosing thrombi and dissection. CT angiography is a minimally invasive means of diagnosing and following up these patients.
The use of CT angiography is described in three patients for the evaluation of intracranial clips after surgery for an aneurysm. A postprocessing technique is described in which shaded-surface-display models were superimposed on maximum intensity projection CT angiograms. CT angiograms showed residual aneurysmal filling adjacent to a clip, patency of a vessel thought to be compromised by recent clip placement, and errant position of a clip, which required repeat surgery.
Primary germ cell tumors confined to the optic nerves and chiasm without suprasellar extension are uncommon. These tumors appear similar to chiasmatic gliomas on both computed tomography and magnetic resonance imaging, potentially resulting in treatment errors if the diagnosis is based on radiologic criteria alone. Unlike chiasmatic gliomas, suprasellar germinomas characteristically present with a clinical triad of endocrine abnormalities, diabetes insipidus, and visual complaints. We report the case of a 9-year-old boy who presented with a 5-month history of fatigue, 16-pound weight gain, polydipsia, polyuria, visual complaints, and intermittent headache. Imaging studies demonstrated findings consistent with a glioma of the chiasm with infiltration into the optic tracts. At surgery, the chiasm and optic tracts were diffusely enlarged with no other suprasellar abnormalities. Biopsy specimens were characteristic of germ cell tumor. Based on this result, the patient received a treatment regimen different from that used at our institution for chiasmatic gliomas. We feel it is imperative to biopsy chiasmatic lesions that radiologically appear to be gliomas if symptoms do not adhere to the classical clinical presentation.
OBJECTIVE: The purpose of this study was to compare CT angiography with digital subtraction angiography (DSA) in the detection and measurement of intracranial aneurysms in patients with acute subarachnoid hemorrhage. SUBJECTS AND METHODS: Thirty consecutive patients with recent subarachnoid hemorrhage shown by unenhanced CT scanning or lumbar puncture were studied with CT angiography and DSA. Using a shaded surface display format and source images, two reviewers working independently blindly interpreted CT angiograms for presence and size of aneurysms. Sensitivity and specificity for aneurysm detection were calculated for each reviewer. Aneurysm size measurements were compared between reviewers and between the two imaging techniques. RESULTS: Thirty aneurysms were found in 22 patients with DSA; eight patients had no aneurysms. The sensitivity and specificity of CT angiography for reviewer A were 0.97 and 1.0, respectively. For reviewer B, the sensitivity and specificity were 0.77 and 0.87, respectively. All cases with single aneurysms on DSA (18 patients) had surgical confirmation of aneurysm location and rupture. In each case with multiple aneurysms (four patients), the aneurysm thought responsible for the hemorrhage was surgically confirmed. In those cases with no aneurysms found on DSA, follow-up DSA studies did not reveal additional findings. Differences between reviewers in aneurysm size measurements made with CT angiography were not significant (p = .10). Mean aneurysm measurements for reviewer A, reviewer B, and DSA were 6.6 mm, 7.0 mm, and 6.9 mm, respectively. CONCLUSION: CT angiography shows potential in the detection and measurement of aneurysms in patients with acute subarachnoid hemorrhage when compared with DSA.
CT angiography is an exciting yet controversial application of helical (spiral) CT technology. Although many radiologists equate CT angiography with three-dimensional (3D) rendering, we believe that axial images, multiplanar reformatted (MPR) images, and true 3D models all contribute to a better evaluation of the vascular system than was possible with conventional CT. This occurs because helical scans are volumetric and are accomplished rapidly with high levels of circulating contrast material. This article reviews the indications for CT angiography, compares CT angiography with other techniques, and offers a practical methodology for neuroradiologic, thoracic, and abdominal applications of CT angiography.
An intracranial mycotic aneurysm developed in a 35-year-old woman with endocarditis, caused by Cardiobacterium hominis, around a prosthetic valve. This type of aneurysm is a rare, life-threatening entity, and C. hominis is extremely uncommon as the causative agent. The pathogenesis and monitoring of intracranial mycotic aneurysm are discussed.
Dysplastic gangliocytoma (Lhermitte-Duclos disease) is a rare entity. Usually presenting as a posterior fossa mass, dysplastic gangliocytoma is not a true neoplasm but a hard-to-characterize lesion that may represent an abnormality of cell migration or a phacomatosis. Previous reports of CT findings are rare in the radiologic literature, and high-field (1.5 Tesla) MR images have never been described in the pediatric age group. We present a case of dysplastic gangliocytoma in a one-year-old boy with CT and MR findings.
Fatty infiltration of the liver has been described in association with a large number of systemic conditions. The authors describe a case of multifocal fatty infiltration simulating metastatic disease. The patient had acquired immunodeficiency syndrome and pathologically proved cytomegalovirus hepatitis. To the authors' knowledge, neither entity has been described in association with this radiologic finding.
Medulloblastoma is a relatively common intracranial neoplasm in childhood. Its extraneural spread was, until recently, thought to be a rare occurrence. Metastases are most commonly to bone. Five patients with medulloblastoma metastatic to bone are presented, and findings are compared to those of previous reports. Two of the five cases showed patchy extensive osteosclerosis of the pelvis and/or proximal femora. One case had concurrent lymph node involvement. In patients with past or present medulloblastoma and bone pain, metastases to bone should be excluded. Medulloblastoma metastatic to bone is a rare cause of extensive osteosclerosis.
Two cases of active hemorrhage from an intracranial aneurysm demonstrated by CT angiography are presented. In each case, extraluminal opacified blood was seen entering a recent hemorrhage surrounding the aneurysm, simulating a vascular structure. This is a potential pitfall in the interpretation of CT angiograms in patients with recent subarachnoid hemorrhage.
Four cases in which the diagnosis of developmental venous anomaly (DVA) was made using CT angiography are illustrated. The diagnosis of DVA was confirmed by either MR (all cases), digital subtraction angiography (two cases), or both (one case). This is the first report, to our knowledge, of the CT angiographic appearance of DVA.