Atlantoaxial stability in ossiculum terminale

2001 ◽  
Vol 95 (1) ◽  
pp. 119-121
Author(s):  
Cheng-Loong Liang ◽  
Chun-Chung Lui ◽  
Kang Lu ◽  
Tao-Chen Lee ◽  
Han-Jung Chen

✓ The authors describe a patient with ossiculum terminale. Thin-section three-dimensional computerized tomography reconstructions, magnetic resonance images, and radiographs of the cervical spine were obtained to evaluate the atlantoaxial stability and structures of the ossiculum terminale. Bone had formed between the ossicles and the body of the odontoid process, and good atlantoaxial stability was clearly demonstrated.

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 191-192 ◽  
Author(s):  
Lee Walton ◽  
Anna Hampshire ◽  
Paul Vaughan ◽  
David M. C. Forster ◽  
Andras A. Kemeny ◽  
...  

✓ The purpose of this paper was to note a potential source of error in magnetic resonance (MR) imaging. Magnetic resonance images were acquired for stereotactic planning for GKS of a vestibular schwannoma in a female patient. The images were acquired using three-dimensional sequence, which has been shown to produce minimal distortion effects. The images were transferred to the planning workstation, but the coronal images were rejected. By examination of the raw data and reconstruction of sagittal images through the localizer side plate, it was clearly seen that the image of the square localizer system was grossly distorted. The patient was returned to the MR imager for further studies and a metal clasp on her brassiere was identified as the cause of the distortion.


2002 ◽  
Vol 97 (2) ◽  
pp. 467-470 ◽  
Author(s):  
John B. Weigele ◽  
John C. Chaloupka ◽  
Walter S. Lesley

✓ The authors report a case in which the clinical and neuroimaging findings were initially considered diagnostic of a brainstem glioma. Angiography revealed a deep venous system (galenic) dural arteriovenous fistula causing brainstem interstitial edema. Successful endovascular surgery resulted in complete clinical recovery of the patient and resolution of the structural abnormalities that had been observed on magnetic resonance images. The neuroimaging and therapeutic significance of this case are discussed.


1996 ◽  
Vol 85 (6) ◽  
pp. 1050-1055 ◽  
Author(s):  
Philippe P. Maeder ◽  
Reto A. Meuli ◽  
Nicolas de Tribolet

✓ This study was undertaken to evaluate the capacity of three-dimensional (3-D) time-of-flight (TOF) magnetic resonance (MR) angiography with VoxelView (VV) 3-D volume rendering to detect and characterize intracranial aneurysms and to compare this rendering technique with that of maximum intensity projection (MIP). Forty patients with a total of 53 intracranial aneurysms (10 giant and subgiant, 43 saccular) were consecutively admitted to University Hospital, Lausanne, Switzerland, and investigated with 3-D TOF MR angiography. Source images of the 43 saccular aneurysms were processed with both MIP and VV. The aneurysm detection rate of the two techniques and their ability to characterize features of an aneurysm, such as its neck and its relation to the parent vessel, were compared. Intraarterial digital subtraction angiography was used as the gold standard to which these techniques could be compared and evaluated. Four aneurysms, less than 3 mm in size, were missed using MIP compared to three missed using VV. The representation of aneurysmal morphology using VV was superior to that found using conventional angiography in nine cases, equal in 16 cases, and inferior in seven cases. The representation of the aneurysm neck using VV was superior to MIP in 21 cases, equal in 17 cases, and inferior in one case; it was superior to that shown using conventional angiography in 10 cases, equal in 18 cases, and inferior in four cases. Time-of-flight MR angiography in conjunction with both MIP and VV 3-D reconstruction was able to visualize all aneurysms that were larger than 3 mm. Compared to MIP, VV provides a better definition of the aneurysm neck and the morphology of saccular aneurysms, making VV valuable for use in a preoperative diagnostic workup.


2002 ◽  
Vol 96 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Marjorie C. Wang ◽  
Ken R. Winston ◽  
Robert E. Breeze

✓ The authors report a case of cerebellar mutism arising from a hemorrhagic midbrain cavernous malformation in a 14-year-old boy. No cerebellar lesion was identified; however, edema of the dorsal midbrain was noted on postoperative magnetic resonance images. Dysarthric speech spontaneously returned and then completely resolved to normal speech. This case provides further evidence for the theory that involvement of the dentatothalamic tracts, and not a cerebellar lesion per se, is the underlying cause of “cerebellar” mutism.


1998 ◽  
Vol 88 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Jesús Pujol ◽  
Gerardo Conesa ◽  
Joan Deus ◽  
Luis López-Obarrio ◽  
Fabián Isamat ◽  
...  

Object. The authors sought to evaluate the advantages and limitations of functional magnetic resonance (fMR) imaging when it was used regularly in the clinical context to identify the central sulcus. Methods. A 1.5-tesla MR system comprising a spoiled gradient recalled acquisition in the steady-state functional sequence and a cross-hand cancellation analysis method were used to evaluate 50 surgical candidates with centrally located space-occupying lesions in the brain. Three-dimensional (3-D) models of the patient's head and brain showing the relative position of the tumor and the eloquent cortex were obtained in each case. A selective and reproducible focal activation was found, indicating the probable central sulcus position in 41 patients (82%). Direct cortical stimulation confirmed the fMR findings in 100% of 22 intraoperatively assessed patients. Failure to identify the central sulcus occurred in 18% of cases and was mainly a consequence of intrinsic damage in the primary sensorimotor region that resulted in severe hand paresis. Conclusions. Although specific factors were identified that contributed to reduced sensitivity of fMR imaging in the clinical context, the present study supports functional assessment and 3-D representation of specific surgical situations as generally feasible in common practice.


2001 ◽  
Vol 94 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Atsuko Harada ◽  
Yukihiko Fujii ◽  
Yuichiro Yoneoka ◽  
Shigekazu Takeuchi ◽  
Ryuichi Tanaka ◽  
...  

Object. The purpose of this study was to assess the utility of high-field magnetic resonance (MR) imaging as a quantitative tool for estimating cerebral circulation in patients with moyamoya disease. Methods. Eighteen patients with moyamoya disease who were scheduled to undergo revascularization surgery and 100 healthy volunteers were examined using T2-reversed MR imaging performed using a 3-tesla system. Ten of the 18 patients underwent a second study between 1 year and 3 years after revascularization. Magnetic resonance images obtained in the patients with moyamoya disease were statistically analyzed and compared with those obtained in healthy volunteers. The MR imaging findings were also correlated with results of single-photon emission computerized tomography and conventional cerebral angiography studies. Transverse lines in the white matter (medullary streaks) were observed in almost all persons. In healthy volunteers, the diameter sizes of the medullary streaks increased significantly with age (p < 0.001). Multiple logistic regression analysis revealed that age-adjusted medullary streak diameters were significantly larger in patients with moyamoya disease (p < 0.001). Diameter sizes also increased significantly with the increased severity of cerebral hypoperfusion (p < 0.001) and a higher angiographically determined stage of the disease (p < 0.001). Diameter sizes decreased significantly after surgery (p < 0.001). Conclusions. The increases in medullary streak diameters observed in patients with moyamoya disease appear to represent vessels dilated due to cerebral hypoperfusion. High-field T2-reversed MR imaging is useful in estimating cerebral circulation in patients with moyamoya disease.


2003 ◽  
Vol 98 (1) ◽  
pp. 43-49 ◽  
Author(s):  
R. Shane Tubbs ◽  
John C. Wellons ◽  
Jeffrey P. Blount ◽  
Paul A. Grabb ◽  
W. Jerry Oakes

Object. The quantitative analysis of odontoid process angulation has had scant attention in the Chiari I malformation population. In this study the authors sought to elucidate the correlation between posterior angulation of the odontoid process and patients with Chiari I malformation. Methods. Magnetic resonance images of the craniocervical junction obtained in 100 children with Chiari I malformation and in 50 children with normal intracranial anatomy (controls) were analyzed. Specific attention was focused on measuring the degree of angulation of the odontoid process and assigning a score to the various degrees. Postoperative outcome following posterior cranial fossa decompression was then correlated to grades of angulation. Other measurements included midsagittal lengths of the foramen magnum and basiocciput, the authors' institutions' previously documented pB—C2 line (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C-2 body), level of the obex from a midpoint of the McRae line, and the extent of tonsillar herniation. Higher grades of odontoid angulation (retroflexion) were found to be more frequently associated with syringomyelia and particularly holocord syringes. Higher grades of angulation were more common in female patients and were often found to have obices that were caudally displaced greater than three standard deviations below normal. Conclusions. These results not only confirm prior reports of an increased incidence of a retroflexed odontoid process in Chiari I malformation but quantitatively define grades of inclination. Grades of angulation were not found to correlate with postoperative outcome. It is the authors' hopes that these data add to our current limited understanding of the mechanisms involved in hindbrain herniation.


1992 ◽  
Vol 77 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Duc H. Duong ◽  
Robert C. Rostomily ◽  
David R. Haynor ◽  
G. Evren Keles ◽  
Mitchel S. Berger

✓ The authors describe a method for quantitation of the area and volume of the resection cavity in patients who have undergone surgery for brain tumors. Using a slide scanner and Image 1.27, a public domain program for the Apple Macintosh II computer, computerized tomography scans and magnetic resonance images can be digitized and analyzed for a particular region of interest, such as the area and volume of tumor on preoperative and postresection scans. Phantom scans were used to analyze the accuracy of the program and the program users. User error was estimated at 2%, program error was 4.5%. This methodology is proposed as a means of retrospectively calculating the extent of tumor resection.


1990 ◽  
Vol 72 (3) ◽  
pp. 433-440 ◽  
Author(s):  
Xiaoping Hu ◽  
Kim K. Tan ◽  
David N. Levin ◽  
Simranjit Galhotra ◽  
John F. Mullan ◽  
...  

✓ Data from single 10-minute magnetic resonance scans were used to create three-dimensional (3-D) views of the surfaces of the brain and skin of 12 patients. In each case, these views were used to make a preoperative assessment of the relationship of lesions to brain surface structures associated with movement, sensation, hearing, and speech. Interactive software was written so that the user could “slice” through the 3-D computer model and inspect cross-sectional images at any level. A surgery simulation program was written so that surgeons were able to “rehearse” craniotomies on 3-D computer models before performing the actual operations. In each case, the qualitative accuracy of the 3-D views was confirmed by intraoperative inspection of the brain surface and by intraoperative electrophysiological mapping, when available.


1993 ◽  
Vol 79 (2) ◽  
pp. 277-279 ◽  
Author(s):  
Shobu Namura ◽  
Junya Hanakita ◽  
Hideyuki Suwa ◽  
Masaki Mizuno ◽  
Toshiyuki Ohtsuka ◽  
...  

✓ The authors report a rare case of intraspinal thoracic mobile neurinoma in a 51-year-old man. The clinical symptoms, especially thoracoabdominal discomfort, changed remarkably according to the patient's posture. Magnetic resonance images demonstrated that the level of the caudal end of the tumor varied between T4–5 and T9–10 with changes in the patient's position. Intraoperative myelography was useful in identifying the tumor location and choosing the level of the laminectomy.


Sign in / Sign up

Export Citation Format

Share Document