Brain surface reformatted images for fast and easy localization of perirolandic lesions

2005 ◽  
Vol 102 (2) ◽  
pp. 302-310 ◽  
Author(s):  
Elke Hattingen ◽  
Catriona Good ◽  
Stefan Weidauer ◽  
Sebastian Herminghaus ◽  
Peter Raab ◽  
...  

Object. The goal of this study was to evaluate a novel form of brain surface representation that allows simple, reliable mapping of the surface neuroanatomy for the preoperative evaluation of the spatial relationship between a focal lesion and the precentral gyrus. Methods. High-resolution three-dimensional (3D) magnetic resonance (MR) imaging data sets were postprocessed using a curved multiplanar reformatting technique to create brain surface reformatted (BSR) images. These BSR images were reconstructed in less than 5 minutes and demonstrated the entire central sulcus with adjacent surface structures in one view. Two experienced neuroradiologists determined the localization of lesions near the central sulcus in 27 patients on standard MR images in three orthogonal planes and on BSR images. In addition, these observers judged whether the lesions were easy or difficult to localize on standard MR and BSR images, and whether diagnoses based on these methods were certain or doubtful. Anatomical localization based on BSR images was compared with that based on functional MR (fMR) images or intraoperative mapping of motor function. The BSR images yielded a perfect concordance with the fMR images and intraoperative mapping (Cohen κ 1.0) and optimal diagnostic accuracy in localizing perirolandic lesions (both sensitivity and specificity were 100%). Localization was judged to be easy for 48 of 54 diagnoses based on BSR images compared with 26 of 54 based on standard MR images. Diagnoses were assessed as certain for 52 cases based on BSR images and 34 cases based on standard MR images. Conclusions. Brain surface reformatted imaging improves the diagnostic accuracy of standard anatomical MR imaging for localizing superficial brain lesions in relation to the precentral gyrus. The complementary use of this technique with standard two-dimensional imaging is supported by the fast and simple postprocessing technique and may provide useful information for preoperative surgical planning.

2004 ◽  
Vol 100 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Vaijayantee Kulkarni ◽  
Vedantam Rajshekhar ◽  
Lakshminarayan Raghuram

Object. The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging. Methods. Preoperative and short-term follow-up (mean duration 17.5 months, range 10–48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classifed as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes. Conclusions. On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.


2002 ◽  
Vol 97 (3) ◽  
pp. 591-597 ◽  
Author(s):  
Emmanuel Cuny ◽  
Dominique Guehl ◽  
Pierre Burbaud ◽  
Christian Gross ◽  
Vincent Dousset ◽  
...  

Object. The goal of this study was to determine the most suitable procedure(s) to localize the optimal site for high-frequency stimulation of the subthalamic nucleus (STN) for the treatment of advanced Parkinson disease. Methods. Stereotactic coordinates of the STN were determined in 14 patients by using three different methods: direct identification of the STN on coronal and axial T2-weighted magnetic resonance (MR) images and indirect targeting in which the STN coordinates are referred to the anterior commissure—posterior commissure (AC—PC) line, which, itself, is determined either by using stereotactic ventriculography or reconstruction from three-dimensional (3D) MR images. During the surgical procedure, electrode implantation was guided by single-unit microrecordings on multiple parallel trajectories and by clinical assessment of stimulations. The site where the optimal functional response was obtained was considered to be the best target. Computerized tomography scanning was performed 3 days later and the scans were combined with preoperative 3D MR images to transfer the position of the best target to the same system of stereotactic coordinates. An algorithm was designed to convert individual stereotactic coordinates into an all-purpose PC-referenced system for comparing the respective accuracy of each method of targeting, according to the position of the best target. Conclusions. The target that is directly identified by MR imaging is more remote (mainly in the lateral axis) from the site of the optimal functional response than targets obtained using other procedures, and the variability of this method in the lateral and superoinferior axes is greater. In contrast, the target defined by 3D MR imaging is closest to the target of optimal functional response and the variability of this method is the least great. Thus, 3D reconstruction adjusted to the AC—PC line is the most accurate technique for STN targeting, whereas direct visualization of the STN on MR images is the least effective. Electrophysiological guidance makes it possible to correct the inherent inaccuracy of the imaging and surgical techniques and is not designed to modify the initial targeting.


2004 ◽  
Vol 1 (3) ◽  
pp. 273-280 ◽  
Author(s):  
L. Fernando Gonzalez ◽  
David Fiorella ◽  
Neil R. Crawford ◽  
Robert C. Wallace ◽  
Iman Feiz-Erfan ◽  
...  

Object. The authors sought to establish radiological criteria for the diagnosis of C1–2 vertical distraction injuries. Methods. Conventional radiography, computerized tomography (CT), and magnetic resonance (MR) imaging findings in five patients with a C1–2 vertical distraction injury were correlated with their clinical history, operative findings, and autopsy findings. The basion—dens interval (BDI) and the C-1 and C-2 lateral mass interval (LMI) were measured in 93 control patients who underwent CT angiography; these measurements were used to define the normal BDI and LMI. The MR imaging results obtained in 30 healthy individuals were used to characterize the normal signal intensity of the C1–2 joint. The MR imaging results were compared with MR images obtained in five patients with distraction injuries. In the 93 patients, the BDI averaged 4.7 mm (standard deviation [SD] 1.7 mm, range 0.6–9 mm) and the LMI averaged 1.7 mm (SD 0.48 mm, range 0.7–3.3 mm). Based on CT scanning in the five patients with distraction injuries, the BDIs (mean 11.9 mm, SD 3.2 mm; p < 0.001) and LMIs (mean 5.5 mm, SD 2 mm; p < 0.0001) were significantly greater than in the control group. Fast—spin echo inversion-recovery MR images obtained in these five patients revealed markedly increased signal distributed throughout the C1–2 lateral mass articulations bilaterally. Conclusions. In 95% of healthy individuals, the LMI ranged between 0.7 and 2.6 mm. An LMI greater than 2.6 mm indicates the possibility of a distraction injury, which can be confirmed using MR imaging. Patients with a suspected C1–2 distraction injury may be candidates for surgical fusion of C1–2.


2000 ◽  
Vol 93 (6) ◽  
pp. 1003-1013 ◽  
Author(s):  
Walter Stummer ◽  
Alexander Novotny ◽  
Herbert Stepp ◽  
Claudia Goetz ◽  
Karl Bise ◽  
...  

Object. It has been established that 5-aminolevulinic acid (5-ALA) induces the accumulation of fluorescent porphyrins in glioblastoma multiforme (GBM), a phenomenon potentially exploitable to guide tumor resection. In this study the authors analyze the influence of fluorescence-guided resection on postoperative magnetic resonance (MR) imaging and survival in a series of patients who underwent surgery in the authors' department.Methods. Fifty-two consecutive patients with GBM received oral doses of 5-ALA (20 mg/kg body weight) 3 hours before induction of anesthesia. Intraoperatively, tumor fluorescence was visualized using a modified operating microscope. Fluorescing tissue was removed whenever it was considered safely possible. Residual enhancement on early postoperative MR imaging was quantified and related to each patient's characteristics to determine which factors influenced resection. Survival was analyzed using the Kaplan—Meier method and multivariate analysis was performed in which the Karnofsky Performance Scale (KPS) score, residual fluorescence, patient age, and residual enhancement on MR images were considered.Intraoperatively, two fluorescence qualities were perceived: solid fluorescence generally reflected coalescent tumor, whereas vague fluorescence mostly corresponded to infiltrative tumor. Complete resection of contrast-enhancing tumor was accomplished in 33 patients (63%). Residual intraoperative tissue fluorescence left unresected for safety reasons predicted residual enhancement on MR images in 18 of the 19 remaining patients. Age, residual solid fluorescence, and absence of contrast enhancement in MR imaging were independent explanatory factors for survival, whereas the KPS score was significant only in univariate analysis. No perioperative deaths and one case of permanent morbidity were encountered.Conclusions. The observations in this study indicate the usefulness of 5-ALA—induced tumor fluorescence for guiding tumor resection. The completeness of resection, as determined intraoperatively from residual tissue fluorescence, was related to postoperative MR imaging findings and to survival in patients suffering from GBM.


1992 ◽  
Vol 76 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Edward D. Wirth ◽  
Daniel P. Theele ◽  
Thomas H. Mareci ◽  
Douglas K. Anderson ◽  
Stacey A. Brown ◽  
...  

✓ Magnetic resonance (MR) imaging was evaluated for its possible diagnostic application in determining the survival of fetal central nervous system tissue grafts in the injured spinal cord. Hemisection cavities were made at the T11—L1 level of eight adult female cats. Immediately thereafter, several pieces of tissue, either obtained from the fetal cat brain stem on embryonic Day 37 (E-37), from the fetal neocortex on E-37, or from the fetal spinal cord on E-23, were implanted into the cavities made in seven cats. The eighth cat served as a control for the effect of the lesion only. In another group of four animals, a static-load compression injury was made at the L-2 level. Seven weeks later, the lesion was resected in three cases and fragments of either fetal brainstem or spinal cord tissue were introduced. A small cyst was observed in a fourth cat in the compression injury group and a suspension of dissociated E-23 brain-stem cells was injected into this region of cavitation without disturbing the surrounding leptomeninges. Five months to 2 years posttransplantation, MR imaging was performed with a 2.0-tesla VIS imaging spectrometer by acquiring multislice spin-echo images (TR 1000 msec, TE 30 msec) in both the transverse and sagittal planes. Collectively, these intermediate-weighted images revealed homogeneous, slightly hyperintense signals at the graft site relative to the neighboring host tissue in seven of the 11 graft recipients. Two of the remaining four cats exhibited signals from the graft site that were approximately isointense with the adjacent host spinal cord, and the final two cats and the lesion-only control presented with very hypointense transplant/resection regions. The hyperintense and isointense images were tentatively interpreted as representing viable graft tissue, whereas the hypointense transplant/resection sites were considered to be indicative of a lack of transplant survival or the absence of tissue in the lesion-only control animal. Postmortem gross inspection of fixed specimens and light microscopy verified the MR findings in the control animal in 10 of the 11 graft recipients by showing either transplants and/or cysts corresponding to the MR images obtained. In one cat in the hemisection group, histological analysis revealed a very small piece of graft tissue that was not detected on the MR images. Therefore, it is suggested that within certain spatial- and contrast-resolution limits, MR imaging can reliably detect the presence of transplanted neural tissue in both the hemisected and compression-injured spinal cord of living animals. Thus, MR imaging can serve as an important adjunct to histological, electrophysiological, and long-term behavioral analyses of graft-mediated anatomical and functional repair of the injured spinal cord. It is further suggested that this noninvasive diagnostic approach offers many advantages in terms of the judicious and optimum use of valuable animal models, and that these findings address an important prerequisite (in situ verification of transplant survival) for any future clinical trials involving these or equivalent neural tissue grafting approaches, when such are warranted.


1994 ◽  
Vol 81 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Nobuhiko Aoki

✓ The pathological process of extracerebral fluid collections in infancy includes subdural effusion and enlargement of the subarachnoid spaces. Both conditions have traditionally been investigated as a single clinical entity, because of difficulty in differentiating between them. The prognosis of subdural effusion is not as benign as that of enlargement of subarachnoid spaces, requiring differential diagnosis between these disorders. The present study was conducted to elucidate whether this differentiation could be made on magnetic resonance (MR) images. The series consisted of 16 infants aged 10 months or younger, including eight with verified subdural effusion and eight in whom a diagnosis of enlargement of the subarachnoid spaces was achieved by neuroimaging studies other than MR imaging. In all eight patients with subdural effusion, the intensity of the fluid was greater than that of cerebrospinal fluid (CSF) in at least one of the sequences using T1-weighted, proton-density, and T2-weighted MR images. The flow-void sign, indicating vessels in the fluid spaces, was not seen in any of these eight patients. On the other hand, in all eight patients with enlargement of the subarachnoid spaces, the fluid was isointense in relation to CSF, and vascular flow-void areas were seen in at least one of the MR imaging sequences. Based on these observations, it is concluded that differentiation between subdural effusion and enlargement of the subarachnoid spaces can be established by focusing on two aspects of MR imaging findings: 1) the intensity of the fluid, which is either iso- or hyperintense relative to CSF, and 2) the presence or absence of vascular flow-void areas in the fluid spaces.


1999 ◽  
Vol 91 (6) ◽  
pp. 903-910 ◽  
Author(s):  
Warren Boling ◽  
André Olivier ◽  
Richard G. Bittar ◽  
David Reutens

Object. The object of this study was to identify a reliable surface landmark for the hand motor area and to demonstrate that it corresponds to a specific structural component of the precentral gyrus.Methods. Positron emission tomography (PET) activation studies for hand motor function were reviewed in 12 patients in whom magnetic resonance imaging results were normal. Each patient performed a hand opening and closing task. Using a computer-assisted three-dimensional reconstruction of the surface of each hemisphere studied, the relationship of the hand motor area with cortical surface landmarks was evaluated.Conclusions. The region of hand motor activation can be reliably identified on the surface of the brain by assessing anatomical relationships to nearby structures. After identification of the central sulcus, the superior and middle frontal gyrus can be seen to arise from the precentral gyrus at a perpendicular angle. A bend or genu in the precentral gyrus is constantly seen between the superior and middle frontal gyrus, which points posteriorly (posteriorly convex). The location of hand motor function, identified using PET activation studies, is within the central sulcus at the apex of this posteriorly pointing genu. The apex of the genu of the precentral gyrus leads to a deep cortical fold connecting the pre- and postcentral gyri and elevating the floor of the central sulcus. This deep fold was described by Paul Broca as the pli de passage fronto-pariétal moyen, and the precentral bank of the pli de passage represents the anatomical substratum of hand motor function. Observers blinded to the results of the activation studies were able to identify the hand motor area reliably after instruction in using these surface landmarks.


2005 ◽  
Vol 102 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Ian F. Parney ◽  
Sandeep Kunwar ◽  
Michael McDermott ◽  
Mitchel Berger ◽  
Michael Prados ◽  
...  

Object. Convection-enhanced delivery (CED) is a novel method for delivering therapeutic agents to infiltrative brain tumor cells. For agents administered by CED, changes on magnetic resonance (MR) imaging directly resulting from catheter placement, infusion, and the therapeutic compound may confound any interpretation of tumor progression. As part of an ongoing multiinstitutional Phase I study, 14 patients with recurrent malignant glioma underwent CED of interleukin (IL) 13—PE38QQR, a recombinant cytotoxin consisting of human IL-13 conjugated with a truncated Pseudomonas exotoxin. Serial neuroradiographic changes were assessed in this cohort of patients. Methods. Patients were treated in two groups: Group 1 patients received IL13—PE38QQR before and after tumor resection; Group 2 patients received infusion only after tumor resection. Preoperative and postinfusion MR images were obtained prospectively at specified regular intervals. Changes were noted along catheter tracks on postresection MR images obtained in all patients. A simple grading system was developed to describe these changes. When MR imaging changes appeared to be related to IL13—PE38QQR, patients were followed up without instituting new antitumor therapy. Conclusions. As CED of therapeutic agents becomes more common, clinicians and investigators must become aware of associated neuroimaging changes that should be incorporated into toxicity assessment. We have developed a simple grading system to facilitate communication about these changes among investigators. Biological imaging modalities that could possibly distinguish these changes from recurrent tumor should be evaluated. In this study the authors demonstrate the challenges in determining efficacy when surrogate end points such as time to tumor progression as defined by new or progressive contrast enhancement on MR imaging are used with this treatment modality.


2003 ◽  
Vol 99 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Jérôme Yelnik ◽  
Philippe Damier ◽  
Sophie Demeret ◽  
David Gervais ◽  
Eric Bardinet ◽  
...  

Object. The aim of this study was to correlate the clinical improvement in patients with Parkinson disease (PD) treated using deep brain stimulation (DBS) of the subthalamic nucleus (STN) with the precise anatomical localization of stimulating electrodes. Methods. Localization was determined by superimposing figures from an anatomical atlas with postoperative magnetic resonance (MR) images obtained in each patient. This approach was validated by an analysis of experimental and clinical MR images of the electrode, and the development of a three-dimensional (3D) atlas—MR imaging coregistration method. The PD motor score was assessed through two contacts for each of two electrodes implanted in 10 patients: the “therapeutic contact” and the “distant contact” (that is, the next but one to the therapeutic contact). Seventeen therapeutic contacts were located within or on the border of the STN, most of which were associated with significant improvement of the four PD symptoms tested. Therapeutic contacts located in other structures (zona incerta, lenticular fasciculus, or midbrain reticular formation) were also linked to a significant positive effect. Stimulation applied through distant contacts located in the STN improved symptoms of PD, whereas that delivered through distant contacts in the remaining structures had variable effects ranging from worsening of symptoms to their improvement. Conclusions. The authors have demonstrated that 3D atlas—MR imaging coregistration is a reliable method for the precise localization of DBS electrodes on postoperative MR images. In addition, they have confirmed that although the STN is the main target during DBS treatment for PD, stimulation of surrounding regions, particularly the zona incerta or the lenticular fasciculus, can also improve symptoms of PD.


2005 ◽  
Vol 102 (5) ◽  
pp. 870-878 ◽  
Author(s):  
Takatoshi Sorimachi ◽  
Yukihiko Fujii ◽  
Naoto Tsuchiya ◽  
Takeo Nashimoto ◽  
Masatsune Saito ◽  
...  

Object. The aim in this study was the investigation of back pressure in arteries distal to the occlusion site during intraarterial thrombolysis as well as the usefulness of back pressure measurement in combination with diffusion-weighted (DW) magnetic resonance (MR) imaging to predict the occurrence of ischemic lesions following good recanalization. Methods. Twenty-five consecutive patients with severe hemiparesis caused by embolism of the internal carotid artery (10 patients) and the proximal middle cerebral artery (15 patients) were treated using intraarterial thrombolysis. Systolic back pressure, measured through a microcatheter in the artery just distal to the emboli, ranged from 22 to 78 mm Hg. According to an angiographic inclusion criterion for good recanalization—that is, recanalization of the M2 or more distal arteries at the end of thrombolysis—21 of 25 patients underwent evaluation in this study. In 14 patients volumes of low-density areas on computerized tomography (CT) scans obtained 2 months postthrombolysis were smaller in comparison with volumes of hyperintense areas on DW MR images acquired before treatment, whereas these low-density areas were larger in seven patients. Compared with those on initial DW MR images, the volume of abnormalities on CT scans obtained 2 months posttreatment were significantly reduced in patients with a systolic back pressure greater than 30 mm Hg (16 patients) than in those with a back pressure of 30 mm Hg or less (five patients) (p < 0.05). Systolic back pressures greater than 30 mm Hg were associated with significantly better modified Rankin Scale scores than those 30 mm Hg or less (p < 0.05). Conclusions. Back pressure measurement in combination with DW MR imaging can be used to predict the occurrence of infarction as demonstrated on CT scans following thrombolysis.


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