Bilateral decompression of lumbar spinal stenosis involving a unilateral approach with microscope and tubular retractor system

2002 ◽  
Vol 97 (2) ◽  
pp. 213-217 ◽  
Author(s):  
Sylvain Palmer ◽  
Robert Turner ◽  
Rosemary Palmer
Keyword(s):  
Mr Imaging ◽  
Blood Loss ◽  
Spinal Stenosis ◽  
Outpatient Basis ◽  
Tubular Retractor ◽  
Content Type ◽  
Unilateral Approach ◽  
Flexion Extension ◽  
The Mean ◽  
Fine Print

Object. The authors studied a consecutive series of patients with spinal stenosis in whom surgery was performed by a single surgeon who used a microscopic tubular retractor system (METRx-MD); patients underwent prospective evaluation involving radiography and magnetic resonance (MR) imaging. The objective was to assess the feasibility and surgery-related efficacy of performing unilateral-approach bilateral decompression and utilization of METRx-MD instrumentation in patients with spinal stenosis. Methods. Seventeen consecutive patients with spinal stenosis underwent bilateral decompression; surgery was performed via a unilateral approach using METRx-MD instrumentation. The procedures were performed on an outpatient basis after induction of general anesthesia. Preoperative and 3-month follow-up plain radiographs with flexion—extension views were obtained. Preoperative and postoperative MR imaging was also performed. All studies were assessed by a single radiologist blinded to the clinical results. Twenty-two levels were surgically decompressed. The mean operative time was 90 minutes and the mean blood loss was 28 ml per level. Preoperatively stenosis was severe at 13 levels, moderate/severe at eight, and moderate at one. Postoperatively stenosis was absent at 13 levels, mild at seven, mild/moderate at one, and moderate at one. Preoperatively degenerative spondylolisthesis was documented in eight patients, with flexion—extension radiography revealing motion in three cases. On early (3-month) postoperative x-ray films there was no evidence of progression in any case. Grade I spondylolisthesis developed postoperatively in one patient, who remained asymptomatic. Conclusions. Minimally invasive bilateral decompression and instrumentation-assisted fusion can be successfully performed via a unilateral approach in patients with acquired spinal stenosis; the procedure can be undertaken on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity rates.

scholarly journals Bilateral decompressive surgery in lumbar spinal stenosis associated with spondylolisthesis: unilateral approach and use of a microscope and tubular retractor system

2002 ◽  
Vol 13 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Sylvain Palmer ◽  
Robert Turner ◽  
Rosemary Palmer
Keyword(s):  
Blood Loss ◽  
Spinal Stenosis ◽  
Clinical Results ◽  
Outpatient Basis ◽  
Tubular Retractor ◽  
Unilateral Approach ◽  
Flexion Extension ◽  
The Mean ◽  
Additional Level ◽  
Lumbar Spinal

Object The objective of this study was to assess the feasibility and efficacy of treating spondylolisthesis-related spinal stenosis via unilateral approach bilateral decompression in which METRx-MD instrumentation is placed. Methods Eight consecutive patients with spinal stenosis underwent bilateral decompressions via a unilateral approach in which METRx-MD instrumentation was placed. The procedures were performed on an outpatient basis after induction of general anesthesia. The patients underwent preoperative and 3-month postoperative plain radiography in which flexion–extension x-ray films were obtained. Preoperative and postoperative magnetic resonance imaging was also performed. All radiographs and neuroimages were read by a single radiologist blinded to the clinical results. Eight vertebral levels in the eight patients were sugically decompressed (in one patient an additional level of non-spondylolisthesis-related stenosis was decompressed). The mean operative time was 92 minutes and the mean blood loss was 33 ml/level. Preoperatively stenosis was severe in five patients, moderate/severe in two, and moderate in one; postoperatively stenosis was absent in five, mild in two, and mild/moderate in one. Motion was detected on flexion–extension radiographs in three patients, but on early (3-month) postoperative radiographs there was no evidence of progression. Conclusions By following the authors' procedure, minimally invasive bilateral decompression of acquired spinal stenosis associated with spondylolisthesis can be successfully performed on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity.

Results of preoperative embolization for metastatic spinal neoplasms

2003 ◽  
Vol 98 (2) ◽  
pp. 156-164 ◽  
Author(s):  
Vikram C. Prabhu ◽  
Mark H. Bilsky ◽  
Kedar Jambhekar ◽  
Katherine S. Panageas ◽  
Patrick J. Boland ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Blood Loss ◽  
Predictive Value ◽  
Preoperative Embolization ◽  
Intraoperative Blood Loss ◽  
Spinal Neoplasms ◽  
Tumor Vascularity ◽  
Content Type ◽  
The Mean ◽  
Fine Print

Object. Arterial embolization reduces blood loss in patients undergoing surgery for hypervascular spinal tumors. The objectives of this study were twofold: 1) to evaluate the role of magnetic resonance (MR) imaging in predicting tumor vascularity and 2) to assess the effectiveness of preoperative embolization in devascularizing these tumors. Methods. Fifty-one patients with metastatic spinal neoplasms underwent angiography, preoperative embolization, and excision of the lesion between 1995 and 2000. The MR imaging studies were correlated with tumor vascularity on angiograms. Embolization was angiographically graded on a five-point scale ranging from no embolization (Grade A) to total embolization (Grade E). The embolization grade was correlated with intraoperative blood loss. The mean age was 57 years, the male/female ratio was 1.2:1, and back pain was present in all patients. Metastatic renal cell carcinoma (30 cases) and thoracic spine involvement (33 cases) were most frequent. The positive predictive value of MR imaging in determining tumor vascularity was 77%, whereas the negative predictive value was 21%. Total embolization (Grade E) was achieved in 34 patients. A shared vascular pedicle between a radiculomedullary artery (RMA) and a tumor diminished the likelihood of complete embolization (p = 0.02). Small asymptomatic cerebellar infarctions were demonstrated in two cases. The mean intraoperative blood loss was 2586 ml. Following Grade D or E embolization, intraoperative bleeding was largely related to unembolized epidural veins. Conclusions. Tumor histology and MR imaging findings are predictive of hypervascularity; however, hypervascular tumors may not be detected by standard MR imaging sequences. Superselective catheterization permits Grade D or E embolization in 80% of patients. Shared blood supply with an RMA is the most important factor precluding complete embolization.

Gamma knife radiosurgery in the management of cavernous sinus meningiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 68-73 ◽  
Author(s):  
Pierre-Hugues Roche ◽  
Jean Régis ◽  
Henry Dufour ◽  
Henri-Dominique Fournier ◽  
Christine Delsanti ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Tumor Growth ◽  
Gamma Knife ◽  
Cavernous Sinus ◽  
Gamma Knife Radiosurgery ◽  
Surgical Removal ◽  
Content Type ◽  
Cavernous Sinus Meningioma ◽  
The Mean ◽  
Fine Print

Object. The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). Methods. Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6–71 years). The mean tumor volume was 5.8 cm3 (range 0.9–18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12–50 Gy), delivered with an average of eight isocenters (range two–18). The median peripheral isodose was 50% (range 30–70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12–79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. Conclusions. Gamma knife radiosurgery was found to be an effective low morbidity—related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.

Scoliosis in pediatric Chiari malformations without myelodysplasia

1992 ◽  
Vol 77 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Michael G. Muhonen ◽  
Arnold H. Menezes ◽  
Paul D. Sawin ◽  
Stuart L. Weinstein
Keyword(s):  
Mr Imaging ◽  
Surgical Intervention ◽  
Craniovertebral Junction ◽  
Spinal Curvature ◽  
Posterior Fossa Decompression ◽  
Content Type ◽  
The Mean ◽  
Spine Radiographs ◽  
Chiari Malformations ◽  
Fine Print

✓ A prospective study was undertaken in 1985 to better understand how the surgical manipulation of hind-brain herniation affected abnormal spinal curvature. Eleven patients under 16 years of age with Chiari malformation (not associated with myelodysplasia) and scoliosis of at least 15° were studied. The mean curve angle at the time of original treatment was 29°, with the convexity to the right in seven patients. The curvature was rapidly progressing in four patients. The most common presenting signs were myelopathy and weakness. Investigative procedures included spine radiographs with the patient standing and magnetic resonance (MR) imaging of the brain, spinal cord, and craniovertebral junction. Eight children had associated hydrosyringomyelia. Surgical intervention consisted of a dorsal posterior fossa decompression in all patients and a transoral ventral decompression of the cervicomedullary junction in five. All patients were followed at 3, 6, and 12 months, and at yearly intervals thereafter with clinical evaluations, spine radiographs in the standing position, and postoperative MR imaging. The mean follow-up period was 35 months. The scoliosis improved in eight patients, stabilized in one, and progressed in two. Only one child required postoperative spinal fusion and instrumentation for progression of scoliosis. Hematomyelia or hematobulbia was associated with persistent scoliosis in two patients. The presence of hydrosyringomyelia and bone erosion did not preclude curve improvement. All patients under 10 years of age had resolution of their scoliosis, despite preoperative curves of more than 40°. These findings emphasize the importance of early surgical intervention, with the restoration of normal cerebrospinal fluid dynamics at the craniovertebral junction in children with symptomatic Chiari malformations.

Preoperative correlation of intraoperative cortical mapping with magnetic resonance imaging landmarks to predict localization of the Broca area

2003 ◽  
Vol 99 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Alfredo Quiñones-Hinojosa ◽  
Steven G. Ojemann ◽  
Nader Sanai ◽  
William P. Dillon ◽  
Mitchel S. Berger
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Inferior Frontal Gyrus ◽  
Type I ◽  
Dominant Hemisphere ◽  
Content Type ◽  
Frontal Operculum ◽  
Pars Opercularis ◽  
The Mean ◽  
Fine Print

Object. Broca identified the posterior third of the inferior frontal gyrus as a locus essential for the production of fluent speech. The authors have conducted this retrospective analysis in an attempt to find readily identifiable landmarks on magnetic resonance (MR) imaging that correspond to intraoperative cortical stimulation-induced speech arrest. These landmarks demonstrate novel structural—functional relationships that can be used preoperatively to predict the location of the Broca area. Methods. Using a neuronavigation system, sites where stimulation produced speech arrest (Broca area) were recorded in a consecutive series of patients undergoing awake tumor resections in the perisylvian territory of the dominant hemisphere. The authors reviewed 33 consecutive patients by projecting the MR imaging data sets and marking the site where the Broca area was identified. Sulcus topography was analyzed with respect to this site by scrolling into neighboring planes and classifying the frontal operculum into one of the four schemes of sulcus variability described by Ebeling, et al. The following categories of frontal opercula were found: 18 (69%) of 26 were Type I, eight (31%) of 26 were Type III, and seven cases eluded classification because of sulcal effacement. For patients with Type I anatomy, the Broca area was adjacent to, and distributed evenly around, the inferior precentral sulcus (IPS). Quantitatively, the site of speech arrest was located a mean of 2.4 ± 0.25 cm from the anteroinferior aspect of the pars opercularis, where it abuts the subarachnoid space surrounding the apex of the pars triangularis. For all patients with Type III anatomy, the Broca area was adjacent to the accessory sulcus that lies immediately posterior to the IPS. In these patients the mean distance from the anterior inferior pars opercularis was 2.3 ± 0.29 cm. The mean distance from the Broca area to the edge of the tumor for the 26 patients with clear sulcal anatomy was 1.29 ± 0.12 cm. Conclusions. The results indicate a correlation between the structure of the frontal operculum as seen on MR imaging and the functional localization of speech arrest in the dominant hemisphere. Additionally, sulcal landmarks that can be used preoperatively to predict the location of the Broca area within the inferior frontal gyrus are described based on the patient population. This information will allow the surgeon to determine if an awake craniotomy is necessary to identify the Broca area when planning a surgical procedure near the dominant frontal operculum.

Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis

1998 ◽  
Vol 88 (1) ◽  
pp. 77-81 ◽  
Author(s):  
David F. Jimenez ◽  
Constance M. Barone
Keyword(s):  
Blood Loss ◽  
Operative Time ◽  
Sagittal Synostosis ◽  
Content Type ◽  
Endoscopic Techniques ◽  
Early Correction ◽  
Hospitalization Costs ◽  
The Mean ◽  
Fine Print

Object. The authors sought to minimize scalp incisions, blood loss, and operative time by using endoscopically assisted strip craniectomies and barrel-stave osteotomies to treat infants with sagittal suture synostosis. Methods. Four patients, aged 2, 4, 9, and 12 weeks, who presented with scaphocephaly underwent endoscopic midline craniectomies through small midline scalp incisions. The mean operative time for the procedure was 1.68 hours (range 1.15–2.8 hours); the mean blood loss was 54.2 ml (range 12–150 ml). Three patients did not require blood transfusions and were discharged within 24 hours. Postoperatively, all patients were fitted with custom cranial molding helmets. Follow-up evaluation ranged between 8 and 15 months. All patients had successful correction of their scaphocephaly with no mortalities, morbidities, or complications. Conclusions. The use of endoscopic techniques for early correction of sagittal synostosis is safe; decreases blood loss, operative time, and hospitalization costs; and provides excellent early surgical results.

Thoracoscopic microsurgical excision of herniated thoracic discs

1998 ◽  
Vol 89 (2) ◽  
pp. 224-235 ◽  
Author(s):  
Daniel Rosenthal ◽  
Curtis A. Dickman
Keyword(s):  
Blood Loss ◽  
Operative Time ◽  
Radicular Pain ◽  
Content Type ◽  
Neurological Outcomes ◽  
Intercostal Neuralgia ◽  
The Mean ◽  
Postoperative Atelectasis ◽  
Fine Print

Object. The authors began using thoracoscopy to treat pathological conditions of the spine in 1992. In this study they delineate their clinical experience in which this procedure was used to resect herniated thoracic discs. Methods. Fifty-five patients underwent thoracoscopy for the resection of herniated thoracic discs. Thirty-six patients presented with myelopathies and 19 with incapacitating thoracic radicular pain. Forty-three patients underwent a single-level, 11 a two-level, and one a three-level discectomy. The mean operative time for thoracoscopic microdiscectomy was 3 hours and 25 minutes (range 80–542 minutes) and the mean blood loss was 327 ml (range 124–1500 ml). Compared with thoracotomy, which was performed in 18 patients, thoracoscopy was associated with a mean of 1 hour less operative time and less than one-half of the blood loss, duration of chest tube drainage, usage of pain medication, and length of hospitalization. Compared with costotransversectomy, which was performed in 15 patients, thoracoscopy permitted more complete resection of calcified and midline thoracic discs because it provided a direct view of the entire anterior surface of the dura. Thoracotomy was associated with a significantly greater incidence of prolonged, disabling intercostal neuralgia compared with the mild transient episodes of intercostal neuralgia associated with thoracoscopy (50% compared with 16%). Thoracotomy also was associated with a significantly higher incidence of postoperative atelectasis and pulmonary dysfunction than thoracoscopy (33% compared with 7%). Clinical and neurological outcomes were excellent (mean follow-up period 15 months). Among the 36 myelopathic patients, 22 completely recovered neurologically; five improved functionally but had some residual myelopathic symptoms; and nine stabilized. Among the 19 patients with isolated thoracic radiculopathies, 15 recovered completely and four improved moderately; no patient had worsened radicular pain. Conclusions. Thoracoscopic microdiscectomy is a reliable surgical technique that can be performed safely with excellent clinical and neurological results.

A prospective comparison between three-dimensional magnetic resonance imaging and ventriculography for target-coordinate determination in frame-based functional stereotactic neurosurgery

1999 ◽  
Vol 91 (6) ◽  
pp. 911-914 ◽  
Author(s):  
P. Richard Schuurman ◽  
Rob M. A. de Bie ◽  
Charles B. L. Majoie ◽  
Johannes D. Speelman ◽  
D. Andries Bosch
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Three Dimensional ◽  
Target Area ◽  
Stereotactic Neurosurgery ◽  
Content Type ◽  
Prospective Comparison ◽  
The Mean ◽  
3D Mr Imaging ◽  
Fine Print

Object. The purpose of this prospective study was to compare stereotactic coordinates obtained with ventriculography with coordinates derived from stereotactic computer-reconstructed three-dimensional magnetic resonance (3D-MR) imaging in functional stereotactic procedures.Methods. In 15 consecutive patients undergoing functional stereotactic procedures, both preoperative frame-based stereotactic 3D-MR imaging and intraoperative ventriculography were performed. Differences between 3D-MR imaging and ventriculography in X, Y, and Z coordinates of the anterior commissure (AC), posterior commissure (PC), and target area were calculated, as well as the 3D distance between the position of AC, PC, and target within stereotactic space as obtained using both methods. The position of the stereotactic MR imaging fiducial markers measured using 3D-MR imaging compared well with the markers' known position embedded in the software (mean error 0.4 mm, maximal error for an individual slice 1.2 mm). For the individual coordinates, only for Y-PC was a difference found between 3D-MR imaging and ventriculography that significantly exceeded half the size of a pixel, the theoretical limit of precision when using a digitized imaging technique. However, the mean difference was smaller than 1 mm. The mean 3D distance between the 3D-MR imaging— and ventriculography-derived coordinates was 1.09 mm for AC, 1.13 mm for PC, and 1.29 mm for the targets.Conclusions. With these data it is shown that there is sufficient agreement between ventriculography-derived and 3D-MR imaging—derived stereotactic coordinates to justify the use of 3D-MR imaging target determination in frame-based functional stereotactic neurosurgery.

Modified open-door laminoplasty for treatment of neurological deficits in younger patients with congenital spinal stenosis: analysis of clinical and radiographic data

1999 ◽  
Vol 90 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Christopher I. Shaffrey ◽  
Gregory C. Wiggins ◽  
Cynthia B. Piccirilli ◽  
Jacob N. Young ◽  
LaVerne R. Lovell
Keyword(s):  
Spinal Stenosis ◽  
Neurological Deficits ◽  
Open Door ◽  
Younger Patients ◽  
Content Type ◽  
Flexion Extension ◽  
Postoperative Flexion ◽  
Cervical Spinal Stenosis ◽  
Fine Print

Object. Multilevel anterior cervical decompressive surgery and fusion effectively treats cervical myeloradiculopathy that is caused by severe cervical spinal stenosis, but degenerative changes at adjacent vertebral levels frequently result in long-term morbidity. The authors performed a modified open-door laminoplasty procedure in which allograft bone and titanium miniplates were used to treat cervical myeloradiculopathy in younger patients with congenital canal stenosis while maintaining functional cervical motion segments. Pre- and postoperative magnetic resonance imaging and/or computerized tomography myelography were performed to assess changes in cervical spinal canal dimensions. Pre- and postoperative flexion—extension radiographs were compared to determine the residual motion of the targeted operative segments. Methods. Twenty younger patients (average age 37.7 years) underwent modified open-door laminoplasty for treatment of myelopathy or myeloradiculopathy related to significant cervical spinal stenosis with or without associated central or lateral disc herniation or foraminal stenosis. These surgeries were performed during a 2-year period and follow-up review remains ongoing (average follow-up period 21.6 months). Reconstructive procedures were performed on an average of 4.1 levels (range three—six). Operative time averaged 186 minutes (range 93–229 minutes). Average blood loss was 305 ml (range 100–650 ml). No cases were complicated by neurological deterioration, infection, wound breakdown, graft displacement, or hardware failure. The patients' Nurick Scale grade improved from a preoperative average of 1.8 to a postoperative average of 0.5. Pre- and postoperative sagittal spinal diameter averaged 11.2 mm (8–14 mm) and 16.6 mm (13–19 mm), respectively. The sagittal compression ratio (sagittal/lateral × 100%) increased from 48% pre- to 72% postoperatively. The spinal canal area increased an average of 55% (range 19–127%). In patients in whom pre- and postoperative flexion—extension radiographs were obtained, 72.7% residual neck motion was maintained. No patient developed increased neck or shoulder pain. Neurological symptoms improved in all patients, with total relief of myelopathy in 50% and partial improvement in 50%. Conclusions. Modified open-door laminoplasty with allograft bone and titanium miniplates effectively treats neurological deficits in younger patients with congenital and spinal stenosis. Although long-term results are unknown, short-term results are good and there is a low incidence of complications.

Dynamic nature of cavernous malformations: a prospective magnetic resonance imaging study with volumetric analysis

2000 ◽  
Vol 93 (6) ◽  
pp. 981-986 ◽  
Author(s):  
Richard E. Clatterbuck ◽  
John L. Moriarity ◽  
Ilhan Elmaci ◽  
Roland R. Lee ◽  
Steven N. Breiter ◽  
...  
Keyword(s):  
Mr Imaging ◽  
De Novo ◽  
Volume Data ◽  
Mr Images ◽  
Cavernous Malformations ◽  
Content Type ◽  
Signal Characteristics ◽  
The Mean ◽  
Fine Print

Object. Although cavernous malformations (CMs) are not detected in angiographic studies, they have a characteristic appearance on magnetic resonance (MR) images. A number of reports published in the last decade have focused on the behavior of these lesions within the clinical environment. However, little has been published about the evolution of CMs over time, as observed in imaging studies. To understand imaging-documented changes in CMs over time, we analyzed MR images of 114 cavernous malformations in 68 patients who were followed prospectively.Methods. For each CM the location, volume, and MR imaging signal characteristics were recorded. Volume data were available for 107 lesions from initial images. The mean volume of these 107 CMs was 2779 mm3. The lesions ranged in size from 0.5 to 46,533 mm3 (46.5 cm3). Volume data from a second set of images were available for 76 CMs (mean interval from first imaging session 26 months), and from a third set of images for 24 lesions (mean interval from second imaging session 18 months). Over the first follow-up interval, the mean volume change was −991 mm3 (a decrease of approximately 1 cm3) and over the second interval the mean volume change was −642 mm3. Although these mean volume changes appear modest, volume changes in single lesions during follow-up intervals were more dramatic, with decreases as large as 45,629 mm3 (45.6 cm3) and increases as large as 6,074 mm3 (6 cm3). Serial examinations of the MR imaging signal characteristics of these CMs demonstrate a trend for maturation of blood products from a subacute, to a mixed, and finally to a chronic appearance. Three lesions appeared de novo during the follow-up period.Conclusions. On the basis of their analysis, the authors conclude that CMs exhibit a range of dynamic behaviors including enlargement, regression, and de novo formation, as well as progression through a series of characteristic MR imaging appearances.

Sign in / Sign up

Export Citation Format

Share Document