Transient postictal magnetic resonance imaging abnormality of the corpus callosum in a patient with epilepsy

2002 ◽  
Vol 97 (3) ◽  
pp. 714-717 ◽  
Author(s):  
Aaron A. Cohen-Gadol ◽  
Jeffrey W. Britton ◽  
Clifford R. Jack ◽  
Jonathan A. Friedman ◽  
W. Richard Marsh
Keyword(s):  
Magnetic Resonance ◽  
Corpus Callosum ◽  
Mr Imaging ◽  
Imaging Study ◽  
Hyperintense Lesion ◽  
Content Type ◽  
History Of ◽  
Antiepileptic Medications ◽  
High Index Of Suspicion

✓ Transient neuroimaging abnormalities associated with seizure activity have received little attention in the literature. The authors report a focal magnetic resonance (MR) imaging abnormality of the corpus callosum in a patient following a secondary generalized seizure. A 27-year-old right-handed man presented with a history of medically refractory partial seizures since the age of 1 year. The results of an MR imaging study obtained 4 months prior to the patient undergoing video-electroencephalography monitoring were unremarkable. After the patient discontinued all antiepileptic medications, a secondary generalized seizure of right temporal origin was recorded. Five days later, repeated MR imaging revealed a nonenhancing 14 × 11—mm ovoid hyperintense lesion in the splenium of corpus callosum. The patient was asymptomatic, and his neurological and neurocognitive examinations remained unremarkable. Follow-up MR imaging 5 weeks and 1 year later demonstrated near-complete resolution of the lesion. Benign and transient abnormalities in the splenium can occur as a periictal phenomenon. A high index of suspicion and follow-up imaging may prevent further unwarranted intervention.

Accelerated spondylotic changes adjacent to the fused segment following central cervical corpectomy: magnetic resonance imaging study evidence

2004 ◽  
Vol 100 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Vaijayantee Kulkarni ◽  
Vedantam Rajshekhar ◽  
Lakshminarayan Raghuram
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Imaging Study ◽  
Degenerative Changes ◽  
Adjacent Segment ◽  
Mr Images ◽  
Short Term ◽  
Content Type ◽  
Fine Print

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.

Magnetic resonance imaging—documented extravasation as an indicator of acute hypertensive intracerebral hemorrhage

1998 ◽  
Vol 88 (4) ◽  
pp. 650-655 ◽  
Author(s):  
Yasuo Murai ◽  
Yukio Ikeda ◽  
Akira Teramoto ◽  
Yukihide Tsuji
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Intracerebral Hemorrhage ◽  
Cerebral Angiography ◽  
Ct Scanning ◽  
Content Type ◽  
Hematoma Enlargement ◽  
Hypertensive Intracerebral Hemorrhage ◽  
Fine Print

Object. The aim of this study was to determine the usefulness of magnetic resonance (MR) imaging—documented extravasation as an indicator of continued hemorrhage in patients with acute hypertensive intracerebral hemorrhage (ICH). Methods. The authors studied 108 patients with acute hyperintensive ICH. Imaging modalities included noncontrast-enhanced computerized tomography (CT) scanning, gadolinium-enhanced MR imaging, and conventional cerebral angiography obtained within 6 hours after the onset of hemorrhage. A repeated CT scan was obtained within 48 hours to evaluate enlargement of the hematoma. Findings on MR imaging indicating extravasation, including any high-intensity signals on T1-weighted postcontrast images, were observed in 39 patients, and 17 of these also showed evidence of extravasation on cerebral angiography. The presence of extravasation on MR imaging was closely correlated with evidence of hematoma enlargement on follow-up CT scans (p < 0.001). Conclusions. Evidence of extravasation documented on MR imaging indicates persistent hemorrhage and correlates with enlargement of the hematoma.

Follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation by using gadolinium-enhanced magnetic resonance imaging

1997 ◽  
Vol 87 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Shinji Nagahiro ◽  
Jun-ichiro Hamada ◽  
Yuji Sakamoto ◽  
Yukitaka Ushio
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Contrast Material ◽  
Intramural Hematoma ◽  
Mr Studies ◽  
Conventional Angiography ◽  
Content Type ◽  
Vertebrobasilar Circulation ◽  
Dissecting Aneurysms

✓ The authors assessed the reliability of magnetic resonance (MR) imaging contrast enhancement for the detection and follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation. Twenty consecutively admitted patients who underwent both gadolinium-enhanced MR imaging and conventional angiography were reviewed. Enhancement of the dissecting aneurysm was seen in all but one of the 20 patients, including 10 (71%) of 14 patients examined in the chronic phases, when the T1-hyperintensity signal that corresponded to the intramural hematoma was unrecognizable. The enhanced area corresponded to the “pearl sign” or aneurysm dilation noted on the comparable angiogram. On follow-up MR studies enhancement had spontaneously disappeared in four patients at a time when comparable vertebral angiograms revealed disappearance of the aneurysm dilation. The enhancement persisted in five of nine patients examined more than 24 weeks after symptom onset; in all five patients the aneurysm dilation remained on comparable angiograms. Dynamic MR studies showed rapid and remarkable enhancements with their peaks during the immediate dynamic phase after injection of the contrast material. The authors conclude that gadolinium-enhanced MR imaging is useful for the detection and follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation.

Utility of relative cerebral blood volume mapping derived from perfusion magnetic resonance imaging in the routine follow up of brain tumors

1997 ◽  
Vol 86 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Tali Siegal ◽  
Rina Rubinstein ◽  
Tzahala Tzuk-Shina ◽  
John M. Gomori
Keyword(s):  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Clinical Assessment ◽  
Cerebral Blood Volume ◽  
Content Type ◽  
Relative Cerebral Blood Volume ◽  
Fine Print

✓ It was recently demonstrated that imaging of brain tumors by relative cerebral blood volume (CBV) maps reconstructed from dynamic magnetic resonance (MR) data provide similar diagnostic information compared to positron emission tomography (PET) or 201Tl single-photon emission computerized tomography (201Tl-SPECT) scans. The authors used relative CBV mapping for routine follow-up evaluation of patients with brain tumors and compared its sensitivity to diagnostic MR imaging, 201Tl-SPECT and clinical assessment. Fifty-nine patients were prospectively followed using 191 concomitant studies of dual section relative CBV maps, MR imaging, 201Tl-SPECT, and neurological evaluations. Studies were repeated every 2 to 3 months (median three evaluations/patient). The relative CBV maps were graded as relative CBV 0 to 4, where Grades 3 and 4 are indicative of proliferating tumors (four = rapid leak). There were 44 high-grade and 15 low-grade tumors followed during treatment. During the follow-up period a change in relative CBV grade was observed in 56% of the patients, revealing an increasing grade in 72% of them. The rapid leak phenomenon was detected in 35% of all studies and in 81% of those with a worsening relative CBV grade. Tumor progression was detected earlier by relative CBV maps as follows: earlier than MR imaging in 32% of the studies (earlier by a median of 4.5 months; p < 0.01); earlier than 201Tl-SPECT in 63% (median 4.5 months; p < 0.01), and earlier than clinical assessment in 55% (median 6 months; p < 0.01). In 82% of studies with positive MR imaging but negative 201Tl-SPECT, the lesions were smaller than 1.5 cm. The relative CBV maps clearly delineated the appearance of rapid leak in these lesions. Routine use of relative CBV maps that can be implemented on any high-field MR unit and added to the regular MR evaluation provides useful functional information in patients with brain tumors. When used as an adjunct follow-up evaluation it proved more sensitive than the other modalities for early prediction of tumor growth. It is very sensitive to small regional changes, unlike functional imaging such as PET or SPECT scans. Based on previous experience with 76 regional CBV studies, the authors conclude that regional CBV mapping correlates with active tumor and it may separate enhancing scar and radiation injury from infiltrative tumor. A new effect named the rapid leak phenomenon was also observed; this phenomenon, as identified on the regional CBV maps, correlates with high malignancy.

Radiation-induced optic neuropathy: a magnetic resonance imaging study

1991 ◽  
Vol 74 (3) ◽  
pp. 426-432 ◽  
Author(s):  
John Guy ◽  
Anthony Mancuso ◽  
Roy Beck ◽  
Mark L. Moster ◽  
Lyn A. Sedwick ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Optic Neuropathy ◽  
Visual Loss ◽  
Imaging Study ◽  
Metastatic Malignant Melanoma ◽  
Presumptive Diagnosis ◽  
Gadolinium Dtpa ◽  
Content Type ◽  
Radiation Induced

✓ Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

Magnetic resonance imaging: an accurate method to evaluate arteriovenous malformations after stereotactic radiosurgery

1996 ◽  
Vol 85 (6) ◽  
pp. 1044-1049 ◽  
Author(s):  
Bruce E. Pollock ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Atul K. Patel ◽  
David J. Bissonette ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Cerebral Angiography ◽  
False Negative ◽  
Resonance Imaging ◽  
Mr Images ◽  
Content Type ◽  
Fine Print

✓ To determine the accuracy of magnetic resonance (MR) imaging in comparison to cerebral angiography after radiosurgery for an arteriovenous malformation (AVM), the authors reviewed the records of patients who underwent radiosurgery at the University of Pittsburgh Medical Center before 1992. All patients in the analysis had AVMs in which the flow-void signal was visible on preradiosurgical MR imaging. One hundred sixty-four postradiosurgical angiograms were obtained in 140 patients at a median of 2 months after postradiosurgical MR imaging (median 24 months after radiosurgery). Magnetic resonance imaging correctly predicted patency in 64 of 80 patients in whom patent AVMs were seen on follow-up angiography (sensitivity 80%) and angiographic obliteration in 84 of 84 patients (specificity 100%). Overall, 84 of 100 AVMs in which evidence of obliteration was seen on MR images displayed angiographic obliteration (negative predictive value, 84%). Ten of the 16 patients with false-negative MR images underwent follow-up angiography: in seven the lesions progressed to complete angiographic obliteration without further treatment. Exclusion of these seven patients from the false-negative MR imaging group increases the predictive value of a negative postradiosurgical MR image from 84% to 91%. No AVM hemorrhage was observed in clinical follow up of 135 patients after evidence of obliteration on MR imaging (median follow-up interval 35 months; range 2–96 months; total follow up 382 patient-years). Magnetic resonance imaging proved to be an accurate, noninvasive method for evaluating the patency of AVMs that were identifiable on MR imaging after stereotactic radiosurgery. This imaging modality is less expensive, more acceptable to patients, and does not have the potential for neurological complications that may be associated with cerebral angiography. The risk associated with follow-up cerebral angiography may no longer justify its role in the assessment of radiosurgical results in the treatment of AVMs.

Asymptomatic microbleeds in moyamoya disease: T2*-weighted gradient-echo magnetic resonance imaging study

2005 ◽  
Vol 102 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Ken-Ichiro Kikuta ◽  
Yasushi Takagi ◽  
Kazuhiko Nozaki ◽  
Takashi Hanakawa ◽  
Tsutomu Okada ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Moyamoya Disease ◽  
Imaging Study ◽  
Mr Studies ◽  
3 Tesla ◽  
Healthy Individuals ◽  
Gradient Echo ◽  
Content Type ◽  
Fine Print

Object. The aim of this study was to investigate the incidence of asymptomatic microbleeds (MBs) in patients with moyamoya disease (MMD) by using a 3-tesla magnetic resonance (MR) imaging unit. Methods. Data on 63 patients hospitalized with MMD between 1999 and 2004 were retrospectively examined to determine the incidence of asymptomatic MBs. Gradient-echo T2*-weighted MR imaging studies obtained using 3- and 1.5-tesla units were available in 25 patients. These patients consisted of five men and 20 women, ranging in age from 17 to 66 years (mean age 41 ± 14 years). Ischemic MMD was diagnosed in 18 patients, and hemorrhagic MMD in seven. The incidence of MBs was also evaluated using the same 3-tesla MR imaging unit in 34 healthy volunteers including seven men and 27 women, ranging in age from 18 to 71 years (mean age 33 ± 12 years). Using the 3-tesla MR unit, asymptomatic MBs were demonstrated in 11 patients (44%); they were detected in seven patients (28%) by using the 1.5-tesla unit. In the 3-tesla MR studies in healthy individuals, MBs were found in two patients (5.8%). Based on 3-tesla MR studies, the incidence of MBs was significantly higher in patients with MMD compared with that in healthy individuals. Asymptomatic MBs were demonstrated in eight (44%) of 18 patients with ischemic MMD and three (43%) of seven patients with hemorrhagic MMD. Conclusions. Microbleeds are significantly more common in patients with MMD than in healthy individuals regardless of the disease type. The evaluation of MBs with T2*-weighted 3-tesla MR imaging might contribute to the treatment of MMD.

Histological yield, complications, and technological considerations in 114 consecutive frameless stereotactic biopsy procedures aided by open intraoperative magnetic resonance imaging

2002 ◽  
Vol 97 (2) ◽  
pp. 354-362 ◽  
Author(s):  
René L. Bernays ◽  
Spyros S. Kollias ◽  
Nadia Khan ◽  
Sebastian Brandner ◽  
Sonja Meier ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Stereotactic Biopsy ◽  
Brain Biopsy ◽  
Ct Scanning ◽  
Complication Rates ◽  
Stereotactic Brain Biopsy ◽  
Content Type ◽  
Fine Print

Object. The authors undertook a prospective study of frameless, magnetic resonance (MR)—guided stereotactic brain biopsy procedures performed with the aid of an open MR system. Morbidity and mortality rates, frequency of postoperative hemorrhage, and histological yield were evaluated, as well as the size and location of the lesions under investigation. Methods. During a period of 51 months (July 1996–November 2000), 114 consecutive frameless stereotactic biopsy procedures were performed with the aid of an open intraoperative MR system to investigate supratentorial lesions in 113 patients. The median volume of the lesions was 33.5 cm3, and 31.9% were deep seated. All biopsy samples comprised pathological tissue and in 111 (97.4%) of 114 a specific neuropathological diagnosis was made. A follow-up computerized tomography (CT) scan was obtained on the 1st postoperative day in all patients to evaluate postoperative complications. In two cases (1.8%), a hemorrhage was found on postoperative CT scans, with no neurological worsening of the patients. Morbidity with neurological worsening was seen in three patients; it was transient in two of them (1.8%), and in one (0.9%) subsequent emergency craniotomy was necessary because of increased edema. There were no infections, but there was one death (0.9%) Conclusions. Open intraoperative MR imaging transforms a blind conventional stereotactic procedure into a visually controlled procedure that is adaptable to dynamic anatomical changes. Routine postprocedural MR imaging makes follow-up CT scanning obsolete. This largest reported series of intraoperative MR—guided biopsy procedures shows results that are at least comparable with those in reports of larger series of conventional stereotactic biopsy sampling. The mean procedure time was 60 minutes including planning, and this method produced low morbidity and complication rates and a high histological yield.

Pathoanatomy of clinical findings in patients with sciatica: a magnetic resonance imaging study

2000 ◽  
Vol 92 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Patrick C. A. J. Vroomen ◽  
Marc C. T. F. M. de Krom ◽  
Jan T. Wilmink
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Nerve Root ◽  
Imaging Study ◽  
Clinical Findings ◽  
Content Type ◽  
Schematic Drawing ◽  
Disc Herniations ◽  
Fine Print

Object. Anatomical details of nerve root compression may explain the production of the signs and symptoms of sciatica. The authors of anatomical studies have offered many theories without clearly demonstrating the clinical relevance of the observations. Clinicoanatomical series are scarce and are affected to a great extent by selection bias. Methods. We created a schematic drawing of the lumbar anatomy based on both the literature and in vitro anatomical observations. A diagnosis was then made with the aid of detailed and standardized clinical and magnetic resonance (MR) imaging studies in primary-care patients who presented with pain that radiated into the leg. Clinical and MR imaging findings were correlated. Finally, the anatomical drawing was compared with the clinical data. The higher the vertebral level of symptomatic disc herniations, the more likely the compression will be more laterally situated. Classic symptoms of sciatica (typically, dermatomal pain; increase in pain when coughing, sneezing, or straining; and testing positive for pain during straight leg raising) were most likely to occur with compression of the nerve root in the axilla and with mediolateral disc herniations. Conclusions. The L-3, L-4, L-5, and S-1 nerve roots each tend to be compressed at different sites along the rostrocaudal course of the nerve root. Disc herniations become symptomatic at different sites for each disc level. The schematic drawing produced a priori could well be used to explain these findings. Expectations of particular clinical findings can be predicted by specific pathoanatomical findings.

Intracranial saccular aneurysm enlargement determined using serial magnetic resonance angiography

2002 ◽  
Vol 97 (5) ◽  
pp. 1023-1028 ◽  
Author(s):  
Thanh G. Phan ◽  
John Huston ◽  
Robert D. Brown ◽  
David O. Wiebers ◽  
David G. Piepgras
Keyword(s):  
Magnetic Resonance ◽  
Mr Angiography ◽  
Content Type ◽  
Aneurysm Size ◽  
Unruptured Intracranial Aneurysms ◽  
Increased Risk ◽  
History Of ◽  
Aneurysm Growth ◽  
Fine Print

Object. The goal of this study was to determine the frequency of enlargement of unruptured intracranial aneurysms by using serial magnetic resonance (MR) angiography and to investigate whether aneurysm characteristics and demographic factors predict changes in aneurysm size. Methods. A retrospective review of MR angiograms obtained in 57 patients with 62 unruptured, untreated saccular aneurysms was performed. Fifty-five of the 57 patients had no history of subarachnoid hemorrhage. The means of three measurements of the maximum diameters of these lesions on MR source images defined the aneurysm size. The median follow-up period was 47 months (mean 50 months, range 17–90 months). No aneurysm ruptured during the follow-up period. Four patients (7%) harbored aneurysms that had increased in size. No aneurysms smaller than 9 mm in diameter grew larger, whereas four (44%) of the nine aneurysms with initial diameters of 9 mm or larger increased in size. Factors that predicted aneurysm growth included the size of the lesion (p < 0.001) and the presence of multiple lobes (p = 0.021). The location of the aneurysm did not predict an increased risk of enlargement. Conclusions. Patients with medium-sized or large aneurysms and patients harboring aneurysms with multiple lobes may be at increased risk for aneurysm growth and should be followed up with MR imaging if the aneurysm is left untreated.

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