Intracerebral metastasis showing restricted diffusion: correlation with histopathologic findings.

OBJECTIVE: We aimed to detect the frequency of restricted diffusion in intracerebral metastases and to find whether there is correlation between the primary tumor pathology and diffusion-weighted MR imaging (DWI) findings of these metastases. MATERIAL AND METHODS: 87 patients with intracerebral metastases were examined with routine MR imaging and DWI. 11 hemorrhagic metastatic lesions were excluded. The routine MR imaging included three plans before and after contrast enhancement. The DWI was performed with spin-echo EPI sequence with three b values (0, 500 and 1000), and ADC maps were calculated. 76 patients with metastases were grouped according to primary tumor histology and the ratios of restricted diffusion were calculated according to these groups. ADCmin values were measured within the solid components of the tumors and the ratio of metastases with restricted diffusion to that which do not show restricted diffusion were calculated. Fisher's exact and Mann-Whitney U tests were used for the statistical analysis. RESULTS: Restricted diffusion was observed in a total of 15 metastatic lesions (19, 7%). Primary malignancy was lung carcinoma in 10 of these cases (66, 6%) (5 small cell carcinoma, 5 non-small cell carcinoma), and breast carcinoma in three cases (20%). Colon carcinoma and testicular teratocarcinoma were the other two primary tumors in which restricted diffusion in metastasis was detected. There was no statistical significant difference between the primary pathology groups which showed restricted diffusion (p>0.05). ADCmin values of solid components of the metastasis with restricted diffusion and other metastasis without restricted diffusion also showed no significant statistical difference (0.72+/-0.16x10(-3)mm(2)/s and 0.78+/-21x10(-3)mm(2)/s respectively) (p=0.325). CONCLUSION: Detection of restricted diffusion on DWI in intracerebral metastasis is not rare, particularly if the primary tumor is lung or breast cancer. However we found that there is no correlation between the metastasis showing restricted diffusion and primary pathology. Prospective studies with larger groups and more information are necessary regarding the correlation between the primary tumor histopathology and the ADC values of metastasis with restricted diffusion.

Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates.

BACKGROUND: Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT. METHODS: Forty-six patients with venous stroke proved on MRI included in our Registry, corresponding to 0.1% of 4650 patients with stroke, were studied. Magnetic resonance angiography (MRA) was performed in all patients, and 18 of them had follow-up MRA. Outcome was evaluated by using the Glasgow Outcome Scale at the time of discharge and during follow-up. RESULTS: Thirty-two patients presented cortical venous stroke; 21 of them had involvement of the dorsomedial venous system, six had a defect in the posteroinferior venous group, and five had a defect in the anteroinferior venous group. Thirteen patients presented simultaneous involvement of the superficial and deep venous system; seven with a defect in the parietal and internal cerebral veins (three with involvement of vein of Gallen), four with a defect in the temporooccipital (vein of Labbé) and basal vein of Rosenthal, two with a deficit in the anterior frontotemporal and uncal-pterygoid venous system. One patient had deep venous thrombosis primarily localized to the thalami bilaterally and the basal ganglia on the right because of occlusion of the thalamostriate veins. The main presenting symptoms of CDVT were headache, focal neurologic signs, partial complex or secondary generalized seizures, and consciousness disturbances in those with deep venous thrombosis, presented alone or in combination at onset. CDVT was more than twofold more frequent in women than in men. Pregnancy, puerperium, oral contraceptive use, and infections were the most common predisposing factors. CONCLUSION: Computerized tomography, conventional MRI and diffusion-weighted imaging showing ischemic and/or hemorrhagic lesion that does not follow the boundary of classical arterial boundaries without signs of sinus thrombosis, and partial or generalized seizures followed by focal neurologic signs may predict CDVT. The outcome of patients with cortical venous stroke was good, but not in those with cortical plus deep venous infarction.

Traumatic Nerve Root Avulsion and Pseudomeningocele Diagnosed by Three Dimensional MRI Technique (CISS Sequence). A Case Report.

This case report demonstrates the importance of the CISS sequence, a fast imaging technique in MRI, in case of suspected nerve root avulsion. We present a case of traumatic pseudomeningoceles at T1-T2 root levels with right T2 ventral root avulsion without associated skeletal fracture diagnosed by MRI using the three dimensional CISS technique. A 28-year-old man presented to the Emergency Department following a motorcycle accident. Clinical examination revealed paresis in intrinsic muscles of the right hand. Traumatic pseudomeningoceles at T1-T2 root levels bilaterally with right T2 ventral root avulsion without associated skeletal fracture were diagnosed by three dimensional cervicothoracic MRI with CISS technique.

Role of the constructive interference in steady-state sequence in the classification of sacral meningeal cysts.

PURPOSE: To investigate the role of the CISS (constructive interference in steady state) sequence in sacral meningeal cysts. MATERIAL AND METHODS: Fourteen patients with sacral meningeal cysts were included. Conventional T1W and T2W sequences and the CISS sequence (TR/TE = 12.25/5.90) were obtained at 1.5-T. The 1-mm-thick base images and multiplanar reformatted images of the CISS sequence were studied. The sacral meningeal cysts were classified by the CISS sequence in accordance with the previously described surgical and histopathological criteria. RESULTS: A total of 25 sacral meningeal cysts were identified in the 14 patients. The cysts and their contents were visualized by the CISS sequence, and the CISS sequence was superior to the T1W and T2W images. Fifteen of the cysts were consistent with type I lesions (extradural meningeal cysts without nerve fibers inside) and 10 cysts with type II lesions (extradural meningeal cysts with nerve fibers inside). There were no type III lesions (intradural meningeal cysts) in the sacral region. CONCLUSION: Previous studies have indicated that conventional MRI as well as magnetic resonance myelography are inconsistent for a classification of sacral meningeal cysts. The CISS sequence with its capability to obtain T2W thin slice acquisitions is superior in showing the nerve root fibers contained in the cysts, which is essential in the differentiation of type I and II cysts. Application of the CISS sequence is recommended in the diagnosis of sacral meningeal cysts.

Wallenberg's lateral medullary syndrome: diffusion-weighted imaging findings.

PURPOSE: To investigate the efficacy of diffusion-weighted imaging in patients with Wallenberg's lateral medullary syndrome. MATERIAL AND METHODS: Thirteen patients with Wallenberg's lateral medullary syndrome were examined with conventional and echoplanar diffusion-weighted magnetic resonance (MR) imaging in a 1.5 T magnetic resonance unit. MR examinations were obtained in the acute or subacute stage of clinical syndrome, and diffusion-weighted imaging (DWI) was considered to be positive for infarction when an increase in signal was seen on b = 1000 s/mm2 images in the posterolateral medullary localization. RESULTS: DWIs were positive in 12 patients in the acute or subacute stages of this clinical syndrome. A false-negative result was obtained in only one patient examined within the first day, 10 h after onset of the symptoms. In the visual evaluation of the DWI, the contrast between normal and infarcted brainstem area was better in the high b-value images than in the apparent diffusion coefficient map images. CONCLUSION: DWI is a valuable technique for examining patients presenting with the signs and symptoms of Wallenberg's syndrome and high b-value images can provide complementary data to T2-weighted images. However, because most of our case group were in either the acute or subacute stage, true sensitivity of the method in the hyperacute stage of the syndrome remains unclear.

Report of diffusion-weighted MRI in two cases with different cerebral hydatid disease.

PURPOSE: To present MRI findings in two cases of cerebral hydatid disease with an emphasis on diffusion-weighted imaging (DWI) findings of Echinococcus granulosus (EG) versus Echinococcus alveolaris (EA). RESULTS: EG lesions were isointense with cerebrospinal fluid in all sequences including DWI. On DWI, EA lesions remained hypointense on b = 1000 s/mm2 diffusion-weighted images. Apparent diffusion coefficient (ADC) values of EG and EA lesions were completely different from each other, 2.88 +/- 0.24 x 10(-3) s/mm2 and 1.33 +/- 0.15 x 10(-3) s/mm2, respectively. CONCLUSION: The ADC values could not be used to discriminate from other differential diagnoses.

Spectrum of anterior cerebral artery territory infarction: clinical and MRI findings.

To evaluate and review the clinical spectrum of anterior cerebral artery (ACA) territory infarction, we studied 48 consecutive patients who admitted to our stroke unit over a 6-year period. We performed magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in all patients, and diffusion magnetic resonance imaging (DWI) in 21. In our stroke registry, patients with ACA infarction represented 1.3% of 3705 patients with ischemic stroke. The main risk factors of ACA infarcts was hypertension in 58% of patients, diabetes mellitus in 29%, hypercholesterolemia in 25%, cigarette smoking in 19%, atrial fibrillation in 19%, and myocardial infarct in 6%. Presumed causes of ACA infarct were large-artery disease and cardioembolism in 13 patients each, small-artery disease (SAD) in the territory of Heubner's artery in two and atherosclerosis of large-arteries (<50% stenosis) in 16. On clinico-radiologic analysis there were three main clinical patterns depending on lesion side; left-side infarction (30 patients) consisting of mutism, transcortical motor aphasia, and hemiparesis with lower limb predominance; right side infarction (16 patients) accompanied by acute confusional state, motor hemineglect and hemiparesis; bilateral infarction (two patients) presented with akinetic mutism, severe sphincter dysfunction, and dependent functional outcome. Our findings suggest that clinical and etiologic spectrum of ACA infarction may present similar features as that of middle cerebral artery infarction, but frontal dysfunctions and callosal syndromes can help to make a clinical differential diagnosis. Moreover, at the early phase of stroke, DWI is useful imaging method to locate and delineate the boundary of lesion in the territory of ACA.

Proton MR spectroscopy in the diagnosis and differentiation of encephalitis from other mimicking lesions.

In this study, proton magnetic resonance spectroscopy (1H MRS) findings of encephalitis were reported. For comparison, other lesions mimicking encephalitis on conventional magnetic resonance (MR) imaging were included in the study. These lesions consisted of acute infarctions and low grade infiltrative gliomas. The 1H MRS findings of encephalitis and gliomas were almost the same whereas infarctions revealed high lactate levels differentiating the disorder from other two pathologies. The differentiation of encephalitis and gliomas based on MR findings could reliably made with short time follow up MR examinations where gliomas tend to grow in contrast to encephalitis which showed regression.

Diagnostic value of electrical stimulation of lumbosacral roots in lumbar spinal stenosis.

OBJECTIVES: This paper compares the diagnostic sensitivity of two tests in lumbar spinal stenosis (LSS): lumbosacral root stimulation with needle electrodes and needle electromyograph (EMG). MATERIAL AND METHODS: Twenty patients with LSS were assigned to two groups: Patients with 'neurogenic intermittent claudication' (NIC) only (n=11), and patients with 'neurological signs' (n=9). Ten normal subjects were also examined. The effects of direct stimulation of the lumbosacral roots and conventional EMG recorded from important muscles [rectus femoris (RF): L4, tibialis anterior (TA): L5, soleus muscle (SOL): S1], were compared with each other and correlated with their respective clinical findings and radiological images. RESULTS: Needle EMG and nerve conduction study revealed pathology in 15/20 patients, and electrical stimulation of the roots in 17/20 patients. Agreement in radiological findings with electrical stimulation of the roots and EMG was found in 12 patients. The other patients were harmonic with radiological findings either in EMG or in electrical stimulation of the roots. CONCLUSIONS: Electrical root stimulation revealed more abnormalities in patients with LSS in comparison with needle EMG. However, both methods seemed to complement each other to show additional pathology in a given patient.

Hemangioblastoma causing cervical neural foraminal widening.

We present the MRI findings in a case of a 24-year-old woman with spinal hemangioblastoma, causing neural foraminal widening by producing a dumbbell mass in the lower cervical region. Hemangioblastomas can very rarely present as an intradural extramedullary lesions and this case is another exceptional pathology which should be considered among the differential diagnosis of enlarged intervertebral foramen due to neoplastic processes.

Catheter and MR angiography of persistent trigeminal artery associated with occipital arteriovenous malformation.

We present a patient with an occipital arteriovenous malformation fed by the posterior cerebral artery coexisting with an ipsilateral persistent trigeminal artery. These anomalies were well demonstrated by MR angiography and confirmed by catheter angiography.

Hypertrophic cranial pachymeningitis involving dural sinuses: a pseudo signal-void appearance on MRI.

A case of hypertrophic cranial pachymeningitis with an unusual and misleading manifestation is reported. CT detected calcified tentorium and superior sagittal sinus. MR imaging and MR angiography depicted tentorial thickening as well as occlusion of all major dural sinuses. Fibrocalcific occlusion of dural sinuses showed interestingly signal-void appearance on spin-echo images which could readily be interpreted as being patent sinuses.

Adhesive arachnoiditis causing cauda equina syndrome in ankylosing spondylitis: CT and MRI demonstration of dural calcification and a dorsal dural diverticulum.

We present the radiological features of a 42-year-old man with long-standing inactive ankylosing spondylitis (AS), demonstrating that arachnoiditis is a cause of a cauda equina syndrome (CES) in this disease. CT showed a dorsal arachnoid diverticulum causing scalloped erosion of the laminae, and punctate and curvilinear dural calcification. MRI revealed adhesion and convergence of the cauda equina dorsally into the arachnoid pouch, causing the dural sac to appear empty canal. To the best of our knowledge, dural calcification on CT is a new finding in AS, which may be related to the CES. Our findings support the hypothesis that chronic adhesive arachnoiditis with subsequent loss of meningeal elasticity may be the main cause of CES in AS.

Multiple intracranial aneurysms in polyarteritis nodosa: MRI and angiography.

In polyarteritis nodosa involvement of the central nervous system is infrequent; small cerebral infarcts are the most common neuroradiological finding. We report a 10-year-old boy with polyarteritis nodosa and intracranial haemorrhage. MRI showed an intracerebral haemorrhage. Angiography revealed two peripheral aneurysms in the posterior cerebral circulation, previously reported on only two occasions, and multiple microaneurysms in the hepatic, renal, mesenteric and even the lumbar arteries.

The so-called transcerebral veins: appearance in three different cases.

The radiologic findings in three patients with dilated transcerebral (medullary) veins detected on routine computed tomography and/or magnetic resonance imaging were reviewed. Sectional imaging showed the dilatation of transcerebral veins as well as the dilated superior ophthalmic veins in all patients. It also demonstrated the primary pathology: vein of Galen aneurysmal malformation; dural sinus fistula with varix; and dural arteriovenous fistula. All three patients had both arteriovenous fistula and sinovenous occlusion. We concluded that the dilated transcerebral veins developing secondary to elevation of the cerebral venous pressure, might be the useful radiologic finding of some dural vascular pathologies on sectional imaging.

Spinal cord compression due to costal Echinococcus multilocularis.

We present computerized tomography (CT) and magnetic resonance imaging (MRI) findings of a costal hydatid cyst (Echinococcus multilocularis) causing spinal cord compression. The hydatid disease was proved histologically. MRI was not only very useful for determining the spinal extension of the disease by its multiplanar imaging capability, but also gave important information about the texture of the cyst, thus aiding the preoperative diagnosis.

Isolated pontine infarction due to rhinocerebral mucormycosis.

We report a patient with rhinocerebral mucormycosis whose initial central nervous system involvement was isolated pontine infarction due to basilar arteritis caused by the fungus. The patient was diagnosed and followed by MRI and CT and basilar arteritis was demonstrated well on MRI studies. Involvement of the skull base was shown on CT in the later stage of the disease. The unusual initial presentation of the infection is discussed.

Varix of the inferior pulmonary vein: computed tomography and magnetic resonance angiography findings.

A 37-yr-old male presented with a 2-week history of intermittent episodes of mild haemoptysis. Computed tomography and magnetic resonance imaging revealed a varix of the inferior pulmonary vein. The diagnosis was confirmed using magnetic resonance angiography and conventional angiography. This condition is relatively rare, and few cases have previously been demonstrated by means of magnetic resonance imaging and angiography.

Associated brain abnormalities in patients with corpus callosum anomalies.

Forty-nine patients with corpus callosum (CC) anomalies were evaluated in terms of the clinical features and magnetic resonance imaging (MRI) findings. CC anomalies were classified as CC agenesis: 6 (12%), CC hypogenesis: 5 (10%), and CC hypoplasia: 38 (78%). In the CC hypoplasia group the mean value of the genu thickness of the CC was 0.29 +/- 0.1 cm, which was less than the normal value of the age-matched normal children (normal range: 0.6-1.2 cm). The associated brain abnormalities were in five distinct groups: gray matter abnormalities, white matter abnormalities, midline brain structure defects, cortical atrophy, and encephalomalacia. There was no uniformity for the clinical spectrum of CC anomalies. Microcephaly, developmental delay and seizures were the prominent findings in patients. The clinical features were more severe in cases with associated brain anomalies.