Nonbifurcating cervical carotid artery diagnosed by MR angiography.

BACKGROUND AND PURPOSE: A nonbifurcating cervical carotid artery is a branching anomaly in which the ECA has no proximal main trunk. We report its incidence and characteristic features on MRA. MATERIALS AND METHODS: We retrospectively reviewed MRAs of 2866 patients obtained by using a standard noncontrast MRA protocol and two 1.5T MR imaging units and reviewed the English language literature to assess the occurrence and features of this nonbifurcating artery. RESULTS: We diagnosed 6 cases, indicating an incidence of 0.21%, and found 11 cases reported in the literature. Analysis of all 17 cases demonstrated no laterality or sex predominance. The most prevalent pattern of branching order from proximal to distal was the F-L trunk, the distal trunk of the ECA, and the OA. CONCLUSIONS: A nonbifurcating cervical carotid artery is rare but not as extremely rare as previously considered, and its correct diagnosis is necessary to avoid complications during interventional radiologic procedures or head and neck surgeries.

Tacrolimus is effective for lupus nephritis patients with persistent proteinuria.

OBJECTIVES: To evaluate the safety and potential efficacy of tacrolimus for the treatment of patients with lupus nephritis and persistent proteinuria. METHODS: A total of 23 Japanese patients with lupus nephritis (21 females/2 males) were enrolled in this study. Patients were administered tacrolimus at a dose of 2-3 mg once daily after the evening meal for 6 months. The dose of tacrolimus was unchanged throughout the study period. Concomitant prednisolone therapy was unchanged or gradually tapered, while other immunosuppressants were stopped at the start of tacrolimus treatment. RESULTS: Tacrolimus was well tolerated, and none of the patients developed adverse drug reactions that required discontinuation of the study. Daily urinary protein loss, the U-prot/U-creat ratio, and serum albumin were significantly improved after 4 months, 3 months, and 1 month of treatment with tacrolimus (p<0.05), respectively, and the improvement persisted until 6 months. The serum complement hemolytic activity (CH50), complement C3 level, and CRP level were also significantly improved after treatment with tacrolimus (p<0.05). Improvement of the U-prot/U-creat ratio was most prominent for patients who were in WHO class IV. CONCLUSIONS: Tacrolimus is safe and effective as maintenance therapy for patients with lupus nephritis, at least for 6 months. A larger randomised, controlled trial over a longer period is needed to confirm these results.

Quantitative assessment of water diffusion changes in brains of children with neurofibromatosis type I using apparent diffusion coefficient.

We measured diffusion changes in the brains of children with neurofibromatosis type 1 (NF1). Using diffusion-weighted and conventional magnetic resonance (MR) images of 42 children with NF1 (19 girls, 23 boys; 7 months-16 years, mean 6.8 years) and 42 age-matched controls (20 boys, 22 girls; 6 months-17 years, mean, 6.9 years), we calculated the apparent diffusion coefficient (ADC) from the automatically generated ADC maps and placed regions of interest in the pons, middle cerebellar and cerebral peduncles, thalami, globus pallidi and frontal white matter. Evaluating only normal-appearing regions on conventional images, we compared mean ADCs using the unpaired Student t test. Means were not significantly different in frontal white matter but were larger in the other regions in the NF1 (P < 0.01). Although conventional MR showed normal intensity, ADCs of the pons, middle cerebellar and cerebral peduncles, thalami and globus pallidi were significantly larger in the NF1.

Two cases of a dural arteriovenous fistula mimicking a brain tumor.

SUMMARY: Dural arteriovenous fistula (d-AVF) is relatively rare. Some cases of atypical locations are often difficult to distinguish from other vascular disorders or tumors because those d-AVFs show various onsets, such as subcortical bleeding and venous infarctions. We encountered two cases of d-AVF with severe brain edema that took adequate time to distinguish from brain tumors. A 68-year-old man visited his local physician complaining of dizziness. He was diagnosed with a cerebral infarction due to the presence of an abnormal cerebellar signal on magnetic resonance imaging (MRI) and was treated by drip infusion. However, he did not recover and was admitted to our hospital with suspicion of a brain tumor. A 75-year-old woman with an onset of progressive dementia and gait disturbance showed severe edema of the right-front temporal lobe on MRI. Both these cases were examined by single photon emission computed tomography or positron emission tomography and were scheduled for craniotomy and biopsy based on the diagnosis of brain tumor. We performed preoperative angiography and found d-AVFs. We embolized the d-AVFs with liquid material and both patients recovered well. Brain edema from d-AVF or a tumor can be distinguished by carefully reading the MRI with findings such as the distribution of the edemas, differences on diffusion-weighted images, and contrast-enhanced images. Therefore, it is important to provide initial accurate diagnoses to prevent patient mistrust and irreversible disease conditions.

Abnormal flow in the cavernous sinus caused by an asymptomatic dural arteriovenous fistula of the contralateral transverse-sigmoid sinus.

A 53-year-old asymptomatic man underwent cranial MR imaging to rule out cerebrovascular disease. On T2-weighted axial images abnormal flow voids were detected at the right cavernous sinus, suggesting a dural carotid-cavernous fistula (CCF). On the MR angiogram, abnormal high intensity signals were observed at the right cavernous sinus and the left transverse-sigmoid (T-S) sinus, suggestive of coexisting right dural CCF and dural arteriovenous fistula (AVF) of the left T-S sinus. Selective cerebral angiography of the left external carotid artery revealed abnormal flow in the right cavernous sinus caused by the dural AVF of the left T-S sinus via the right inferior petrosal sinus due to occlusion of both the distal left sigmoid sinus and proximal right internal jugular vein.

Visualization of the Superior Ophthalmic Veins by 3 Tesla 3D-TOF-MR Angiography.

The superior ophthalmic veins (SOVs) are sometimes visualized on three-dimensional time-of-flight magnetic resonance (3D-TOF-MR) angiograms obtained with a 3 Tesla system. The purpose of this retrospective study was to determine the incidence of visualization of normal SOVs on 3D-TOF-MR angiograms, and their characteristic features. We reviewed 3D-TOF-MR angiograms of 345 consecutive patients obtained with a 3 Tesla MR device. Patients comprised 170 males and 175 females, aged five to 93 years. Most of the patients had, or were thought to have, cerebrovascular disease. The SOV was visualized in 13 of the 345 patients (3.8%). The visualized SOV was on the left side in seven of the 13, and on the right side in two. Both the right and left SOVs were visualized in four patients. The left SOV was more clearly visualized in two of these patients, whereas the SOVs were equally visible on both sides in the other two. There was a female predominance (M:F = 1:12) but no relation between age and visualization of SOVs. None of the visualized SOVs were dilated, and no dilated cavernous sinus was seen. The facial veins and angular veins were also visualized, continuing to the SOVs, suggesting rapid retrograde flow in the facial veins. SOVs are sometimes visualized on 3D-TOF-MR angiograms. This phenomenon should not be misdiagnosed as an asymptomatic dural carotid-cavernous fistula.

Manganese accumulation in the brain: MR imaging.

Manganese (Mn) accumulation in the brain is detected as symmetrical high signal intensity in the globus pallidi on T1-weighted MR images without an abnormal signal on T2-weighted images. In this review, we present several cases of Mn accumulation in the brain due to acquired or congenital diseases of the abdomen including hepatic cirrhosis with a portosystemic shunt, congenital biliary atresia, primary biliary cirrhosis, congenital intrahepatic portosystemic shunt without liver dysfunction, Rendu-Osler-Weber syndrome with a diffuse intrahepatic portosystemic shunt, and patent ductus venosus. Other causes of Mn accumulation in the brain are Mn overload from total parenteral nutrition and welding-related Mn intoxication.

Middle cerebral artery occlusion causing intracerebral hemorrhage: radiologic findings.

Middle cerebral artery (MCA) occlusion usually leads to cerebral infarction but rarely causes cerebral hemorrhage without infarction. We retrospectively investigated the unique radiographic manifestations in cases of cerebral hemorrhage without infarction. Computed tomography (CT) and angiographic images obtained in four patients (aged 26 to 70 years) with MCA occlusion associated with intracerebral hemorrhage were reviewed. Two patients also underwent magnetic resonance imaging (MRI), and one of these underwent magnetic resonance angiography as well; these images were also examined. Cranial CT revealed periventricular hemorrhage with ventricular penetration in one patient and with putaminal penetration in two. Solitary ventricular hemorrhage was found in the fourth patient. Angiography showed ipsilateral occlusion at the M1 portion of the MCA, accompanied by moyamoya-like vessels. No aneurysm or arteriovenous malformation was detected. MRI showed absence of the flow void in the affected MCA and an abnormal flow void in dilated collateral vessels in the basal ganglia. MCA occlusion can cause periventricular or ventricular hemorrhage, which appears to result from bleeding from fragile dilated collateral vessels and, thus, to have an etiology similar to that of adult moyamoya disease. MRI shows promise as a tool for evaluating the occlusion site.

Acquired lesions of the corpus callosum: MR imaging.

In this pictorial review, we illustrate acquired diseases or conditions of the corpus callosum that may be found by magnetic resonance (MR) imaging of the brain, including infarction, bleeding, diffuse axonal injury, multiple sclerosis, acute disseminated encephalomyelitis, Marchiafava-Bignami disease, glioblastoma, gliomatosis cerebri, lymphoma, metastasis, germinoma, infections, metabolic diseases, transient splenial lesion, dilated Virchow-Robin spaces, wallerian degeneration after hemispheric damage and focal splenial gliosis. MR imaging is useful for the detection and differential diagnosis of corpus callosal lesions. Due to the anatomical shape and location of the corpus callosum, both coronal and sagittal fluid-attenuated inversion recovery images are most useful for visualizing lesions of this structure.

Brainstem and cerebellar changes after cerebrovascular accidents: magnetic resonance imaging.

We illustrate the various types of secondary degeneration in the brainstem and/or cerebellum detected on magnetic resonance (MR) images obtained after cerebrovascular accidents. The changes include: (a) ipsilateral nigral degeneration after striatal infarction; (b) Wallerian degeneration of the pyramidal tract in the brainstem after supratentorial pyramidal tract or motor cortex injury; (c) Wallerian degeneration of the corticopontine tract in the brainstem after frontal lobe infarction; (d) ipsilateral brainstem atrophy and crossed cerebellar atrophy due to an extensive supratentorial lesion; (e) ipsilateral superior cerebellar peduncle atrophy, contralateral rubral degeneration, contralateral inferior olivary degeneration and ipsilateral cerebellar atrophy after dentate nucleus hemorrhage; (f) ipsilateral inferior olivary degeneration after pontine tegmentum hemorrhage; (g) bilateral wallerian degeneration of the pontocerebellar tracts after ventromedial pontine infarction or basis pontis hemorrhage; and (h) ipsilateral cerebellar atrophy after middle cerebellar peduncle hemorrhage.

Transient detection of early wallerian degeneration on diffusion-weighted MRI after an acute cerebrovascular accident.

We report three patients with a cerebrovascular accident studied serially by MRI, including diffusion-weighted imaging (DWI). In case 1, DWI 1 day after the onset of left frontoparietal cortical infarcts showed no abnormal signal in the left corticospinal tract. DWI 12 days after onset showed high signal in the corticospinal tract, interpreted as early wallerian degeneration. This had disappeared by 22 days after onset. In case 2, DWI obtained 7 days after the onset of a right internal capsule lacunar infarct showed high signal from the right corticospinal tract in the brainstem, which was less marked 15 days after onset. In case 3, MRI on postnatal day 7 showed a cerebral haemorrhage in the right corona radiata and high signal from the right corticospinal tract on DWI. The latter disappeared by day 23. DWI shows early wallerian degeneration; transient signal abnormalities within 2 weeks of stroke should not be mistaken for new ischaemic lesions.

Spontaneous Thrombosis of a High-flow Carotid-Cavernous Fistula after Failed Transarterial Balloon Occlusion.

SUMMARY: A 62-year-old man with a traumatic high-flow right carotid-cavernous fistula was treated by transarterial balloon occlusion technique. However, because of the relatively small size of the fistula, the balloon could not enter into the cavernous sinus via the fistula. During the procedure, the shunt flow decreased significantly, and we stopped the procedure. Follow-up angiography performed 14 days after the procedure showed complete occlusion of the fistula with a small residual pseudoaneurysm. One year later, the pseudoaneurysm had decreased in size. Repeated transient decrease and stagnancy of blood flow at the fistula during the balloon procedure may have played an important role in the thrombosis in this patient.

Congenital absence of the internal carotid artery diagnosed during investigation of trigeminal neuralgia.

Congenital absence of the unilateral internal carotid artery (ICA) was found in a patient during MR imaging examination for right trigeminal neuralgia. Magnetic resonance angiography showed complete absence of the right ICA and a large tortuous basilar artery (BA). The source images revealed a deformed right trigeminal nerve resulting from compression by the BA. Computed tomography of the skull base showed absence of the right carotid canal, suggesting agenesis of the right ICA. Longstanding hemodynamic stress may have caused the BA to become extremely tortuous, resulting in the trigeminal neuralgia.

Extreme fenestration of the basilar artery associated with cleft palate, nasopharyngeal mature teratoma, and hypophyseal duplication.

The authors present the case of a newborn girl with extreme fenestration of the basilar artery. This anomaly was found incidentally during MR imaging study for cleft palate and nasopharyngeal teratoma. Magnetic resonance angiography showed a totally duplicated basilar artery with connections at the proximal and distal ends of the artery, suggesting an extreme fenestration. Duplicated pituitary gland was also found on MR imaging.

Quantitative MRI findings and cognitive impairment among community dwelling elderly subjects.

OBJECTIVES: To study the factors which influence cognitive impairment among elderly subjects living in a local community, based on both MRI and clinical findings, to further elucidate the causes of dementia, and also to help develop strategies for its prevention. METHODS: Cranial MRI and other medical examinations were performed on non-demented elderly subjects who resided in one rural community. A total of 254 subjects aged from 60 to 91 years of age, with a mean age of 73.9 (SD 6.8) were examined. The mini mental state examination (MMSE) was used to identify cognitive impairment. White matter lesions and cerebral atrophy on MR images were measured quantitatively. A multivariate analysis was also performed with the existence of cognitive impairment as the dependent variable, and the MRI findings and clinical observations were used as the independent variables. RESULTS: Cognitive impairment was present in 46 subjects (18.1%). They were older, had a lower educational level, and more frequent hypertension compared with those without cognitive impairment. The packed cell volume was lower in the impaired group. In addition, their MRI findings showed significantly larger quantities of white matter lesions and cerebral atrophy, as well as more infarcts. A logistic regression analysis demonstrated a significant relation among such factors as white matter lesions (odds ratio (OR) 1.575, 95% confidence interval (95% CI) 1.123-2.208), cerebral atrophy (OR 0.761, 95%CI 0.587-0.987), and lower education (OR 0.682, 95%CI 0.544-0.855) for subjects with a cognitive impairment. CONCLUSIONS: White matter lesions and cerebral atrophy are factors which induce a cognitive impairment in community dwelling elderly subjects without dementia. It is important to carefully watch for any abnormalities in these factors, and to perform cohort studies to check for the above risk factors, to both prevent and make an early diagnosis of dementia.

Moyamoya disease associated with an anterior inferior cerebellar artery arising from a persistent trigeminal artery.

The authors present a case of moyamoya disease associated with a persistent trigeminal artery from which the anterior inferior cerebellar artery arose. We reviewed previously reported cases of moyamoya disease associated with persistent carotid-basilar arterial anastomosis and investigated the embryology of this rare arterial variation.

Extreme fenestration of the right vertebral artery: magnetic resonance angiographic demonstration.

The authors describe an extreme fenestration of the right vertebral artery. This anomaly was found incidentally in a female patient undergoing MR imaging and MR angiography evaluation for severe dizziness and headache. Magnetic resonance angiography showed that the right posterior inferior cerebellar artery originated possibly extracranially and anastomosed with the terminal portion of the right vertebral artery, indicating the presence of an extremely large fenestration. This, to our knowledge, is the first report of MR angiographic demonstration of this variation.

Technetium-99m-ECD SPECT in antiphospholipid antibody syndrome: a drastic improvement in brain perfusion by antiplatelet therapy.

We present a case of antiphospholipid antibody syndrome (APS) with repeated transient ischemic attacks (TIAs). Magnetic resonance imaging showed multiple cerebral infarcts and ischemic changes in the cerebral white matter. Cerebral angiographies showed no abnormalities. Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) brain SPECT showed multiple decreased perfusion areas, which were more extensive than the lesions demonstrated on MRI. After treatment with an antiplatelet agent, the patient subsequently recovered from the TIAs. Although no interval changes were observed by MRI after therapy, follow-up Tc-99m-ECD SPECT revealed a marked improvement in brain perfusion. This is the first imaging report of remarkable post-therapy improvement in brain perfusion in APS cases.