Comparison of nephrotoxicity between two gadolinium-contrasts, gadodiamide and gadopentetate in patients with mildly diminished renal failure.

Although gadolinium (Gd)-based contrast media have been found to be nephrotoxic, their nephrotoxicity, and the dependence of nephrotoxicity on chelate types, have not been assessed in patients with normal or mildly diminished renal failure. This prospective, randomized study compared the nephrotoxicity of low doses of the nonionic Gd-based contrast medium gadodiamide (Omniscan®) and the ionic Gd-based contrast medium gadopentetate (Magnevist®) in patients with serum creatinine < 1.6 mg/dL. Patients aged 20 to 80 years, weighing 45 to 70 kg and with normal or < 1.6 mg/dL Serum-creatinine in the 3 months prior to undergoing magnetic resonance imaging (MRI) of brain, were enrolled. Patients were randomized to receive 0.1 mol/kg gadodiamide or gadopentetate. Serum-creatinine, serum cystatin-C, estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) formula, and estimated creatinine clearance rate (eCCr) using the Cockcroft-Gault formula were measured just before and 16-80 hr after MRI. Groups were compared statistically by Mann-Whitney U-tests and Wilcoxon signed-rank tests. There were no significant differences in clinical characteristics between the gadodiamide (n = 43) and gadopentetate (n = 59) groups. Serum-creatinine, eGFR and eCCr before and 16-80 hr after MRI did not differ significantly within either group or between the two groups. Serum cystatin-C was significantly higher 16-80 hr after than before MRI only in the gadodiamide group (0.79 ± 0.21 vs. 0.74 ± 0.14 mg/L, p = 0.028). The ionic contrast medium, gadopentetate, did not affect renal function during MRI, whereas the nonionic contrast medium, gadodiamide, affected renal function transiently.

[CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids)].

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) has been recently identified as an inflammatory central nervous system (CNS) disorder. Punctate and curvilinear gadolinium enhancement (peppering) the pons is a characteristic magnetic resonance imaging (MRI) feature of CLIPPERS. Pathogenesis of this disorder remains unknown. A specific serum or cerebrospinal fluid biomarker for this disorder is currently unknown. Whether CLIPPERS is an actual new disease or just represents overlapping symptoms from multiple diseases is still debated. Many differential diagnoses exist even when using imaging as a tool. Pre-lymphoma states, such as grade I LYG (lymphomatoid granulomatosis) and sentinel lesions of primary CNS lymphoma are the most difficult to distinguish.

[Imaging diagnosis of central nervous system malignant lymphoma].

With a typical case, imaging diagnosis of central nervous system malignant lymphoma is not difficult. High density on non contrast CT, periventricular location, homogenous contrast enhancement, iso- to hypointensity to gray matter on T(2) weighted MR imaging and high intensity on diffusion weighted MR imaging are characteristic findings. Hemorrhage is rare. When a patient is immunocompromised, irregular ring enhancement is noted on enhanced study. Intravascular lymphomatois is a rare type of lymphoma. A variety of imaging findings are reported. Differential diagnosis are many. Most difficult to distinguish is a tumefactive multiple sclerosis. Most of the reported cases of tumefactive multiple sclerosis are diagnosed by brain biopsy when the brain tumor, especially malignant lymphoma is suspected. CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) has been recently identified. However, there still remains whether CLIPPERS is an actual new disease entity or represents overlapping disease.

Signal intensity changes for the middle cerebral artery on 3-dimensional time-of-flight magnetic resonance angiography indicate acute hemodynamic changes after carotid endarterectomy.

BACKGROUND: For 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA), the signal intensity (SI) loss depends on the flow velocity. In this study, we aimed to evaluate whether 3D-TOF-MRA could be used as an alternative to single-photon emission computed tomography (SPECT) for assessing the increase in the regional cerebral blood flow (rCBF) after carotid endarterectomy (CEA). To do this, we compared the SI of the middle cerebral artery (MCA) on magnetic resonance angiography (MRA) and the rCBF on SPECT. METHODS: We enrolled 30 patients with internal carotid artery stenosis. SPECT and MRA were performed before and 3-4 days after CEA. rCBF was assessed using SPECT, and the SI of the MCA was assessed using single-slab 3D-TOF-MRA. Regions of interest were placed in the bilateral middle M1 portions of the MCA on MRA, and their mean SI was measured. The increase ratio of the rCBF on SPECT and the increase ratio of the SI of the MCA on MRA were calculated using the formula: (post-CEA ipsilateral/post-CEA contralateral)/(pre-CEA ipsilateral/pre-CEA contralateral). RESULTS: A significant correlation was observed between the increase ratio of the rCBF on SPECT and the increase ratio of the SI of the MCA on MRA (r=.894, y=.4863+.5184x, P<.001). All values obtained by MRA were greater than or equal to the SPECT values, indicating that MRA tends to overestimate the post-CEA rCBF increase. CONCLUSION: Because MRA identified increased rCBF after CEA, we recommend that patients first be screened using MRA.

Altered hemodynamics associated with pathogenesis of the vertebral artery dissecting aneurysms.

The etiology of the vertebral dissecting aneurysms is largely unknown, and they frequently occurs in relatively healthy young men. Objectives and Methods. A series of 57 consecutive cases defined by angiography were evaluated with regard to deviation in the course of the affected and contralateral vertebral arteries. Division was into 3 types: Type I without any deviation, Type II with mild-to-moderate deviation but not over the midline; and Type III with marked deviation over to the contralateral side beyond the midline. Results. The most frequent type of VA running was Type III for the affected and Type I nonaffected side, with this being found in all 17 patients except one. All of the Type III dissections occurred just proximal to a tortuous portion, while in cases with Type-I- and Type-II-affected sides, the majority (33 of 39) occurred near the union of the vertebral artery. In 10 of 57, a non-dominant side was affected, all except one being of Type I or II. With 12 recent patients assessed angiographically in detail for hemodynamics, eleven patients showed contrast material retrograde inflowing into the pseudolumen from the distal portion of the dissection site. Turbulent blood flow was recognized in all of these patients with retrograde inflow. Conclusions. Turbulent blood flow is one etiology of vertebral artery dissection aneurysms, with the sites in the majority of the cases being just proximal to a tortuous portion or union of vessels. In cases with dissection proximal to the tortuous course of the vertebral artery, retrograde inflow will occur more frequently than antegrade, which should be taken into account in designing therapeutic strategies.

A new transvenous approach to the carotid-cavernous sinus via the inferior petrooccipital vein.

OBJECT: The transvenous approach via the inferior petrosal sinus (IPS) is commonly used as the most appropriate for carotid-cavernous fistula (CCF) or cavernous sinus sampling. However, sometimes the IPS is not accessible because of anatomical problems and/or complications, therefore an alternative route is needed. In this paper, the authors present and discuss the utility of a transvenous approach to the cavernous sinus via the inferior petrooccipital vein. METHODS: Four patients, 3 with dural CCFs and the other with Cushing disease, in whom endovascular surgical attempts failed using a conventional venous approach via the IPS, underwent a transvenous approach to the cavernous sinus via the inferior petrooccipital vein (IPOV). One dural CCF case had only cortical venous drainage, the second CCF also mainly drained into the cortical vein with slight inflow into the superior ophthalmic vein and inferior ophthalmic vein, and the third demonstrated drainage into the superior and inferior ophthalmic veins and IPOV. RESULTS: In all cases, the cavernous sinus could be accessed successfully via this route and without complications. CONCLUSIONS: The transvenous approach to the cavernous sinus via the IPOV should be considered as an alternative in cases when use of the IPS is precluded by an anatomical problem and there are no other suitable venous approach routes.

Neurovascular changes in prolonged migraine aura in FHM with a novel ATP1A2 gene mutation.

OBJECTIVES: To report cerebral blood flow changes during attacks of hemiplegic migraine with prolonged aura (HMPA) longer than 24 h in patients with familial hemiplegic migraine (FHM) with a novel gene mutation. METHODS: The authors performed serial neuroimaging studies during acute stage and after recovery of aura symptoms in eight HMPA attacks in two affected individuals of the Japanese family of FHM during a 10-year-observational period. The authors also performed a mutational analysis for all exons of the CACNA1A, ATP1A2 and SCN1A genes in three individuals of this family. RESULTS: Each patient had an individual 'predominantly affected hemisphere,' that is, susceptible to hemiplegia during an HMPA attack. Migraine aura lasted 4 to 12 days. Neuroimaging studies performed on days 1 to 4 showed hyperperfusion in the affected hemisphere contralateral to hemiplegia in five attacks, hypoperfusion in three, middle cerebral artery vasodilation in five and augmented vasogenic leakage with cortical oedema in one. Hyperperfusion developed more frequently than hypoperfusion in the 'predominantly affected hemisphere,' whereas only hypoperfusion developed in the 'non-predominantly affected hemisphere.' All changes were fully reversible. The authors identified a novel heterozygous p.H916L mutation in the ATP1A2 gene in all three individuals. CONCLUSIONS: Although the perfusion state could be different depending on the time course of migraine or the timing of scans in relation to cortical spreading depression, prolonged aura symptoms in this family were frequently associated with hyperperfusion and middle cerebral artery vasodilation. Hyperperfusion tended to occur in the 'predominantly affected hemisphere,' but the mechanism of HMPA awaits further investigations on additional cases of FHM2.

Contrast stasis in large and giant internal carotid artery aneurysms as a good prognostic factor for endovascular coil embolization: retrospective study.

OBJECTIVE: Before treatment for large and giant aneurysms, we need some of the predictors to prognose a good result. In this retrospective study, we attempted to determine criteria such as angiographic signs to identify good candidates for effective endovascular surgery. METHODS: This study involved 45 patients with large or giant aneurysms treated by endovascular embolization. For angiographic study, we delivered a bolus injection of contrast medium. All aneurysms were confirmed angiographically and the morphology was defined in detail before endovascular embolization. We divided the patients into two groups based on angiographic findings. Group A (n=16) manifested stasis of the contrast medium in the aneurysm on venous phase. Group B (n=29) exhibited other findings. We retrospectively evaluated the relationship between stasis of the contrast medium in the aneurysm and results of endovascular embolization. RESULTS AND DISCUSSION: There was no significant difference between the two groups with respect to the size of the aneurysm. However, the neck/dome ratio (P=0·04) and size of the neck (P=0·003) were significantly different between groups A and B. The morphological outcome was better in group A than group B (P=0·03). We demonstrate that contrast stasis is a good predictor of outcome in patients with large or giant aneurysms to consider the endovascular embolization. Hemodynamic studies on large patient populations may reveal other factors predictive of a good treatment outcome.

Diffusion-weighted imaging of the breast: principles and clinical applications.

Diffusion-weighted imaging provides a novel contrast mechanism in magnetic resonance (MR) imaging and has a high sensitivity in the detection of changes in the local biologic environment. A significant advantage of diffusion-weighted MR imaging over conventional contrast material-enhanced MR imaging is its high sensitivity to change in the microscopic cellular environment without the need for intravenous contrast material injection. Approaches to the assessment of diffusion-weighted breast imaging findings include assessment of these data alone and interpretation of the data in conjunction with T2-weighted imaging findings. In addition, the analysis of apparent diffusion coefficient (ADC) value can be undertaken either in isolation or in combination with diffusion-weighted and T2-weighted imaging. Most previous studies have evaluated ADC value alone; however, overlap in the ADC values of malignant and benign disease has been observed. This overlap may be partly due to selection of b value, which can influence the concomitant effect of perfusion and emphasize the contribution of multicomponent model influences. The simultaneous assessment of diffusion-weighted and T2-weighted imaging data and ADC value has the potential to improve specificity. In addition, the use of diffusion-weighted imaging in a standard breast MR imaging protocol may heighten sensitivity and thereby improve diagnostic accuracy. Standardization of diffusion-weighted imaging parameters is needed to allow comparison of multicenter studies and assessment of the clinical utility of diffusion-weighted imaging and ADC values in breast evaluation.

Linear fractures invisible on routine axial computed tomography: a pitfall at radiological screening for minor head injury.

Computed tomography (CT) is now widely used as the only screening method for fractures in patients with head injury. However, clear depiction of a fracture requires a discontinuity in the skull, so linear fractures parallel to the CT slice may not be visualized. We retrospectively evaluated 302 patients with minor head injuries aged from 0 to 91 years, who had undergone routine skull radiography (anteroposterior and lateral views) and head CT to study these types of fracture and discuss the risk of nondetection. Three patients had linear fractures (0.99%) that were invisible on bone window axial CT but detected on skull radiography, which all ran parallel to the scan slice. Two patients developed acute epidural hematoma or traumatic subarachnoid hemorrhage. Evaluation of head injury by only axial CT may miss such fractures and result in sequelae, so diagnosticians should be alert to the possible presence of this type of fracture.

Linear fractures occult on skull radiographs: a pitfall at radiological screening for mild head injury.

BACKGROUND: Skull radiography is widely used to screen for fractures in patients with mild head injury. However, the clear depiction of a fracture requires a gap in the skull separated by the fracture that is wide enough to allow the passage of x-rays. We studied atypical linear fractures that were not visualized clearly, because a specific anatomical configuration hampered the passage of x-rays. METHODS: We retrospectively evaluated 278 patients with mild head injuries who had undergone routine skull radiography (anteroposterior and lateral views) and head computed tomography (CT). We found that some patients negative for linear fracture on skull radiographs were positive on bone window CT scans. RESULTS: Of the 278 patients aged between 2 months and 66 years, 8 (2.9%) manifested a linear fracture on CT scans that presented as a cross section of the fracture oblique to the direction of the x-rays. Four of the 8 developed acute epidural hematoma; 2 of these patients underwent craniotomy. CONCLUSIONS: Radiographic study returned false-negative results, because x-rays were absorbed by the double-layered skull along fractures whose cross section was oblique to the direction of the x-rays. The evaluation of head injury by radiography only may miss these fractures and their undetected presence may result in sequelae such as intracranial hematoma.

Anterior-wall aneurysm of the internal carotid artery successfully treated solely by stenting: With special reference to etiology.

In this case, a ruptured anterior wall aneurysm of the internal carotid artery disappeared on angiography immediately after stent placement. We focus on the underlying nature of the lesion and this possible alternative treatment.

Dural arteriovenous fistulas in the cavernous sinus: clinical research and treatment.

Introduction. The purpose of this paper is to clarify the clinical course, with the dural carotid cavernous fistula (CCF), featuring a pallet of symptoms, paying special attention to radiological findings. Methods. Seventy-six consecutive patients with dural CCFs were investigated in detail, all of whom were defined by angiography. Results. The most common initial symptom was diplopia in 47 patients (62%) and the most frequently observed on arrival were type II, featuring cranial nerve palsies followed by the classical triad in 27, and then type I only with cranial nerve palsies. The time until admission with type I (mean: 6.7 W ± 6.0) was significantly shorter than that with type II (mean: 25.1 W ± 23.5). Branches from bilateral carotid arteries widely inflowing into bilateral carotid cavernous sinus were present in 30 (39%), 20 (26%) of which also demonstrated direct inflow into the intercavernous sinus. type I and II had more multiple venous drainage routes as compared with type III (classical triad only on arrival) and IV (initial development of the classical triad followed by cranial nerve palsy). Conclusion. In our series of dural CCF patients, the most common initial symptom was cranial nerve palsy, mostly featuring multiple venous drainage including cortical drainage. Such palsies should be added to the classical triad as indicative symptoms. Bilateral carotid arteries often inflow into cavernous and intercavernous sinuses, which should be taken into account in choice of therapeutic strategy.

[A case of pure motor isolated finger palsy due to cerebral infarction].

A 73-year-old man, a right-handed, has been pointed out his atrial fibrillation and seen a doctor regularly for varicose veins of left leg and hypertension. He had complaint of a sudden paralysis of his left thumb and index finger while drinking beer. The next day, there was no improvement and he was admitted to our hospital. Neurological examination revealed mild weakness of the most muscles of both thumb and index finger which were innervated by radial nerve, ulner nerve, and median nerve. But he had no any other neurological deficits including sensory system. A brain MRI revealed the acute-stage cerebral infarction in the right precentral knob. With other examinations, we diagnosed the cerebral infarction as cardiogenic embolism. Pure motor isolated finger palsy (PMIFP) in association with cerebrocortical small lesion is rare. It is probable that some cases with diagnosed of peripheral neuropathy was actually PMIFP from central nervous system disturbance.

Reversible brain atrophy in anti-NMDA receptor encephalitis: a long-term observational study.

The long-term neuroimaging correlates of clinical recovery have not been described in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. The aim of the study is to evaluate the long-term outcome of brain atrophy in anti-NMDAR encephalitis. Patients were two women (ages 17 and 33 years) with severe anti-NMDAR encephalitis resulting in decreased level of consciousness, autonomic instability, hypoventilation, and dyskinesias requiring continuous infusion of anesthetic agents for 6-7 months. Brain MRI and cerebral blood flow SPECT obtained at the time of maximal neurological disability were compared with similar studies obtained 5-7 years later. Both patients were hospitalized for 9-14 months and developed frontotemporal atrophy and hypoperfusion 7-12 months after symptom presentation. In both patients, cognitive functions gradually improved over the next 4-5 years. Comparative neuroimaging studies obtained 5-7 years after symptom presentation showed dramatic improvement of the atrophy and frontotemporal hypoperfusion. The severe and protracted deficits and the frontotemporal atrophy that occur in some patients with anti-NMDAR encephalitis are potentially reversible. This suggests that a functional rather than a structural neuronal damage underlies the pathogenesis of this disorder.

Identification of residual breast carcinoma following neoadjuvant chemotherapy: diffusion-weighted imaging--comparison with contrast-enhanced MR imaging and pathologic findings.

PURPOSE: To compare the capability of diffusion-weighted (DW) and contrast material-enhanced magnetic resonance (MR) imaging to provide diagnostic information on residual breast cancers following neoadjuvant chemotherapy and to assess apparent diffusion coefficients (ADCs) of the carcinoma prior to neoadjuvant chemotherapy to determine if the method could help predict response to chemotherapy. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Three hundred ninety-eight patients underwent MR imaging of the breast, including DW MR (b values, 0 and 1500 sec/mm(2)) and contrast-enhanced MR imaging. Of these, the contralateral breast in 73 women was used as a control. Seventy-two patients with 73 lesions with malignant disease were treated by using neoadjuvant chemotherapy and were examined for residual disease following therapy. Three were excluded because of prolonged intervals between final MR imaging and surgery. Thus, 69 patients (70 lesions) with DW and contrast-enhanced MR imaging results were compared with postoperative histopathologic findings. The ADCs of the carcinoma prior to neoadjuvant chemotherapy were calculated for each patient, and those with complete response and residual disease were compared. RESULTS: The accuracy for depicting residual tumor was 96% for DW MR imaging, compared with an accuracy of 89% for contrast-enhanced MR imaging (P = .06). There was no significant difference in prechemotherapy ADCs between pathologic complete response cases and those with residual disease. CONCLUSION: DW MR imaging had at least as good of accuracy as did contrast-enhanced MR imaging for monitoring neoadjuvant chemotherapy. The ADCs prior to chemotherapy did not predict response to chemotherapy. The use of DW imaging to visualize residual breast cancer without the need for contrast medium could be advantageous in women with impaired renal function.

Brachial plexopathy due to massive swelling of the neck associated with craniotomy in the park bench position.

BACKGROUND: During prolonged neurosurgical procedures, anesthetized patients are at risk for position-related complications. We report a rare combination of neck swelling and brachial plexopathy as operative position-related complications. CASE DESCRIPTION: This 56-year-old woman was placed in the left park bench position for removal of a tentorial meningioma in the right posterior fossa. At 2 hours after the 10-hour procedure, her left neck began to swell with progression during the next 10 hours to involve the face on the same side and the face and neck on the opposite side. Computed tomography showed swelling of the muscles and deep soft tissue primarily on the left. No brain edema was observed. She was conservatively treated with orotracheal intubation, placed in the head-up position, and received anticoagulants. Her swelling subsided by the 20th postoperative day; however, she manifested weakness in the proximal muscles of the left upper extremity. Magnetic resonance imaging revealed swelling of the brachial plexus on the left; electrophysiologic studies were compatible with damage to the upper trunk of the brachial plexus. She was discharged 2 months after surgery with improved weakness. CONCLUSION: Possible pathologic mechanisms are kinking of the jugular vein due to extremely flexed neck position during surgery and associated delayed swelling of the neck and brachial plexus. The cerebral venous return may have been maintained by anastomosis between the internal jugular and the vertebral venous system. To prevent such complications, we must take great care of the anesthetized patients when placed in the forced neck position.

Shortening of ventricular shunt catheter associated with cranial growth: effect of the frontal and parieto-occipital access route on long-term shunt patency.

OBJECT: The authors present the difference of shortening the ventricular shunt catheter associated with growth of the cranium between the frontal and parieto-occipital access, a key for long patency of the shunt implanted in children. MATERIALS AND METHOD: Our retrospective study included 28 children. In group A (n=9), the catheter was inserted through a frontal burr hole and in group B (n=19), through a parieto-occipital burr hole. To compare changes that occurred in the interval between the time of insertion and follow-up in the length of the ventricular catheter in the cranium and to assess displacement of the burr used for catheter entry. RESULTS: The results show that ventricular catheter shortening and burr-hole displacement were more pronounced in group A. CONCLUSIONS: This study documents that insertion of the ventricular catheter via the frontal route in children resulted in a higher incidence of shortening due to greater displacement of the burr hole adjacent to the coronal suture. Therefore, we recommend that the parieto-occipital route be used to maintain long-term shunt function.

Acquired lacunar skull deformity following ventriculoperitoneal shunt placement.

A female infant developed hydrocephalus as a result of intraventricular hemorrhage related to premature birth. Radiography showed no sign of lacunar skull deformity (LSD). Lateral and fourth ventricle ventriculoperitoneal shunts were placed. The fourth ventricle shunt required replacement at age 3 years. Radiography and computed tomography showed LSD. Follow-up radiography at age 8 years showed the LSD was becoming unclear. LSD generally appears before birth, and disappears shortly after birth. LSD is most commonly associated with spina bifida cystica or encephalocele. This case of acquired LSD indicates that abnormal disorganized collection of collagen fibers of the skull plates may be triggered by iatrogenic intracranial hypotension even after infancy.

[Superior sagittal sinus thrombosis caused by Crohn's disease and macrocytic anemia : a case report].

A 32-years-old man with a past history of hemorrhoids presenting with hemiparesis was diagnosed as having sagittal sinus thrombosis with hemorrtagic infarction. Laboratory data revealed macrocytic anemia (Hb 11.2 g/d/) with hypoproteinernia (5.5 g/d). After discharge the patient developed abdominal pain, diarrhea, edema in the leg and sustained anemia. Final diagnosis through colon fiberscope findings was Crohn's disease Macrocytic anemia seemed to be induced by Vit. B12 deficiency due to malabsorption. The mechanism and causal relationship between Crohn's disease and sinus thrombosis is discussed.