A case of a resectable single hepatic epithelioid hemangioendothelioma with characteristic imaging by ADC map.

A 47-year-old woman with a single-nodule hepatic tumor was referred to our hospital. She had no symptoms. The tumor was located at the surface of the right lobe of the liver; it showed peripheral low signal intensity on a magnetic resonance imaging apparent diffusion coefficient (ADC) map, and an influx of blood flow into the peripheral area of the tumor at the early vascular phase on perflubutane microbubble (Sonazoid(®)) contrast-enhanced (CE) ultrasonography. Since we suspected a malignant tumor, the patient underwent surgical resection. The hepatic tumor was resected curatively. Pathological examination revealed that the tumor was composed of epithelioid cells with an epithelioid structure and/or cord-like structure. Immunohistochemical staining was positive for cluster of differentiation 34 and factor VIII-related antigen. Based on the above, a final diagnosis of hepatic epithelioid hemangioendothelioma (EHE) was made. Hepatic EHE is a rare hepatic tumor: only a few cases of hepatic EHE with curative resection have been reported. We were unable to reach a diagnosis of hepatic EHE by imaging studies; however, an ADC map was useful in showing the malignant potential of the tumor, and CE ultrasonography was useful in revealing the peripheral blood flow of the tumor. When an unusual hepatic mass is encountered, hepatic EHE should be kept in mind, and the mass should be inspected with more than one imaging modality, including an ADC map, in the process of differential diagnosis.

High-signal-intensity abnormalities evaluated by 3D fluid-attenuated inversion recovery imaging within the drainage territory of developmental venous anomalies identified by susceptibility-weighted imaging at 3 T.

PURPOSE: To evaluate brain parenchymal high-signal-intensity abnormalities within the drainage territory of developmental venous anomalies (DVAs) identified by susceptibility-weighted imaging (SWI) at 3 T. METHODS: One hundred and thirty patients with 137 DVAs identified by SWI were retrospectively studied. 3D fluid-attenuated inversion recovery (FLAIR) images were reviewed for parenchymal high-signal-intensity abnormalities and SWI images were reviewed for hypointense foci (microhemorrhages or cavernous malformations) adjacent to DVAs. Patient age, the degree of underlying white matter disease, DVA location (supratentorial or infratentorial), and the presence or absence of hypointense foci were compared across DVAs with and without high-signal-intensity abnormalities. The correlation between patient age and the size of any high-signal-intensity abnormality was analyzed using linear regression. RESULTS: Forty-two of 137 DVAs (30.7 %) had high-signal-intensity abnormalities. An adjusted prevalence of 18/71 (25.4 %) was obtained after excluding patients with considerable underlying white matter disease. Only DVA location (supratentorial) was associated with the presence of high-signal-intensity abnormalities (p < 0.05). There was a significant correlation between patient age and the size of high-signal-intensity abnormalities (p < 0.01). CONCLUSIONS: 3D FLAIR imaging permits detection of small high-signal-intensity abnormalities within the drainage territory of DVAs. The size of high-signal-intensity abnormalities increased with patient age.

Source localization of posterior slow waves of youth using dipole modeling.

AIM: Posterior slow waves of youth have a well-known electroencephalographic pattern that peaks in adolescence and usually disappears in adulthood. In general, posterior slow waves of youth are regarded as normal, but some reports have suggested that their presence is related to immature personalities or inappropriate social behavior. The physiological significance of this electroencephalographic pattern, however, remains unclear. The purpose of this study was to investigate the neural origins of posterior slow waves of youth using dipole source modeling. METHODS: Electroencephalographic epochs, including clear posterior slow waves of youth, were visually selected from electroencephalograms obtained from six normal adolescents using 25 scalp electrodes. The selected epochs were then averaged by arranging the negative peak of the slow waves at the occipital area of each epoch on the time axis. The averaged waveforms consisting of six right and one left posterior slow waves of youth were used for dipole source analysis. A single equivalent current dipole was estimated for the averaged waveforms. RESULTS: The best equivalent current dipoles were estimated to be located in or around the fusiform and middle occipital gyrus ipsilateral to the posterior slow waves of youth. CONCLUSIONS: The location of the estimated dipoles of posterior slow waves of youth was on the so-called ventral visual pathway. Further research is required to clarify the physiological significance of posterior slow waves of youth with respect to their origin.

Reversible splenial lesion in the corpus callosum following rapid withdrawal of carbamazepine after neurosurgical decompression for trigeminal neuralgia.

Reversible splenial lesions (RSL) of the corpus callosum have been described in various clinical conditions, and some are attributed to the action of antiepileptic drugs (AED). Abrupt withdrawal of an AED in preparation for surgical treatment can result in RSL of the corpus callosum in patients with trigeminal neuralgia who do not have epilepsy. We report two patients who developed RSL following surgical treatment of trigeminal neuralgia. Since our two patients did not have epilepsy, it is strongly suggested that the AED, rather than convulsive status epilepticus, could be a contributing factor in RSL. The pathogenesis of AED-associated RSL is not clear. Similar RSL can appear under various circumstances, implying that factors other than AED can influence a common end-point mechanism that results in RSL. Nevertheless, delirium after surgery may be a cue for inquiring about RSL. This condition is transient and represents a clinicoradiological syndrome with an excellent prognosis. We should consider this phenomenon in the perioperative period after surgery for trigeminal neuralgia to avoid invasive diagnostic and therapeutic procedures.

Relation between FDG uptake and apparent diffusion coefficients in glioma and malignant lymphoma.

OBJECTIVE: This study evaluates the relation between 2-deoxy-2-[18F]fluoro-D: -glucose (FDG) uptake using positron emission tomography/CT and the apparent diffusion coefficient (ADC) in patients with glioma and malignant lymphoma. METHODS: For 36 patients (30 with glioma and 6 with malignant lymphoma), the standardized uptake value (SUV) ratio was calculated to assess the FDG uptake. Pearson's correlation analysis was used to assess the relation between the SUV ratio and the ADC value: those of low-grade glioma and high-grade glioma were compared, as were those of glioblastoma and malignant lymphoma. RESULTS: Inverse correlation between the SUV ratio and the minimum ADC was found for all cases (P < 0.0001, r = 0.68) and for glioma cases (P < 0.0001, r = 0.67). High-grade gliomas showed a significantly higher SUV ratio than low-grade gliomas did (P < 0.0001); they also showed significantly lower minimum ADC than low-grade gliomas did (P < 0.001). Cut-off values used for the SUV ratio of 0.9 and for the minimum ADC of 0.99 × 10(-3 )mm(2)/s were used to differentiate high-grade from low-grade gliomas, with high accuracy. Malignant lymphoma showed a significantly higher SUV ratio than glioblastoma (P < 0.0001). No significant difference in the ADC value was found between glioblastoma and malignant lymphoma (the minimum ADC: P = 0.13, the mean ADC: P = 0.084, respectively). CONCLUSIONS: An inverse correlation was found between the SUV ratio and the minimum ADC in glioma and malignant lymphoma. The SUV ratio and the minimum ADC are useful to evaluate the grading of gliomas. The SUV ratio might be more useful for differentiating malignant lymphoma from glioblastoma than the ADC value is.

Electroencephalographic dipole source modeling of frontal intermittent rhythmic delta activity.

BACKGROUND: Frontal intermittent rhythmic delta activity (FIRDA) on electroencephalography (EEG) consists of a run of rhythmic delta waves with frontal predominance. Although FIRDA is a relatively common abnormal EEG finding, the underlying mechanisms that produce FIRDA remain unclear. The aim of this study was to investigate the cortical source of FIRDA using dipole source modeling. METHODS: We selected EEG epochs, including typical FIRDAs, from EEG recordings obtained using 25 scalp electrodes on 5 subjects. We averaged these epochs by arranging the negative peaks of the delta waves at the Fp electrodes and estimated dipoles for nine averaged waveforms. RESULTS: Averaged waveforms were explained by a single-dipole model in seven FIRDAs and by a two-dipole model in the remaining two FIRDAs with high reliability. Estimated dipoles had a radial orientation with respect to the frontal pole and were located in the medial frontal region. The anterior cingulate cortex was the most common dipole location. CONCLUSIONS: This is the first study to approach the fundamental FIRDA mechanism by dipole source modeling and to clarify that FIRDA may be generated from the medial frontal region, particularly from the anterior cingulate cortex.

Recanalization and reversal of diffusion abnormalities and markedly reduced cerebral blood volume in a patient with transient ischemic attack.

Resolution of diffusion abnormalities is a finding that is rarely seen in hyperacute cerebral ischemia. We report a serial study of diffusion and perfusion magnetic resonance imaging (MRI) in a case of transient ischemic attack (TIA). In the current case, marked decrease of cerebral blood volume (CBV) as well as reduced diffusion in the affected middle cerebral arterial territory was shown by the initial diffusion and perfusion MRI at 1.5 h after onset. The initial MRI findings as well as neurological symptoms recovered probably due to prompt and spontaneous recanalization of thrombosed vessel.

Autoimmune pancreatitis successfully treated with ursodeoxycholic acid.

A 51-year-old woman with autoimmune pancreatitis is reported in whom treatment with ursodeoxycholic acid (UDCA) was beneficial. Complaining of epigastric discomfort, she presented with liver dysfunction of the cholestatic type, and diabetes mellitus. Pancreatic imaging revealed a diffuse swelling of the body, an irregular narrowing of the main pancreatic duct, and a terminal stricture of the common bile duct. Histologically, the biopsied pancreas was replaced by fibrous tissue with a small amount of mononuclear cell infiltration. She had anti-carbonic anhydrase-II antibody and anti-lactoferrin antibody. After treatment with UDCA, her liver dysfunction and diabetes mellitus improved and the pancreas size was reduced. Steroid therapy is usually indicated for this disorder, but UDCA may be given as an alternative choice.