Evaluation of Parkinson disease and Alzheimer disease with the use of neuromelanin MR imaging and (123)I-metaiodobenzylguanidine scintigraphy.

BACKGROUND AND PURPOSE: Progressive changes in the substantia nigra pars compacta and locus ceruleus of patients with Parkinson disease and Alzheimer disease visualized by neuromelanin MRI and cardiac postganglionic sympathetic nerve function on (123)I-metaiodobenzylguanidine scintigraphy have not been fully evaluated. We compared the diagnostic value of these modalities among patients with early Parkinson disease, late Parkinson disease, and Alzheimer disease. MATERIALS AND METHODS: We compared contrast ratios of signal intensity in medial and lateral regions of the substantia nigra pars compacta and locus ceruleus with those of the tegmentum of the midbrain and the pons, respectively, by use of neuromelanin MRI in patients with early Parkinson disease (n = 13), late Parkinson disease (n = 31), Alzheimer disease (n = 6), and age-matched healthy control subjects (n = 20). We calculated heart-to-mediastinum ratios on (123)I-metaiodobenzylguanidine scintigrams after setting regions of interest on the left cardiac ventricle and upper mediastinum. RESULTS: The signal intensity of the lateral substantia nigra pars compacta on neuromelanin MRI was significantly reduced in early and late Parkinson disease, and that of the medial substantia nigra pars compacta was gradually and stage-dependently reduced in Parkinson disease. The signal intensity of the locus ceruleus was obviously reduced in late Parkinson disease. Signal reduction was not significant in the substantia nigra pars compacta and locus ceruleus of patients with Alzheimer disease. The heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams was stage-dependently reduced in Parkinson disease and normal in Alzheimer disease. The signal intensity ratios in substantia nigra pars compacta and locus ceruleus on neuromelanin MRI positively correlated with the heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams. CONCLUSIONS: Both neuromelanin MRI and (123)I-metaiodobenzylguanidine scintigraphy can help to evaluate disease progression in Parkinson disease and are useful for differentiating Parkinson disease from Alzheimer disease.

Parenchymal hypointense foci associated with developmental venous anomalies: evaluation by phase-sensitive MR Imaging at 3T.

BACKGROUND AND PURPOSE: The risk of hemorrhage in the context of developmental venous anomaly is considered to be very low, but it has never been evaluated by susceptibility-weighted MR imaging at 3T. The goal of the present study was to evaluate the prevalence of hypointense foci (ie, microhemorrhage or cavernous malformation) associated with DVA on phase-sensitive MR imaging, on the basis of principles similar to those of susceptibility-weighted MR imaging, and to evaluate the relationship between the hypointense foci and several factors, such as white matter hyperintense lesions adjacent to DVA on T2-weighted imaging, DVA morphology, and clinical symptoms. MATERIALS AND METHODS: This study retrospectively evaluated 61 lesions in 59 consecutive patients with DVA who underwent MR imaging including phase-sensitive MR imaging. Two neuroradiologists independently assessed for the presence of hypointense foci and other factors such as DVA location, depth, size, direction of draining vein on phase-sensitive MR imaging, and white matter hyperintense lesion on T2-weighted imaging. Clinical symptoms were also assessed. RESULTS: Hypointense foci were observed in 62.3% (38/61) of lesions. White matter hyperintense lesion was more frequently observed in patients with hypointense foci (26/38) than in patients without hypointense foci (7/23) (P < .01). There was no significant association between hypointense foci and other factors. CONCLUSIONS: Our results support the hypothesis that microhemorrhage or cavernous malformation can be related to venous congestion caused by abnormal venous drainage. We conclude that phase-sensitive MR imagingis useful for the detection of microhemorrhage or cavernous malformation in patients with DVA, especially when associated with white matter hyperintense lesion.

Subarachnoid hyperattenuation on flat panel detector-based conebeam CT immediately after uneventful coil embolization of unruptured intracranial aneurysms.

BACKGROUND AND PURPOSE: Flat panel detector-based CBCT can provide CT-like images of the brain without transferring patients from the angiography suite to a conventional CT facility. Conventional brain CT after uneventful endovascular treatment sometimes shows focal subarachnoid hyperattenuation with contrast leakage, mimicking SAH. Differentiating this finding from SAH is important for immediate postprocedural medical management. We investigated CBCT for detecting subarachnoid hyperattenuation immediately after coil embolization of unruptured cerebral aneurysms. MATERIALS AND METHODS: Thirty-six patients with unruptured cerebral aneurysms undergoing CBCT immediately after uncomplicated coil embolization were included. The relationship between the presence of subarachnoid hyperattenuation and total volume of contrast medium injected, aneurysm size and location, and balloon and stent assistance during embolization was investigated. Statistical analyses were performed with the χ(2) test (P < .05). RESULTS: Nine of the 36 patients (25.0%) showed focal subarachnoid hyperattenuation within the relevant parent artery territory harboring the aneurysm. Subarachnoid hyperattenuation locations included the ipsilateral superior frontal sulcus (n = 5), the bilateral superior frontal sulcus (n = 1), and the ipsilateral superior frontal and precentral sulci (n = 3). Statistically significant differences were observed between the presence of a subarachnoid hyperattenuation and the total volume of contrast medium injected (P < .001) and aneurysm size (P < .05). CONCLUSIONS: Subarachnoid hyperattenuation can be detected by CBCT immediately after coil embolization for unruptured aneurysms. The increased amounts of contrast medium to be given before CBCT and the specific location of the hyperattenuation may help differentiate benign subarachnoid contrast leakage from SAH.

Successful closure of intractable tracheoesophageal fistula using a combination of a modified silicon stent and metallic stents.

Although surgery is the usual management strategy for acquired benign tracheoesophageal fistula, sometimes this approach is contraindicated or the patient declines surgical management. In this report, we describe a case of a patient with tracheoesophageal fistula at the level of the carina due to bronchial arterial infusion chemotherapy. Closure could not be achieved in response to multiple treatment strategies, including airway stenting, esophageal stenting, occlusion with microcoils, or cyanoacrylate glue. We subsequently achieved closure of this fistula through the combination of a modified silicon stent and metallic stents.

Percutaneous radiofrequency lung ablation combined with transbronchial saline injection: an experimental study in swine.

To evaluate the efficacy of radiofrequency lung ablation with transbronchial saline injection. The bilateral lungs of eight living swine were used. A 13-gauge bone biopsy needle was inserted percutaneously into the lung, and 1 ml of muscle paste was injected to create a tumor mimic. In total, 21 nodules were ablated. In the saline injection group (group A), radiofrequency ablation (RFA) was performed for 11 nodules after transbronchial saline injection under balloon occlusion with a 2-cm active single internally cooled electrode. In the control group (group B), conventional RFA was performed for 10 nodules as a control. The infused saline liquid showed a wedge-shaped and homogeneous distribution surrounding a tumor mimic. All 21 RFAs were successfully completed. The total ablation time was significantly longer (13.4 +/- 2.8 min vs. 8.9 +/- 3.5 min; P = 0.0061) and the tissue impedance was significantly lower in group A compared with group B (73.1 +/- 8.8 Omega vs. 100.6 +/- 16.6 Omega; P = 0.0002). The temperature of the ablated area was not significantly different (69.4 +/- 9.1 degrees C vs. 66.0 +/- 7.9 degrees C; P = 0.4038). There was no significant difference of tumor mimic volume (769 +/- 343 mm(3) vs. 625 +/- 191 mm(3); P = 0.2783). The volume of the coagulated area was significantly larger in group A than in group B (3886 +/- 1247 mm(3) vs. 2375 +/- 1395 mm(3); P = 0.0221). Percutaneous radiofrequency lung ablation combined with transbronchial saline injection can create an extended area of ablation.

Magnetic resonance imaging findings of ovarian stromal hyperthecosis.

Ovarian stromal hyperthecosis is characterized by diffuse distribution of luteinized stromal cells accompanied by varying degrees of stromal hyperplasia. We report a case of ovarian stromal hyperthecosis with particular regard to magnetic resonance (MR)-pathologic correlation. At initial MR imaging, the central areas of the bilateral ovarian masses showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images, while the peripheries of the bilateral masses showed isointensity to myometrium on T1-weighted images and heterogeneous signal intensities on T2-weighted images. At 15 days after the initial MR imaging examination, a second MR imaging demonstrated shrinkage of the bilateral ovarian masses. Change in the peripheries to predominantly isointensity to myometrium on the T2-weighted images was also observed. The patient underwent bilateral oophorectomy. Microscopic examination revealed scattered nests of lutein cells on a background of densely proliferated ovarian stroma with minimal collagen production in both ovaries. Edema was occasionally seen in the outer portion but was marked in the central zone of the ovaries, particularly on the left. The final pathologic diagnosis was stromal hyperthecosis. With regard to MR-pathologic correlation, the MR findings in the peripheries of the bilateral masses (isointensity relative to myometrium on both T1- and T2-weighted imaging) showed the characteristics of stromal hyperthecosis.

Cerebellar lesions in multiple system atrophy: postmortem MR imaging-pathologic correlations.

BACKGROUND AND PURPOSE: Cerebellar atrophy and white matter T2-hyperintensities have been characterized as cerebellar lesions of multiple system atrophy (MSA). The aim of the study was to correlate MR images with histologic findings in cerebellar lesions of MSA. MATERIALS AND METHODS: Postmortem T2-weighted images using 1.5T were compared with histologic findings in 7 postmortem-proved cases with MSA. The MR imaging findings in the cerebellar cortices and deep white matter dentate nucleus regions were compared with their histologic findings in each case. RESULTS: We detected 3 types of cerebellar changes: type 1, no apparent atrophy or signal-intensity changes; type 2, cerebellar atrophy and inhomogeneous (patchy and/or confluent) cerebellar white matter hyperintensities; and type 3, cerebellar atrophy and diffuse white matter hyperintensities. Hypointensities were seen in the dentate nucleus regions. Atrophy of the cerebellar white matter was more severe than that of cerebellar cortices, and this anatomy was well depicted on coronal images. Histologically, degeneration was more severe in the cerebellar white matter than in the cerebellar cortices. Hyperintensities in the cerebellar white matter showed loss of myelinated fibers and gliosis. Hypointensities in the dentate nucleus regions revealed diffuse ferritin deposition in preserved dentate nuclei and white matter both around and within the nuclei. CONCLUSIONS: Hyperintensities in the cerebellar white matter reflect degenerated white matter associated with loss of myelinated fibers and gliosis, whereas hypointensities in the dentate nucleus regions reflect diffuse ferritin deposition in preserved dentate nuclei and white matter around and within the nuclei. Degeneration is more severe in the cerebellar white matter than in the cerebellar cortices.

Creation of a tumor-mimic model using a muscle paste for radiofrequency ablation of the lung.

The purpose of this study was to develop an easily created tumor-mimic model and evaluate its efficacy for radiofrequency ablation (RFA) of the lung. The bilateral lungs of eight living adult swine were used. A tumor-mimic model was made by percutaneous injection of 1.0 ml muscle paste through the bone biopsy needle into the lung. An RFA probe was then inserted into the tumor mimics immediately after tumor creation. Ablation time, tissue impedance, and temperature were recorded. The tumor mimics and their coagulated regions were evaluated microscopically and macroscopically. The muscle paste was easily injected into the lung parenchyma through the bone biopsy needle and well visualized under fluoroscopy. In 10 of 12 sites the tumor mimics were oval shaped, localized, and homogeneous on gross specimens. Ten tumor mimics were successfully ablated, and four locations were ablated in the normal lung parenchyma as controls. In the tumor and normal lung parenchyma, ablation times were 8.9 +/- 3.5 and 4.4 +/- 1.6 min, respectively; tissue impedances at the start of ablation were 100.6 +/- 16.6 and 145.8 +/- 26.8 Omega, respectively; and temperatures at the end of ablation were 66.0 +/- 7.9 and 57.5 +/- 7.6 degrees C, respectively. The mean size of tumor mimics was 13.9 x 8.2 mm, and their coagulated area was 18.8 x 13.1 mm. In the lung parenchyma, the coagulated area was 15.3 x 12.0 mm. In conclusion, our tumor-mimic model using muscle paste can be easily and safely created and can be ablated using the ablation algorithm in the clinical setting.

Gadolinium enhanced three-dimensional magnetic resonance portography with subtraction.

The aim was to evaluate a subtraction technique for breath-hold gadolinium enhanced three-dimensional magnetic resonance portography (3D-MRP). 26 patients with gastric and/or duodenal varices related to portal hypertension were investigated by 3D-MRP with two phase acquisitions. A partial volume maximum intensity projection (MIP) image after subtracting selective arterial phase images from subsequent portal venous phase images (subtraction 3D-MRP) was compared with the partial volume MIP without subtraction (non-subtraction 3D-MRP) to assess visualization of the portal vein and its collaterals. Subtraction 3D-MRP depicted excellent visualization of the portal vein, although this was not significantly better than non-subtraction 3D-MRP. However, subtraction 3D-MRP gave superior visualization of portal collaterals, with effective suppression of arterial and renal signal intensities, compared with non-subtraction 3D-MRP (p<0.001).

Angiographic and histologic changes in artery, vein and portal vein after placement of bare or covered Z-stent; an experimental study in dogs.

The aim of this study was to examine stenosis in the aorta, portal vein (PV), and inferior vena cava (IVC) after bare and covered Z-stent placement. Eight beagles underwent bare (n=4) or polytetrafluoroethylene (PTFE) covered (n=4) Z-stent placement in the aorta, PV, and IVC. Angiography was performed 1 and 3 weeks later to evaluate stenosis. The animals were sacrificed after 3 weeks for histopathologic examination. Angiographic findings revealed that stenosis in the bare stent group tended to be smaller than in the covered stent group in 3 vessels and stenosis tended to be smaller in the order of the aorta, PV and IVC in either group. In both groups, stenosis in the PV and IVC was mainly caused by organized thrombus. In addition, in the covered stent group, the space between the cover and native vessel wall (subgraft space) was formed and filled with neointima in every vessel. Preventing thrombus formation in the PV and IVC after bare and covered stent placement and reducing the subgraft space in the aorta after covered stent placement are important for minimizing stenosis.

An experimental study on hepatotoxicity of sclerosant ethanolamine oleate flowed into portal vein.

Although endoscopic injection sclerotherapy has been a main treatment option for gastroesophageal varices, intraportal inflow of the sclerosant, ethanolamine oleate, induce liver damage. The aim of this study was to clarify the liver damage due to intraportal inflow of ethanolamine oleate. Ethanolamine oleate suspension was injected into livers of male Wistar rats via the portal (ileocolic) vein. Degrees of liver damage were evaluated by serum levels of transaminases and by histological examination. Intraportal injection of ethanolamine oleate led to extensive liver necrosis, which was marked 1 day after the injection and recovered by 7 days after injection. Liver necrosis became severe as the dose of the injected sclerosant increased. Histologically, neither portal thrombosis nor embolism was evident. Carbon powder particles of India ink, which were injected together with ethanolamine oleate, reached and deposited in sinusoids of the necrotic portions of the liver. These findings suggested that the liver damage had not developed simply as a result of impairment of portal blood flow. Ethanolamine oleate may itself have direct hepatotoxic effects.

Heterogeneity of hepatic parenchymal enhancement on computed tomography during arterial portography: quantitative analysis of correlation with severity of hepatic fibrosis.

Background/Aims: In patients with chronic liver disease, heterogeneous enhancement of liver parenchyma is often noted on computed tomography during arterial portography (CTAP). We investigated the factors contributing to the heterogeneous enhancement and its relationship with postoperative histopathological findings. Methodology: Eighty-seven patients who had undergone a right lobectomy for liver tumor after CTAP were evaluated. The heterogeneity of hepatic parenchymal enhancement on CTAP was assessed quantitatively using standard deviation of mean CT numbers for five ROIs (S.D.) set in the right hepatic lobe, and comparatively evaluated among three histological groups (liver cirrhosis (LC, n=41), chronic hepatitis (CH, n=33), and normal liver (Normal, n=13)). Severity of fibrosis and degree of splenomegaly (Sp) were taken up as factors contributory to the heterogeneity, and were assessed for correlation with the S.D. Results: The range (mean) of S.D. was LC, 3.07-17.64 (9.10); CH, 1.83-11.12 (6.77); and Normal, 2.06-8.89 (5.64) (Scheffe's F-test: LC vs CH, P<0.0005; LC vs Normal, P<0.0002). The higher fibrosis group exhibited significantly greater S.D. values as compared with the lower fibrosis group (Scheffe's F-test: P<0.00003). Coefficient of correlation between the S.D. and the Sp was 0.295 (P<0.005). Conclusion: There was a fair possibility of LC in patients with heterogeneous enhancement of liver parenchyma on CTAP. The severity of liver fibrosis and the degree of splenomegaly were considered to be factors contributing to the heterogeneous enhancement.

Clinical studies on the visualization of gastric lesions using virtual CT endoscopy.

OBJECTIVE: We evaluated the clinical usefulness of virtual CT gastroendoscopy (VCTGE). METHODS: The subjects were 124 patients with endoscopically identified gastric lesions. VCTGE images were obtained using a GE-Navigator. We evaluated VCTGE in the visualization of gastric lesions for their presence and morphology. RESULTS: The detection rate of all gastric lesions by VCTGE was 76% (94 of 124 patients). The smallest detectable early gastric cancer was II c measuring 10 x 8 mm. The detection rates of each gastric lesion by VCTGE were 73% in early gastric cancer, and 90% in advanced gastric cancer. VCTGE imaging in the advanced gastric cancer was good in 12 (30%), fair in 25 (60%) and poor in 4 (10%). VCTGE imaging in early gastric cancer was good in 20 (46%), fair in 12 (27%) and poor in 12 (27%). The significance P level was 0.005 between the evaluation of the imaging of advanced and early gastric cancer. CONCLUSIONS: VCTGE visualized the characteristics of diverse gastric lesions and was considered useful for the detection and the diagnosis of these lesions.

The hemodynamics of dysplastic nodules in the liver evaluated by CT angiography and immunohistochemistry.

BACKGROUND/AIMS: Dysplastic nodules diagnosed pathologically exhibit various hemodynamic patterns. To evaluate these differences in their hemodynamics, we observed basement membrane formation of sinusoids. METHODOLOGY: For 12 low-grade dysplastic nodules, 24 high-grade dysplastic nodules and 16 hepatocellular carcinomas, both computed tomography during arterial portography and CT arteriography were performed preoperatively. Resected specimens were examined immunohistochemically for COL IV (type IV collagen) and laminin to observe basement membrane formation. We compared their hemodynamics on computed tomography during arterial portography and CT arteriography with the expressions of COL IV and laminin. RESULTS: All of the low-grade dysplastic nodules were not hypervascular on CT arteriography, and negative for COL IV and laminin. All of the hepatocellular carcinomas were hypervascular on CT arteriography, and positive for COL IV and laminin. High-grade dysplastic nodules exhibit four hemodynamic patterns on CT during Arterial Portography/CT arteriography. All of 7 iso/iso and 5 iso/hypo nodules were negative for COL IV and laminin. Of the 9 hypo/hyper nodules, which exhibited hemodynamics similar to hepatocellular carcinoma, COL IV was identified in 7 and laminin identified in 8 nodules. Of the 3 hypo/hypo nodules, COL IV and laminin were identified in one. CONCLUSIONS: In high-grade dysplastic nodules, most cases exhibited a correlation between the hemodynamic patterns and the degree of the sinusoidal basement formation.

Proton MR spectroscopy of the brain in patients treated with TIPS.

PURPOSE: To evaluate the utility of proton MR spectroscopy (MRS) for the early detection of hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunting (TIPS). MATERIAL AND METHODS: Six patients, who underwent TIPS for treatment of portal hypertension, were examined by MRS I week before and 1 week after TIPS. They were simultaneously clinically examined for number connection test, blood NH3 level, liver function test and the Fischer ratio. RESULT: Three of 6 patients showed overt HE 1 to 5 weeks after TIPS and the other 3 patients did not show overt HE. The overt HE group showed the larger ratio of the amounts of glutamine and glutamate/myo-inositol (Glx/MI) than that of non-overt HE group (p<0.05). CONCLUSION: The Glx/MI ratio estimated by MRS was useful for early detection of HE after TIPS.

Castleman's disease of the spleen: CT, MR imaging and angiographic findings.

Since Castleman and Towne [Castleman and Towne, Hyperplasia of mediastinal lymph nodes, New Engl. J. Med. 250 (1954), 26-30] first described hyperplasia of the mediastinal lymph nodes in 1954, many cases of Castleman's disease have been reported. Lesions originating in the spleen arc extremely rare, and we here describe the imaging appearances for such a case, and discuss with a brief review of the literature.

Embolotherapy for venous impotence: use of ethanol.

PURPOSE: To evaluate the usefulness of embolotherapy with ethanol for the treatment of venous impotence. MATERIALS AND METHODS: Twenty-three patients with venous impotence underwent embolotherapy. The diagnosis of venous impotence was made by means of pharmacocavernosometry and cavernosography. After exposure of the deep dorsal penile vein, a intravenous catheter was inserted directly into the deep dorsal penile vein and advanced into just front of the preprostatic plexus. Fifty percent ethanol was injected through the catheter and the endpoint of the procedure was determined based on results of venography immediately after injection. The procedure was finished when lack of venous leakage was confirmed. RESULTS: In all patients, the deep dorsal penile vein was successfully exposed surgically, the sclerosing agent successfully injected, and the endpoint successfully achieved. Immediate clinical therapeutic effect (restoration of erection) was obtained in 20 cases (87%). No severe complications were observed during or after the procedure. The follow-up period was 6-50 months. Long-term therapeutic effect was confirmed for 18 of 23 patients (78%). CONCLUSION: The authors' findings suggest that this treatment had satisfactory short-term and long-term clinical results and that longer follow-up is necessary to confirm its safety.

Tumor marker and MR imaging criteria for evaluating the efficacy of cyclic balloon-occluded arterial infusion for advanced cancer of the uterine cervix.

We have already reported satisfactory therapeutic results of cisplatin-based cyclic balloon-occluded arterial infusion chemotherapy (BOAI) enabling treatment by simple total hysterectomy (STH) in patients with advanced cervical cancer of the uterus (cervical cancer), with 2- and 5-year survival rates of 88.9% and 66. 7%, respectively. Considering the fact that 3 to 4 months are needed to complete BOAI, the present study was a retrospective assessment of 18 cervical cancer patients to prepare criteria for the early determination of the efficacy of BOAI in patients who can be treated by STH. The results showed that STH could be performed after the first BOAI in patients with SCC value decreased to 34.3+/-8.2% of the pretreatment value (p=0.0001) and whose tumor size had decreased by 45.1+/-7.5% (p=0.0002).