Hiroshi Demachi

Immunoglobulin G4–related Lung Disease: CT Findings with Pathologic Correlations

PURPOSE To retrospectively analyze radiologic findings of immunoglobulin G4 (IgG4)-related lung disease as correlated with pathologic specimens. MATERIALS AND METHODS This study was approved by the institutional review board, and all patients had consented to the use of their medical records for the purpose of research. This study included 13 patients with IgG4-related lung disease (nine men and four women; age range, 43-76 years). Computed tomographic (CT) findings were retrospectively analyzed with regard to the characteristics, shape, and distribution of the radiologic findings and were correlated with surgically resected or biopsy lung specimens in seven patients. Statistical analysis was not used in this study. RESULTS On the basis of the predominant radiologic abnormality, IgG4-related lung disease could be categorized into four major subtypes: solid nodular type having a solitary nodular lesion that included a mass (four patients); round-shaped ground-glass opacity (GGO) type characterized by multiple round-shaped GGOs (two patients); alveolar interstitial type showing honeycombing, bronchiectasis, and diffuse GGO (two patients); and bronchovascular type showing thickening of bronchovascular bundles and interlobular septa (five patients). Pathologically, solitary nodular lesions consisted of diffuse lymphoplasmacytic infiltration with fibrosis. Thickened bronchovascular bundles or interlobular septa and GGO on CT images pathologically corresponded to lymphoplasmacytic infiltration and fibrosis in peribronchiolar or interlobular interstitium and alveolar interstitium, respectively. The radiologic findings of honeycombing corresponded to disrupted alveolar structures and dilated peripleural air spaces. CONCLUSION IgG4-related lung disease manifested as four major categories of CT features. Pathologically, these features corresponded to IgG4-related sclerosing inflammation along the intrapulmonary connective tissue.

Immunoglobulin G4–related Periaortitis and Periarteritis: CT Findings in 17 Patients

PURPOSE To retrospectively evaluate computed tomographic (CT) findings of immunoglobulin G4 (IgG4)-related disease involving the vascular system. MATERIALS AND METHODS This study was approved by the institutional review board, and all patients included had consented to the use of their medical records for the purpose of research. The study consisted of 17 patients (16 men and one woman; age range, 54-86 years). CT findings of IgG4-related periarterial lesions were retrospectively analyzed. Radiopathologic correlations were examined on the basis of surgically resected specimens. RESULTS A total of 22 periarterial lesions were detected in 17 patients. The lesions were located in the thoracic aorta (n = 4), abdominal aorta to iliac arteries (n = 13), superior mesenteric artery (n = 3), inferior mesenteric artery (n = 1), and splenic artery (n = 1). Radiologically, they were characterized by arterial wall thickening (mean thickness, 11 mm), relatively clear circumscription, possible association with luminal change (mostly dilated and rarely stenotic), exaggerated atherosclerotic change, and homogeneous enhancement at the late phase of contrast material-enhanced CT. Twelve patients (71%) had IgG4-related disease in other organs. Pathologically, diffuse lymphoplasmacytic infiltration, numerous IgG4-positive plasma cells, and irregular fibrosis were noted in the thickened arterial wall, especially at the adventitia. Steroid therapy administered to eight patients rapidly diminished the arterial wall thickening. One patient who did not receive steroid therapy showed spontaneous improvement at follow-up CT. CONCLUSION IgG4-related arterial lesions occur mainly in the aorta and its main branches and are radiologically characterized by homogeneous arterial wall thickening corresponding to pathologic features of IgG4-related sclerosing inflammation in the adventitia.

Subsegmental transcatheter arterial embolization for small hepatocellular carcinomas: local therapeutic effect and 5-year survival rate

The local therapeutic effects and 5-year survival rates obtained following subsegmental transcatheter arterial embolization (TAE) therapy for small hepatocellular carcinomas (HCCs) were retrospectively analyzed. A total of 124 nodular-type HCC lesions measuring less than 4 cm in diameter in 100 patients with liver cirrhosis were subjected to the analysis. All lesions became opaque on digital subtraction angiography. Complete necrosis was seen in 64% of 11 resected lesions. Among the remaining 113 lesions, the 1- and 5-year local recurrence rates following one performance of TAE were 18% and 33%, respectively. The 1- and 5-year survival rates were 100% and 53%, respectively. No significant side effect was observed after TAE therapy. Subsegmental TAE therapy significantly improved the long-term survival rates of patients with small HCCs associated with liver cirrhosis as compared with those treated by conventional TAE therapy.

Dynamic MRI using a surface coil in chronic cholecystitis and gallbladder carcinoma: radiologic and histopathologic correlation.

PURPOSE The purpose of this study was to determine whether dynamic MRI could differentiate gallbladder carcinoma from chronic cholecystitis. METHOD The dynamic MR findings of 50 patients with pathologically proven chronic cholecystitis and 13 with gallbladder carcinomas were correlated with the pathological findings. RESULTS In chronic cholecystitis with thickened wall, mucosa and muscle were shown in early images as smoothly delineated enhancement except in one case, and the subserosa with fibrosis was enhanced in late or delayed images. Unenhanced foci in the wall correlated with Rokitansky-Aschoff sinuses or mural stones. In carcinomas, all tumors showed irregularly delineated enhancement in early images. In late or delayed images, noncancerous portions were also enhanced. The outer margin of early enhancement correlated with the extension of the tumor. CONCLUSION Dynamic MRI is useful for the differentiation of chronic cholecystitis from carcinoma and for the evaluation of its local extension.

IgG4-Related Perineural Disease

Aims. To elucidate characteristics of IgG4-related disease involving the peripheral nervous system. Methods. Retrospective review of 106 patients with IgG4-related disease identified 21 peripheral nerve lesions in 7 patients. Clinicopathological and radiological features were examined. Results. Peripheral nerve lesions were commonly identified in orbital or paravertebral area, involving orbital (n = 9), optic (n = 4), spinal (n = 7), and great auricular nerves (n = 1). The predominant radiological feature was a distinct perineural soft tissue mass, ranging 8 to 30 mm in diameter. Histologically, the epineurium was preferentially involved by massive lymphoplasmacytic infiltration rich in IgG4+ plasma cells. All lesions were neurologically asymptomatic and steroid-responsive at the first presentation, but one recurrent lesion around the optic nerve caused failing vision. Conclusion. IgG4-related disease of the peripheral nervous system is characterized by orbital or paravertebral localization, perineural mass formation, and rare neurologic symptoms. The term “IgG4-related perineural disease” seems appropriate to describe this entity.

Mr Imaging of Spinal Neurinomas with Pathological Correlation

Eight patients with nine spinal neurinomas were examined with magnetic resonance (MR) imaging. We attempted to correlate MR images with the gross and microscopic characteristics of the tumors. On T1-weighted images (T1WIs) all tumors were iso- to slightly hyperintense to CSF, although two comprised hyperintense areas. On the T2-weighted pulse images (T2WIs), available for seven tumors, two tumors were markedly and two relatively hyperintense to CSF. Three tumors exhibited mixed signal intensity. On macroscopic examination, the markedly hyperintense areas on T2WIs corresponded to the cystic portions and relatively hyperintense areas to the solid portions. Areas that were hypointense on T2WIs and isointense or markedly hyperintense on T1WIs corresponded to hemorrhage. On microscopic examination it was impossible to establish a correlation between Antoni A and Antoni B tissue types and features recognized on T1WIs and T2WIs. Gadolinium-diethylenetriamine pentaacetic acid enhanced T1WIs were performed in four patients with five tumors. All tumors enhanced, demonstrating the tumor contours and the cystic degeneration within.

Scanning electron microscopy of intrahepatic microvasculature casts following experimental hepatic artery embolization

The initial site of occlusion of the intrahepatic microvasculature in rats following hepatic artery embolization was studied by scanning electron microscopy of microvasculature casts. The rats were divided into four groups: embolization with gelatin powder (n=3), polyvinyl alcohol (n=3, 125–150 μm), gelatin sponge (n=3, 212–250 μm), and ionized oil. Not only the hepatic arteires but also vessels in the peribiliary plexus were occluded. However, the size of the hepatic arteries and vessels of the peribiliary plexus occluded correlated with the size of the embolic material, except in the case of the gelatin powder which occluded vessels smaller than the particle size.

Simulation Model Based on Non-Newtonian Fluid Mechanics Applied to the Evaluation of the Embolic Effect of Emulsions of Iodized Oil and Anticancer Drug

AbstractPurpose: To verify the difference in embolic effect between oil-in-water (O-W) and water-in-oil (W-O) emulsions composed of iodized oil and an anticancer drug, epirubicin, using a simulation model based on non-Newtonian fluid mechanics. Methods: Flow curves of pure iodized oil and two types of O-W and W-O emulsions immediately and 1 hr after preparation were examined with a viscometer. Using the yield stress data obtained, we simulated the stagnation of each fluid with steady flow in a rigid tube. Results: The W-O emulsions were observed to stagnate in the thin tube at a low pressure gradient. However, the embolic effect of the W-O emulsions decreased 1 hr after preparation. The O-W emulsions were stable and did not stagnate under the conditions in which the W-O emulsions stagnated. Conclusion: The simulation model showed that the embolic effect of the W-O emulsions was superior to that of the O-W emulsions.

Histological influence on contrast-enhanced CT of pancreatic ductal adenocarcinoma

PURPOSE The purpose of our study was to examine the influence of the histology of pancreatic ductal adenocarcinoma on its appearance with contrast-enhanced CT. METHOD Early-phase and late-phase dynamic CT images were obtained in 34 patients who underwent pancreaticoduodenostomy. The attenuating areas of the tumors (n = 58) on early- and late-phase images were classified as hyperattenuated, isoattenuated, hypoattenuated, or unenhanced. The histologic findings of these lesions were compared to the CT appearances. RESULTS The isoattenuated areas on both early- and late-phase images histologically showed increasing cellularity of tumor cells (n = 1) or coexisting acinar tissues and tumor cells (n = 2) within the tumor. Hypoattenuated areas on early-phase images and isoattenuated or hyperattenuated areas on late-phase images (n = 27) showed dense fibrosis except in one tumor with an abscess. Hypoattenuated areas on early- and late-phase images and unenhanced areas (n = 28) showed mucin and/or necrosis within the tumor. CONCLUSION The contrast-enhanced CT appearance of pancreatic ductal adenocarcinoma is influenced by the histologic features associated with tumor cells.

The protective effect of portoarterial shunts after experimental hepatic artery embolization in rats with liver cirrhosis

AbstractPurpose: The role of the portal system after hepatic artery emboiization (HAE) was examined. Methods: Using a Wistar strain rat model of liver cirrhosis, the route and occurrence of portoarterial (PA) shunts before and after HAE by scanning electron microscopic (SEM) and histologic methods were evaluated. HAE was performed with iodized oil and gelatir sponge particles. Results: In the SEM study, PA shunts did not develop in normal rats regardless of whether they did (n = 10) or did not have HAE (n = 5). The cirrhotic rat model showed PA shunts in both HAE (n = 5) and non-HAE (n = 5) animals. PA shunts were established via the peribiliary plexus and direct arterioportal anastomosis In the histologic study, the occurrence of PA shunts ir liver cirrhosis was significantly increased by HAE (HAE-6, non-HAE = 6,p < 0.01). Conclusion: The development of PA shunts, which help perfuse liver parenchyma, may explain why HAE can be safely performed in patients with liver cirrhosis, Key words: Hepatic artery emboiization-Portoarterial shunt-Liver cirrhosis-Scanning electron microscopy