The Steroid Effect on the Blood-Ocular Barrier Change Induced by Triolein Emulsion as seen on Contrast-Enhanced MR Images

OBJECTIVE: The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. MATERIALS AND METHODS: An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. RESULTS: Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). CONCLUSION: Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion. Dexamethasone seems to decrease the breakdown of the blood-aqueous barrier in the PC.

Usefulness of Magnetic Resonance Cholangiography and Additional T2-Weighted Axial Image in Evaluating Focal Intrahepatic Ductal Dilatation

PURPOSE: To evaluate the value of MR cholangiography (MRC) and MRC with additional T2-weighted axial imaging for evaluating the cause and determining the therapeutic plan in patients with a focal dilatation of the intrahepatic bile ducts(IHBD). MATERIALS AND METHODS: Forty nine patients (male, 27; female, 22; age range, 12-72 (mean, 51) years) with a focal intrahepatic ductal dilatation confirmed surgically and pathologically (lobectomy, 34; biopsy, 7; surgical finding and T-tube cholangiography, 7; percutanous transhepatic biliary drainage with bile cytology, 1) underwent MRC and T2-weighted axial imaging. The MRC were obtained in one of two ways (a single slab or multi-slice acquisition under chemical fat saturation) using RARE (31 patients, source images and single slice images), or TSE (18 patients, source images and MIP reconstruction images). Two radiologists reviewed the MRC images alone, and the MRC images with the T2-weighted axial images. A diagnosis was determined by consensus. RESULTS: In 37 out of 49 patients, the causes of a bile duct dilation were benign diseases (IHBD stones in 33 cases, liver abscesses with IHBD stones in three cases, one inflammatory pseudotumor). Twelve patients had cholangiocarcinomas (mass-forming type in seven cases, intraductal type in three cases, and periductal infiltrating type in two cases). A correct diagnosis was confirmed in 47 out of 49 cases(96.0%), i.e. all the 37 benign lesions and 10 out of 12 malignant lesions. The addition of the T2-weighted axial image to the MRC did not alter the diagnosis of the causes of the focal intrahepatic ductal dilatation, but was helpful in 10 cases (20.4%). Nine cases (7 cholangiocarcinomas and 2 abscesses), in which MRC showed masses, were visualized more definitely on the additional T2-weighted axial images to the MRC than on the MRC alone. The remaining cases were hepatolithiasis, where stones could be easily differentiated from air by the air-fluid level on the axial images. CONCLUSION: MRC is a good diagnostic modality for evaluating a focal dilatation of IHBD, and the addition of T2-weighted axial image to MRC is helpful.

Radiologic Evaluation of the Therapeutic Effect of Gamma Knife Radiosurgery in Cerebral Vasular Malformation

PURPOSE: To evaluate the therapeutic effect of gamma knife radiosurgery in cerebral vascular malformationusing a radiologic imaging method such as MRI or angiography. MATERIALS AND METHODS: We retrospectively reviewedMRIs, Ct scans and angiograms of 29 cases of arteriovenous malformation and 15 of cavernous malformation beforeand after gamma knife radiosurgery. The patients underwent follow-up radiologic studies for between 6 and 35months after radiosurgery. No patient underwent ofter surgery of embolization. Radiological imaging analysisfocused on changes in the volume of the nidus or central core. Other findings of edema, cystic change, hemorrhage,signal intensity, enhancement and distributional vascular markings were also studied. The volume of the AVM niduswas measured and assigned ot one of four groups : 4-10cc and> 10cc. RESULTS: In arteriovenousmalformation cases, the volume of the nidus decreased by mean 60.2%; reduction was greatest(68.1%) in the 1-4ccgroup. Three cases showed complete loss of the nidus at 9, 12 and 25 months after radiosurgery, respectively. Innine cases, dereased caliber or loss of draining vein was noted. High signal intensity on T2-weighted MR images,suggesting either edema or demyelination, was observed in four cases. In cavernous angioma cases, core volume wasreduced by 36.8%. Transient cerebral edema and presumed radiation necrosis were observed in two cases and one,respectively. CONCLUSION: Gamma knife suregery was effective in nearly all cases of arteriovenous malformationand some cases of cavernous malformation. More than two years follow-up involving radiologic imaging such as MRIis needed for the evaluation of therapeutic effect and diagnosis of complications.

CT and MR Findings of Parotid Masses: Benign versus Malignant

PURPOSE: To determine the differential findings of benign and malignant parotid masses, as seen on CT and MRimaging. MATERIALS AND METHODS: The CT(24 cases of benign and 10 cases of malignant masses) and MR imaging(18cases of benign and 9 cases of malignant masses) findings of parotid gland masses confirmed by surgery orhistopathology were analyzed by two radiologists ; they focused on size, cystic change, the presence ofcalcification within the mass, density or signal intensity and margin, degree of contrast enhancement andhomogeneity, location and bilaterality, associated findings-including infiltration into surrounding structures andlymphadenopathy. RESULTS: In one of the 34 cases seen on CT, precontrast images were not available. In 15 of 23benign cases(65.2%), the density of the mass, as seen on pre-contrast enhanced CT scan, was lower than that ofmuscle. In ten malignant cases, density lower than that of muscle was noted in only two cases (20%). OnT2-weighted images, low signal intensity to fat was noted in five of nine cases(55.5%) of malignant lesion, but inno cases involving benign parotid masses. On CT scanning, an indistinct margin of the masses was observed in fiveof 24 benign cases(20.8%) and three of ten malignant cases(30%), but on MR imaging, this was seen in three of 18benign cases(16.7%) and 6 of 9 malignant cases(66.7%). On pre-contrast enhanced CT scan, 15 of 23 benign casesshowed homogenous density, but 12 of these 15 (80%) changed to inhomogenous on post-contrast enhanced CT scan.Among the 12, pleomorphic adenoma accounted for ten cases(83.3%). On CT scanning, infiltration into surroundingstructures including subcutaneous fat tissue was observed in three of 24 benign cases(12.5%) and four of tenmalignant cases(40.0%) ; and on MR imaging, in one of 18 benign cases(5.5%) and six of nine malignantcases(66.7%). CONCLUSION: If a mass of lower attenuation than that of muscle is seen on pre-contrast enhanced CTscan, or density patterns change from homogenous on pre-contrast CT to inhomogenous on post-contrast CT scan, themass may be benign. However, for the differential diagnosis of benign and malignant parotid masses, the margin ofthe mass is not helpful. Masses which on T2-weighted MR images show an indistinct margin, lower signal intensityto fat and infiltration into surrounding structure are more likely to be malignant. CT and MR findings relating tomass size, cystic change within mass, and lymphadenopathy are not, however, helpful for the differential diagnosisof benign and malignant parotid masses.

Radiologic Findings of Intraspinal Epidural Arachnoid Cyst

PURPOSE: To evaluate the radiologic findings of intraspinal epidural arachnoid cyst. MATERIALS AND METHODS: Six pateuts with surgically proven intraspinal epidural arachnoid cyst were included in this study. Four were freeof specific past history, but two had a history of trauma. All underwent examination by plain radiography,CT-myelography and MRI, and the following aspects were retrospectively analysed : vertebral pressure erosion,interpedicular distance, enlargement of neural foramina, as seen on plain radiograph, contrast-filling and lateralbulging of lesions through neural foramina on CT-myelograph, and signal intensity, size and shape of margin andepidural fat pattern, as seen on MRI. RESULTS: Three of four congenital intraspinal epidural arachnoid cysts weresingle in the thoracolumbar region, while in the other case, there were multiple cysts in the mid- and lowerthoracic regions. Cysts were equivaleut in size to between four and six vertebral bodies. Plain radiographicfindings of pedicular pressure erosion, widened interpedicular distance, and bilateral neural foraminalenlargement of several contiguous vertebrae were observed in all four cases. One showed posterior vertebralscalloping. On CT-myelograph, a contrast-filled cystic lesion occupying the posterior epidural space, with lateralbulging through neural foramina and anterior displacement of the contrast-filled thecal sac, was seen. On MRI,longitudinally elongated, well-demarcated cysts were seen to be present in the posterior epidural space; theirsignal intensity was the same as in CSF. An epidural fat cap pattern enveloping the upper and lower ends of thecysts was apparent in all cases. In two cases, traumatic intraspinal epidural arachnoid cysts were situated in thethoracolumbar and lumbosacral region, respectively, near a previously injured region and were smaller (equivalentto the height of three vertebral bodies). CT-myelograph and MRI showed that their effect on the thecal sac wascompressive only. CONCLUSION: When pressure erosion of vertebral odies and pedicles of contiguous severalvertebrae in the thoracic or thoracolumbar region is recognized on plain radiograph, intraspinal epiduralarachnoid cyst should be included in differential diagnosis, and for accurate evaluation, CT-myelograph and/or MRIare needed.

Two Cases of HPV 16 - positive Bowenoid Papulosis Treated with Diphenylcyclopropenone Immunotherapy / 대한피부과학회지

Bowenoid papulosis(BP) is characterized by multiple papules with a benign clinical course but having a histopathology of squamous cell carcinoma in situ on the external genitalia of sexually active men and women. It is well known that the Human papilloma virus(HPV) is connected with the development of BP. Out of these, HPV 16 which has been frequently found in the BP lesions is an oncogenic virus and the theory that BP might progress to intraepithelial neoplasia and advanced carcinoma has been postulated. Local destructive therapy including electrodessication, laser surgery, cryosurgery, and surgical excision is effective and produces a low recurrence rate. However, pain, bleeding, restriction in activity, and postoperative scars are inevitable with complete destruction of the multiple lesions. It has been suggested that diphenylcyclopropenone(DCP) might be a promising therapeutic agent for various viral diseases including HPV-related warts, It is a potent sensitizer which is not mutagenic and works by the induction of type IV hypersensitivity response in HPV infected tissue, leading to wart destruction. We herein, report 2 cases of HPV 16-positive BP treated with DCP immunotherapy.