Intraocular Lymphoma after Cardiac Transplantation: Magnetic Resonance Imaging Findings

We report a case of intraocular lymphoma in a 65-year-old man, 15 months after cardiac transplantation. On Magnetic Resonance (MR) images, the iris and the anterior chamber of the right eye were found to be involved with an enhancing soft-tissue lesion. To our knowledge, this is the first case of post-transplantation intraocular lymphoma evaluated with MR imaging.

Choroidal Osteoma: US and CT Ffindings

PURPOSE: The purpose of this study was to evaluate US and CT features of choroidal osteoma. MATERIALS AND METHDOS: US and CT scans of seven cases of choroidal osteoma occurring in six patients were retrospectively analyzed. We analysed US and CT findings with particular attention to the location, size, and shape of calcification associated with choroidal osteoma, and sought the possible cause of the tumor, if any. RESULTS: None of six patients had any possible cause related to choroidal osteoma. All of seven cases of choroidal osteoma were manifested as calcified mass which were located in the posterior wall of the eyeball near the juxtapapillary region. Calcification ranged in size from 1 to 2 cm and had curvilinear shape. Both US and CT were equally useful to evaluate choroidal osteoma. CONCLUSION: By depicting the characteristic calcification, US and CT are useful imaging modalities in evaluating choroidal osteoma.

Comparison of Orbital Pseudotumor and Lymphoma: Clinical and Radiological Findings

PURPOSE: To compare the clinical and radiological findings of orbital pseudotumor with those of orbital lymphoma. MATERIALS AND METHODS: The clinical and radiological features of 12 orbital pseudotumors were compared with those of 17 orbital lymphomas, the nature of all lesions being confirmed by tissue biopsy. Twenty-four CT scans and nine MR images were retrospectively reviewed and compared, with special focus on the location of a tumor in the orbit, the invasion of periorbital structures, tumor margin, bilaterality, and signal intensity. The initial symptoms at admission were also classified and compared. RESULTS: In 50% of cases, orbital pseudotumors were located in both extraconal and intraconal space; 75% involved two or more extraocular muscles, and 33% involved the optic nerve. Margins were either infiltrative (75%) or ill-defined (92%). As for orbital lymphomas, 64% occupied extraconal space, invading one or less extraocular muscle (76%) and conjunctiva (29%). Seventy-one percent had a sharp margin, and 65% were lobulated or round. In pseudotumors, orbital pain and visual loss were major symptoms, while in lymphomas a painless orbital mass was the initial symptom. CONCLUSION: CT or MR image analysis of lesion location, margin, and the involvement of adjacent extra-ocular muscle or optic nerves may help differentiate between orbital lymphoma and orbital pseudo tumor.

Diffusion-weighted MR imaging in benign and malignant orbital masses / 中华放射学杂志

Objective To analyse the characteristics of orbital benign and malignant masses on diffusion weighted imaging in combination with conventional MR imaging and evaluate the diagnostic value of apparent diffusion coefficient in distinguishing benign and malignant orbital lesions.Methods Seventy- seven cases with orbital masses,including fifty-five benign lesions and twenty-two malignant tumors,who underwent conventional MRI and diffusion imaging scanning were studied with use of a 1.5 T magnetic resonance system.Quantitative ADC measurements of masses(ADC_M)and of the white matter of eontralateral temporal lobe(ADC_W)were made with two different b-values of 0 and 1000 s/mm~2.The ADC ratio(ADCR)of the lesion to the control was calculated.The receiver operating characteristic curves(ROC) were constructed using various cut points of ADC_M and ADCR for different parameters to differentiate between benign and malignant masses.The area under the ROC curve for each parameter was also calculated. Results All cases were proved by histopathology.The mean ADC_M and ADCR of benign orbital masses were(1.56?0.75)?10~(-3)mm~2/s and 1.85?0.91,respectively.The mean ADC_M and ADCR of malignant orbital masses were(1.09?0.42)?10~(-3)mm~2/s and 1.28?0.53,respectively.There were significant difference both between ADC_M and ADCR of benign and malignant masses(t=2.803,2.735,P

MR Imaging of the Eyeball: Anatomy and Pathology

The eyeball can be divided into the anterior and posterior compartment bordering on the lens. The ocular wallis composed of three layers, namely the sclera, choroid and retina. Different pathologic conditions can occur,depending on the anatomic location. This paper illustrates the anatomical features of normal eyeball, as seen onMRI, and a variety of pathologic conditions of the compartments. An understanding of the MR features of variousintraocular lesions is thus facilitated

CT and MR Findings in Retinoblastoma: Correlation with Histopathologic Examination

PURPOSE: To evaluate histopathologic correlation of the component of the lesion on CT and MR of retinoblastomas. MATERIALS AND METHODS: Gross pathologic findings of 24 enucleated eyeballs in 24 patients with retinoblastomas were compared with preoperative CT (n=19) and MR (n=5) findings. In eight eyeballs, in which there were findings other than mass, histopathologic findings were reviewed and correlated with image findings. RESULTS: Retinal detachment and subretinal hemorrhage which were not detected on CT were demonstrated in two of eight eyeballs on histopathologic examination. In one eyeball, retinal detachment and subretinal effusion were detected on both CT and in a pathologic specimen. In two eyeballs with peripheral heterogeneous MR enhancement of the masses, tumor necrosis and calcification were demonstrated in the central non-enhancing portion of the mass. In two eyeballs, linear soft tissue along the retina apart from the main mass were revealed as tumor spread along the retinal surface. In one patient, retinal thickening on MR was presumed to be an MR artifact and no lesion was found in the gross specimen. CONCLUSION: On CT, retinal detachment and subretinal hemorrhage associated with retinoblastoma can mimic mass, and tumor spread along the retinal surface can be seen as a linear retinal lesion. On MR, tumor necrosis and calcification can be a cause of heterogeneous enhancement.

Radiological findings of hemangioendotheliomas in the orbit / 中华放射学杂志

Objective Radiological findings of very rare hemangioendotheliomas in the orbit have not been reported.Radiological findings on different imaging studies of four cases with hemangioendotheliomas in the orbit were described and the literature was reviewed so as to understand features of hemangioendotheliomas in the orbit.Methods CT and MR imaging findings of four cases with hemangioendotheliomas in the orbit confirmed by histopathology were analyzed retrospectively.Results A mass was found in the superotemporal quadrant in the anterior extraconal space of the orbit in three cases and in the inferonasal quadrant in one case. CT studies revealed a homogeneously ovoid tumor with benign remodeling of the adjacent bone in three cases and a homogeneously irregular mass without any bony change in one case.MR imaging showed a mass in the orbit that was mildly hypointense on T_1-weighted sequences and hyperintense on T_2-weighted images with areas of flow voids representing vessels within the peripheral portion of the tumor in four cases.All four patients demonstrated significant enhancement immediately after intravenous administration of contrast material and a type D time-signal intensity curve (TIC)pattern on MR dynamic contrast enhancement scanning.Conclusions Hemangioendotheliomas in the orbit appeared as a hypervascular tumor predominantly in the extraconal space with areas of flow voids within the tumor and early significant enhancement of the tumor after intravenous administration of contrast material.MR imaging is the best method in demonstration of features of hemangioendotheliomas in the orbit and in diagnosis of these tumors.