Tetsuro Okimura

Mri of Subperiosteal Hematoma of the Orbit

Objective The MR findings of two cases of subperiosteal hematoma of the orbit are described. Materials and Methods We present two cases of subperiosteal hematoma of the orbit following minor head trauma, the first presenting with chronic progressive exophthalmos and the second with acute proptosis. Results Both cases showed a well-defined biconvex mass with a curvilinear hypointense band in the superior portion of the orbit. In Case 1 chronic hematoma demonstrated high signal on both T1− and T2-weighted imaging, and in Case 2 acute hematoma displayed intermediate signal on T1-weighted imaging and high signal on T2-weighted imaging. Follow-up MRI in Case 2 demonstrated the typical signal changes from acute to subacute hematoma. Conclusion Subperiosteal hematoma has a characteristic appearance on MRI which is virtually diagnostic. In proper clinical settings MRI is the modality of choice for the detection and characterization of this hematoma.

Calcified mediastinal metastases from ovarian cancer imaged with Tc-99m MDP SPECT

A 41-year-old woman was hospitalized for dyspnea. Seventeen years earlier, she had had surgery for papillary ovarian cancer. Her chest CT revealed massive calcified mediastinal lymph node metastases and tracheal stenosis. Surgery confirmed the presence of calcified metastatic ovarian carcinoma of the mediastinal lymph nodes, and a tracheobronchial stent was inserted. Five months later, Tc-99m MDP bone scintigraphy showed no bone metastases, but there was remarkable radionuclide uptake in the right supraclavicular region and the mediastinum. SPECT images precisely visualized the radionuclide accumulation in the calcified lymph node metastases.

Single photon emission CT images in a case of intraventricular neurocytoma

Although Tc-99m HMPAO uptakes in various brain tumors have been reported, SPECT images of neurocytoma have not been described. The authors report a patient with intraventricular neurocytoma (IN) who demonstrated significant uptake of Tc-99m HMPAO and Tl-201 Cl before brain biopsy. Residual tumor after biopsy showed significant uptake of I-123 IMP on early SPECT images, but this uptake was decreased on delayed images. The three radionuclides seem to have different uptake mechanisms.

Clinical usefulness of integrated images of the radionuclide liver angiogram to evaluate diffuse hepatic disease

New imaging method that was integrated image of radionuclide liver angiogram was proposed. Patients were placed supine beneath gamma camera, so that the liver, spleen, heart, and lung were included in an anterior image. Integrated image was recorded for 100 s, following injection of 111-222 MBq (3-6 mCi) of 99mTc tin-colloid. 595 cases were examined, and classified into 3 groups as follows. Group I: Cases without hepatic dysfunction Group II: Cases with hepatic dysfunction Group III: Liver cirrhosis. Numbers of each group were 208 (35%), 305 (51%), and 82 (14%) respectively. Integrated images were qualitatively determined by macroscopic inspection. Comparing liver intensity and lung intensity, 3 patterns of integrated image were classified. Pattern I: Liver intensity was greater than lung intensity Pattern II: Liver intensity was equal to lung intensity Pattern III: Liver intensity was less than lung intensity Numbers of each pattern were 412 (69%), 125 (21%), and 58 (10%) respectively. Numbers of group III distributed into each pattern were 8 (10%) in pattern I, 29 (35%) in pattern II, and 45 (55%) in pattern III. The correct diagnosis of liver cirrhosis as follows. In a case of choosing pattern III as diagnostic criterion, sensitivity was 55%, and specificity was 97%. The positive predictive value was 78%, and the negative predictive value was 93%. Total accuracy was 92%. This new method seems useful in evaluating diffuse hepatic disease.