Biomedical subjects
Publications and source records attributed to H Y Choi.
With two ultrasonographic and two CT films of three cases of thyroid tuberculosis, we evaluate the ultrasonographic and CT findings and correlate them with the pathologic findings. They are demonstrated as heterogeneous hypoechoic mass on ultrasonogram and peripheral-enhancing low-density abscess on CT scan with regional lymphadenopathy. Ultrasonography (US) and CT can help the diagnosis of thyroid tuberculosis.
To evaluate the usefulness of T1-weighted images using the fast inversion recovery (T1FIR) technique as compared with routine T1-weighted spin echo (T1SE) images in various intracranial lesions. Routine spin echo and T1FIR images were performed in 15 consecutive patients with 18 lesions, cerebral infarction in five, astrocytoma in four, vascular lesion in three, encephalomalacia and hemorrhage in each two, arachnoid cyst and meningioma in each one. T1FIR images were performed with 1.5-T Signa [repetition time (TR)/echo time (TE)/inversion time (TI) was 2000/34/800 in 14, 4000/34/1200 in four lesions] and qualitatively compared with the T1SE images in signal intensity, lesion detectability, determination of lesion extent and conspicuity, contrast between lesion and background. Additionally, gray-to-white matter and cerebrospinal fluid (CSF)-to-white matter contrast were evaluated. The signal intensity of the lesions was similar on both T1FIR and T1SE images in all cases. The lesion detectability was similar on both sequences in 15 lesions, and the determination of the lesion extent was definitely higher in 16 lesions on the T1FIR images. Lesion conspicuity was superior in 11, similar in 5, and inferior in 2 patients on the T1FIR images. And also, contrast of lesion-to-background, gray-to-white matter, and CSF-to-white matter was superior on the T1FIR images. The T1FIR technique improved the determination of lesion extent and lesion conspicuity and was qualitatively superior for image contrast as compared with T1SE, but it takes more time than T1SE. The clinical application of T1FIR images depends on whether the superior aspect of the T1FIR images outweighs the disadvantage of the longer time required for this technique.
The objective of this article is to evaluate the significance of resistive index in differentiation between benign and malignant breast lesions on duplex ultrasonographic examination. Resistive indices obtained in 106 breast lesions of 104 patients were included. Sixty-four were benign (mean age: 32.4 +/- 11.1 years), and 42 were malignant lesions (mean age: 47.8 +/- 11.4 years). The resistive index was classified as follows: below 0.49, from 0.5 to 0.59, 0.6 to 0.69, 0.7 to 0.79, and above 0.8. We analyzed and defined the optimal threshold value of RI between benign and malignant lesions. The mean values of the RI of benign and malignant lesions were 0.62 +/- 0.095 (range 0.44-0.86) and 0.74 +/- 0.097 (range, 0.50-0.92), respectively. The resistive index exceeded 0.7 in 80% of malignant lesions. The difference of the RI between malignant and benign lesions was statistically significant when the threshold value was 0.7 (P < 0.001). A resistive index over 0.7 may suggest malignant lesions. Due to the considerable overlap of the range of the RI, it may not be diagnostic in any single patient; however, it may be helpful in conjunct with gray-scale image.
A rare case of extranodal Hodgkin disease of the maxillary sinus is presented. The CT findings are similar to those of squamous cell carcinoma; however, differences in nodal and bony involvement may help to distinguish the two conditions.
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We present a case in which an arterial rupture occurring during embolization of an arteriovenous malformation of the left occipital lobe with a flow-directed microcatheter, was successfully sealed with a small amount of glue. We navigated a 1.8-Fr Magic catheter through the posterior cerebral artery, and during superselective test injection, extravasation was observed at the parieto-occipital branch. The catheter was not removed and the perforation site was successfully sealed with a small amount of glue injected through the same catheter. Prompt recognition and closure of the perforation site is essential for good prognosis.
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Four types of cells that may be the source of important diagnostic pitfalls in cerebrospinal fluid cytology are presented: (1) nucleus pulposus cells, (2) keratinized squamous cells from craniopharyngioma and sphenoid sinus carcinoma, (3) reactive leptomeningeal cells and (4) epitheloid cells from sarcoidosis. For each the cellular morphology is described and representative clinical, cytologic and histologic presentations are discussed.