The Clinical Usefulness of 99mTc-MIBI Scintimammography in Diagnosis of Breast Cancer / 한국유방암학회지

PURPOSE: Imaging studies for the diagnosis of breast cancer such as ultrasonography or mammography, play an essential role; however, it is well known that they have some limitations; the low specificity of ultrasonography and the low sensitivity of mammography, especially in the dense breasts of Korean women. Recently, 99mTc-MIBI scintimammography was introduced for the detection of breast cancer, and showed acceptable results in its diagnostic accuracy. In this study, the clinical usefulness of 99mTc-MIBI scintimammography was evaluated for the determination of a better imaging study for the diagnosis of breast cancer. METHODS: This study included 75 patients with breast masses, and 3 imaging studies were performed; mammography, ultrasonography and 99mTc-MIBI scintimammography and the results compared on the basis of the pathological reports from core needle or excisional biopsies of the patients. RESULTS: From the pathological reports of 75 patients, 45 cases were confirmed as malignant and 30 as benign diseases. Based on the pathological reports, the sensitivities of mammography, ultrasonography and 99mTc-MIBI scintimammiography were 62.2, 88.9, and 86.7%, and the specificites of 3 imaging studies were 90.0, 76.7, and 90.3% respectively. The positive predictive values were 90.3, 85.1, and 92.9% and the negative predictive values were 61.4, 82.1, and 81.8%, respectively. 99mTc-MIBI mammoscintigraphy showed a comparable sensitivity to ultra-sonography, and a similar specificity to mammography, in the diagnosis of breast cancer. CONCLUSION: Clinically, as a primary imaging tool, 99mTc-MIBI mammoscintigraphy showed acceptable results in the diagnosis of breast cancer. Considering the weak points of ultrasonography and mammography, 99mTc-MIBI mammoscintigraphy would be a very useful tool in the diagnosis of breast cancer.

Pallidotomy Guided by MRI and Microrecording for Parkinson's Disease

OBJECTIVE: The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. METHODS: Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence. Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of 1nm diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. RESULTS: Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. CONCLUSION: The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

Evaluation of Glioma with Thallium-201 Brain SPECT : The Correlation with 1H MR Spectroscopy and Pathology / 대한핵의학회잡지

PURPOSE: Thallim-201 (201Tl) brain SPECT and proton (1H) magnetic resonance spectroscopy (MRS) have been used to evaluate tumor grade and viability of glioma. We assessed the correlations between 201Tl brain index or spectrum of metabolites of 1H MRS and grade of glioma or histopathologic findings. MATERIALS AND METHODS: We studied 17 patients (4 astrocytoma, 7 anaplastic astrocytoma and 6 glioblastoma). On 201Tl Brain SPECT, 201Tl index was measured as the ratio of average counts for region of interest to those for the contralateral normal brain. On 1H MRS, we calculated choline (Cho) /creatine (Cr) ratio and N-acetylaspartate (NAA)/Cr ratio in ROI defined as tumor center. Histopathologic findings were graded by Ki-67 index, cellularity, mitosis, pleomorphism, necrosis and endothelial proliferation. An unpaired t test and statistical correlations were performed to evaluate these data. RESULTS: Tl-index showed the best correlation with Ki-67 index (p<0.01), less correlations with cellularity, mitosis, and endothelial proliferation, but no correlation with results of MRS, pleomorphism, or necrosis. The findings of MRS did not correlate with all of the above. The cases of glioblastoma demonstrated a higher Tl-index, Cho/Cr ratio, Ki-67 index and lower NAA/Cr ratio, albeit without statistical significance. CONCLUSION: Even though 201Tl brain SPECT did not correlate directly with grade of malignancy, it may still be useful in determining biological aggressiveness of tumor and prognosis of patients because it correlated well with Ki-67 index, a growth fraction of glioma, cellularity, mitosis and endothelial proliferation.

Diagnosis of Functional Nasolacrimal Duct Obstruction Using Dacryoscintigraphy / 대한핵의학회잡지

PURPOSE: To evaluate the value of dacryoscintigraphy in the assessment of patients with a clinical diagnosis of functional nasolacrimal duct obstruction. MATERIALS AND METHODS: Dacryoscintigraphy was performed in symptomatic 35 lacrimal drainage systems in 18 patients (age range: 37~76, 8 males, 10 females) that were patent on syringing. RESULTS: Abnormalities were detected with dacryoscintigraphy in 75.8% of systems. The positive scintigrams were subdivided into those demonstrating prelacrimal sac delay (31.8%), delay at the lacrimal sac/junction (40.9%), or delay within the duct (27%). CONCLUSION: Dacryoscintigraphy is noninvasive useful technique in the assessment of the functional nasolacrimal duct obstruction and very sensitive at detecting abnormalities in patients with lid laxity caused by senile change and facial nerve palsy.

Development of Formulas for the Estimation of Renal Depth and Application in the Measurement of Glomerular Filtration Rate in Koreans / 대한핵의학회잡지

PURPOSE: There is no established formula for estimating renal depths in Korean. As a result, we undertook this study to develop a new formula, and to apply this formula in the calculation of glomerular filtration rate (GFR). MATERIALS AND METHODS: We measured the renal depth (RD) on the abdominal CT obtained in 300 adults (M:F=167:133, mean age 50.9 years) without known renal diseases. The RDs measured by CT were compared with the estimated RDs based on the Tonnesen and Taylor equations. New formulas were derived from the measured RDs in 200 out of 300 patients based on several variables such as sex, age, weight, and height by multiple regression analysis. The RDs estimated from the new formulas were compared with the measured RDs in the remaining 100 patients as a control. In 48 patients who underwent Tc-99m DTPA renal scintigraphy, GFR was measured with three equations (new formula, Tonnesen and Taylor equations), respectively, and compared with each other. RESULTS: The mean values of the RDs measured from CT were 6.9 cm for right kidney of the men (MRK), 6.7 cm for left kidney of the men (MLK), 6.7 cm for right kidney of the women (WRK), and 6.6 cm for left kidney of the women (WLK). The RDs estimated from Tonnesen equation were shorter than the ones measured from CT significantly. The newly derived formulas were 12.813 (weight/height)+0.002 (age)+ 2.264 for MRK, 15.344 (weight/height)+0.011 (age)+0.557 for MLK, 12.936 (weight/height)+ 0.014 (age)+1.462 for WRK and 13.488 (weight/height)+0.019 (age)+0.762 for WLK. The correlation coefficients of the RD measured from CT and estimated from the new formula were 0.529 in MRK, 0.729 in MLK, 0.601 in WRK, and 0.724 in WLK, respectively. The GFRs from the new formula were significantly higher than those from the Tonnesen equation significantly, which was the most similar to normal GFR values. CONCLUSION: We generated new formulas for estimating RD in Korean from the data by CT. By adopting these formulas, we expect that GFR can be measured by the Gates method accurately in Korean.

Segmental Colon Transit Time with Radiopaque Markers in a Delayed-release Capsule / 대한소화관운동학회지

BACKGROUNDS/AIM: Scintigraphic measurement of colon transit has been proven useful clinically and in the research area, however this method requires well equipped laboratories. The aim of this study was to develop a new colon transit test using radiopaque markers instead of radiolabeled pellets in a methacrylate-coated capsule. METHODS: Ten healthy volunteers were studied. After simultaneous administration of two methacrylate-coated gelatin capsules containing activated charcoal mixed with 8 mCi of 99mTc or a commercially used radiopaque marker, scintigraphies and plain abdominal X-rays were performed. We compared colon transit profiles as the geometric center at 4, 8, 24, and 48 hours after ingestion of gelatin capsules. This new radiopaque marker test was validated with a scintigraphic method as the gold standard. RESULTS: Geometric centers (mean+/-SEM) of 99mTc-scintigraphy were 0.50+/-0.18 at 4 hours, 1.16+/-0.05 at 8 hours, 3.31+/-0.36 at 24 hours, and 4.16+/-0.29 at 48 hours. Geometric centers of the radiopaque marker method were 0.40+/-0.16, 1.13+/-0.05, 3.33+/-0.37, and 4.18+/-0.30 respectively. Transit profiles were the same with both methods and highly correlated (r=0.994, p < 0.001). The difference between the two methods against the mean for the geometric center was within 2SD. CONCLUSIONS: A colon transit test using radiopaque markers in a methacrylate-coated, delayed release capsule was inexpensive, simple, and reliable. This new test could be applicable when a gamma camera is not available.

Preoperative Evaluation of Brain Lesion with 201Tl Brain SPECT: Is It Useful to Differentiate Benign and Malignant Lesions? / 대한핵의학회잡지

PURPOSE: Thallim-201 (201Tl) brain SPECT, which can represent cellular activity of brain lesions, may provide more useful information in differentiating between benign and malignant brain lesions more so than CT or MRI, that merely represents anatomic changes or breakdown of blood brain barrier. We used 201Tl brain SPECT prospectively to evaluate the utility of 201Tl-indices as an indicator of benign or malignant lesions. MATERIALS AND METHODS: We studied 28 patients. There were 13 cases of benign lesions (3: nonspecific benign lesion, 3: meningioma, 2: low grade glioma, 1: tuberculoma, central neurocytoma, hemangioblastoma, radiation necrosis, and choroid plexus papilloma) and 15 cases of malignant lesions (6: glioblastoma multiforme, 5: anaplastic glioma, 2: medulloblastoma, 1: metastasis and lymphoma). In all patients, CT and/or MRI were obtained and then 201Tl brain SPECT was obtained with measuring mean 201Tl index and peak 201Tl index. An unpaired t-test was performed to compare the 201Tl-indices and pathologic diagnoses to evaluate the utility of 201Tl-indices as an indicator of benign or malignant lesions. RESULTS: There were no statistically significant difference in 201Tl-indices between benign and malignant brain lesions (P>0.05). CONCLUSION: These results demonstrated that we could not use 201Tl indices on brain SPECT alone as an indicator of benign or malignant brain lesions.