Hiperplasia de las 4 glándulas paratiroides en hiperparatiroidismo terciario, una imagen infrecuente visualizada en la gammagrafía con Tc-99m MIBI

RESUMEN El hiperparatiroidismo terciario es una complicación presentada en pacientes con enfermedad renal crónica llevados a trasplante renal cuyo manejo quirúrgico requiere de la ubicación mediante imágenes diagnosticas para garantizar el éxito de esta intervención. Se presenta caso de mujer en hemodiálisis crónica que presentó hiperparatiroidismo terciario por hiperplasia paratiroidea confirmada con Tc-99m MIBI SPECT.

ABSTRACT Tertiary hyperparathyroidism is a complication presented in patients with chronic kidney disease subjected to renal transplantation whose surgical management requires location through diagnostic images to guarantee the success of this intervention. We present the case of a woman on chronic hemodialysis who presented tertiary hyperparathyroidism due to parathyroid hyperplasia confirmed by Tc-99m MIBI SPECT.

The value of Dedicated Tc-99m MIBI Scintimammography in the Evaluation of Patients with Palpable Breast Lesions in Comparison with Mammography: Preliminary Result / 핵의학분자영상

PURPOSE: There are few studies evaluating the usefulness of dedicated high-resolution scintimammography and no studies using delayed washout with this dedicated high resolution scintimammography for the evaluation of breast lesions. We underwent this study to evaluate the clinical usefulness of Tc-99m MIBI in evaluating patients with palpable breast lesions using dedicated high-resolution scintimammography. MATERIALS AND METHODS: This study included 19 patients with 23 palpable breast lesions who underwent mammography. Tc-99m MIBI was taken to further characterize these lesions. Scintimammography images were acquired with standard craniocaudal and mediolateral oblique views and delayed images were additionally taken. Final conclusions were based on histopathology, either by biopsy or mastectomy results. RESULTS: Eighteen lesions were malignant and five were benign. Mammography was indeterminate for thirteen lesions, nine of those were malignant. Mammography also categorized one lesion as benign in a dense breast, but scintimammography and pathology results showed malignancy. Of the five benign lesions, two were visible on scintimammography, but delayed images showed washout. CONCLUSION: Based on our preliminary results, dedicated high resolution scintimammography seems to be very useful in characterizing palpable lesions that were indeterminate or negative on mammography.

In Vitro Study of Tumor Seeking Radiopharmaceutical Uptake by Human Breast Cancer Cell Line MCF-7 after Paclitaxel Treatment / 핵의학분자영상

PURPOSE: This study was designed to investigate the cellular uptake of various tumor imaging radiopharmaceuticals in human breast cancer cells before and after paclitaxel exposure considering viable cell number. MATERIALS AND METHODS: F-18-fluorodeoxyglucose, C-11-methionine, Tl-201, Tc-99m-MIBI, and Tc-99m-tetrofosmin were used to evaluate the cellular uptake in MCF-7 cells. MCF-7 cells were cultured in multi-well plates. Wells were divided into DMSO exposure control group, and paclitaxel exposure group. The exposure durations of paclitaxel with 10 nM or 100 nM were 2 h, 6 h, 12 h, 24 h, and 48 h. RESULTS: Viable cell fraction was reduced as the concentration and exposure time of paclitaxel increased. After 10 nM paclitaxel exposure, the cellular uptake of all 5 radiopharmaceuticals was not reduced significantly, irrespective of exposure time and viable cell fraction. After 100 nM paclitaxel exposure, the cellular uptake of all 5 radiopharmaceuticals was enhanced significantly irrespective of viable cell fraction. The peak uptake was observed in experimental groups with paclitaxel exposure for 6 to 48 h according the type of radiopharmaceutical. When the cellular uptake was adjusted for the viable cell fraction and cell count, the peak cellular uptake was observed in experimental groups with paclitaxel exposure for 48 h, irrespective of the type of radiopharmaceutical. CONCLUSION: The cellular uptake of F-18-fluorodeoxyglucose, C-11-methionine, Tl-201, Tc-99m-MIBI, and Tc-99m-tetrofosmin did not reflect viable cell number in MCF-7 cells after paclitaxel exposure for up to 48 h.

Unexpected Uptake of Tc-99m MIBI in Thymic Carcinoma: Ring-like Appearance / 핵의학분자영상

A 59-year-old man with thymic carcinoma underwent Tc-99m MIBI myocardial SPECT, and Tc-99m MIBI uptake in the mass was unexpectedly found in a planar image. SPECT images of the thorax showed an increased uptake area with central photon deficiency (a ring-like appearance), which reflected central tumor irreversible ischemia or progressing necrosis with peripheral viable tumor tissue.

Reference Values of Functional Parameters in Gated Myocardial Perfusion SPECT: Comparison with QGS (R) and 4DM (R) Program / 대한핵의학회잡지

PURPOSE: The objectives of this study were - First, to determine the normal range of left ventricular end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) from gated myocardial perfusion SPECT for Quantitative Gated SPECT (QGS) and 4D-MSPECT (4DM), respectively. Second, to evaluate the relationships between values produced by both software packages. MATERIALS AND METHODS: Tc-99m MIBI gated myocardial perfusion SPECT were performed for 77 patients (mean age: 49.6+/-13.7y, n=37 (M), 40 (F) ) with a low likelihood ( 0.05). In 4DM, the mean EDV, ESV and EF for all patients were 89.1+/-26.4ml, 29.1+/-12.8ml and 68.5+/-6.7% at stress test. Most cases in 4DM, there was no significant difference statistically between stress and rest test (p> 0.05). But statistically significant difference was found in EF (68.5+/-6.7% at stress vs 70.9+/-8.0% at rest, p< 0.05). Correlation coefficients between the methods for EDV, ESV and EF were comparatively high (0.95, 0.93, 0.71 at stress test and 0.95, 0.90, 0.69 at rest test, respectively). However, Bland-Altman plots showed a large range of the limit value of agreement for EDV, ESV and EF between both methods (-30ml 10ml, -12ml 8ml, -14% 11% at stress test and -32ml 5ml, -13ml 13ml, -18% 12% at rest test). CONCLUSION: We found the normal ranges of EDV, ESV and EF for patients with a low likelihood of CAD in both methods. We expect these values will be a good reference to interpret gated myocardial perfusion SPECT. Although good correlation was observed between both methods, they should not be used interchangeably. Therefore, when both programs are used at the same site, it will be important to apply normal limits specific to each method.

Reproducibility of Adenosine Tc-99m sestaMIBI SPECT for the Diagnosis of Coronary Artery Disease / 대한핵의학회잡지

PURPOSE: Adenosine myocardial perfusion SPECT has proven to be useful in the detection of coronary artery disease, in the follow up the success of various therapeutic regimens and in assessing the prognosis of coronary artery disease. The purpose of this study is to define the reproducibility of myocardial perfusion SPECT using adenosine stress testing between two consecutive Tc-99m sestaMIBI (MIBI) SPECT studies in the same subjects. METHODS: Thirty patients suspected of coronary artery disease in stable condition underwent sequential Tc-99m MIBI SPECT studies using intravenous adenosine. Gamma camera, acquisition and processing protocols used for the two tests were identical and no invasive procedures were performed between two tests. Mean interval between two tests were 4.1 days (range: 2-11 days). The left ventricular wall was divided into 18 segments and the degree of myocardial tracer uptake was graded with four-point scoring system by visual analysis. Images were interpretated by two independent nuclear medicine physicians and consensus was taken for final decision, if segmental score was not agreeable. RESULTS: Hemodynamic responses to adenosine were not different between two consecutive studies. There were no serious side effects to stop infusion of adenosine and side effects profile was not different. When myocardial uptake was divided into normal and abnormal uptake, 481 of 540 segments were concordant (agreement rate 89%, Kappa index 0.74). With four-grade scoring system, exact agreement was 81.3% (439 of 540 segments, tau b=0.73). One and two-grade differences were observed in 97 segments (18%) and 4 segments (0.7%) respectively, but three-grade difference was not observed in any segment. Extent and severity scores were not different between two studies. The extent and severity scores of the perfusion defect revealed excellent positive correlation between two test (r value for percentage extent and severity score is 0.982 and 0.965, p< 0.001) CONCLUSION: Hemodynamic responses and side effects profile were not different between two consecutive adenosine stress tests in the same subjects. Adenosine Tc-99m sestaMIBI SPECT is highly reproducible, and could be used to assess temporal changes in myocardial perfusion in individual patients.

Effect of Verapamil on Cellular Uptake of Tc-99m MIBI and Tetrofosmin on Several Cancer Cells / 대한핵의학회잡지

PURPOSE: Cellular uptake of 99mTc-sestamibi (MIBI) and 99mTc-tetrofosmin (TF) is low in cancer cells expressing multidrug resistance (MDR) by p-glycoprotein (Pgp) or multidrug related protein (MRP). Verapamil is known to increase cellular uptake of MIBI in MDR cancer cells, but is recently reported to have different effects on tracer uptake in certain cancer cells. This study was prepared to evaluate effects of verapamil on cellular uptake of MIBI and TF in several cancer cells. MATERIALS AND METHODS: Cellular uptakes of Tc-99m MIBI and TF were measured in erythroleukemia K562 cell, breast cancer MCF7 cell, and human ovarian cancer SK-OV-3 cells, and data were compared with those of doxorubicin-resistant K562 (Ad) cells. RT-PCR and Western blot analysis were used for the detection of mdr1 mRNA and Pgp expression, and to observe changes in isotypes of PKC enzyme. Effects of verapamil on MIBI and TF uptake were evaluated at different concentrations upto 200 micro M at 1x10 (6) cells/ml at 37degrees C. Radioactivity in supernatant and pellet was measured with gamma counter to calculate cellular uptake ratio. Toxicity of verapamil was measured with MTT assay. RESULTS: Cellular uptakes of MIBI and TF were increased by time in four cancer cells studied. Co-incubation with verapamil resulted in an increase in uptake of MIBI and TF in K562 (Adr) cell at a concentration of 100 micro M and the maximal increase at 50 micro M was 10-times to baseline. In contrast, uptakes of MIBI and TF in K562, MCF7, SK-OV3 cells were decreased with verapamil treatment at a concentration over 1 micro M. With a concentration of 200 micro M verapamil, MIBI and TF uptakes in K562 cells were decreased to 1.5 % and 2.7% of those without verapamil, respectively. Cellular uptakes of MIBI and TF in MCF7 and SK-OV-3 cells were not changed with 10 micro M, but were also decreased with verapamil higher than 10 micro M, resulting 40% and 5% of baseline at 50 micro M. MTT assay of four cells revealed that K562, MCF7, SK-OV3 were not damaged with verapamil at 200 micro M. CONCLUSION: Although verapamil increases uptake of MIBI and TF in MDR cancer cells, cellular uptakes were further decreased with verapamil in certain cancer cells, which is not related to cytotoxicity of drug. These results suggest that cellular uptakes of both tracers might differ among different cells, and interpretation of changes in tracer uptake with verapamil in vitro should be different when different cell lines are used.

The Usefulness of Mammography and Scintimammography in Differential Diagnosis of Breast Tumor / 대한핵의학회잡지

PURPOSE: It is very important to differentiate breast cancer from benign mass. There are many reports to evaluate the differential diagnosis under the several diagnostic tools. We evaluated the usefulness of mammography and Tc-99m MIBI scintimammography in the differential diagnosis of breast mass and correlated with pathologic findings. MATERIALS AND METHODS: This study included 80 patients (age: 24-72, mean: 48.4) who underwent mammography and Tc-99m MIBI scintimammography for breast masses. Scintimammographies (anterior-posterior and lateral projections) were acquired in 10 minutes and 2 hours after intravenous injection of Tc-99m MIBI. Four specialists in diagnostic radiology and nuclear medicine evaluated the findings of breast masses under the mammography and Tc-99m MIBI scintimammography, and calculated the tumor to background (T/B) ratio. The pathologic results were obtained and we statistically analyzed the correlations between pathologic results and imaging findings under the mammography and Tc-99m MIBI scintimammography by chi-square and correlation test. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of mammography for detection of breast cancer were 87.5%, 56.3%, 75.0%, and 75.0% respectively. 45 cases of 80 patients were suspicious for breast cancer under the Tc-99m MIBI scintimammography. 41 cases of 45 patients were confirmed as breast cancer and the remaining 4 cases were confirmed as benign masses. The sensitivity, specificity, positive predictive value and negative predictive value of Tc-99m MIBI scintimammography for detection of breast cancer were 85.4%, 87.5%, 91.1%, and 80.8% respectively. The sensitivity of scintimammography was lower than that of mammography for detection of breast cancer, however the specificity, positive predictive value, and negative predictive value were higher. In the benign mass, the mean T/B ratio in 10 minutes was 1.409 +/- 0.30, and that in 2 hours was 1.267 +/- 0.42. The maximal T/B ratio of benign mass in 10 minutes was 1.604 +/- 0.42, and that in 2 hours was 1.476 +/- 0.50. In the malignant mass, the mean T/B ratio in 10 minutes was 2.220 +/- 1.07, and that in 2 hours was 1.842 +/- 0.75. The maximal T/B ratio of malignant mass was 2.993 +/- 1.94, and that in 2 hours was 2.480 +/- 1.34. And the T/B ratio under the early and delayed images were meaningful. CONCLUSION: The scintimammography is useful diagnostic tool to differentiate breast cancer from benign mass, although the sensitivity of mammography for detection of breast mass is high. Especially, the use of the T/B ratio is helpful to diagnose breast cancer.

Evaluation of Patients with Rheumatoid Arthritis by Tc-99m MIBI Imaging / 대한핵의학회잡지

PURPOSE: We investigated whether Tc-99m MIBI imaging is useful to predict the response of drug treatment in patients with rheumatoid arthritis. MATERIALS AND METHODS: 24 patients (15 women and 9 men, age 49 +/- 12 year) rheumatoid arthritis and treated with disease modifying antirheumatic drugs (DMARDs) were included in this study. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured, and Tc-99m MIBI scan was obtained before drug treatment. Quantitative analysis of uptake in diseased joints was performed and expressed as joint-to background ratio (J/B) and percent retention (%R) of Tc-99m MIBI. Clinical symptoms were evaluated and graded from 0 (no) to 3 (severe) regarding to presence of tenderness and swelling. RESULTS: J/B of the diseased joints were significantly correlated with ESR and CRP (p< 0.05). A highly significant correlation was found between the improvement of clinical symptoms and %R of Tc-99m MIBI (p< 0.05). CONCLUSION: The results demonstrate that Tc-99m MIBI scan may be used to predict the therapeutic response in patients with rheumatoid arthritis.

Fibrous Dysplasia Associated with Primary Hyperparathyroidism Absent of McCune-Albright Syndrome: Tc-99m MIBI and Tc-99m MDP Findings / 대한핵의학회잡지

No abstract available.

Tc-99m MIBI and Tl-201 Uptake in a Thymic Carcinoma / 대한핵의학회잡지

Tc-99m methoxyisobutylisonitrile (MIBI) and Tl-201/technetium subtraction scintigraphy have been used for localization of abnormal parathyroid gland. The uptake mechanism of tracers has been postulated to be increased cellular density and vascularity, or dependent on the presence of mitochondria-rich cells. However, the uptake of these tracers was not specific for abnormal parathyroid gland. The author report a case of thymic carcinoma that would have been mistaken for carcinoma of parathyroid because of Tc-99m MIBI and Tl-201 uptake.

Comparison of the Uptakes of Tc-99m MIBI and Tc-99m Tetrofosmin in A549, an MRP-expressing Cancer Cell, In Vitro and In Vivo / 대한핵의학회잡지

PURPOSE: Uptakes of Tc-99m MIBI (MIBI) and Tc-99m tetrofosmin (tetrofosmin) in human non-small cell lung cancer A549, multidrug-resistance associated protein (MRP) expressing cell, were investigated in vitro and in vivo. MATERIALS AND METHODS: Western blot analysis and immunohistochemistry were used for detection of MRP in A549 cells with anti-MRPr1 antibody. Cellular uptakes of two tracers were evaluated at 100 umM of verapamil (Vrp), 50 umM of cyclosporin A (CsA) and 25 umM of butoxysulfoximide (BSO) after incubation with MIBI and tetrofosmin for 30 and 60 min at 37degrees C, using single cell suspensions at 1x10 (6) cells/ml. Radioactivities in supernatants and pellets were measured with gamma well counter. A549 cells were inoculated in each flanks of 24 nude mice. Group 1 (Gr1) and Gr3 mice were treated with only MIBI or tetrofosmin, and Gr2 and Gr4 mice were treated with 70mg/kg of CsA i.p. for 1 hour before injection of 370KBq of MIBI or tetrofosmin. Mice were sacrificed at 10, 60 and 240 min. Radioactivities of organs and tumors were expressed as percentage injected dose per gram of tissue (%ID/gm). RESULTS: Western blot analysis of the A549 cells detected expression of MRPr1 (190 kDa) and immunohistochemical staining of tumor tissue for MRPr1 revealed brownish staining in cell membrane but not P-gp. Upon incubating A549 cells for 60 min with MIBI and tetrofosmin, cellular uptake of MIBI was higher than that of tetrofosmin. Coincubation with modulators resulted in an increase in cellular uptakes of MIBI and tetrofosmin. Percentage increase of MIBI was higher than that of tetrofosmin with Vrp by 623% and 427%, CsA by 753% and 629% and BSO by 219% and 140%, respectively. There was no significant difference in tumoral uptakes of MIBI and tetrofosmin between Gr1 and Gr3. Percentage increases in MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively higher by the time up to 240 min with CsA. CONCLUSION: These results indicate that MIBI and tetrofosmin are suitable tracers for imaging MRP-mediated drug resistance in A549 tumors. MIBI may be a better tracer than tetrofosmin for evaluating MRP reversal effect of modulators.

Comparison of Ga-67, Tl-201 and Tc-99m MIBI Imaging in Lymphoma Patients / 영남의대학술지

PURPOSE: Ga-67 scintigraphy has been used for the evaluation of tumors, especially lymphoma. Recently, Tl-201 and Tc-99m MIBI were also used to tumor imaging. Tl-201 and Tc-99m MIBI had better physiologic characteristics than Ga-67, so we studied 32 biopsy proven lymphoma patients (male 24, female 8, mean age 46 years) with Ga-67, Tl-201 or Tc-99m MIBI and compared the scan findings. MATERIALS AND METHODS: Twenty-three of 32 patients were injected 74-111 MBq (2-3 mCi) of Tl-201, before chemotherapy and imaged with dual-headed SPECT (Prism 2000, Picker, USA) at 30 minutes after injection. Delayed images were obtained after 3 hr in 8 patients. Twenty seven of 32 patients were injected 740 MBq (20 mCi) of Tc-99m MIBI and imaged at 30 minutes after injection. 111-185 MBq (3-5 mCi) of Ga-67 was injected in 12 patients and imaged at 48 and 72 hours after injection. Twenty eight patients were diagnosed as non-Hodgkin's lymphoma and others were Hodgkin's lymphoma. RESULTS: Twenty patients were positive on Tl-201 scan and 3 patients showed negative findings. One of these 3 patients, Tc-99m MIBI and Ga-67 scan were positive. Twenty two patients were positive on Tc-99m MIBI scan and 5 patients showed negative findings. One of these 5 patients, Tl-201 was positive and 2 were positive on Ga-67 scan. Ten of 12 patients showed positive findings on Ga-67 scan. The sensitivity of these agents were 83.3%, 87.0% and 81.5% for Ga-67, Tl-201 and Tc-99m MIBI, respectively. The sensitivity was highest in Tl-201 scan, but there were no significant differences among three tests. In this study, there was no significant difference of uptake ratios between early and delayed images of Tl-201. CONCLUSION: Scintigraphy with Tl-201 and Tc-99m MIBI in lymphoma patients have similar sensitivity with Ga-67.

Differentiation of Parathyroid and Thyroid Nodule by Tc-99m Sestamibi Scintigraphy / 대한내분비외과학회지

PURPOSE: Differentiation of parathyroid and thyroid nodule is often difficult even with aids of ultrasonography and computed tomography. Tc-9m sestamibi (MIBI) scintigraphy is useful in the detection of hyperfuntioning parathyroid nodules. However, its role in the differentiation between parathyroid and thyroid nodules including malignancies is not well studied. Therefore, the purpose of this study is to evlauate the role of Tc-99m MIBI imaing in the differentiation of parathyroid adenoma from thyroid malignancy. METHODS: Six patients (4 women, 2 men, mean age 43 years) with parathyroid adenoma and 4 patients (2 women, 2 men, mean age 56 years) with thyroid papillary cancer were enrolled. Ten and 180 minutes after injection of 740 MBq Tc-99m MIBI, pinhole image of the anterior neck was obtained. Nodule-to-thyroid ratio (N:T) was measured from same sized region of interests over nodule and normal thyroid bed. Retention Index (RI) was calculated as N:T 10 minus N:T 180 divided by N:T 10. RESULTS: as those with thyroid cancer (1.09 ± 0.35, 1.24 ± 0.36, respectively, P>0.05 ). However, RI of parathyroid patients was higher than thyroid cancer patients (0.64 ± 0.29, -0.12 ± 0.20, respectively, P<0.05). CONCLUSION: Parathyroid adenoma showed higher retention rate of Tc-99m MIBI than thyroid cancer. Therefore, differntiation of parathyroid and thyroid nodule could be possible using Tc-99m MIBI scintigraphy.

Diagnostic Role of Tc-99m MIBI Scintimammography in Suspected Breast Cancer Patients: Results of Unicenter Trial / 대한핵의학회잡지

PURPOSE: Tc-99m MIBI scintimammography has been validated as an useful non-invasive diagnostic tool for the primary breast cancer. But most studies have included small population of patients. We have experienced a large study population and investigated the diagnostie usefulness of Tc-99m MIBI scintimammography in detection of primary breast cancer and axillary Iymph node metastasis. MATERIALS AND METHODS: This study included 30S patients who underwent scintimammography for palpable breast masses or abnormal radiologic findings. Tc-99m MIRI scintirnammography was performed 10 minutes after intravenous injection of 925 MBq of Tc-99m MIBI. If the early image revealed abnormal finding, 3 hour delayed image was also acquired. We calculated early and delayed lesion to non-lesion ratios (L/N). The pathologic diagnosis was obtained from surgical operation or F.4AB and compared with the results of Tc-99m MIBI scintimammography. RESULTS: Malignant breast diseases were 155 and benign ones were 150. Tc-99m MIBI scintimammography revealed 132 true positive, 23 false negative, 10 false positive, and 140 true negative cases. The sensitivity, specificity, positive predictive value and negative predictive value for the primary breast cancer detection were 85.2%, 93.4%, 92.9%, and 85.9%, respectively. The sensitivity, specificity, positive predictive and negative predictive values of Tc-99m MIBI scintimammography in detecting metastatic axillary lymph node involvement were 22%, 90.4%, 61.9% and 62.3%, respectively. Early L/N of malignant breast disease was significantly higher than that of benign one (2,44+/-0.97 vs 1.94+/-0.78, p=0.01). Delayed L/N had no significant difference between malignant an

Comparison of Tc-99m-Tetrofosmin and Tc-99m-MIBI Scintimammography in Differential Diagnosis of Breast Mass / 대한핵의학회잡지

PURPOSE: Tc-99m-MIBI (MIBI) and Tc-99m-Tetrofosmin (TF) are commonly used for scintimammography (SMM). We compared the diagnostic ability of SMM using Tc-99m-MIBI and Tc-99m-TF for the differential diagnosis of breast mass. MATERIALS AND METHODS: The study subjects were comprised of 123 breast lesions and 86 normal breasts of 114 patients who underwent SMM. Bilateral prone images and anterior supine images were obtained at 5 minutes and 1 or 3 hours after intravenous injection of 740 MBq of either MIBI or TF. Sizes of tumors were not significantly different between the MIBI and TF groups. First, two observers independently read the SMM without clinical information (1st interpretation), then read again with information about mass location (2nd interpretation). Sensitivity and specificity of each radiopharmaceutical for the diagnosis of breast cancer were evaluated in terms of image acquisition time, tumor size, and location. RESULTS: The SMM showed a good agreement between two observers for 1st and 2nd interpretation, except for TF SMM at 3 hr. For the first interpretation, the sensitivities at 5 min, 1 hr, and 3 hr were not significantly different between MIBI and TF SMM (81.6%, 80.0%, 60.9% in MIBI vs. 88.9%, 80.6%, 42.9% in TF), although the senstivities of 3 hr images were significantly lower than 5 min images in both MIBI and TF SMM. The specificity of TF at 5 min was superior to that of MIBI (81.5%, 90.0%, 82.9% in MIBI vs. 96.7%, 100%, 90.0% in TF, p<0.01 MIBI vs. TF at 5 min). For the second interpretation with information of mass location, the sensitivities at 3 hr images were significantly lower than 5 min images (86.8%, 86.7%, 78.3% in MIBI vs. 88.9%, 93.5%, 57.1% in TF) between MIBI and TF SMM. However, there was no significant difference in the specificity (60.0%, 53.8%, 75.0% for MIBI vs. 86.7%, 100%, 100% for TF). MIBI and TF SMM showed lower sensitivities for the tumors with less than 1 cm than tumors with more than 1 cm. However, the location of tumors did not influence the sensitivity and specificity between MIBI and TF SMM. CONCLUSION: The ability for the differential diagnosis of breast tumor is similar between MIBI and TF SMM, and delayed image is not necessary. TF may be better than MIBI considering the specificity of SMM without clinical information and labeling convenience.

Reproducibility of an Automatic Quantitation of Regional Myocardial Wall Motion and Systolic Thickening on Gated Tc-99m-MIBI Myocardial SPECT / 대한핵의학회잡지

PURPOSE: The aim of this study is to investigate the reproducibility of the quantitative assessment of segmental wall motion and systolic thickening provided by an automatic quantitation algorithm. MATERIALS AND METHODS: Tc-99m-MIBI gated myocardial SPECT with dipyridamole stress was performed in 31 patients with known or suspected coronary artery disease (4 with single, 6 with two, 11 with triple vessel disease; ejection fraction 51+/-14%) twice consecutively in the same position. Myocardium was divided into 20 segments. Segmental wall motion and systolic thickening were calculated and expressed in mm and % increase respectively, using AutoQUANTTM software. The reproducibility of this quantitative measurement of wall motion and thickening was tested. RESULTS: Correlations between repeated measurements on consecutive gated SPECT were excellent for wall motion (r=0.95) and systolic thickening (r=0.88). On Bland-Altman analysis, two standard deviation was 2 mm for repeated measurement of segmental wall motion, and 20% for that of systolic thickening. The weighted kappa values of repeated measurements were 0.807 for wall motion and 0.708 for systolic thickening. Sex, perfusion, or segmental location had no influence on reproducibility. CONCLUSION: Segmental wall motion and systolic thickening quantified using AutoQUANTTM software on gated myocardial SPECT offers good reproducibility and is significantly different when the change is more than 2 mm for wall motion and more than 20% for systolic thickening.

Diagnostic Ability of Tc-99m MIBI SPECT in Coronary Artery Diseases is not Affected by the Degree of Exercise / 대한핵의학회잡지

PURPOSE: The sensitivity of ST-depression in the electrocardiogram during exercise is influenced by the level of efforts. However, unlike the prevalence of ST-depression on exercise ECG, the degree of exercise is reported to do not influence the diagnostic ability of myocardial perfusion scan. Furthermore, the relation between the prevalence of myocardial ischemia and effort is still controversial. We evaluated the effect of the degree of exercise on the ability of SPECT imaging to detect coronary artery stenosis. MATERIALS AND METHODS: The patient population was comprised of 111 patients (73 men and 38 women, mean age 56 years) who underwent an exercise test in conjunction with Tc-99m MIBI and cardiac catheterization within 3 months apart each other. The degree of exercies was classified into four groups according to the percentage of maximal predicted heart rate. The sensitivity and specificity was compared between each group. RESULTS: The overall diagnostic sensitivity was significantly higher with Tc-99m MIBI SPECT than exercise ECG. The specificity was not significantly different between two tests. Sensitivity and specificity of Tc-99m MIBI was not different between four groups. Sensitivity for individual coronary stenosis seemed to be lower in subjects who had premature termination of exercise due to early appearance of ST depression. CONCLUSION: These RESULTS suggest that the overall diagnostic sensitivity of Tc-99m MIBI myocardial perfusion SPECT is not significantly affected by the degree of exercise in stable patients undergoing symptom-limited treadmill exercise testing. Myocardial perfusion SPECT imaging should be added to routine exercise stress testing for the detection of coronary artery disease.

Diagnostic Accuracy of Quantitative Scintimammography Using Tc-99m MIBI According to ROC Curve Analysis for Breast Cancer

BACKGROUND: Technetium-99m sestamibi scintimammography (SMM) has been shown to be a useful diagnostic test in the detection of breast cancer, and the receiver operating characteristic (ROC) curve analysis provides detailed information about the diagnostic test. A ROC curve analysis was performed to evaluate the feasibility of Tc-99m sestamibi quantitative scintimammography (qSMM) for differentiating malignant from benign breast lesions. METHODS: Prone anterior, lateral planar, and supine SPECT imagings were performed on 75 female patients (mean age=43.4 yr) with breast masses (size> or =0.8 cm) after intravenous injection of 30 mCi of Tc-99m sestamibi. 45 malignant and 30 benign lesions were histologically proven. Three regions of interest (ROIs) were drawn over designated areas: lesion (L), normal breast opposite to the lesion (NL), and right chest wall (CW). L/NL and the L/CW ratios on both the SPECT and the planar images were analyzed. RESULTS: ROC curve analysis revealed that planar L/NL ratio and the SPECT L/NL and L/CW ratios provide better diagnostic accuracies for detecting breast cancer than the planar L/CW ratio did (p<0.05). From the qSMM (mean), which was an arithmetic mean of the planar L/NL, ratio the SPECT L/NL ratio and the SPECT L/CW ratio, the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy were 84%, 77%, 84%, 77%, and 81%, respectively. Presence of axillary lymph-node metastasis showed a higher qSMM (mean) value (4.09 {n=17} vs 3.09 {n=28}, p=0.06). CONCLUSIONS: qSMM (mean) is a useful objective method for differentiating malignant from benign breast lesions.

Comparison of Thallium-201, Tc-99m MIBI and I-131 Scan in the Follow-up Assessment after I-131 Ablative Therapy in Differentiated Thyroid Cancer / 대한핵의학회잡지

PURPOSE: We conducted a comparative study to evaluate the diagnostic values of Tl-201, Tc-99m MIBI and I-131 scans in the follow-up assessment after ablative I-131 therapy in differentiated thyroid cancer. MATERIALS AND METHODS: The study population consisted of 20 patients who underwent surgical removal of thyroid cancer and ablative radioactive iodine therapy, and followed by one or more times of I-131 retreatments (33 cases). In all patients, Tl-201, Tc-99m MIBI, diagnostic and therapeutic I-131 scans were performed and the RESULTS were analyzed retrospectively. Also serum thyroglobulin levels were measured in all patients. The final diagnosis of recurrent or metastatic thyroid cancer was determined by clinical, biochemical, radiologic and/or biopsy findings. RESULTS: Positive rates (PR) of Tc-99m MIBI, Tl-201, diagnostic and therapeutic I-131 scans in detecting malignant thyroid tissue lesions were 70% (19/27), 54% (15/28), 35% (17/48) and 63% (30/48), respectively. The PR in the group of 20 cases (28 lesions) who underwent concomitant Tl-201 and I-131 scans were in the order of therapeutic 131 scan 71%, Tl-201 scan 54% and diagnostic I-131 scan 36%. There was no statistically significant difference between Tl-201 and diagnostic I-131 scans (p>0.05). In the group of 20 cases (27 lesions) who underwent concomitant Tc-99m MIBI and I-131 scans, the PR were in the order of Tc-99m MIBI scan 70%, I-131 therapeutic scan 52% and I-131 diagnostic scan 33%. The PR of Tc-99m MIBI was significantly higher than that of diagnostic I-131 scan (p<0.05). CONCLUSION: Tc-99m MIBI scan is superior to diagnostic I-131 scan in detecting recurrent or metastatic thyroid cancer following ablation therapy in patients with differentiated thyroid cancer. Tl-201 scan did not showed significantly higher positive rate than diagnostic I-131 scan. Instead of diagnostic I-131 scan before the I-131 retreatment, Tc-99m MIBI scan without discontinuing thyroid hormone replacement would be a prudent and effective approach in the management of these patients.