Evaluation of Optimal Combination of Commercially Available Superparamagnetic Iron Oxide Nanoparticles and Transfection Agents for Labelling of Human Mesenchymal Stem Cells

PURPOSE: To determine the optimal combination of commercially available superparamagnetic iron oxide (SPIO) nanoparticles with transfection agents (TA). MATERIALS AND METHODS: Protamine sulfate (Pro) and poly-L-lysin (PLL) were incubated with ferumoxide and ferucarbotran in human mesenchymal stem cells at various concentrations, and cellular viability were evaluated. Cellular iron uptake was qualitatively and quantitatively evaluated. Cell visibility was assessed via MR imaging and the T2-relaxation time was calculated. RESULTS: The cellular viabilities with ferucarbotran were more significantly decreased than those with ferumoxide (p < 0.05). Iron uptake with ferumoxide was significantly higher than that for those with with ferucarbotran. The T2-relaxation time was observed to be shorter with ferumoxide in comparison to those with ferucarbotran (p < 0.05). Ferumoxide at a concentration of 25 microg/ml in combination with either Pro or PLL at a concentration of 3.0 microg/ml did not adversely impact cell viability, maximized iron uptake, and exhibited a lower T2-relaxation time in comparison to other combinations. CONCLUSION: Stem cells with ferumoxide exhibited a higher cellular viability and iron uptake in comparison to ferucarbotran- treated stem cells. A 25 microg/ml of ferumoxide with a 3.0 microg/ml of TA is sufficient to label mesenchymal stem cells.

Histopathologic Findings Related to the Indeterminate or Inadequate Results of Fine-Needle Aspiration Biopsy and Correlation with Ultrasonographic Findings in Papillary Thyroid Carcinomas

OBJECTIVE: To determine histopathologic findings related to the indeterminate or inadequate result of fine-needle aspiration biopsy (FNAB) in papillary thyroid carcinomas (PTCs) and to correlate histopathological findings with ultrasonographic features of tumors. Materials and METHODS: We retrospectively reviewed the medical records of FNAB, histopathologic characteristics, and sonographic findings of the solid portion of 95 PTCs in 95 patients. All cases were pathologically confirmed by surgery. Histopathologic characteristics were analyzed for tumor distribution, microcystic changes, fibrosis, and tumor component. We assumed several histopathologic conditions to be the cause of indeterminate or inadequate results of FNAB, including: 1) an uneven tumor distribution, 2) > 30% microcystic changes, 3) > 30% fibrosis, and 4) < 30% tumor component. Ultrasonographic findings of each PTC were evaluated for echotexture (homogeneous or heterogeneous), echogenicity (markedly hypoechoic, hypoechoic, isoechoic, or hyperechoic), and volume of the nodule. We correlated histopathologic characteristics of the PTC with results of the FNAB and ultrasonographic findings. RESULTS: From 95 FNABs, 71 cases (74%) were confirmed with malignancy or suspicious malignancy (PTCs), 21 (22%) had indeterminate results (atypical cells), and three (4%) were negative for malignancy. None of the assumed variables influenced the diagnostic accuracy of FNAB. Tumor distribution and fibrosis were statistically correlated with ultrasonographic findings of the PTCs (p < 0.05). Uneven tumor distribution was related with small tumor volume, and fibrosis over 30% was correlated with homogeneous echotexture, markedly hypoechoic and hypoechoic echogenicity, and small tumor volume (p < 0.05). CONCLUSION: No histopathologic component was found to correlate with improper results of FNAB in PTCs. In contrast, two histopathologic characteristics, uneven distribution and fibrosis, were correlated with ultrasonographic findings.

Comparison between FDG Uptake and Pathologic or Immunohistochemical Parametersin Pre-operative PET/CT Scan of Patient with Primary Colorectal Cancer / 핵의학분자영상

PURPOSE: To evaluate the relationship between F-18 FDG uptake of tumor in PET/CT scan and pathological or immunohistochemial parameters of colorectal cancer. MATERIALS AND METHODS: 147 colorectal cancer patients who underwent both pre-operative F-18 FDG PET/CT scan and surgery were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The pathologic results such as site, size, depth of invasion (T stage), growth pattern, differentiation of primary tumor, lymph node metastasis and Dukes-Astler & Coller stage and immunohistochemical markers such as expression of EGFR, MLH1, MSH2 and Ki-67 index were reviewed. RESULTS: 146 out of 147 PET/CT scans with colorectal cancer showed perceptible focal FDG uptake. SUVmax showed mild positive linear correlation with size of primary tumor (r=0.277, p=0.001) and Ki-67 index (r=0.226, p=0.019). No significant difference in F-18 FDG uptake was found according to site, depth of invasion (T stage), growth pattern, differentiation of primary tumor, presence of lymph node metastasis, Dukes-Astler & Coller stage and expression of EGFR. CONCLUSION: The degree of F-18 FDG uptake in colorectal cancer was associated with the size and the degree of Ki-67 index of primary tumor. It could be thought that FDG uptake of primary tumor has a correlation with macroscopic and microscopic tumor growth.

Comparison of FDG Uptake with Pathological Parameters in the Well-differentiated Thyroid Cancer / 핵의학분자영상

PURPOSE: Differentiated thyroid cancer (DTC) has variable degree of F-18 FDG avidity. The purpose of this study was to evaluate the relationship between F-18 FDG uptake and pathological or immunohistochemical features of DTC. MATERIALS AND METHODS: DTC patients who underwent both pre-operative F-18 FDG PET/CT scan and surgery were included in the study. Maximum standardized uptake values (SUVmax) of primary tumor were calculated. If the primary tumor showed no perceptibly increased F-18 FDG uptake, region of interest was drawn based on finding of CT portion of the PET/CT images. Pathological and immunohistochemical markers such as presence of lymph node (LN) metastasis and underlying thyroiditis, tumor size, Ki-67 labeling index, expressions of EGFR, COX-2, and Galectin-3 were evaluated. RESULTS: Total of 106 patients was included (102 papillary carcinomas, 4 follicular carcinomas). The mean SUVmax of the large tumors (above 1 cm) was significantly higher than the mean SUVmax of small (equal to or less than 1 cm) ones (7.8+/-8.5 vs. 3.6+/-3.1, p=0.004). No significant difference in F-18 FDG uptake was found according to the presence or absence of LN metastasis and underlying thyroiditis, or the degree of Ki-67 labeling index, expression of EGFR, COX-2 and Galectin-3. CONCLUSION: In conclusion, the degree of F-18 FDG uptake in DTC was associated with the size of primary tumor. But there seem to be no relationship between F-18 FDG uptake of DTC and expression of Ki-67, EGFR, COX-2 and Galectin-3.

Comparison between FDG Uptake and Clinicopathologic and Immunohistochemical Parameters in Pre-operative PET/CT Scan of Primary Gastric Carcinoma / 핵의학분자영상

PURPOSE: The purpose of this study was to find out what clinicopathologic or immunohistochemical parameter that may affect FDG uptake of primary tumor in PET/CT scan of the gastric carcinoma patient. MATERIALS AND METHODS: Eighty-nine patients with stomach cancer who underwent pre-operative FDG PET/CT scans were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The clinicopathologic results such as depth of invasion (T stage), tumor size, lymph node metastasis, tumor differentiation and Lauren's classification and immunohistochemical markers such as Ki-67 index, expression of p53, EGFR, Cathepsin D, c-erb-B2 and COX-2 were reviewed. RESULTS: Nineteen out of 89 gastric carcinomas showed imperceptible FDG uptake on PET/CT images. In cases with perceptible FDG uptake in primary tumor, SUVmax was significantly higher in T2, T3 and T4 tumors than T1 tumors (5.8+/-3.1 vs. 3.7+/-2.1, p=0.002). SUVmax of large tumors (above or equal to 3 cm) was also significantly higher than SUVmax of small ones (less than 3 cm) (5.7+/-3.2 vs. 3.7+/-2.0, p=0.002). The intestinal types of gastric carcinomas according to Lauren showed higher FDG uptake compared to the non-intestinal types (5.4+/-2.8 vs. 3.7+/-1.3, p=0.003). SUVmax between p53 positive group and negative group was significantly different (6.0+/-2.8 vs. 4.4+/-3.0, p=0.035). No significant difference was found in presence of LN metastasis, tumor differentiation, Ki-67 index, and expression of EGFR, Cathepsin D, c-erb-B2 and COX-2. CONCLUSION: T stage of gastric carcinoma influenced the detectability of gastric cancer on FDG PET/CT scan. When gastric carcinoma was perceptible on PET/CT scan, T stage, size of primary tumor, Lauren's classification and p53 expression were related to degree of FDG uptake in primary tumor.

Role of 18F-fluorodeoxyglucose PET/CT in Recurrent Ovary Cancer / 핵의학분자영상

PURPOSE: To date, anatomical imaging modalities of the pelvis and tumor markers have been the mainstay of surveillance for recurrent ovary cancer. This study aimed to assess the role of 18F-FDG PET/CT in evaluation of ovary cancer recurrences, especially in comparison with enhanced CT and tumor marker CA 125. Materials and METHODS: 73 patients who had PET/CT scan for restaging of confirmed ovary cancer, and additional imaging with enhanced CT of the pelvis within one month were included. CA 125 level was available in all patients. From the PET/CT images, maximum standard uptake values (SUVmax) of suspected recurrence sites were recorded. Confirmation was available through re-operation or biopsy in 26 cases, and clinical assessment with series of follow-up images in 47. RESULTS: PET/CT had 93% sensitivity and 88% specificity for detecting recurrent ovary cancer. Enhanced CT of pelvis had sensitivity and specificity of 83% and 88%, and CA 125 50% and 95%. CONCLUSION: PET/CT has higher sensitivity for detecting recurrent ovary cancer compared to enhanced CT though the differences were not significant. PET/CT has significantly higher sensitivity than CA 125. However, the three tests all agreed in only 43% of the recurrence cases, and recurrence should be suspected when any of the tests, especially PET/CT, show positive findings.

Comparison of Prevalence of Visceral Obesity between Hemodialysis and Peritoneal Dialysis Patients / 대한신장학회지

PURPOSE: Visceral obesity is a more reliable indicator of cardiovascular risk factor than BMI. Our study was designed to compare the prevalence of visceral obesity in peritoneal dialysis (PD) patients to hemodialysis (HD) patients with abdominal fat CT in a single center. METHODS: In this cross sectional study, the result of abdominal fat CT of dialysis patients was investigated from January, 2007 to March, 2007 in Uijeongbu St. Mary s Hospital. To evaluate the risk factors related to visceral obesity, we analyzed patients medical records such as duration of dialysis, lipid profiles, anthropometric data and the presence of DM. RESULTS: We enrolled 65 HD patients and 67 PD patients. PD group had higher mean body weight, mean body mass index (BMI), and triglyceride level, compared to HD group. The PD group had higher visceral fat area, measured by abdominal fat CT than HD group. The prevalence of visceral obesity was higher in PD group than HD group. Visceral fat area showed positive co-relation with BMI in HD group, but did not in PD group. The age related prevalence of visceral obesity was significantly increased in the patients with older age group (>65). CONCLUSION: Our cross sectional study points to the fact that visceral obesity is more common in PD patients than HD patients. It is necessary to control weight and nutritional status, especially in PD patients for preventing metabolic complications.

Assessment of Cerebrovascular Reserve before and after STA-MCA Bypass Surgery by SPECT and SPM Analysis

OBJECTIVE: The purpose of this study was to objectively assess the efficacy of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery using Technetium (Tc)-99m-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients who underwent STA-MCA bypass surgery. MATERIALS AND METHODS: Brain perfusion SPECT images obtained at baseline and after the administration of acetazolamide were reconstructed using statistical parametric mapping in 23 patients, both before and after STA-MCA bypass surgery. The clinical outcomes of the surgery were also recorded and compared with the hemodynamic changes. A voxel with an uncorrected p-value of less than 0.001 was considered to be statistically significant. RESULTS: SPECT images of the territory supplied by the bypass graft showed an increase in both cerebrovascular flow and reserve at baseline, and the increase was significantly higher following the administration of acetazolamide. All patients showed improvement of clinical symptoms and increased blood flow to the left temporal, parietal, and frontal cortices as well as the thalamus. CONCLUSION: Brain SPECT effectively and objectively demonstrated the improved outcomes of STA-MCA bypass surgery, and thus may be used in postoperative analyses.

Sonographic Findings of Hashimoto's Thyroiditis and Associated Nodular Lesions

PURPOSE: To evaluate the sonographic findings of Hashimoto's thyroiditis and associated nodular lesions. MATERIALS and METHODS: We retrospectively reviewed the sonographic findings of twenty patients who had surgically confirmed Hashimoto's thyroiditis between 1 March 2005, and 26 November 2005. In these patients, we reviewed the sonographic findings of the associated focal nodular lesion. Assessed were size, homogeneity, and echogenicity of the diseased thyroid gland and shape, echogenicity, margin, rim, microcal cification of the associated nodules. Without knowledge of the pathological diagnosis of the nodular lesions, based on the sonographic criteria, the nodules were classified as either malignant or benign. RESULTS: Hashimoto's thyroiditis demonstrates a variety of sonographic findings for size, homogeneity, and echogenicity. Among the nineteen nodules that were sonographically diagnosed and pathologically confirmed, nine papillary cancers, seven nodular hyperplasias, two Huthle cell adenomas, and one focal hyalinized fibrosing nodule were included. All of the nine papillary cancers showed more than one malignant finding such as marked hypoechogenicity, an irregular shape, a taller than wide shape, a spiculated margin, or microcalcifications that were classified as malignant nodulea, and all of the ten benign nodules showed no malignant findings. Circumscribed isoechoic, hyperechoic, or hypoechoic nodules without calcification were classified as bending nodules. CONCLUSION: Hashimoto's thyroiditis demonstrates various findings on a sonographic examination,and associated various benign and malignant lesions. Moreover, a sonographic examination is helpful to differentiate between malignant and benign lesions in Hashimoto's thyroiditis as in the normal thyroid.

Effect of Repetitive Transcranial Magnetic Stimulation in Drug Resistant Depressed Patients / 핵의학분자영상

PURPOSE: Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. MATERIALS AND METHODS: Twelve patients with drug-resistant depression (7 male, 5 female; age range: 19~52 years; mean age: 29.3+/-9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected p<0.01, voxel=100). RESULTS: Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in: the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. CONCLUSION: Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant depressed patients.

Brain Abscess Uptake at Tl-201 Brain SPECT / 핵의학분자영상

A 22-year-old woman with a history of acute lymphoblastic leukemia was hospitalized for headache and vomiting. CT scan showed a well-defined, ring like enhancing mass in the left frontal lobe with surrounding edema and midline shift. Magnetic resonance imaging demonstrated a round homogeneous mass with a ring of enhancement in the left frontal lobe. Tl-201 brain SPECT showed increased focal uptake coinciding with the CT and MRI abnormality. Aspiration of the lesion performed through a burr hole yielded many neutrophils, a few lymphocytes and histiocytes with some strands of filamentous microorganism-like material. Modified AFB stained negative for norcardia. Gram stain showed a few white blood cells and no microorganism. Antibiotics were started and produced a good clinical response. After one month, CT scan showed markedly reduction in size and extent was observed.

Transient Diffuse Hepatic Uptake of 99mTc-MDP after Hepatitis B Vaccination / 핵의학분자영상

A 38-year-old female with arthralgia in right elbow joint for 6 months was referred for a bone scan which showed diffuse uptakes of 99mTc-MDP in the liver and spleen without hepatosplenomegaly. She had a history of hepatitis B vaccination 3 days ago. These uptakes were disappeared on the follow-up bone scan after 4 months. We suggest this transient diffuse hepatic uptake after vaccination of hepatitis B might be due to aluminum component within the hepatitis B vaccine as adjuvant.

Determination of Appropriate Sampling Frequency and Time of Multiple Blood Sampling Dual Exponential Method with 99mTc-DTPA for Calculating GFR / 핵의학분자영상

PURPOSE: To determine appropriate sampling frequency and time of multiple blood sampling dual exponential method with 99mTc-DTPA for calculating glomerular filtration rate (GFR). MATERIALS AND METHODS: Thirty four patients were included in this study. Three mCi of 99mTc-DTPA was intravenously injected and blood sampling at 9 different times, 5ml each, were done. Using the radioactivity of serum, measured by gamma counter, the GFR was calculated using dual exponential method and corrected with the body surface area. Using spontaneously chosen 2 data points of serum radioactivity, 15 collections of 2-sample GFR were calculated. And 10 collections of 3-sample GFR and 12 collections of 4-sample GFR were also calculated. Using the 9-sample GFR as a reference value, degree of agreement was analyzed with Kendall's tau correlation coefficients, mean difference and standard deviation. RESULTS: Although some of the 2-sample GFR showed high correlation coefficient, over or underestimation had evolved as the renal function change. The 10-120-240 min 3-sample GFR showed a high correlation coefficient (tau=0.93), minimal difference (Mean+/-SD=-1.784+/-3.972), and no over or underestimation as the renal function changed. The 4-sample GFR showed no better accuracy than the 3-sample GFR. CONCLUSIONS: In the wide spectrum of renal function, the 10-120-240 min 3-sample GFR could be the best choice for estimating the patients' renal function.

Usefulness of 18F-FDG PET/CT in the Diagnosis of Cervical Lymph Node Metastases of Head and Neck Cancer / 대한핵의학회잡지

PURPOSE: This study evaluated the diagnostic value of 18F-FDG PET/CT in detecting cervical lymph node metastases in head and neck cancer patients. MATERIALS AND METHODS: The patients were divided into two groups, 46 patients underwent PET/CT scan for initial staging before surgery, and 20 patients for restaging of recurrence after primary treatment. Increased FDG uptakes in cervical lymph nodes were evaluated retrospectively and correlated with the histopathologic results. RESULTS: In the initial staging group, 21 lymph nodes were detected by PET/CT in 15 patients. 20 lymph nodes were confirmed as metastases with a mean peak SUV of 5.84, and the remaining one lymph node was an inflammatory lesion, with a peak SUV of 2.75. Seven metastatic lymph nodes were reported only by histopathology. The sensitivity, specificity, positive predictive value and negative predictive value were 74.0%, 99.6%, 95.2% and 97.3%, respectively. In the recurrence group, 11 lymph nodes were detected in 9 patients, and 8 nodes were true positive, with a mean peak SUV of 5.65. The other three were inflammatous lymph nodes, and the peak SUVs were 2.16, 2.94 and 3.53. One false negative lymph node was reported. The sensitivity, specificity, positive predictive value and negative predictive value were 88.8%, 97.7%, 72.7% and 92.9%, respectively. CONCLUSIONS: FDG-PET/CT shows higher positive predictive value in the initial staging group, and better sensitivity in the recurrence group. Therefore PET/CT could be useful for both initial staging and restaging of recurrent cervical lymph node metastases.

Incidental Visualization of Hepatic Hemangioma by Tc-99m-HDP Bone Scan / 대한핵의학회잡지

Hepatic hemangioma is the most common benign liver tumor and must be considered in the differential diagnosis of other space occupying hepatic masses. A 54-year-old man was referred to evaluate bone metastases of lung adenocarcinoma. In our case, we thought that a focal hepatic uptake in the bone scan was a metastatic lesion, because of underlying lung adenocarcinoma. However, the findings of abdominal CT and Tc-99m RBC scan results were deemed to be characteristic of hepatic hemangioma. The biopsy of the lesion was not performed.

Osteoporotic Vertebral Fractures: SPECT findings / 대한핵의학회잡지

PURPOSE: The purpose of this study was to evaluate the usefulness of single photon emission computed tomography (SPECT) of bone using Tc-99m MDP in the diagnosis of osteoporotic vertebral fractures. MATERIALS AND METHODS: Thirty two patients with osteoporotic vertebral fracture were included in this study (mean age: 67 +/- 8, male: 5, female: 27). Seventy nine vertebral fractures were detected (38 thoracic/thoracolumbar lesions and 41 lumbar lesions), which were classified by type of deformity (wedge, biconcave or compression). The patterns and locations of increased uptakes were examined and analyzed. RESULTS: Forty seven wedge fractures, 20 biconcave fractures and 12 compression fractures were found. Diffuse and asymmetric uptakes were common in fractured bodies. More than one uptake were examined in 69 posterior elements of fractured vertebrae (87.3%) including 40 of 47 wedge fractures (85.1%), 17 of 20 biconcave fractures (85.0%) and 12 of 12 compression fractures (100%). Wedge fractures were predominant fracture in thoracic/thoracolumbar spine whereas incidence of biconcave or compression type was similar to that of wedge fracture in lumbar spine (p=0.04). Spinous process uptake was more frequently seen in lumbar lesions than thoracic/thoracolumbar lesions (p=0.009). Facet joint uptake in biconcave fracture was more common in lumbar spine (92.3%) than thoracic/thoracolumbar spine (57.1%). Spinous process uptake in biconcave fracture was also more frequently detected in lumbar spine (p=0.043). CONCLUSION: Bone SPECT was useful in the evaluation of osteoporotic vertebral fracture, especially posterior elements of vertebrae.

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.

GFRs Measured by Gates' Method According to 5 Background Sites: Comparison with GFR Measured by I-125-Iothalamate Method / 대한핵의학회잡지

PURPOSE: The aim was to assess how the background site affects the Gates' glomerular filtration rate (GFR) measurement using Tc-99m-DTPA in correlation with GFR by I-125-iothalamate method. MATERIAL AND METHODS: The study populations were 63 adults with 39 men and 24 women aged from 20 to 59 yrs (mean = 37.9 yrs). The following five background regions of interest were used in measurement of GFR using Gates' method: 1) lower side of each kidney (subrenal), 2) around each kidney (circumferential), 3) upper side of each kidney (suprarenal), 4) lateral side of each kidney (lateral), 5) between the two kidneys (inter-renal). We also measured GFR using I-125-iothalamate in each subject. The two studies were separated by 1 to 3 weeks. The subjects were divided into two groups by renal depth. Group 1 with renal depth> or=7cm and group 2 with renal depth or=7cm. CONCLUSION: GFRs measured with Gates' method showed higher correlation with the GFR measured by I-125-iothalamate when the regions of interest were placed over the suprarenal and inter-renal backgrounds. And GFRs measured with Gates method showed statistically significant correlation with the GFR measured by I-125-iothalamate in the group with renal depth < 7cm.

99mTc-HDP Pinhole SPECT Findings of Foot Reflex Sympathetic Dystrophy: Radiographic and MRI Correlation and a Speculation about Subperiosteal Bone Resorption

Reflex sympathetic dystrophy (RSD) is a common rheumatic disorder manifesting painful swelling, discoloration, stiffening and atrophy of the skin. Radiographic alterations include small, spotty subperiosteal bone resorption (SBR) and diffuse porosis, and MR imaging shows bone and soft-tissue edema. The purposes of current investigation were to assess 99mTc HDP pinhole SPECT (pSPECT) findings of RSD, to correlate them with those of radiography and MRI and to speculate about causative mechanism of SBR which characterizes RSD. pSPECT was performed in five patients with RSD of the foot. pSPECT showed small, discrete, spotty hot areas in the subperiosteal zones of ankle bones in all five patients. Diffusely increased tracer uptake was seen in the retrocalcaneal surface where the calcaneal tendon inserts in two patients with atrophic RSD. pSPECT and radiographic correlation showed spotty hot areas, that reflect focally activated bone turnover, to closely match with SBR. Further correlation with MRI showed both spotty hot areas and SBR to coincide in location with the insertions of ligaments and tendons, onto which pulling strain is constantly exerted. In contrast, the disuse osteoporosis in unstrained bones did not show any more significantly increased tracer uptake than normal cancellous bones.

Predictive Factors of Renal Scarring in Children with Acute Urinary Tract Infection / 대한핵의학회잡지

PURPOSE: The purpose of this study was to evaluate the usefulness of 99mTc DMSA scintigraphy on the dignosis of a renal scar in children with urinary tract infections. MATERIALS AND METHODS: Eighty three patients were included in this study, who were diagnosed as the urinary tract infection on the basis of symptom, urinalysis and urine culture. 99mTc DMSA scintigraphy and voiding cystoureterography were performed within 7days before the treatment in all patients. We classified the scintigraphic findings as follows: 1; a large hypoactive upper or lower pole. 2; a small hypoactive area. 3; single defect resulting in localized deformity of the outlines. 4; deformed outlines in a small or normal sized kidney. 5; multiple defects. 6; diffuse hypoactive kidney without regional impairment. Follow-up scintigraphy was done at least 6 months after the initial study. When the abnormality on the initial scintigraphy was not completely resolved on the follow-up scan, the lesion was defined as containing a scar. RESULTS: One hundred and fifteen renal units of 166 units (69.3%) showed abnormal findings on the DMSA scintigraphy. 65 units (56.5%) was diagnosed as containing renal scars on follow-up scintigraphies. Incidences of renal scar among renal units showing pattern 3, 4 and 5 on the initial scan was 75%, 78% and 78%, respectively. Whereas many of renal units showing 1, 2 and 6 pattern were recovered (65%, 76%, 50%). Sensitivity, specificity and accuracy of pattern-based DMSA scintigraphic findings on the diagnosis of renal scar was 76.9%, 85.1% and 81.9%, respectively. VUR was significantly associated with the renal scar when the initial DMSA shows unrecoverable findings (pattern 3, 4, 5). Odds ratio of the renal scar in a kidney showing unrecoverable initial scintigraphic findings was 19.1. Odds ratio in a kidney with mild or moderate-to-severe VUR was 3.5 and 14.4 respectively. CONCLUSION: In the urinary tract infection, renal scar was significantly developed in a kidney showing unrecoverable findings on the initial DMSA scan and VUR on voiding cystoureterography.