Different Uptake of Tc-99m ECD and Tc-99m HMPAO in the Normal Brains - Analysis by Statistical Parametric Mapping / 대한핵의학회잡지

No abstract available.

SPECT Imaging of Dopamine Transporter with I-123 IPT in Normal Controls and Parkinson's Patients

OBJECTIVES: Dopamine transporter concentrations have been known to decrease in Parkinson's disease(PD). The aim of the present study was to evaluate the correlation between SPECT measurements of [I-123]N-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl) tropane(IPT) as an imaging agent for measuring changes in transporter concentrations with PD. PATIENTS AND METHODS:IPT labelled with 4.87+/-1.29mCi(180.19+/-47.73 MBq) of [I-123] was intravenously injected into 23 patients(age:58+/-12) with PD and three normal controls(NC)(age:37+/-7) as bolus. Brain SPECT were then performed at 1 hour and 2 hours after injection on a double headed camera. The statistical parameters were the contrast ratio of left basal ganglia(BG) and right basal ganglia to occipital cortex(OCC) per milli curies of injected radiotracer at 1 hour and 2 hours. The correlations were evaluated between these parameters and Hoehn-Yahr classification of the patients. RESULTS: The(BG-OCC)/OCC/mCi ratios at 1 hour and 2 hours for PD and NC were 0.14+/-0.07 and 0.27+/-0.07(1 hour) and 0.12+/-0.07 and 0.34+/-0.04(2 hour), respectively. The(BG-OCC)/OCC/mCi ratios of Parkinson's disease were decreased with higher grade of Hoehn-Yahr classification of the patients. The ratio between BG and OCC for PD were clearly separated from NC and may be useful outcome measures for clinical diagnosis. CONCLUSION: The findings suggest that IPT may be a very useful tracer for early diagnosis and treatment of PD and study of dopamine re-uptake site.

Dynamic Salivary Gland Scintigraphy in Clinical Sicca Syndrome: Comparison with Static images / 대한핵의학회잡지

PURPOSE: In this study, we compared the quantitative characteristics of dynamic salivary gland scintigraphy with static scintigraphy in patients with clinical sicca syndrome using Tc-99m pertechnetate. MATERIALS AND METHODS: Fifty-two parotid glands and 52 submandibular glands out of 26 patients with clinical sicca syndrome were studied by dynamic and static salivary gland scintigraphy. Ten normal volunteers were also studied as a control group for comparison of scintigraphic parameters. Ten minutes after injection of 370 MBq Tc-99m pertechnetate, we obtained pre-stimulus static images for a few minutes. Then dynamic salivary gland scintigraphy with lemon juice stimulation was performed for 20 minutes. Finally we obtained post-stimulus static images after dynamic images. On dynamic study, functional parameters such as uptake rate, secretion rate and re-uptake rate were calculated. The results of dynamic study and static images were compared. RESULTS: On dynamic study, we could obtain functional parameters of salivary glands successfully. On dynamic study, 22 parotid glands and 22 submandibular glands out of each of 52 glands are abnormal. The static images demonstrated somewhat different results, of which reasons we could assume via dynamic study. CONCLUSION: Dynamic salivary gland scintigraphy using Tc-99m perechnetate were more functional than static images and might be useful in the assessment of the functional change of the salivary gland in patients with clinical sicca syndrome.

High Resolution MR Images from 3T Active-Shield Whole-Body MRI System

PURPOSE: Within a clinically acceptable time frame, we obtained the high resolution MR images of the human brain, knee, foot and wrist from 3T whole-body MRI system which was equipped with the world first 3T active shield magnet. MATERIALS AND METHODS: Spin echo (SE) and Fast Spin Echo (FSE) images were obtained from the human brain, knee, foot and wrist of normal subjects using a homemade birdcage and transverse electromagnetic (TEM) resonators operating in quadrature and tuned to 128 MHz. For acquisition of MR images of knee, foot and wrist, we employed a homemade saddle shaped RF coil. Typical common acquisition parameters were as follows: matrix= 512x512, field of view (FOV) = 20 cm, slice thickness = 3 mm, number of excitations (NEX) = 1. For T1-weighted MR images, we used TR= 500 ms, TE = 10 or 17.4 ms. For T2-weighted MR images, we used TR=4000 ms, TE = 108 ms. RESULTS: Signal to noise ratio (SNR) of 3T system was measured 2.7 times greater than that of prevalent 1.5T system. MR images obtained from 3T system revealed numerous small venous structures throughout the image plane and provided reasonable delineation between gray and white matter. CONCLUSION: The present results demonstrate that the MR images from 3T system could provide better diagnostic quality of resolution and sensitivity than those of 1.5T system. The elevated SNR observed in the 3T high field magnetic resonance imaging can be utilized to acquire images with a level of resolution approaching the microscopic structural level under in vivo conditions. These images represent a significant advance in our ability to examine small anatomical features with noninvasive imaging methods.

Disturbed Functional Asymmetry of Sensorimotor Cortex in Schizophrenia: A Study with Functional Magnetic Resonance Imaging

PURPOSE: The purpose of this study was to investigate the pattern of cerebral response to motor tasks in patients with schizophrenia compared with normal subjects using functional MRI. MATERIALS AND METHODS: Nine right handed-schizophrenic patients and six right-handed normal subjects were included. We used right hand movement as task. Series of 120 consecutive echo-planar images per section were acquired during three cycles of task and rest activations. Lateralization index of cortical response was measured and compared between patients and normal subjects. RESULTS: Right hand motor task was associated with greater activation in left sensorimotor cortex than the right in normal subjects. Schizophrenia patients showed relatively decreased activation in left cortex and increased activation in right cortex compared with normal subjects. In one patient, reversed lateralization was noted. CONCLUSION: Normal hemispheric asymmetry of cortical response to motor task was found in different pattern in schizophrenia. Our result is consistent with functional disturbance of motor circuitry in this disorder. Functional MRI will play an important role in diagnosis and research of this disorder.

Crossed Cerebellar Diaschisis : Comparison of SPECT, MRI, Clinical Sign

No abstract available.

Neuronal Dysfunction in Patients with Chronic Alcoholism Evaluated by In Vivo 1H Magnetic Resonance Spectroscopy

PURPOSE: With the use of localized, water-suppressed in vivo 1H magnetic resonance spectroscopy (MRS), we evaluated the proton metabolic alterations in patients with chronic alcoholism and healthy normal controls. MATERIALS AND METHODS: Patients with chronic alcoholism (N=10) and normal control subjects (N=10) underwent MRS examinations using a stimulated echo acquisition mode (STEAM) pulse sequence with 2X2X2 cm3 volume of interest (VOI) in the left cerebellum and basal ganglia. Proton metabolite ratios relative to creatine (Cr) were obtained using a Marquart algorithm. RESULTS: The specific feature in patients with chronic alcoholism was a significant decrease of N-acetylaspartate (NAA)/Cr ratio in the left cerebellum, compared with normal controls. No clear correlation of other metabolite ratios such as choline (Cho)/Cr and inositols (Ins)/Cr was established. CONCLUSION: Our preliminary study suggests that the reduction of NAA/Cr ratio may indicate neuronal loss in patients with chronic alcoholism. Thus, in vivo 1H MRS may be a useful modality in the clinical evaluation of patients with chronic alcoholism based on the proton metabolite ratios.

The Comparison of Susceptibility Changes in 1.5T and 3.0T MRIs due to TE Change in Functional MRI

PURPOSE: The purpose of this study was to find the optimum TE value for enhancing T2* weighting effect and minimizing the SNR degradation and to compare the BOLD effects according to the changes of TE in 1.5T and 3.0T MRI systems. MATERIALS AND METHODS: Healthy normal volunteers (eight males and two females with 24-38 years old) participated in this study. Each volunteer was asked to perform a simple finger-tapping task (sequential opposition of thumb to each of the other four fingers) with right hand with a mean frequency of about 2Hz. The stimulus was initially off for 3 images and was then alternatively switched on and off for 2 cycles of 6 images. Images were acquired on the 1.5T and 3.0T MRI with the FLASH (fast low-angle shot) pulse sequence (TR : 100ms, FA : 20degrees, FOV : 230mm) that was used with 26, 36, 46, 56, 66, 76ms of TE times in 1.5T and 16, 26, 36, 46, 56, 66ms of TE in 3.0T MRI system. After the completion of scan, MR images were transferred into a PC and processed with a home-made analysis program based on the correlation coefficient method with the threshold value of 0.45. To search for the optimum TE value in fMRI, the difference between the activation and the rest by the susceptibility change for each TE was used in 1.5T and 3.0T respectively. In addition, the functional T2* map was calculated to quantify susceptibility change. RESULTS: The calculated optimum TE for fMRI was 61.89+/-2.68 at 1.5T and 47.64+/-13.34 at 3.0T. The maximum percentage of signal intensity change due to the susceptibility effect in activation region was 3.36% at TE 66ms in 1.5T and 10.05% at TE 46ms in 3.0T, respectively. The signal intensity change of 3.0T was about 3 times bigger than that of 1.5T. The calculated optimum TE value was consistent with TE values which were obtained from the maximum signal change for each TE. CONCLUSION: In this study, the 3.0T MRI was clearly more sensitive, about three times bigger than the 1.5T in detecting the susceptibility due to the deoxyhemoglobin level change in the functional MR imaging. So the 3.0T fMRI is more useful than 1.5T.

Evaluation of Severity in Aplastic Anemia by MR Imaging

PURPOSE: To evaluate the role of bone marrow (BM) magnetic resonance(MR) imaging for assessment of theseverity of aplastic anemia (AA). MATERIALS AND METHODS: Eighty patients with AA, ranging in age from 16 to 44years underwent MR imaging. Fifty four patients had clinically severe AA (SAA),while in 26 the condition wasmoderate(MAA). Sagittal T1-weighted images (T1WI) and short tau inversion recovery(STIR) images of lumbarvertebral BM were analysed. Bulk T1, T2 and rho values (msec) were also measured, with mixed sequences. Signalintensity (SI) on both T1WI and STIR was classified into four patterns according to the amount of fatty marrow :pattern I, homogeneous fatty marrow ; II, fatty marrow with focal cellular nodules ; III, mixed fatty and cellularmarrow ; IV, cellular marrow with focal fatty nodules. These SI patterns and bulk T1, T2 and rho values of thelumbar BM were compared with the clinical severity of AA. RESULTS: On both T1WI & STIR sequences, MR imaging oflumbar vertebral BM in patients with AA showed various SI patterns. Pattern I, II and III were much frequently seenin the SAA group (48 of 54 patients on T1WI and 43 of 54 on STIR) and pattern IV was common in the MAA group (16of 26 patients on T1WI and 18 of 26 on STIR). The SI patterns of AA seen on both T1WI and STIR sequences closelycorrelated with clinical severity (x2 test, p = 0.0001). Bulk T1 value was significantly different between SAA andMAA ( SAA : 382.82 msec +/- 113.91; MAA: 517.99 msec +/- 151.92 ; t test , p = 0.0001). CONCLUSION: The SI patternseen on MR imaging, and T1 relaxation time of lumbar spinal BM can be useful for assessing the severity of AA.

A Case of Muscular Sarcoidosis diagnosed by Gallium-67 Scintigraphy and Magnetic Resonance Imaging / 대한핵의학회잡지

Gallium-67 scintigraphy is helpful in the assessment of active extrapulmonary sarcoidosis. Muscular involvement of sarcoidosis is often asymptomatic or nonspecific, and laboratory examinations do not provide convincing evidence of muscular involvement. We report a case of muscular sarcoidosis, which was detected by gallium-67 scintigraphy. In a patient who was suffering from fever and arthralgia of knee joint, gallium-67 scintigraphy showed mediastinal and hilar involvement of sarcoidosis with unexpected extensive muscular uptake. Magenetic resonance imaging revealed the detailed depiction of intramuscular infiltration of sarcoid granuloma. Gallium-67 scintigraphy is useful in detecting inflammatory muscular involvement of sarcoidosis as well as other multiorgan involvement.

Carcinoma of Ampulla of Vater: Emphasis on the CT Technique

PURPOSE: To demonstrate a CT technique by which carcinoma of the ampulla of Vater can be more accurately diagnosed, and to describe the radiologic findings this carcinoma. MATERIALS AND METHODS: We retrospectively reviewed CT findings in 26 patients with pathologically proven carcinoma of the ampulla of Vater. One additional cup of diluted oral contrast medium was ingested immediately before the scan. We analysed the difference in detection rate of the mass in the duodenal lumen with and without duodenal luminal opacification of gastrografin.We also evaluated the size and shape of the mass, dilatation of CBD and the pancreatic duct, and lymph node metastasis. In addition, we analyzed multimodality imaging findings ultrasonogram (US) : 13; hypotonic duodenogram (HTDG): 7; ERCP : 17) of carcinoma of the ampulla of Vater. RESULTS: Nodular soft tissue masses protruding into the duodenal lumen were identified in 21 of 26 cases. In 95% of cases (21/22) with favorable opacification and distension of the duodenum, masses were clearly identified on CT imaging. However, in four caseswith poor opacification and distension of the duodenum, masses could not be observed(P=0.000). The mass on CT scanshowed a well-defined margin, round or lobulated contour, and contrast enhancement similar to that of thepancreas. CBD dilatation was identified in 20 cases and pancreatic duct dilatation in 12. On US, protruding massesin the distal CBD were observed in nine of 13 cases(60%) and on HTDG, in six of seven cases(86%). as well-definedfilling defects. Conclusion : Since the accuracy of CT diagnosis of intestinal lesions is directly proportional tothe degree of intestinal distension and opacification with oral contrast, we believe that adequate ct techniquefor distending and opacitying the duodeual lumen are necessary for early diagnosis of carcinoma of the ampulla ofVater.