Comparison of 99mTc-tetrofosmin uptakes on planar images with those in excised rats organs.

UNLABELLED: The radioactivity in the organs adjacent to the heart causes interference with the quantitative assessment of myocardial uptake of tracer on scintigraphy. In order to investigate how much the functions of these organs affect myocardial uptake seen in imaging, we compared the myocardial uptake measured by means of a gamma camera with the actual activity in the excised organs. METHODS: Thirty-three rats were imaged at 5, 10, 15, 30, 45, 60, 90 and 120 min after the administration of 99mTc-tetrofosmin, and % injected dose per pixel (%ID/pixel) for each organ was assessed on planar images (PI measurement). Percent injected dose per gram of tissue (%ID/g) in the heart as well as lungs, liver, gastrointestines and blood was measured by means of a well scintillation counter (WC measurement). Comparison between PI and WC measurements was performed with % uptake, the PI-to-WC ratio and heart-to-organ ratios. RESULTS: Our WC measurement showed an increase in cardiac uptake until 30 min (1.67 +/- 0.31%) postinjection and subsequent gradual decrease, whereas PI measurement showed maximum activity of 1.81 +/- 0.52% at 15 min postinjection. There was a prominent difference between the two measurements, particularly at 10 min, with a PI/WC ratio of about 1.6 times. Our WC measurement showed maximum pulmonary uptake at 15 min (0.87 +/- 0.31%) and a gradual decrease over 15 min, whereas PI measurement showed maximum uptake at 10 min (1.14 +/- 0.38%). There was hardly any variation in activity observed later than at 10 min. Our WC measurement showed hardly any variance in hepatic activity from 5 min (0.77 +/- 0.19%) to 30 min (0.69 +/- 0.27%) with a subsequent gradual decrease. The percent uptake in PI measurement was generally greater than that in WC measurement, and high values were found at 10 min and 15 min with PI/WC ratios of about 3.3 times and 2.3 times, respectively. CONCLUSION: Percent uptakes in PI measurement were greater than those in WC measurement. The difference between the two measurements was prominent in the early phases. The cardiac uptake in PI measurement was significantly greater than that in WC measurement at 10 min. It was considered that this discrepancy between the two measurements was caused by the Compton scatter from the organs adjacent to the heart.

False aneurysm of the profunda femoris artery after total hip arthroplasty.

A false aneurysm of the profunda femoris artery occurred after metal-on-metal total hip arthroplasty in 70-year-old woman. At 39 days after the operation, the wound suddenly opened, and a large hematoma was discharged. Eleven tornade coils were inserted into the base of the false aneurysm, and the bleeding was arrested. The prevention and management of this complication are discussed.

New functional polar maps for estimating regional cardiac function using ECG-gated technetium-99m-tetrofosmin SPECT.

OBJECTIVE: The purpose of this work was to develop functional parameters to analyze regional cardiac function using ECG-gated 99mTc-tetrofosmin SPECT. Our goal was to develop a methodology that used slice thickness correction, the generation of a time-activity curve and a polar map. METHODS: Fourteen normal patients without evidence of coronary artery disease were studied. One hour after intravenous injection of 740-1110 MBq (20-30 mCi) 99mTc-tetrofosmin, ECG-gated SPECT data were acquired by dividing a cardiac cycle into 12 frames. The SPECT data were reconstructed from 11 of 12 frames into 3 views. The reconstruction of these images was repeated after performing slice thickness correction. Excluding the effect of different apex-to-base lengths at any frame during a cardiac cycle, 10 short-axis images with the same slice thickness were obtained. Each short-axis image was divided by 40 radii into 40 segments. The time-activity curve was generated from the total counts included in each segment plus both neighboring segments. Subsequently the curve fitting was performed using the second Fourier function. RESULTS: From fitted curves and their differentials, we calculated end-systolic count, end-diastolic count, percent count increase, uptake, peak contraction rate, peak distention rate and contraction time. CONCLUSION: The functional polar maps visually demonstrated regional myocardial function. This method is expected to be helpful for assessing regional cardiac function using 99mTc-tetrofosmin.

3D-CT stereoscopic imaging in maxillofacial surgery.

We obtained stereoscopic 3D-CT images in maxillofacial bone fracture patients. These images are made at two different angles. One is equivalent to the view obtained by a subciliary incision during surgery. Another is equivalent to the view obtained by oral incision during surgery. A stereoscopic image is created with a pair of images that differ from each other by a 6 degree shift of the z axis.

MR images of ovarian carcinosarcoma.

The MR imaging of an ovarian carcinosarcoma is described. The tumor was heterogeneous and showed very high-intensity on T2-weighted images and iso-intensity on T1-weighted images, with visible enhancement. Even though signal intensities were somewhat different from those of ovarian adenocarcinoma, the preoperative diagnosis of ovarian carcinosarcoma is still difficult.

[Clinical evaluation of MRCP].

Recently, MRCP can be obtained with good spacial resolution within a few seconds using half fourier fast spin echo technique. From July 1995 to August 1997, 1000 patients suspected of having pancreatobiliary diseases were examined with MRCP. MRCP was performed with 1.5 T scanner using Fast Asymmetric Spin Echo sequence (FASE). Satisfactory images of the main pancreatic duct were obtained in 98%, of Santorini's duct in 90%, and of uncinate process branch in 83%. Pancreas divism was accurately diagnosed. In the patients with pancreatic ductal adenocarcinomas, MRCP depicted stenosis and proximal dilatation of the main pancreatic duct in 89%, and in the remaining patients no abnormalities were seen in the main pancreatic ducts because tumors were limited to side branches or Santorini's duct or distal end of the tail of the pancreas. Diagnosis of small pancreatic carcinomas (smallest lesion measured 10 mm in diameter) were feasible. In the patients with intraductal papillary neoplasms, dilatation of the main pancreatic duct and cystic dilatation of side branches were depicted, and polypoid lesions were detectable with source images. In the patients with serous cystadenomas, accumulation of the microcysts were visualized. In the patients with chronic pancreatitis, dilatation and stenosis of the main pancreatic duct, as well as side branch dilatation was depicted despite overestimation of the extent of the stenosis. Stones in the main pancreatic duct were well visualized as intraductal filling defects. In conclusion, MRCP is an effective imaging technique in the diagnosis of various pancreatic diseases.

[Cystic lesions of the pancreas].

The number of the literature and classification of the cystic pancreatic diseases is increasing recently. We describe MR cholangiopancreatography (MRCP) findings of the cystic pancreatic diseases according to the clinical oriented classification. Intraductal papillary tumor, mucinous cystadenoma and serous cystadenoma showed characteristic MRCP findings. However small non-neoplastic true cysts are difficult to differentiate from cystic tumors even by MRCP.

[A modified method of cardiac functional analysis for ECG gated SPECT: study of functional G-maps].

To evaluate the cardiac function accurately using ECG gated SPECT images, we performed a modified method of cardiac functional analysis (Functional G-maps). One hour after the intravenous injection of 1,110 MBq of 99mTc-tetrofosmin, gated SPECT data was acquired dividing a cardiac cycle into 12 frames. Every short-axis images were usually reconstructed using first 11 of 12 frames. The reconstruction of these images was repeated performing slice thickness correction. Because the apex-to-base length is different at any frame during a cardiac cycle, 10 slices of short-axis images were obtained with the same thickness for each frame. Subsequently each short-axis image was divided by 40 radii, and the time activity curve was generated from the total counts included in each segment plus both neighboring segments. Afterwards the curve fitting was performed using the second reverse Fourier function. From fitted curves and their differentials, we estimated a variety of parameters including Max (End-systolic count), Min (End-diastolic count), %CI (Percent count increase), Uptake, PCR (Peak contraction rate), PDR (Peak distention rate) and CT (Contraction time). In 5 normal subjects, %Max was greater in the anterior and septal regions, whereas %Min was greater in the apex and lateral regions. %CI and %PCR were similarly greater in the septal, anterior and inferior regions. On the other hand, %PDR in the lateral or inferior region was lower than the values in the other regions. In conclusion, this modified method is expected to be useful for accurate assessment of regional cardiac function and myocardial perfusion.

[2D-FASE MRCP for pediatrics with congenital biliary dilatation: usefulness of non-breath-hold one-shot MRCP].

The usefulness of magnetic resonance cholangiopancreatography (MRCP) using the non-breath-hold one-shot technique was evaluated. Ten children suffering from congenital biliary dilatation (CBD) were included. Four of them were preoperative cases, and the remaining six postoperative. All MR images taken were compared with endoscopic retrograde cholangiopancreatography or intraoperative cholangiography. MR images using the non-breath-hold one-shot technique clearly showed the confluence of the common bile duct and the main pancreatic duct in seven of the cases. The confluence of the common bile duct and main pancreatic duct was obscure in the other three cases, mainly due to motion artifact. These results show that this non-breath-hold one-shot technique is useful for diagnosis and postoperative follow-up of congenital biliary dilatation in children.

Unilateral megalencephaly in linear nevus sebaceous syndrome: a neuroradiological case report.

We report a case of linear nevus sebaceous syndrome with seizure, mental retardation, and hemiparesis. Magnetic resonance imaging (MRI) clearly demonstrated associated brain malformations of unilateral megalencephaly with cortical dysplasia and white matter change ipsilateral to the sebaceous nevi of the face and neck. Although magnetic resonance angiography (MRA) demonstrated only distortion of the main cerebral arteries without any occlusive or dysplastic findings, single photon emission computed tomography (SPECT) using [123I]N-Isopropyl-p-iodoamphetamine (IMP) revealed hypoperfusion in the affected cerebral hemisphere.

[Applicability of the dual interval echo train (DIET) method for female pelvic diseases].

Dual interval echo train fast SE (DIET-FSE) is a modified fast SE technique. It attenuates fat signals by applying a time interval between an excitation pulse and the first echo, which is the odd-number of the following echo interval, and by decreasing the number of high frequency refocusing pulses before collecting echoes in the center of the k space, which determines the contrast. Unlike many other fat-suppression methods, this technique is less affected by susceptibility effects. In this study, we compared DIET-FSE with FSE and conventional SE of the female pelvis. The results of DIET-FSE showed a stable, obvious fat suppression effect which resulted in the easy detection of pelvic organs such as the intestines and ovaries, as compared with FSE. The reductions in imaging time and motion artifacts also permitted more precise differentiation between the normal pelvic organs and lesions than conventional T2-weighted SE. These results imply that the DIET-FSE is useful for the diagnosis of female pelvic disorders.

Vitamin D receptor alleles, bone mineral density and turnover in premenopausal Japanese women.

Recent studies have shown that genetic effects on bone mineral density (BMD) and bone turnover are related to allelic variation in the vitamin D receptor (VDR) gene. We examined allelic influences of the VDR gene on bone turnover and density in 202 normal healthy premenopausal Japanese women (age 30.1 +/- 1.2, mean +/- SEM). The VDR effect on BMD and turnover is similar to that observed in Caucasian women; however, there are major differences in allele frequency. The B allele by BsmI restriction fragment length polymorphisms (RFLPs), associated with low BMD and high bone turnover, is found in only 12% of Japanese women (1.4% homozygote BB), compared with 41% of Caucasians (16.7% homozygote BB). In comparing the two most frequent genotypes, Bb heterozygotes (21.5%) and bb homozygotes (77.1%), BMD is 5.3% lower in Bb heterozygotes, and levels of bone formation markers including osteocalcin and bone-specific alkaline phosphatase are 20-32% higher with lower serum calcium (2.30 +/- 0.02 vs 2.35 +/- 0.01 mmol/l) and higher 1,25-dihydroxyvitamin D (95 +/- 4.8 vs. 76 +/- 3.8 pmol/l). Further discrimination of the genotype was achieved using two additional RFLPs (ApaI, A and TaqI, T); the lumbar spine BMD of the common genotype BbAATt was 9.3% (0.94 SD) lower than in the bbaaTT genotype in premenopausal Japanese women. These data confirm that VDR RFLPs affect bone mineral metabolism regardless of racial differences. Moreover, the VDR genotypes based on haplotype analysis should yield useful insights into the potential prevention of osteoporosis.

Systemic arterial supply to normal basal segments of left lower lobe: CT findings.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of CT in making a diagnosis of systemic arterial supply to normal basal segments of the left lower lobe. MATERIALS AND METHODS: We retrospectively reviewed chest radiography (three cases), CT (three cases), and angiography (two cases). RESULTS: An anomalous systemic artery arising from the descending aorta was shown as a retrocardiac density on posteroanterior radiography and as a nodular density behind the heart on lateral radiography. Contrast enhanced CT revealed the vascular nature of the density adjacent to the descending aorta. Dynamic CT in one patient demonstrated that the nodular density was composed of an anomalous systemic artery and a prominent inferior pulmonary vein. High-resolution CT showed the interlobar artery distal to the origin of the superior segmental artery to be absent. The bronchial system of the left basal segments was normal as was the pulmonary parenchyma on CT. CONCLUSION: Characteristic CT findings consist of absence of the interlobar artery distal to the origin of the superior segmental artery and origination of an anomalous artery from the descending aorta that gives off branches to normal left basal segments. With a constellation of these CT findings, angiography would be obviated for definite diagnosis of this anomaly.

Retroperitoneal schwannomas simulating adrenal tumors.

Tumors in the area of the adrenal were detected by chance in two patients who underwent a regular physical check-up. On arteriography the tumors were found to be fed by the adrenal artery. The diagnosis was retroperitoneal schwannoma, but in both patients it was difficult to differentiate the schwannoma from an adrenal tumor preoperatively.

[Magnetic resonance imaging of the inner ear and its application to cochlear implant candidates].

Magnetic resonance (MR) images of normal and abnormal inner ears obtained with a 1.5T unit without the use of a surface coil were analyzed to evaluate the effectiveness of this method in the screening of cochlear implant candidates. In a series with sixteen normal adult volunteers, 22 to 45 years in age, 100% of the cochleae, vestibules, and lateral and posterior semicircular canals were clearly demonstrated in T2 weighted images. Satisfactory images were not obtained for 22% of the superior semicircular canals, 22% of the cochlear aqueduct, and 81% of the vestibular aqueduct in axial images, but coronal and sagittal reconstructed images by use of a three-dimensional Fourie transformation sequence provided better detectability of these structures. In five ear surgery patients with proven obliteration of the labyrinth, decreased signal intensity was observed in the T2 weighted images. Ten cochlear implant candidates were examined by MRI prior to implantation, and the results were compared with the surgical findings. In two ears in which the cochlea showed a decrease in signal intensity, the cochlea had been obliterated by inflammatory granulations. On the other hand, the lumens of all nine cochleae which were clearly visualized by MRI were found to be patent.

[Remission state and five-year survival after transcatheter arterial embolization therapy in patients with hepatocellular carcinoma].

Repeated transcatheter arterial embolization (TAE) therapy was done for 138 cases with hepatocellular carcinoma. Relationship was investigated between long term survival more than 3 years and tumor necrosis rate estimated on radiological images (superselective angiogram and/or computerized tomography) after therapy. Excellent tumor necrosis (radiological disappearance of viable tumor) was attained in 35 out of 138 cases through repeated TAE. When "remission" is defined as excellent tumor necrosis and normal alphafetoprotein value lasting for more than one year, remission state was attained in 17 cases (12.3%). Cumulative three-year survival rate was 37.0%, and 5-year survival was 26.5%. Out of 37 three-year-survivors, only 12 cases (32.4%) experienced remission state in their clinical course. On the other hand, 7 cases (77.7%) of 9 five-year-survivors experienced remission at least one time. Though good tumor necrosis and 3-year survival were achieved by only performing repeated TAE therapy, "remission" state was important and necessary to get 5-year survival.