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Shigeru Furui

Publications and source records attributed to Shigeru Furui.

At least 19 recordsLinked to original sources
PubMed2006

Brown tumor with fluid-fluid levels in a patient with primary hyperparathyroidism: radiological findings.

We report a case of a brown tumor with fluid-fluid levels in a patient with primary hyperparathyroidism. A 19-year-old woman presented with a 3-month history of pain in the left pubic region. The laboratory data showed elevated serum calcium and intact parathyroid hormone, confirming the diagnosis of primary hyperparathyroidism. Plain radiography and computed tomography (CT) showed an expansile lytic lesion of the superior ramus of the left pubis. The cortex was thinned. On magnetic resonance (MR) images, the lesion was solid and cystic. The solid area of the lesion showed heterogeneous low to intermediate signal intensity on T1-weighted images and heterogeneous low to high signal intensity on T2-weighted images. The cystic area showed several fluid-fluid levels on T2-weighted images. Dynamic contrast-enhanced MR images after administration of Gd-DTPA showed marked, early enhancement of the solid area of the lesion. A delayed image showed prolonged enhancement of the solid area and enhancement of the septa and walls of the cystic area. Histopathology of a biopsy specimen showed fibroblastic proliferation, abundant giant cells, and focal hemosiderin deposition, which supported the diagnosis of a brown tumor. After removing the parathyroid adenoma, the brown tumor regressed and became sclerotic on radiographs.

Adult↗
PubMed2006

Radiosensitive functional dye: clinical application for estimation of patient skin dose.

Institutional review board approval and informed patient consent were obtained. The purpose of the study was to prospectively evaluate the use of radiosensitive indicators to estimate patient entrance skin dose (ESD). Forty-six patients wore a jacket with 48 or 52 indicators adhered to the back during percutaneous coronary interventions; they had eight additional indicators on their upper arms. The patients' ESDs were calculated according to the change in color of the indicators. There were good correlations between the ESDs estimated by using color measurements performed with an optical instrument and those estimated at visual observation (P < .001) and between the ESDs estimated by using a thermoluminescent dosimeter and those estimated by using color measurements (P < .001). The radiosensitive indicator method seems to be useful for estimating ESDs and their distribution during percutaneous coronary intervention; however, visual observation is reliable for estimating doses of up to 5 Gy only. (c) RSNA, 2006.

Aged↗
PubMed2006

Accuracy of attenuation measurement of vascular wall in vitro on computed tomography angiography: Effect of wall thickness, density of contrast medium, and measurement point.

OBJECTIVES: We sought to assess the effects of measurement point, wall thickness, and intravascular density of contrast material on attenuation measurement of vascular wall. MATERIALS AND METHODS: We used vascular models (actual attenuation value of the wall: 83 HU) with wall thicknesses of 1.5, 1.0, or 0.5 mm, filled with contrast material of 254, 325, or 400 HU. The 9 vascular models were fixed in an oil-filled container and scanned with a 16-detector computed tomography. The wall attenuation values were measured at 1 point for 0.5-mm thickness models, 3 for 1.0-mm thickness models, and 5 for 1.5-mm thickness models with the same interval of 0.25 mm. Total 20 measurements were done for each point. RESULTS: For 1.0-mm and 1.5-mm thickness models, wall attenuation progressively increased as the measurement points approached the lumen (P < 0.0001). At all the measurement points for 0.5-mm and 1.0-mm thickness models and the 2 inner measurement points for 1.5-mm thickness models, the densities of contrast material affected the wall attenuations significantly (P < 0.0001). At the midportion for 1.5-mm thickness models, the wall attenuations were not affected by the densities of the contrast material (P = 0.6301), and were 65-68 HU. CONCLUSIONS: The effects of the intravascular density of contrast material, measurement point, and wall thickness should be considered in the attenuation measurement of the wall.

Angiography↗
PubMed2006

Accuracy and efficiency of left ventricular ejection fraction analysis, using multidetector row computed tomography: effect of image reconstruction window within cardiac phase, slice thickness, and interval of short-axis sections.

BACKGROUND: The aim of the present study was to assess the accuracy and efficiency of left ventricular ejection fraction (LVEF) analysis by multidetector row computed tomography (CT). METHODS AND RESULTS: The CT data of 21 patients were analyzed by semi-automated software on a workstation. In analysis of LVEF using systolic volumes in the 6 phases (30-55%), systolic images of 10% interval (35, 45, 55%) were underestimated with a mean measurement error of -0.4% and the standard error of the estimate (SEE) of 0.6%, compared with the LVEF using images of 5% interval. In analysis of LVEF using 3-slice thicknesses of axial images (1, 2, and 3 mm), and 3-slice numbers of short-axis sections (10 14, and 30 slices), there was no significant difference between the SEE of the intraobserver reproducibility and that of the analysis with 30 short-axis sections using axial images of 1-, 2- and 3-mm thickness, and that with 14 short-axis sections using axial images of 1- and 2-mm thickness. The mean analysis times were 96.9 s, 119.8 s, and 227.0 s for the analysis with 10, 14, and 30 short-axis sections, respectively. CONCLUSION: The proper selection of the reconstruction interval in the cardiac phase, the slice thickness of the axial images, and the number of short-axis sections reduces the analysis time, maintaining the accuracy of LVEF analysis. This will be acceptable for practical use at present, although more accurate analysis is preferable.

Adult↗
PubMed2006

Radiation exposure to patient's skin during percutaneous coronary intervention for various lesions, including chronic total occlusion.

BACKGROUND: Radiation skin injuries have been reported as a result of various procedures, so in the present study the patients' entrance skin dose (ESD) during percutaneous coronary intervention (PCI) was evaluated. METHODS AND RESULTS: ESDs were assessed during 97 procedures (13 for chronic total occlusion (CTO), 14 for multivessel stenoses, 22 for single-vessel multiple stenoses, and 48 for single stenosis). The patients wore jackets that had 48 or 52 radiosensitive indicators placed on the back during the PCI procedures, with 8 other indicators placed on both upper arms. After the procedure, the color of the indicators was analyzed with a color measuring instrument, and the patients' ESDs were calculated from the color difference of the indicators. The average maximum ESDs of the patients were 4.5 +/- 2.8 Gy (median: 4.6 Gy) for CTO, 2.3 +/- 0.7 Gy (median: 2.4 Gy) for multivessel stenoses, 1.8 +/- 1.0 Gy (median: 1.5 Gy) for single-vessel multiple stenoses, and 1.4 +/- 0.9 Gy (median: 1.2 Gy) for single stenosis. CONCLUSIONS: Skin injury can occur during PCI, especially for CTO, so it is important to estimate each patient's ESD and attempt to reduce it.

Aged↗
PubMed2005

Regional cerebral blood flow in a patient with Nasu-Hakola disease.

We report a functional neuroimaging study of a 43-year-old woman with Nasu-Hakola disease (NHD). Regional cerebral blood flow (rCBF) images were measured with technetium-99m ethyl cysteinate dimer single photon emission computed tomography (SPECT). rCBF was decreased in the bilateral frontal lobes and thalamus. This finding was consistent with the known underlying neuropathology in patients with NHD. Brain SPECT is useful for demonstrating the pathophysiologic brain region in patients with NHD.

Adult↗
PubMed2005

Evaluation of coronary stents in vitro with CT angiography: effect of stent diameter, convolution kernel, and vessel orientation to the z-axis.

BACKGROUND: The aims of the present study were to assess the effect of the stent diameter, convolution kernel, and vessel orientation to the z-axis on the evaluation of coronary stents, in vitro with computed tomography (CT) angiography. METHODS AND RESULTS: Seven vascular models (2 models without stenosis, 2 with obstruction, and 3 with stenosis) with an approximate inner diameter of 3 or 4 mm, filled with contrast material (79 or 330 HU) were scanned with a 16-detector CT. The diameter measurement of the stent lumen and stenosis evaluation were both done in an orientation parallel to the z-axis of the scanner using 4 convolution kernels. The measured diameters of the stented lumen were 47-57% and 36-45% smaller than the actual inner diameter of the 3- and 4-mm diameter models, respectively. The diameter measurement of the stent lumen and visualization of the in-stent stenosis were improved by using convolution kernels with higher spatial resolution. The in-stent artifacts were evaluated in 4 orientations (0 degrees , 30 degrees , 60 degrees , 90 degrees ) to the z-axis. The artifact was the minimum in 0 degrees to the z-axis, and the maximum in 90 degrees . CONCLUSION: Visualization of the lumen of a stent by CT is affected by its diameter, convolution kernel, and vessel orientation to the z-axis, and these factors should be taken into consideration in the stent evaluation.

Angiography↗
PubMed2005

Radiation dose to patients and radiologists during transcatheter arterial embolization: comparison of a digital flat-panel system and conventional unit.

OBJECTIVE: The objective of our study was to evaluate the exposure doses to patients and radiologists during transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) using a new angiographic unit with a digital flat-panel system. SUBJECTS AND METHODS: Doses were assessed for 24 procedures: 12 using a new unit with a digital flat-panel system and 12 using a conventional unit. Doses to patients' skin were evaluated with thermoluminescent dosimeters behind the left, middle, and right portions of the liver. The doses to the radiologists were measured by an electronic personal dosimeter placed on the chest outside a lead protector. The maximal skin doses to the patients and the dose equivalents, Hp(0.07), to the radiologists were compared between the two procedure groups with each angiographic unit. RESULTS: For procedures with the new unit, the mean maximal skin dose to the patients was 284 +/- 127 (SD) mGy (range, 130-467 mGy), and Hp(0.07) to the radiologists was 62.8 +/- 17.4 muSv. For procedures with the conventional unit, the maximal skin dose to the patients was 1,068 +/- 439 mGy (range, 510-1,882 mGy), and Hp(0.07) to the radiologists was 68.4 +/- 25.7 muSv. The maximal skin dose to the patients was significantly lower with the new unit than with the conventional unit (p < 0.0005). There was no significant difference in the Hp(0.07) to the radiologists between the two procedure groups. CONCLUSION: The new digital flat-panel system for angiographic imaging can reduce the radiation dose to patients' skin during TAE for HCC as compared with the conventional system.

Carcinoma, Hepatocellular↗
PubMed2005

Accuracy of automated CT angiography measurement of vascular diameter in phantoms: effect of size of display field of view, density of contrast medium, and wall thickness.

OBJECTIVE: The objective of this study was to assess the effect of wall thickness, density of intravascular contrast material, and size of the display field of view on the accuracy of measurements of vascular diameter in phantoms yielded by automated software for CT angiography. MATERIALS AND METHODS: Vascular models with three wall thicknesses (1.0, 0.8, and 0.5 mm) and an inner diameter of approximately 4 mm were filled with contrast material of three different densities (198, 270, and 350 H) and scanned with helical CT. Three sizes of display field of view (10, 15, and 20 cm) were used. We evaluated the measurement error of the automated software, which was defined as the difference between the diameter measurement of the automated software and the true inner diameter of the vascular model. Statistical analysis involved three-way analysis of variance with repeated measures. RESULTS: There were significant differences in the measurement errors among the three wall thicknesses of the vascular model, three densities of intravascular contrast material, and three sizes of display field of view. The overall measurement errors progressively increased with larger sizes of display field of view (p < 0.01) and with lower densities of intravascular contrast material (p < 0.001). The measurement errors tended to progressively increase as the thickness of the wall of the vascular models increased. CONCLUSION: The accuracy of the diameter measurements by automated software for CT angiography was affected by the size of the display field of view, intravascular density of the contrast material, and wall thickness of the vessel. It is necessary to consider the effects of these factors on the diameter measurements of small arteries.

Angiography↗
PubMed2005

Usefulness of MR imaging in assessment of tumor extent of aggressive fibromatosis.

PURPOSE: We evaluated the usefulness of MR imaging for aggressive fibromatoses in order to determine tumor extent. MATERIALS AND METHODS: 17 lesions of 16 patients were examined with a 1.5-Tesla MR unit with unenhanced and gadolinium-enhanced T1WI, and T2WI. We retrospectively reviewed the MR features. RESULTS: The tumor had a smooth margin in 41% of cases, while an irregular margin was present in 59%. A low signal intensity band (LSB) followed a normal muscle tendon or fascia. LSBs were seen in all of the lesions with an irregular margin, but not in those with a smooth margin. LSB resembled thickened or uneven tendons. Five of the seven lesions with LSB had a positive surgical margin at the LSB on pathological feature, and they recurred. CONCLUSION: Detection of LSBs on MR images is important for the determination of tumor extent, which allows the surgical method to be decided and postoperative recurrence predicted.

Adolescent↗
PubMed2005

[Insufficiency fracture of the sacrum after hormonal therapy and radiotherapy for prostate cancer: A case in which 99mTc-MDP bone scintigraphy was useful for differential diagnosis].

A case in which radiotherapy was requested for bone metastases from prostate carcinoma after hormonal and radiation therapy and diagnosed as insufficiency fracture of the sacrum on bone scan was reported. A 78-year-old man underwent endocrine therapy with luteinizing hormone releasing hormone agonists and radical radiotherapy toward pelvis for prostate cancer. The onset of buttock pain started from the nine-month after the beginning of radiotherapy, and was diagnosed as sacrum metastasis by MRI, and radiotherapy was requested again for pain control. However, on bone scan, butterfly-like changed accumulation was noted, therefore sacrum insufficiency fracture was suspected. Addition of CT inspection and reconfirmation of MRI were performed, and bone metastases became negative, and serial observation was performed of the painkilling effect after that. No tumor marker rise was seen after five months without sigh of new bone metastases and the final diagnosis became insufficient fracture. In order to avoid unnecessary treatment, we think that the view of bone scintigram for diagnosis of sacrum insufficient fracture should be known.

Aged↗
PubMed2004

Measurement of vascular diameter in vitro by automated software for CT angiography: effects of inner diameter, density of contrast medium, and convolution kernel.

OBJECTIVE: This investigation was performed to evaluate the accuracy of diameter measurement of vessels in vitro by automated software for CT angiography. MATERIALS AND METHODS: Vascular models with three inner diameters ( approximately 3, 4, and 6 mm) filled with contrast medium of three different densities ( approximately 460, 350, and 210 H) were scanned with helical CT. Five convolution kernels (soft, standard, detail, bone, and lung) were used. We evaluated the measurement error, defined as the difference between the diameter measured by the automated software and the true inner diameter of the vascular model. Statistical analysis involved three-way analysis of variance with repeated measures. RESULTS: Significant differences occurred in measurement error among the three vascular model inner diameters, among the three densities of intravascular contrast medium, and among the five convolution kernels (p < 0.01). In all the convolution kernels except lung, measurement errors progressively decreased with higher densities of intravascular contrast medium (p < 0.01). In vascular models filled with contrast medium of 350 H, measurement errors were significantly smaller in soft (mean +/- standard deviation [SD], 0.29 +/- 0.16 mm) and bone (0.23 +/- 0.05 mm) than in other convolution kernels (p < 0.01). CONCLUSION: The accuracy of diameter measurement was affected by the vascular model inner diameter, the density of contrast medium, and the convolution kernel. A higher density of intravascular contrast medium and selection of the proper convolution kernel will improve accuracy.

Angiography↗
PubMed2004

[Accuracy of diameter measurement in vitro using automated software for CT angiography: effect of convolution kernels].

The purpose of this study was to evaluate the accuracy of diameter measurement in vitro using automated software for CT angiography with five convolution kernels. Vascular models with three diameters (about 3, 5, and 8 mm) in three materials (water, oil, and air) were scanned by helical CT. Five convolution kernels were used for reconstruction. The accuracy of diameter measurement was affected by the diameter of the vascular model, material around the model, and convolution kernels. Selection of the proper convolution kernels may improve accuracy.

Angiography↗
PubMed2003

The usefulness of 99mTc-hexamethylpropyleneamineoxime white blood cell scintigraphy in a patient with eosinophilic gastroenteritis.

White blood cell (WBC) 99mTc-hexamethylpropyleneamineoxime (HMPAO) scintigraphy was performed in a patient with eosinophilic gastroenteritis. WBC accumulation was detected in the terminal ileum to descending colon, and pathological studies demonstrated eosinophilic infiltration at the same region. 99mTc-HMPAO-WBC scintigraphy was proved to be a useful tool for the detection of eosinophilic infiltration in eosinophilic gastroenteritis.

Adult↗
PubMed2002

Optimum iodine concentration of contrast material through microcatheters: hydrodynamic analysis of experimental results.

It is important to increase the iodine delivery rate (I), that is the iodine concentration of the contrast material (C) x the flow rate of the contrast material (Q), through a catheter to obtain high quality arteriograms. The iodine delivery rate varies depending on the iodine concentration of the contrast material. The purpose of this study is to estimate the optimum iodine concentration (Copt) of contrast material (i.e. the iodine concentration at which I becomes maximum) through a microcatheter of a given length (L), inner diameter (D) and injection pressure (P). Iohexol, ioversol and iopamidol of 11-12 iodine concentrations (140-350, 160-350 or 160-370 mg cm(-3)) at 37 degrees C are used. I and Reynolds number (Re) of the flow of each contrast material through four microcatheters (0.49-0.68 mm in inner diameter, 1000-1500 mm in length) at injection pressures of 1.38, 2.76, 4.14 and 5.52 x 10(6) Pa (200, 400, 600 and 800 pounds per square inch) are obtained experimentally. The relationships between I and C and between I and Re are examined for each catheter and injection pressure. Copt is 160-280 mg cm(-3) for iohexol, 180-280 mg cm(-3) for ioversol and 200-300 mg cm(-3) for iopamidol. I becomes maximum when Re approximates the critical Reynolds number (Re approximately 2300). Utilizing this principle, we can estimate Copt and its flow rate through a microcatheter of a given L, D and P.

Angiography↗