Faculty Profiles - NAGANAWA, Shinji

Papers - NAGANAWA, Shinji

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Three-dimensional Fast spin echo MR of inner ear

American Journal of Neuroradiology Vol. 19 page： 739-741 1998

Interobserver agreement in sonographic diagnosis of breast tumors. Reviewed

Shimamoto K, Sawaki A, Ikede M, Satake H, Naganawa S, Tadokoro M, Isomura T, Hirota H, Ishigaki T

Eur J Ultrasound Vol. 8 ( 1 ) page： 25-31 1998

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: To evaluate interobserver agreement in the interpretation of breast ultrasonography. METHODS: 55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' final impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (kappa) values were employed. RESULTS: The kappa values of shape and posterior echoes were significantly higher than those of the other four criteria (P<0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher kappa values compared with more ambiguous cases (P<0.05). CONCLUSION: Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.Copyright 1998 Elsevier Science Ireland Ltd.

Three-dimensional fast spin-echo MR of the inner ear: ultra-long echo train length and half-Fourier technique.

Naganawa S, Itoh T, Fukatsu H, Ishigaki T, Nakashima T, Kassai Y, Miyazaki M, Takai H

AJNR Am J Neuroradiol Vol. 19 ( 4 ) page： 739-741 1998

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

We compared the image quality of the newly developed ultra-long echo train length (ETL) 3-D fast spin-echo (FSE) and half-Fourier technique, which is performed in less than 3 minutes, with the conventional 3D-FSE imaging technique, which takes 15 minutes, in assessing MR examinations of the inner ear. The new method's images were almost comparable to the conventional 3D-FSE images in depicting anatomic details and pathologic findings. Implementation of the ultra-long ETL and half-Fourier 3D-FSE imaging technique enables acquisition of inner ear MR studies in a vastly reduced time and with high spatial resolution without significant penalty, opening the possibility for low-cost screening of acoustic tumors without contrast enhancement in less than 3 minutes.

Screening helical CT for mass screening of lung cancer: application of low-dose and single-breath-hold scanning. Reviewed

Itoh S, Ikeda M, Isomura T, Endo T, Yamakawa K, Itoh K, Naganawa S, Maruyama K, Ishigaki T

Radiat Med Vol. 16 ( 2 ) page： 75-83 1998

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To investigate the usefulness of helical CT with low-dose and single-breath-hold scanning for lung cancer screening. MATERIALS AND METHODS: Twenty-four helical CT scans of the lung were performed using various parameters in 10 healthy volunteers. The effects of tube current and pitch were evaluated by assessment of image quality and detection of simulated nodules. Screening helical CT was performed at 120 kVp, 50 mA, 1 sec/rotation, 10 mm collimation, and a pitch of 2.0 in 110 patients. The ability of this method to detect nodules and masses, focal parenchymal opacities, and diffuse fibrotic changes was evaluated using conventional CT as the gold standard. RESULTS: A reduction in tube current to 50 mA did not significantly change the assessment of image quality or detection of simulated nodules. Although these factors were degraded by increasing the pitch, there was no significant difference between 1.5 and 2.0. Screening helical CT permitted the entire lung to be scanned with ease during a single-breath-hold in all patients. This method detected 177 of 196 nodules and masses (87 of 91 lesions greater than 5 mm in diameter), 54 of 57 focal parenchymal opacities, and 15 of 15 cases with fibrotic changes. CONCLUSION: Screening helical CT with low-dose and single-breath-hold scanning shows promise for lung cancer screening.

MR imaging of the inner ear: comparison of a three-dimensional fast spin-echo sequence with use of a dedicated quadrature-surface coil with a gadolinium-enhanced spoiled gradient-recalled sequence. Reviewed

Naganawa S, Ito T, Fukatsu H, Ishigaki T, Nakashima T, Ichinose N, Kassai Y, Miyazaki M

Radiology Vol. 208 ( 3 ) page： 679-685 1998

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To prospectively evaluate the sensitivity and specificity of magnetic resonance (MR) imaging in the inner ear with a long echo train, three-dimensional (3D), asymmetric Fourier-transform, fast spin-echo (SE) sequence with use of a dedicated quadrature-surface phased-array coil to detect vestibular schwannoma in the cerebellopontine angle and the internal auditory canal. MATERIALS AND METHODS: In 205 patients (410 ears) with ear symptoms, 1.5-T MR imaging was performed with unenhanced 3D asymmetric fast SE and gadolinium-enhanced 3D gradient-recalled (SPGR) sequences with use of a quadrature surface phased-array coil. The 3D asymmetric fast SE images were reviewed by two radiologists, with the gadolinium-enhanced 3D SPGR images used as the standard of reference. RESULTS: Nineteen lesions were detected in the 410 ears (diameter range, 2-30 mm; mean, 10.5 mm +/- 6.4 [standard deviation]; five lesions were smaller than 5 mm). With 3D asymmetric fast SE, sensitivity, specificity, and accuracy, respectively, were 100%, 99.5%, and 99.5% for observer 1 and 100%, 99.7%, and 99.8% for observer 2. CONCLUSION: The unenhanced 3D asymmetric fast SE sequence with a quadrature-surface phased-array coli allows the reliable detection of vestibular schwannoma in the cerebellopontine angle and internal auditory canal.

分岐型ステントグラフトを留置した腹部大動脈瘤の１例

岩井宏悦、石口恒男、鈴木耕次郎、新畑昌滋、長縄慎二、丸山邦弘、石垣武男、小林英昭、松下昌裕、櫻井恒久

映像情報メディカル Vol. 30 page： 753-755 1998

フェリデックス投与後のT1強調像が評価に有用であった2例

深津博、長縄慎二　岩山恵理子、石垣武男

映像情報メディカル Vol. 30 page： 1030-1032 1998

3D-fast spin echo法を用いた小脳橋角部のMR cisternography

映像情報メディカル Vol. 29 ( 6 ) page： 341-343 1997

Cerebral black blood MR angiography with the interleaved multi-slab three-dimensional fast spin echo sequence. Reviewed

Naganawa S, Ito T, Shimada H, Nagao R, Endo T, Uchiumi K, Ishigaki T

Radiat Med Vol. 15 ( 6 ) page： 385-388 1997

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

To overcome the disadvantages of conventional three-dimensional time-of-flight MR angiography (3D-TOF), such as saturation or intravoxel dephasing, black blood MR angiography (BB-MRA) using an interleaved multi-slab 3D fast spin echo sequence was developed and evaluated clinically. In major branches, the contrast-to-noise ratio of the flow was not as good as 3D-TOF in BB-MRA. However, in-plane slow flow and large aneurysm were visualized better on BB-MRA than on 3D-TOF. Furthermore, BB-MRA could provide wider coverage than 3D-TOF. BB-MRA using interleaved multi-slab 3D fast spin echo is now feasible and complementary to 3D-TOF.

著明な心、肺血管内進展を示した肺門部腫瘍の１例

河津省司、伊藤都紀子、加藤加代子、稲垣弘、長縄慎二、丸山邦弘、深津博、石口恒男、小林英敏、石垣武男、碓氷章彦、吉田光伸

映像情報メディカル Vol. 29 page： 1542-1545 1997

High speed and high resolution MR imaging og the inner ear asinng ultra-long echo train length 3D fast spin echo sequence and half Eonrier imaging

Proceedings of ISMRM page： 631 1996

MR imaging of the primary breast lymphoma

Breast Cancer Vol. 3 ( 3 ) page： 209-213 1996

従来型CT装置における造形剤投与法の腹部域での検討

映像情報メディカル Vol. 28 ( 3 ) page： 332-335 1996

High resolution T₂ weighted MR imaging of the inner ear using a long echo train length 3D fast spin echo sequence

European Radiology ( 6 ) page： 369-374 1996

MR lmaging of the Primary Breast Lymphoma: A Case Report. Reviewed

Naganawa S, Endo T, Aoyama H, Ichihara S

Breast Cancer Vol. 3 ( 3 ) page： 209-213 1996

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Recently magnetic resonance (MR) imaging has been investigated for the detection and differentiation of benign and malignant breast lesions. Dynamic scan using the contrast material has been shown to increase the specificity of breast MR imaging. Primary breast lymphoma (PBL) is a rare disease and its MR imaging finding has not been described before. We recently experienced a case of PBL that was demonstrated on MR imaging as an early enhancing mass similar to common carcinomas. Other imaging findings including sonography, mammography were also non-specific. Furthermore, lymphoma cells had spread beyond the early enhanced area. Thus the precise delineation of the tumor extent was impossible. However, features such as a quite unclear border on pre-contrast T2-weighted image, and increased uptake of gallium-67-citrate may allow diagnosis of such lesions as malignant lymphoma.

High-resolution T2-weighted MR imaging of the inner ear using a long echo-train-length 3D fast spin-echo sequence.

Naganawa S, Yamakawa K, Fukatsu H, Ishigaki T, Nakashima T, Sugimoto H, Aoki I, Miyazaki M, Takai H

Eur Radiol Vol. 6 ( 3 ) page： 369-374 1996

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

The purpose of this study was to assess the value of a long echo-train-length 3D fast spin-echo (3D-FSE) sequence in visualizing the inner ear structures. Ten normal ears and 50 patient ears were imaged on a 1.5T MR unit using a head coil. Axial high-resolution T2-weighted images of the inner ear and the internal auditory canal (IAC) were obtained in 15 min. In normal ears the reliability of the visualization for the inner ear structures was evaluated on original images and the targeted maximum intensity projection (MIP) images of the labyrinth. In ten normal ears, 3D surface display (3D) images were also created and compared with MIP images. On the original images the cochlear aqueduct, the vessels in the vicinity of the IAC, and more than three branches of the cranial nerves were visualized in the IAC in all the ears. The visibility of the endolympathic duct was 80%. On the MIP images the visibility of the three semicircular canals, anterior and posterior ampulla, and of more than two turns of the cochlea was 100%. The MIP images and 3D images were almost comparable. The visibility of the endolymphatic duct was 80% in normal ears and 0% in the affected ears of the patients with Meniere's disease (p < 0.01). In one patient ear a small intracanalicular tumor was depicted clearly. In conclusion, the long echo train length T2-weighted 3D-FSE sequence enables the detailed visualization of the tiny structures of the inner ear and the IAC within a clinically acceptable scan time. Furthermore, obtaining a high contrast between the soft/bony tissue and the cerebrospinal/endolymph/ perilymph fluid would be of significant value in the diagnosis of the pathologic conditions around the labyrinth and the IAC.

副乳腺に発生した乳癌の一例.

林崎理子、遠藤登喜子、長縄慎二、青山英昭、関谷正徳、長田和久、市原周.

映像情報メディカル Vol. 28 page： 735-738 1996

High resolution T-2 weighted image of the inner ear with 3D-Fast Spin echo sequence

European Radiology Vol. 5 ( Suppl ) page： 366 1995

Internal anotomy of the inner ear at MR imaging with a Long-Echo-Train-Length 3D,Fast SE sequence

Radiology Vol. 197 ( 9 ) page： 134-135 1995

Visualization of the internal anatomy of the inner ear using a long echo train length 3D fast spin echo sequence

Proceedings of SMR page： 230 1995

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Papers - NAGANAWA, Shinji