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Biomedical subjects

S Kudo

Publications and source records attributed to S Kudo.

443 records · Page 25Linked to original sources
PubMedDate not supplied

Basilar artery fenestrations detected by MR angiography.

Basilar artery (BA) fenestrations are the most frequently observed fenestrations of the cerebral arteries. Our goal was to examine the magnetic resonance (MR) angiographic incidence, location, and characteristic configuration of BA fenestration. Between April 1996 and March 2000, 600 cranial MR angiographies were performed at our institution. The majority of the patients examined had or were suspected to have cerebrovascular disease. We retrospectively reviewed these 600 MR angiograms. A 1.5 Tesla scanner was used in all studies, and maximum intensity projection (MIP) images obtained using the three-dimensional time-of-flight (3D-TOF) technique were displayed stereoscopically. Ten BA fenestrations (1.7%) were detected on MR angiograms. In 87 cases from the early period, the vertebrobasilar (VB) junction was unfortunately not included in the imaging slices. Eight of the 10 fenestrations were located at the proximal BA: six of them were small with a slit-like shape, and two were relatively large with a convex-lens-like shape. A small fenestration was located at the distal BA, and the remaining one was a total duplication of the BA. We stress that knowledge and recognition of BA fenestration are useful and important in the interpretation of cranial MR angiography. Since saccular aneurysms are reported to arise frequently at BA fenestration, the VB junction should be included in the imaging slices of routine cranial MR angiography.

Basilar Artery↗
PubMedDate not supplied

Atypical arteriographic features of myositis ossificans circumscripta (MOC).

Earlier reports on the angiographic features of MOC concluded that there may be hypervascularity and tumor stain but no A-V shunting, pooling, or vessel amputation as a result of the lesion. However, our cases demonstrated A-V shunting in MOC, and showed that the vascularity of this lesion can closely mimic that of malignant neoplasms. Therefore, the possibility of MOC should not be excluded because of the presence of A-V shunts or "tumor vessels" in suspected MOC lesion on plain radiography. These points are underscored by the findings in two MOC patients, whose cases are described.

Adult↗
PubMedDate not supplied

Digital subtraction angiography for leg venography.

Venography was performed in 25 legs of 17 patients using digital subtraction angiography (DSA). Reliable diagnoses of deep vein thrombosis or patency were made in the majority of these cases. There were no complications. Multiple injections of contrast material were required to image the entire leg; however, the total quantity of iodine necessary for each leg averaged 9 g, significantly less than with conventional techniques. The preferred method consisted of injecting 15 ml of 100 mg iodine/ml contrast material followed by 15 ml of heparinized saline. DSA proved a safe and useful means of evaluating veins of the leg.

Aged↗
PubMedDate not supplied

Tracheobronchial calcification in members of a fixed population sample.

In a review of the chest radiographs of 1152 consecutively examined subjects, 10 cases (0.87%) of extensive tracheobronchial calcification were identified. In addition, 51 subjects having this coded diagnosis were identified among 11,758 members of a fixed population sample. Sixty of these 61 subjects were women. Tracheobronchial calcification usually appeared after the age of 60. The subjects' clinical and other radiologic diagnoses were reviewed and tracheobronchial calcification appeared to have no clinical significance. Histologic findings in autopsied cases showed the calcifications and ossifications to be in the cartilaginous rings themselves. However, the reason for the overwhelming prevalence of this entity in women remains to be resolved.

Adolescent↗
PubMedDate not supplied

Testicular malignant lymphoma; imaging and diagnosis.

The sonographic and magnetic resonance imaging findings of three cases of surgically proven malignant lymphoma of the testis were reviewed and their diagnostic implications were evaluated. In all three cases ultrasonography showed striated hypoechoic bands with paralleling hyperechoic lines radiating peripherally from the mediastinum testis. We believe they represented blood vessels. On T1-weighted MR images, the tumor showed homogenous hyperintensity in one case and homogenous isointensity in the other two. On T2-weighted images the tumor showed homogenous hypointensity in two cases and homogenous isointensity in one. After Gd-DTPA administration, the tumor showed homogenous enhancement in two cases and inhomogenous enhancement in one. In two cases there were enhancing striated bands in the tumor. Despite the diffuse infiltration by the tumor, the basic architecture of the testis, epididymis, and spermatic cord was preserved. When MRI and ultrasonography show an infiltrative disease preserving the basic architecture of the testis and ultrasonography presents hypoechoic bands radiating peripherally from the mediastinum testis, a diagnosis of malignant lymphoma should be considered.

Contrast Media↗
PubMedDate not supplied

MR imaging of idiopathic trigeminal neuralgia: correlation with non-surgical therapy.

Magnetic resonance (MR) findings in patients with idiopathic trigeminal neuralgia were evaluated and correlated with the effectiveness of non-surgical treatments. Thirty-four patients with idiopathic trigeminal neuralgia (ITN) were examined using T1- and T2-weighted spin-echo (SE) pulse sequence techniques to evaluate their trigeminal root-entry zones and the vessels contacted prior to non-surgical treatment (retrogasserian glycerol injection, peripheral nerve block, or only oral analgesics). Vascular contact at the proximal portion of the preganglionic segment (PGS) of the trigeminal nerve and deformity of the PGS on the affected side were observed in 97% and 47% of the patients, respectively. Non-surgical treatments were curative in 12 (67%) but failed in two (11%) of the 18 patients without deformed PGS. However, among 16 patients with deformed PGS, they were curative in only six (37.5%) and failed in four (25%). Results of this study suggest that MR imaging could be useful in the clinical assessment of trigeminal neuralgia prior to instituting non-surgical treatment.

Administration, Oral↗
PubMedDate not supplied

Computed radiography angiography using storage phosphor imaging plates: eight year's experience.

We reviewed the indications, modalities, and quality of angiographic examinations performed in our department from 1987 to 1994 and compared the image characteristics and technical convenience of three modalities: conventional film-screen angiography, fluorographic digital subtraction angiography (F-DSA), and computed radiography angiography using biplane rapid changers of storage phosphor imaging plates (IP-CRA). IP-CRA has practically eclipsed conventional film-screen angiography in our radiology department. Sixty-percent of the total 700 examinations carried out in 1994 were performed using a combination of IP-CRA and fluorographic digital subtraction angiography (F-DSA). The remainder were performed with F-DSA alone. The post-processing functions of IP-CRA like subtraction and change of contrast or density were useful especially in such regions as pulmonary, bronchial, or external carotid arterial territories, where high natural contrast made image processing difficult with both F-DSA and film-screen angiography. The spatial resolution of IP-CRA was superior to that of F-DSA and comparable to the film-screen method. It was concluded that angiography using imaging plates was a useful part of the digital radiography system.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Dural ectasia of the optic nerve sheath in neurofibromatosis type 1: MRI manifestations.

Patients with neurofibromatosis type 1 (NF-1) have an increased incidence of optic glioma. Although spinal dural ectasia or meningocele is well represented in the NF-1 literature, radiologists are not as familiar with dural ectasia of the optic nerve sheath as spinal dural ectasia. This is a report of a pediatric patient with NF-1 with dural ectasia of the optic nerve sheath. This is the second reported case of dural ectasia of the optic nerve sheath demonstrated by magnetic resonance imaging.

Cheek↗
PubMedDate not supplied

CT angiography using electron-beam computed tomography (EBCT): a phantom study.

The purpose of this study was to evaluate the accuracy of CT angiography in small vessels using electron-beam computed tomography (EBCT). Vessel phantoms with inner diameters of 8 mm, 6 mm, and 4 mm were prepared with segments of 75%, 50%, and 25% stenosis in each vessel. The vessels were filled with contrast medium (Iopamidol 300 at 1/24 dilution, approximately 380 HU). The EBCT apparatus used was an Imatron C- 150. The step volume scan mode was used with slice thicknesses of 1.5 mm and 3.0 mm, scan time of 0.3 sec, and 210 mm field of view. Images with a slice thickness of 1.5 mm were definitely better than those with a slice thickness of 3.0 mm. The quality of maximum intensity projection (MIP) images was quite similar to that of three-dimensional (3D) images. Using the 8 mm vessel phantom, all stenotic segments were accurately visualized on CT angiography. The 50% stenotic segments were accurately estimated in all vessels. However, the 75% stenotic segments were slightly overestimated in smaller vessels, and the 25% stenotic segments were slightly underestimated in smaller vessels. We consider CT angiography using EBCT to be a useful, less invasive diagnostic modality for stenoocclusive lesions.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Plain CT findings of brain death confirmed by hollow skull sign in brain perfusion SPECT.

Computed tomographic (CT) findings of 13 patients manifesting brain death were reviewed. This diagnosis was confirmed by the so-called "hollow skull" pattern observed in brain perfusion single photon emission computed tomography (SPECT), which was performed between 4 hours before and 3 days after the CT scans, and by subsequent corporal death. The brain perfusion SPECT was performed with the intravenous administration of technetium (Tc)-99m-hexamethylpropyleneamine oxime (HMPAO) or iodine (I)-123-N-isopropyl-p-iodoamphetamine (IMP). CT scans showed diffuse cerebral edema and the loss of gray-white matter differentiation in all the cases, and transtentorial herniation in 12 patients. These CT findings were considered predictive of brain death.

Adolescent↗