Anorectal malignant melanoma: preoperative usefulness of magnetic resonance imaging.

Magnetic resonance imaging (MRI) findings in three patients with primary anorectal malignant melanoma are described. Two patients had melanotic and one had amelanotic anorectal melanoma. The findings of MRI with a pelvic coil and an endorectal coil were consistent with pathologic findings.

MRI diagnosis of mesorectal lymph node metastasis in patients with rectal carcinoma. what is the optimal criterion?

Background: Preoperative diagnosis of lymph node metastasis is often difficult. A number of different criteria have been advocated in the literature, however, an optimal criterion has not yet been determined in patients with rectal carcinoma.

Patients And Methods: Fifty-one patients, undergoing radical surgery with total mesorectal excision, were examined with reference to regional lymph node status.

Utility of cine MR urography of the urinary tract and comparison with static MR urography.

Purpose: MR urography using heavily T2-weighted images can depict the urinary tract without the need for contrast medium. However, this technique has potential problems with regard to evaluating the non-dilated ureter. We compared the efficacy of cine MR urography (C-MRU) with static MR urography (S-MRU).

Three-dimensional MR digital subtraction angiography using parallel imaging and keyhole data sampling in cerebrovascular diseases: initial experience.

We assessed the feasibility of MR digital subtraction angiography (DSA) using parallel imaging and keyhole data sampling in the diagnosis of cerebrovascular diseases (CVDs) in 11 patients. Their diseases included arterial trunk stenosis/occlusion ( n=4), aneurysm ( n=3), arteriovenous malformation ( n=2), venous angioma ( n=1), and sinus thrombosis ( n=1). The technique depicted not only anatomical features, comparably to MR angiography ( n=10/11), but also hemodynamics such as collateral flow at a temporal resolution of 1.

Diffusion-weighted MR imaging in acute spinal cord ischemia.

We report diffusion-weighted (DW) MR findings for acute spinal cord ischemia in a 56-year-old patient. MR imaging obtained approximately 3 h after symptom onset demonstrated an area of hyperintensity on DW images, but no conspicuous signal abnormality on T2-weighted images in the conus medullaris. DW imaging of the spinal cord can contribute to the early detection of spinal cord vascular compromise.

Gadolinium enhanced endorectal coil and air enema magnetic resonance imaging as a useful tool in the preoperative examination of patients with rectal carcinoma.

Background/aims: In the present study, we attempted to evaluate the usefulness of gadolinium enhanced endorectal coil and air enema magnetic resonance imaging with slice adjustments in patients with rectal carcinoma.

Methodology: The subjects were patients with rectal cancer from June 1997 to September 1999 who were examined with a 1.5 Tesla magnetic resonance device.

MR digital subtraction angiography with three-dimensional data acquisition in the diagnosis of brain tumors: preliminary experience.

MR digital subtraction angiography (DSA) visualizes intracranial vasculature using a rapid T1-weighted sequence and a bolus injection of gadolinium. Although two-dimensional sequences are most frequently used, we applied a three-dimensional technique in combination with a fast method of k-space filling to improve both the temporal and spatial resolutions. In this preliminary study, we assessed the feasibility of using this technique for the diagnosis of brain tumors in 21 patients by reviewing the obtained images and, in 10 patients, comparing the images with conventional angiograms.

[Dose investigation of superparamagnetic iron oxide (SPIO) SH U 555 A in liver MR imaging].

SH U 555 A, a new superparamagnetic iron oxide (SPIO) contrast agent for liver MR imaging, was investigated in terms of safety and efficacy. Eighty-four patients with suspected malignant liver tumor were randomly allocated to two groups: the L dose group (8 mumol Fe/kg) and H dose group (12 mumol Fe/kg). Efficacy was qualitatively evaluated through blinded reading of the MR images.

Evaluation of MR cisternography of the cerebellopontine angle using a balanced fast-field-echo sequence: preliminary findings.

We evaluated the feasibility of MR cisternography by the balanced fast-field-echo (bFFE) sequence, comparing with that by a turbo-spin-echo (TSE) sequence, for cerebellopontine angle lesions on a 1.5-T imager (Gyroscan Intera, Philips, Best, The Netherlands). The bFFE MR cisternograms depicted target cranial nerves with less cerebrospinal fluid pulsation artifacts than TSE cisternograms and visualized an acoustic schwannoma in 6 of 44 patients with suspicion and a causative vessel of hemifacial spasm in all of 3 patients in a short scanning time (1 min 53 s).

Case report: spinal cord infarction demonstrated on diffusion-weighted MR imaging with a single-shot fast spin-echo sequence.

We describe the diffusion-weighted (DW) MR imaging findings in three cases of spinal cord infarction using a recently developed single-shot fast spin-echo (SSFSE) technique. The SSFSE-DW MR images, which were obtained 20 hours, 3 days, and 18 days, respectively, after the ischemic event, demonstrated conspicuous areas of hyperintensity in the affected portions. Follow-up DW MR images, obtained in two of the patients at 17 days and 3 months, respectively, showed persistent decreased apparent diffusion coefficient values.

A prospective comparison between multidetector-row computed tomography and magnetic resonance imaging in the preoperative evaluation of rectal carcinoma.

Background: Multidetector-row computed tomography (MDCT, or multislice CT) is a new modality with four detectors, which makes examination time shorter and produces higher resolution and multiplanar reformation of the images. Its diagnostic role in patients with rectal carcinoma has not been determined.

Methods: Twenty-one patients with rectal carcinoma were preoperatively examined by both MDCT and magnetic resonance imaging (MRI).

Application of multi-detector row helical scanning to postmyelographic CT.

The advent of a multi-detector row helical CT has made it possible to attain images over a broader area with good spatial resolution. We assessed whether postmyelographic CT scans obtained using this system provided more information than conventional imaging techniques. Postmyelographic CT scans were preoperatively obtained in 46 patients using a multi-detector row helical CT system.

MR digital subtraction angiography in the diagnosis of meningiomas.

Objective: MR digital subtraction angiography (DSA) is a technique for demonstrating the vasculature combining a rapid two-dimensional T1-weighted sequence with a bolus injection of gadolinium. We attempted to determine its contribution to the diagnosis of intracranial meningiomas.

Methods And Patients: MR DSA was performed in 18 patients with meningioma as well as in 28 patients with other tumors.

Visualization of extracranial-intracranial bypass using multidetector-row helical computed tomography angiography.

Purpose: The advent of multidetector-row computed tomography (MDCT) has enabled images with good spatial resolution to be obtained over a wide range in a short scanning time. Our purpose was to determine whether CT angiography using the MDCT system could effectively depict extracranial-intracranial (EC-IC) bypass routes.

Method: Helical CT angiography was performed using an MDCT scanner in 12 patients who had undergone EC-IC bypass surgery: 10 patients had undergone superficial temporal artery-middle cerebral artery (MCA) anastomosis, 1 patient had undergone an encephaloduroarteriosynangiosis procedure for the treatment of moyamoya disease, and 1 patient had undergone an external carotid artery-MCA anastomosis using a graft.

Comparison between endorectal coil and pelvic phased-array coil magnetic resonance imaging in patients with anorectal tumor.

Background: Magnetic resonance imaging (MRI) has been used as one of the diagnostic tools in the preoperative evaluation of rectal cancer. However, the usefulness of endorectal coil (ERC) compared with phased array coil (PA) MRI is still unknown.

Patients And Methods: Nineteen patients with rectal (17 patients) and anal (2 patients) tumors undergoing both ERC-MRI and PA-MRI preoperatively were included in the study.

Magnetic resonance cholangiopancreatography for postoperative follow-up of intraductal papillary-mucinous tumors of the pancreas.

Background: After resection of an intraductal papillary-mucinous tumor (IPMT), benign tumors or portions of the resected tumor are sometimes left in place to avoid total pancreatectomy. We evaluated the role of magnetic resonance cholangiopancreatography (MRCP) in postoperative follow-up.

Methods: Twenty-two patients underwent MRCP 0.

The pearl necklace sign: an imaging sign of adenomyomatosis of the gallbladder at MR cholangiopancreatography.

Purpose: To evaluate the demonstration of the pearl necklace sign at magnetic resonance (MR) cholangiopancreatography (MRCP) in patients with proven adenomyomatosis and carcinoma of the gallbladder.

Materials And Methods: MRCP findings and those of a combination of unenhanced and arterial phase computed tomography (CT) and arterial phase MR imaging were retrospectively compared in 29 patients who were pathologically proven to have adenomyomatosis of the gallbladder and in 18 patients with pathologically proven gallbladder carcinoma. Receiver operating characteristic (ROC) analysis was used with a five-point confidence scale.

MR-angiogram-added surface anatomy scanning of superficial cerebral arteriovenous malformations.

Our purpose was to evaluate the utility of surface anatomy scanning (SAS) of the brain with superimposition of MR angiograms in the diagnosis and presurgical planning of superficial cerebral arteriovenous malformations (AVMs). We performed SAS in 15 patients with superficial cerebral AVMs. Two-dimensional phase-contrast MR angiograms were then obtained in the same section and superimposed on the SAS images.

Preoperative staging by multidetector-row computed tomography in patients with rectal carcinoma.

Background: Multidetector-row computed tomography (MDCT, or multi-slice CT) has been introduced in 2000. So far, there has been no published study on this modality in patients with rectal carcinoma.

Methods: Twenty patients with rectal carcinoma were preoperatively examined by MDCT and conventional CT (CCT).

Preoperative evaluation by magnetic resonance imaging in patients with bowel obstruction.

Background: Bowel obstruction is a problematic condition because the main clinical issue is to determine whether emergency laparotomy or observation with a long tube is required. The recent development of imaging diagnostic modalities such as magnetic resonance imaging (MRI) is thought to be promising to support therapeutic decisions in patients with bowel obstruction.

Methods: Twenty-seven patients with bowel obstruction who underwent laparotomy were evaluated by plain x-ray film, computed tomography (CT) scan, and MRI preoperatively with regard to the presence or absence of bowel obstruction, and the site and cause of bowel obstruction.

[Japanese radiological report creation with continuous speech recognition].

Ten Japanese radiological reports consisting of 1381 characters (681 words) were created by two board-certified radiologists who used conventional typing and a continuous speech-recognition system called AmiVoice (Advanced Media, Inc., Tokyo, Japan). The two radiologists had not had any special training prior to their use of the continuous speech-recognition system.