Recent developments in medical imaging technology and their clinical application for the diagnosis and management of hepatocellular carcinoma (HCC) are reviewed. Real-time ultrasound is effective for the screening of HCC in high-risk patients with liver cirrhosis. Information on blood flow is available by color Doppler or power Doppler technique. Dynamic computed tomography (CT) using a fast scanner and the modified contrast administration technique is useful for detection, differential diagnosis, and staging of HCC. Application of magnetic resonance (MR) imaging is increasing with rapid improvements in speed of image acquisition and resolution. Dynamic MR imaging and MR angiography have also been available. Diagnostic and interventional hepatic angiography are now performed less invasively, more safely, and more quickly with modern technologies of digital subtraction angiography (DSA) and catheters. CT during hepatic arteriography (CT arteriography) and arterial portography (CTAP) are used for evaluation of small focal nodules in the cirrhotic liver.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Radiologic diagnosis of pancreatic carcinoma.

Radiological diagnostic techniques for the evaluation of pancreatic duct cell adenocarcinoma and their findings are discussed. Pancreatic carcinoma may demonstrate one or more of these diagnostic signs: focal enlargement or deformity, density changes, obliteration and dilatation of the pancreatic and/or biliary duct, local invasion, and metastases. Ultrasonography is commonly used as a screening examination. The presence of pancreatic carcinoma may best be evaluated by dynamic computed tomography (CT) or dynamic magnetic resonance (MR) imaging with administration of intravenous contrast material. Both CT and MR imaging are used for the preoperative assessment of local invasion and vascular involvement. MR cholangiopancreatography (MRCP) allows noninvasive three-dimensional delineation of the pancreatic and biliary duct systems. Angiography may demonstrate vascular involvement questionable on noninvasive examinations. In the near future, the value and efficacy of MR imaging in the diagnosis of small pancreatic carcinoma need to be assessed in comparison with CT and endoscopic studies.

Angiography↗

PubMedDate not supplied

The treatment with tranilast, a mast cell blocker, for idiopathic oligozoospermia.

Although many drug treatments have been reported to theoretically improve semen parameters in male infertility, a standard method has not been established. The authors examined whether tranilast, a mast cell blocker, improves fertility and/or semen parameters in severe oligozoospermia. Seventeen patients with a sperm density of less than 10 x 10(6) sperm/mL and their fertile partners were enrolled in this study. Patients were prescribed tranilast 300 mg/day for at least 12 weeks. Semen and blood samples were collected before and after the prescription of tranilast for 12 weeks. Semen parameters, serum gonadotropins, luteinizing hormone, follicle-stimulating hormone, serum testosterone, and testicular size were evaluated. One patient complained of mild drowsiness during treatment. The sperm count was significantly increased after administration of tranilast in 7 patients (41.1%), although sperm motility was not altered. Semen volume and normal morphology were also unaltered. Three pregnancies were achieved. Endocrine profile and testicular size were unchanged. Tranilast, a mast cell blocker, is clinically useful for the treatment of severe idiopathic oligozoospermic men.

Adult↗

PubMedDate not supplied

Treatment of oligoasthenozoospermia with tranilast, a mast cell blocker, after long-term administration.

The authors retrospectively examined whether long-term administration of tranilast improves semen parameters in severe oligoasthenozoospermia. Fifty-two patients presenting with sperm concentration of less than 10 x 10(6) sperm/mL were enrolled. Subjects were partitioned into 3 groups as follows: patients displaying an atrophic testis with elevated (FSH) (group 1), patients exhibiting normal testicular volume with elevated FSH (group 2), and patients with normal testicular volume and normal FSH levels (group 3). Tranilast (300mg/day) was administered until pregnancy was achieved or for a period of up to 12 months. Sperm concentration was significantly increased at 3 months in 16 subjects (44%) in groups 1 and 3. In group 2, sperm concentration was increased at 12 months (5 of 16 subjects; 31%). Total sperm count was obviously elevated at 3 months in groups 1 and 2, and at 6 months in group 3. Six pregnancies were achieved via natural intercourse. Tranilast, a mast cell blocker, demonstrates a certain clinical benefit in terms of improvement of semen parameters involving severe oligoasthenozoospermia, but it does not appear to afford clinical benefit in long-term administration.

Adult↗

PubMedDate not supplied

Clinical evaluation of three-dimensional MR-cholangiopancreatography using three-dimensional Fourier transform fast asymmetric spin echo method (3DFT-FASE): usefulness of observation by multi-planar reconstruction.

MR-cholangiopancreatography (MRCP) is a new method that is non-invasive and permits volume data collection and three-dimensional expression. With the three-dimensional Fourier transform fast asymmetric spin echo (3DFT-FASE) method, a higher spatial resolution can be obtained both in-pain and in slice selecting direction. In this paper, the usefulness of this new technique is investigated in the clinical diagnosis of MIP images and MPR. The study was performed in 10 normal volunteers and 21 patients with abnormalities in the pancreas or bile-duct sustem. The study was done using a 1.5 Tesla super-conductive machine. The MRCP images were interpreted by three radiologists. In most cases good images were obtained. The additional clinical information provided by MPR was remarkably useful in cystic lesions, especially in mucinous cystic neoplasm of the pancreas. Even when the intestine overlapped the pancreas, it was possible to evaluate the pancreatic duct by MPR. Three-dimensional observation and clinically useful diagnosis were possible by utilizing the advantageds of the 3DFT-FASE method appears quite useful in clinical application.

Adult↗

PubMedDate not supplied

Interactive fusion of three-dimensional images of upper abdominal CT and FDG PET with no body surface markers.

The aim of this study was to propose and validate a new method of making fused images from CT and FDG PET images for the upper abdominal area with no body surface marker. PET and CT were carried out in patients with pancreatic cancer (N = 5) and mass-forming pancreatitis (N = 2). First, we determined the midsagittal plane from PET and CT data. From the difference in location of the midsagittal planes, rotations of Y (from back to front) and Z axes (from foot to head) and X translation (from right to left) were calculated. An upper pole of the kidney was determined from PET and CT data. It showed Y and Z translations. The images of the three-dimensional data sets were fused on a workstation. Reproducibility was assessed with randomly misaligned PET and CT data sets. Pancreatic cancer and its lymph node metastases were identified easily on fused images. In reproducibility assessment, the average error of rotation was 0.77 degree. The average errors of translation were 3.43, 4.70, and 9.23 mm on the X, Y, and Z axes, respectively. In conclusion, this PET/CT image registration technique is feasible and practical. It allows precise anatomical assessment of normal and abnormal FDG accumulation.

Aged↗

PubMedDate not supplied

High-resolution MR cisternography of the cerebellopontine angle, obtained with a three-dimensional fast asymmetric spin-echo sequence in a 0.35-T open MR imaging unit.

High-resolution MR cisternography performed with 3D fast asymmetric spin-echo imaging (3D fast spin-echo with an ultra-long echo train length and asymmetric Fourier imaging) was optimized in a 0.35-T open MR imaging unit. The 0.35- and 1.5-T images of the two volunteers and three patients with acoustic schwannomas were then compared. The optimal parameters for images obtained by 3D fast asymmetric spin-echo imaging at 0.35 T were as follows: field of view, 15 cm; matrix, 256 x 256 x 40; section thickness, 1 mm; echo train length, 76; and imaging time, 10 minutes 44 seconds. Scans obtained from both normal volunteers showed the facial, cochlear, and superior and inferior vestibular nerves separately in the internal auditory canal on both 0.35- and 1.5-T images. All three acoustic schwannomas were depicted on both 0.35- and 1.5-T images. Screening for disease at the cerebellopontine angle and in the internal auditory canal, without the administration of contrast material on a low-field open MR imaging unit and within a clinically acceptable imaging time, may be possible. Further controlled prospective studies are required, however, before implementation on a wide basis. If proved effective, this may be of particular value for reducing healthcare costs and for imaging claustrophobic and pediatric patients in an open system.

Cerebellopontine Angle↗

PubMedDate not supplied

High-resolution MR images of inner ear internal anatomy using a local gradient coil at 1.5 Tesla: correlation with histological specimen.

PURPOSE: To obtain high-resolution MR images of the inner ear at 1.5 Tesla with a local gradient coil and to correlate these images with the histological specimen. MATERIALS AND METHODS: All studies were performed on a 1.5 Tesla MR unit with a local gradient coil (23 mT/m, slew rate of 107 mT/m/ms). The cranio-facial region of a cadaver was examined using 3D-fast spin echo (FSE) imaging with the voxel size of 0.27 mm x 0.27 mm x 0.5 mm in 9 h 37 min. Two normal volunteers were examined with the same system using 3D-FSE imaging with the voxel size of 0.20 mm x 0.26 mm x 1.0 mm in 57 min. These images were correlated with the cadaver images and histological specimens. RESULTS: On cadaver images, internal structures such as the macula utriculi, macula sacculi, crista ampullaris, lamina spiralis ossea, ligamentum spirale cochleae, modiolus, scala tympani, scala vestibuli, and cochlear aqueduct were visualized. On the images of both volunteers, the same structures were visualized as on the cadaver images. CONCLUSIONS: This study confirmed that high-resolution MR images obtained at 1.5 Tesla can visualize inner ear internal anatomy. Knowledge obtained in this study may be of significant value for the diagnosis of pathology in the area of the inner ear.

Aged↗

PubMedDate not supplied

Arachnoid granulations on high-resolution MR images and diffusion-weighted MR images: normal appearance and frequency.

Arachnoid granulations (AGs), protrusions into the cerebral venous sinus lumen, have been reported on cerebral venography, contrast enhanced CT, and conventional MR imaging. Although thin-sliced high-resolution MR images and diffusion-weighted images are frequently obtained, there have been no detailed reports concerning AGs on these images. In this study, the frequency and positional distribution of AGs in the transverse sinus was investigated on thin-sliced high-resolution MR images, and their appearance on diffusion-weighted MR images was evaluated. At least one AG was found in 107 of 151 subjects (70.9%). No statistically significant differences were noticed between males and females or between the right and left sides. No significant correlations between age and size or between age and the number of AGs were noted. On diffusion-weighted images, all AGs showed iso-intensity to normal brain tissue, which was higher than the reported signal intensity of arachnoid cyst and lower than that of epidermoids. In conclusion, AGs are normal structures that are frequently found in the cerebral venous sinuses on high-resolution MR images. Knowledge regarding their frequency and normal appearance would be helpful to avoid confusion between pathological processes and AGs. It is also important to know that AGs are frequently found even in the younger population.

Adolescent↗

PubMedDate not supplied

Holmium laser incision technique for ureteral stricture using a small-caliber ureteroscope.

BACKGROUND AND OBJECTIVES: The holmium laser has a short absorption depth in tissue and possesses excellent properties both in ablation and hemostasis. We have performed endoscopic incision for ureteral stricture using the holmium laser through a small-caliber ureteroscope. METHODS: This method was used on five patients and seven ureters. The etiology of the stricture was stone scar in two patients, ureteroenteroanastomosis of Indiana urinary pouch in two, and primary in one. We used an 8F semi-rigid or 6.9F flexible ureteroscope. No prior procedures, such as balloon dilation, were necessary in any of the cases. The stricture was incised with the holmium laser using a 365-microm fiber through the working channel of the ureteroscope. The holmium laser operated at a wavelength of 2100 nm, with an output of 1.0 J/pulse at a rate of 10 Hz. After completion of the incision, a 12F Double-J catheter was left in for six weeks. RESULTS: The mean operative time was 89 minutes. The stricture resolved completely in all cases at an average follow-up of 8.6 months. CONCLUSIONS: The holmium laser incision for ureteral stricture using a small-caliber ureteroscope is an easy-to-perform, safe and effective procedure.

Aged↗

PubMedDate not supplied

MR cisternography of the cerebellopontine angle: comparison of three-dimensional fast asymmetrical spin-echo and three-dimensional constructive interference in the steady-state sequences.

BACKGROUND AND PURPOSE: MR cisternography has been used as the noninvasive screening tool of the cerebellopontine angle. The purpose of this study was to directly compare two currently dominant types of sequences for heavily T2-weighted MR cisternography. METHODS: Three-dimensional fast asymmetric spin-echo (3D-FASE) sequences, which are 3D half-Fourier rapid acquisition with relaxation enhancement and 3D constructive interference in the steady-state (3D-CISS) sequences, were compared on a clinical 1.5-T MR unit using the same scan times. In five healthy volunteers, the contrast-to-noise ratio (C/N) between CSF and the cerebellum was measured at three locations. Then, for qualitative analysis, the quality of the labyrinth was scored on the original source multiplanar reformatted images, the virtual endoscopic images, and the maximum intensity projection (MIP) images. In 20 consecutive patients with suspected cerebellopontine angle tumors, visualization of the tumors was evaluated using 3D contrast-enhanced spoiled gradient-echo imaging as the standard of reference. RESULTS: Both sequences showed comparable mean C/N values; however, in qualitative analysis, the scores for 3D-CISS on the source, virtual endoscopic, and MIP images were significantly lower than those on the images obtained with 3D-FASE, owing to more prominent flow and magnetic susceptibility artifacts on the 3D-CISS sequences. In all subjects, discontinuity of the semicircular canals was seen on the virtual endoscopic and MIP images obtained with 3D-CISS, owing to susceptibility artifacts, but not on those obtained with 3D-FASE. All 12 tumors were detected by both sequences, but 3D-CISS gave one false-positive result. CONCLUSION: 3D-FASE is considered the method of choice because artifacts are reduced and specificity is increased.

Adult↗

PubMedDate not supplied

CT and MR imaging of pancreatic cancer.

Recent improvements in imaging techniques have made it possible to improve the diagnostic accuracy for detection, staging, and indicating surgical resectability of pancreatic cancer. The latest advance in the computed tomography technique, is the introduction of subsecond multislice helical scanning that improves z-axis resolution in the reformatted images and three-dimensional rendering with a large volume data. Magnetic resonance imaging provides versatile information including magnetic resonance cholangiopancreatography that allows noninvasive delineation of the pancreatic and biliary duct systems. The presence of pancreatic cancer may best be evaluated by dynamic computed tomography or dynamic magnetic resonance imaging with administration of intravenous contrast material. Both computed tomography and magnetic resonance imaging are valuable for the preoperative assessment of local invasion and vascular involvement. Multislice helical computed tomography is currently considered as the best single modality for the diagnosis of pancreatic cancer as it provides excellent image quality. When advanced magnetic resonance imaging equipment is used as a primary modality, in the future, it may have a possibility to replace other imaging modalities.

Adenocarcinoma↗

PubMedDate not supplied

Contrast-enhanced MR angiography of the carotid artery using 3D time-resolved imaging of contrast kinetics: comparison with real-time fluoroscopic triggered 3D-elliptical centric view ordering.

PURPOSE: To evaluate contrast-enhanced MR angiography using the 3D time-resolved imaging of contrast kinetics technique (3D-TRICKS) by direct comparison with the fluoroscopic triggered 3D-elliptical centric view ordering (3D-ELLIP) technique. METHODS: 3D-TRICKS and 3D-ELLIP were directly compared on a 1.5-Tesla MR unit using the same spatial resolution and matrix. In 3D-TRICKS, the central part of the k-space is updated more frequently than the peripheral part of the k-space, which is divided in the slice-encoding direction. The carotid arteries were imaged using 3D-TRICKS and 3D-ELLIP sequentially in 14 patients. Temporal resolution was 12 sec for 3D-ELLIP and 6 sec for 3D-TRICKS. The signal-to-noise ratio (S/N) of the common carotid artery was measured, and the quality of MIP images was then scored in terms of venous overlap and blurring of vessel contours. RESULTS: No significant difference in mean S/N was seen between the two methods. Significant venous overlap was not seen in any of the patients examined. Moderate blurring of vessel contours was noted on 3D-TRICKS in five patients and on 3D-ELLIP in four patients. Blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. However, qualitative analysis scores showed no significant differences. CONCLUSION: When the spatial resolution of the two methods was identical, the performance of 3D-TRICKS was found to be comparable in static visualization of the carotid arteries with 3D-ELLIP, although blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. 3D-TRICKS is a more robust technique than 3D-ELLIP, because 3D-ELLIP requires operator-dependent fluoroscopic triggering. Furthermore, 3D-TRICKS can achieve higher temporal resolution. For the spatial resolution employed in this study, 3D-TRICKS may be the method of choice.

Adult↗