K. Hiramatsu

Efficacy of gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging for differentiation between superficial and muscle-invasive tumor of the bladder: A comparative study with computerized tomography and transurethral ultrasonography

Gadolinium-labeled diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) was evaluated in an effort to clarify whether MRI could replace or be proved to be superior to computerized tomography (CT) and/or transurethral ultrasonography. A total of 57 bladder cancer patients was evaluated. MRI was performed with a superconducting magnet operating at 1.5 Tesla. The images acquired were multisections, having a fast spin-echo pulse sequence of less than a 14-second breath holding. Serial scans were performed before and immediately after Gd-DTPA venous injection. The findings on different imaging techniques were compared with the histological stagings. A proper diagnosis was made in 42 of 57 cases (73.7%) by Gd-DTPA-enhanced MRI, in 27 of 57 (47.4%) by CT and in 31 of 57 (54.4%) by transurethral ultrasonography when comparing the histological findings. The sensitivity and specificity for differentiating superficial and muscle-invasive tumor of each imaging method were, respectively, 96.2 and 83.3% in Gd-DTPA-enhanced MRI, 96.0 and 58.3% in CT, and 88.0 and 66.7% in transurethral ultrasonography. These data suggest that the staging of bladder cancer by Gd-DTPA-enhanced MRI appears to be superior and more accurate than the staging obtained by CT and transurethral ultrasonography.

Congenital absence of the portal vein in a boy.

Abstract Congenital absence of the portal vein (CAPV) is a malformation that is generally thought to be limited to females. We encountered an 11-year-old boy with this malformation. In 17 previously reported cases of CAPV, 2 were male. Three male patients, including our case, were Abernethy type Ib malformation. They had no associated liver tumour and two had no additional congenital abnormality. Conversely, 13 of the 15 female patients had congenital abnormalities and 6 had liver mass lesions.

Swallowing Dysfunction and Aspiration in Neonates and Infants

In children, swallowing dysfunction and aspiration are common causes of recurrent pneumonia and can be fatal. The underlying mechanism is still unknown. In this study, we evaluated the swallowing function in 72 neonates and infants by fluoroscopy and followed the course of 39 patients for more than one year. The results of all the examinations were recorded on videotape or a digital imaging system. All 10 patients with neurologic disorder presented cricopharyngeal dysfunction. Of the 12 patients with near miss sudden infant death syndrome, 10 showed nasopharyngeal reflux, and 5 demonstrated cricopharyngeal dysfunction. In the 50 patients without neurologic disorder, 29 revealed cricopharyngeal dysfunction. Laryngeal elevation was not seen in 75%. Three of these 29 patients had no other abnormality. All patients without neurologic disorder recovered well. Seven patients demonstrated prolonged aspiration. Four of them had neurologic disorder, and the rest had near miss sudden infant death syndrome. Fluoroscopic examination showed two types of aspiration: one was caused not only by pharyngeal but also by lingual muscles. It was not associated with any neurologic disorders and the symptoms were transient. The other was caused by cricopharyngeal dysfunction and most of these patients had neurologic diseases and prolonged symptoms.

Clinical usefulness of digital radiography in the gastrointestinal tract: Efficacy of magnification method

We assessed the performance capabilities of image intensifier digital radiography (II DR) in the detection of minute lesions in patients with early stomach cancer. The DR system was a prototype II DR system developed by Toshiba Corp (Tokyo, Japan). This system was able to acquire images with a 1,024-× 1,024-pixel matrix and 13 bits. Radiography was performed using a 0.3-mm tube focus. For the detectability of early stomach cancer, DR was judged to be superior to conventional screen-film system (CFSS) (DR superior, 55.7%; CFSS superior, 22.6%). In depicting the characteristics of the surface of the lesion, DR was also judged to be superior to CFSS (DR superior, 56.6%; CFSS superior, 17.0%). The II DR system used in this study was able to achieve almost the same spatial resolution as conventional radiography using the magnification method. It was also able to visualize subtle findings of early gastric cancer more clearly by the use of postprocessing. In addition, II DR has the advantages of reducing the patient exposure dose and permitting the acquisition of real-time images.

Visualization of tumor vessels in renal tumors. Comparison between power Doppler ultrasonography and angiography.

Purpose: To compare the ability of power Doppler ultrasonography (PDUS) with that of renal angiography for assessment of renal tumor vessels. Material and Methods: We performed PDUS and angiography in 52 histologically proven renal parenchymal tumors (50 renal cell carcinomas (RCCs) and 2 oncocytomas), and compared vascularity on PDUS and angiography. The vascularity of PDUS was graded as follows: grade 0 - no recognizable tumor vessel; grade 1 - hypovascular to surrounding renal interlobar arteries; grade 2 - hyper- or isovascular to surrounding renal interlobar arteries. Results: With PDUS, 41 tumors were grade 2 and 11 were grade 1. With angiography, 44 lesions had iso/hypervascular pattern, 6 hypovascular pattern, and 2 were judged to be avascular. Among 44 iso/hypervascular tumors, 41 were grade 2, and 3 were grade 1. These latter 3 were located deeper than 7 cm. Six hypovascular tumors and 2 avascular tumors were grade 1. The 2 avascular tumors were small and hypovascular. The κ-level of agreement was 0.81. Conclusion: There was very good agreement betweeen PDUS and angiography in visualizing renal tumor vessels. PDUS appears appropriate for assessing renal tumor vascularity as compared to angiography in small and hypovascular lesions, but deep location reduced the detectability of tumor vessels with PDUS.

Small Solid Renal Lesions: Usefulness of Power Doppler US

PURPOSE To evaluate whether the vascular pattern at power Doppler ultrasonography (US) improves diagnostic accuracy in small solid renal lesions over that at gray-scale US. MATERIALS AND METHODS Gray-scale and power Doppler US were performed prospectively in 64 small (1.5-3.0-cm-diameter) solid renal lesions (26 renal cell carcinomas [RCCs], 34 angiomyolipomas, two oncocytomas, two pseudotumors). At gray-scale US, echogenicity and homogeneity of the lesion, an anechoic rim, intratumoral cysts, shadowing, or a central scar were sought. At power Doppler US, the vascular distribution was divided into four patterns. RESULTS Findings at gray-scale US included an anechoic rim or intratumoral cysts in 20 of 26 RCCs (77%) and the two oncocytomas. Shadowing was seen in seven of 34 angiomyolipomas (21%). Echogenicity, homogeneity, and a central scar were not pathognomonic. At power Doppler US, pattern 3 (peripheral) or 4 (mixed penetrating and peripheral) was seen in all RCCs, seven of 34 angiomyolipomas, and the two oncocytomas. Pattern 1 (intratumoral focal) or 2 (penetrating) was seen in 27 angiomyolipomas. Pattern 1 or 2 was characteristic of angiomyolipoma. The rate of correct diagnosis was significantly increased with combined US (78%) as compared to that with gray-scale (42%) or power Doppler (45%) US alone. CONCLUSION The vascular distribution at power Doppler US could add important information to gray-scale US findings for differential diagnosis of small solid renal lesions.