Quality Assessment of Ultrasonographic Equipment Using an ATS-539 Multipurpose Phantom

PURPOSE: To determine the rate of congruence and to standardize assessment of US (ultrasound) phantom images with the use of an ATS-539 multipurpose phantom for US equipment currently utilized in Korea MATERIALS AND METHODS: US phantom images were scanned with a 3.0-5.0 MHz convex transducer and were digitized by use of an analogue-digital converter. Members of a committee with consent evaluated the US phantom images from 108 types of ultrasound equipment. The dead zone, vertical and horizontal measurement, axial/lateral resolution, focal zone, sensitivity, functional resolution and gray scale/dynamic range were evaluated. Congruence or incongruence of ultrasound equipment was determined based on the results of dead zone, axial/lateral resolution and gray scale/dynamic range measurements. Other factors were evaluated for the possibility as criteria with the use of the Mann-Whitney U test and receiver operator characteristic (ROC) curve analysis. RESULTS: The dead zone, axial/lateral resolution and gray scale/dynamic range were 91.7%, 94.4% and 76.9%, respectively, for suitable US equipment. Considering all three factors, 78 types of ultrasound equipment were passed. The congruence rate of focal zone and functional resolution were 62.4% and 69.3% of the US equipment, respectively. CONCLUSION: Of the US equipment, 72.2% of the equipment was acceptable based on the dead zone, axial/lateral resolution, and gray scale/dynamic range measurements as determined with the use of an ATS-539 phantom. Focal zone and 8 mm-functional resolution can be useful as a standard in the assessment of a US phantom image.

Zebra Pattern in CT during Arterial Portography: Analysis of Associated Factors

PURPOSE: To analyze the factors associated with the zebra pattern in CT during arterial portography(CTAP). MATERIALS AND METHODS: In 275 CTAP procedures, the factors associated with the zebra pattern, such as laminar flow in the portal vein, the presence of liver cirrhosis, the artery selected for CTAP, location of the catheter tip in the superior mesenteric artery(SMA), splenic volume, and the existence of an aberrant right hepatic artery(RHA) emerging from the SMA were analyzed. RESULTS: In 106 of 275 procedures (38.5%), a zebra pattern was apparent. Portal venous laminal flow was seen in 92 % of procedures in the group with this pattern and in 63 % in the group without it. Eighty-three of 235 procedures (35.3 %) in which the SMA was injected and 23 of 40(57.5 %) involving splenic artery injection showed the zebra pattern. In 22 of 35(62.8 %) in which the catheter tip was located in the distal SMA and 61 of 200 ( 30.5 %) in which this was at a proximal site, the zebra pattern was evident. Mean splenic volume was less in the group with the zebra pattern. The effect on the zebra pattern of liver cirrhosis and an aberrant RHA emerging from the SMA was not statistically significant. CONCLUSION: In CTAP, the incidence of the zebra pattern was 38.6%, and was related to laminal flow in the portal vein. The pattern is frequently seen in CTAP involving contrast injection via the splenic artery, distal location of a catheter tip in the SMA, and small splenic volume.

MR Imaging of Traumatic Brachial Plexus Injury

PURPOSE: The aim of our study was to evaluate the usefulness of MR imaging in cases of traumatic brachial plexus injury. MATERIALS AND METHODS: We evaluated 25 patients with traumatic brachial plexus injury as seen on MR images prior to surgical exploration and repair. MR images were retrospectively evaluated for nerve root avulsion and pseudomeningocele, and postganglionic lesions. Results were correlated with final diagnosis after surgical exploration . RESULTS: One hundred and four of 125 root levels (83%) were adequately imaged. Neve root avulsion was shown at 28 levels(54%). Avulsion with or without pseudomeningocele was seen at 37 levels(71%)(80% sensitivity, 91% specificity). The presence of ten of 12 postganglionic lesions (83%) was revealed by MR imaging. CONCLUSION: MR imaging is valuable for revealing preganglionic nerve root avulsion in patients with traumatic brachial plexus injury or postganglionic lesions.

MR Imaging of Traumatic Brachial Plexus Injury

PURPOSE: The aim of our study was to evaluate the usefulness of MR imaging in cases of traumatic brachial plexus injury. MATERIALS AND METHODS: We evaluated 25 patients with traumatic brachial plexus injury as seen on MR images prior to surgical exploration and repair. MR images were retrospectively evaluated for nerve root avulsion and pseudomeningocele, and postganglionic lesions. Results were correlated with final diagnosis after surgical exploration . RESULTS: One hundred and four of 125 root levels (83%) were adequately imaged. Neve root avulsion was shown at 28 levels(54%). Avulsion with or without pseudomeningocele was seen at 37 levels(71%)(80% sensitivity, 91% specificity). The presence of ten of 12 postganglionic lesions (83%) was revealed by MR imaging. CONCLUSION: MR imaging is valuable for revealing preganglionic nerve root avulsion in patients with traumatic brachial plexus injury or postganglionic lesions.