Scott W. Wise

Localized hypertrophic neuropathy : Magnetic resonance imaging findings and long-term follow-up

Four patients with painless, progressive focal neurological deficits that localized to peripheral nerve or plexus were eventually found to have the relatively rare condition of localized hypertrophic neuropathy or intraneural perineurioma. Magnetic resonance imaging (MRI) was an excellent tool for aiding in the precise localization of the lesion, if specifically tailored with regard to imaging planes and specific MRI sequences. Fat‐saturated T2‐weighted and fat‐saturated T1‐weighted postgadolinium images provided the best visualization, particularly with a high‐field magnet and phase array body coil. Two patients stabilized following resection of the lesion and sural nerve grafting, and 1 had partial improvement in a proximal muscle following neurolysis.

Appendiceal imaging: Which test is best?

Radiologic imaging has been clearly shown to be useful for the evaluation of patients clinically suspected of having appendicitis with CT and ultrasound being the most frequently recommended modalities. However, controversy still exists as to which modality is the technique of choice for appendiceal imaging. Our experience has led us to conclude that a standard helical abdominopelvic CT is the initial test of choice for the evaluation of the adult patient suspected of having acute appendicitis. Focused appendiceal CT with colonic contrast is then utilized as a problem solving technique for equivocal cases after this initial assessment.

Assessment of resident knowledge: Subjective assessment versus performance on the ACR in-training examination

RATIONALE AND OBJECTIVES The authors assessed the ability of faculty and residents to predict the ranked performance of residents on the American College of Radiology (ACR) In-Training Examination. MATERIALS AND METHODS Radiology faculty at Penn State Geisinger Health System (PSGHS), the Medical College of Virginia (MCV), and the University of Virginia (UVA) and residents at PSGHS and MCV ranked the expected performances of residents taking the 1997 ACR In-Training Examination. Surveyed faculty and residents were blinded to the actual performances on the examination. Forty-nine residents took the examination (21 at PSGHS, 22 at MCV, six at UVA), and 37 faculty members (11 at PSGHS, 11 at MCV, 15 at UVA) participated in the study. Correlation analysis was performed to assess the agreement between the subjective and actual ranking of residents in each residency class. RESULTS Faculty were moderately accurate in the overall ranking of resident performances (r = 0.34). High levels of concordance for ranking individual residents correlated with accuracy in only certain cases. Differences in agreement and accuracy of the respondents existed between PSGHS and MCV (P = .0001 and .0014, respectively). The concordance of respondents increased significantly from the 1st- to the 2nd-year class at MCV (P = .0002), whereas accuracy increased significantly between these classes for the PSGHS (P = .042). CONCLUSION Faculty are only moderately successful in ranking resident performances on the ACR In-Training Examination, and a high level of agreement is not necessarily indicative of increased accuracy. The concordance and accuracy of subjective rankings differ among residency programs and classes.

The clinical usefulness of routine stacked multiplanar reconstruction in helical abdominal computed tomography.

RATIONALE AND OBJECTIVES The authors evaluate the usefulness of stacked multiplanar reconstructions in routine, thick-section abdominal computed tomography. MATERIALS AND METHODS Twenty-five routine, thick-section contrast abdominal CTs performed with equivalent technique were reformatted by multiplanar reconstructions in sagittal and coronal planes sequentially from side-to-side and front-to-back. The image sets were submitted, first axial images only followed by axial plus multiplanar reconstructions (MPRs), to 5 separate physician readers including 2 radiologists and 3 nonradiologists. These readers graded the visualization of a variety of normal and up to 5 pathologic lesions per patient on a scale of 1 to 5 (5 = best). RESULTS The addition of sagittal and coronal multiplanar reconstructions significantly improved the visualization of all normal anatomic structures (mean axial only, 3.8; mean axial plus MPR, 4.1; P < 0.0001). In addition, most pathologic lesions were statistically better visualized with the addition of multiplanar reconstructions (mean axial images only, 3.9; mean axial plus MPR, 4.1; P < 0.0001). All five readers found improved visualization in nearly every category with the addition of the multiplanar reconstructions. However, in only 7% of cases, did a reviewer find new diagnostic information with the addition of MPR images. CONCLUSIONS Stacked multiplanar reconstructions of routine, thick-section abdominal CT has clinical value in both the display of normal anatomic and pathologic lesions. Further studies, however, are required to confirm these findings before it is commonly used.

Optimization of Shaded Surface Display for CT Angiography

RATIONALE AND OBJECTIVES The authors performed this study to determine the optimum threshold for performing computed tomographic (CT) angiography with shaded surface display (SSD). MATERIALS AND METHODS A dedicated phantom was developed with an 8-mm luminal diameter. Each of 19 vessels had stenoses ranging from 0% to 93.8%. Five blinded, experienced reviewers separately measured each vessel by using SSD with display thresholds of 50, 100, 150, and 200 HU. RESULTS For vessel diameters of 2 mm and larger, the best threshold value was 100 HU. This yielded measurements within 2% of the actual diameter and produced no false occlusions. For vessels 1 mm in diameter, the best threshold remained 100 HU, but this threshold was significantly less accurate than the standard (P = .0001) and produced two false occlusions in 15 vessels. For vessels 0.5 mm in diameter, the best threshold was 50 HU, although this still produced measurements significantly less accurate than the gold standard (P = .036) and one false occlusion in 15 vessels. CONCLUSION CT angiography with SSD and an optimized threshold value is a useful technique in vessels 1 mm and larger.

Recurrent short rib-polydactyly syndrome with unusual associations

Short rib–polydactyly syndrome (SRPS) is manifested by short‐limb dwarfism, short ribs with thoracic hypoplasia, and polydactyly. This inheritable syndrome has distinct imaging findings on prenatal sonography, and ancillary findings on both pre‐ and postnatal assessments may enable individual cases to be classified into 1 of 4 subtypes. In this report, we present a recurrent case of SRPS that was associated with a cystic hygroma and choroid plexus cysts. Although cystic hygromas are not uncommonly seen in skeletal dysplasias, the presence of concomitant cystic hygroma and choroid plexus cysts suggests a chromosomal abnormality such as trisomy 18.

The optimization of helical thoracic CT

PURPOSE Our purpose was to determine the optimal helical thoracic CT scanning protocol. METHOD Three adult Suffolk sheep under general anesthesia were repeatedly scanned by a variety of variable thickness helical and conventional plus thin section high resolution (lung gold standard) CT sequences, reconstructed for mediastinal (standard interpolator and algorithm) and lung parenchymal (extrasharp interpolator, bone algorithm) detail. The images were evaluated in a random order by five separate blinded, experienced imagers utilizing a predetermined grading scale. RESULTS At equivalent slice thicknesses, the mediastinal images showed no statistically significant differences between conventional and helical CT using pitches of 1.0, 1.5, and 2.0. However, the 5-mm-thick sections, regardless of technique, performed better than did either the 2- or the 10-mm-thick section images. For the lung interstitium, there was an obvious and marked advantage to reconstructing the lung images separately from the mediastinal images with edge-enhancing algorithms and interpolators. With 1-mm-high mA thin section, high resolution lung CT as the gold standard, 2 mm conventional and helical pitch 1.0, 1.5, and 2.0 images were all graded equivalent. Of the 5 mm images, the helical pitches of 1.0 and 1.5 were graded equivalent to the gold standard. All of the 10 mm lung sections using both conventional and helical CT were graded statistically worse than the gold standard (p < 0.05). CONCLUSION The use of helical CT with a 5 mm beam collimation and a pitch of 1.0 or 1.5 reconstructed twice to maximize both the mediastinal and the lung parenchymal detail provides the optimal way to routinely evaluate the chest.

Impact of the Armed Forces Institute of Pathology Radiologic Pathology Course on radiology resident performance on the ACR In-Training and ABR written Examinations

RATIONALE AND OBJECTIVES The purpose of this study was to assess resident scores on the American College of Radiology (ACR) In-Training Examination and on the written American Board of Radiology (ABR) Examination relative to attendance at and timing of the Armed Forces Institute of Pathology (AFIP) Radiologic Pathology Course. MATERIALS AND METHODS A survey of 200 radiology residency program directors requested the type of residency program, whether the program sent residents to the AFIP course, dates of AFIP attendance for individual residents, percentile scores of residents on the ACR examination from 1995 through 1998, and ABR examination scores for 1997. Scores were analyzed before and after AFIP attendance and also temporally for examinations during or after AFIP attendance. Improvement in percentile scores for residents undergoing the ACR examination while attending the AFIP were compared with scores of matched residents from their programs who had not attended. RESULTS Thirty-six (18%) program directors responded, providing data on 619 residents who underwent the ACR examination, ABR examination, or both. No significant improvement was found between pre- and post-AFIP ACR Examination scores for residents at university or military programs. There were statistically significantly improved scores for residents at community programs (mean percentile improvement, 8.1 points; P = .0064). Residents who underwent the ACR examination during the AFIP course improved their scores by 10.7 percentile points compared with matched residents who had not attended the AFIP course (P = .041). CONCLUSION Residents undergoing the ACR examination while attending the AFIP improve their percentile scores more than residents who have not attended the AFIP.

Sonographic incidence of deep venous thrombosis contralateral to hip or knee replacement surgery

This study assesses the sonographic incidence of deep venous thrombosis (DVT) contralateral to and the venographic incidence ipsilateral to hip or knee replacement surgery and the role of sonography in routine surveillance.

Infected hepatic infarction: an unusual cause of portal venous gas

Abstract Portal venous gas is a radiologic finding that usually is due to extrahepatic abdominal processes, most commonly ischemic bowel. In this case report, we present a case of hepatic infarction and fulminant hepatic infection that resulted in extensive portal venous gas.