Linda K. Olson

The roentgenographic findings associated with air embolism in sport scuba divers

Records on all patients with arterial gas embolism (AGE) presenting to UCSD from 1982-1989 and for whom chest radiographs were available were reviewed. Of the 31 patients, 13 roentgenograms (42%) showed evidence of pulmonary barotrauma demonstrated by pneumomediastinum (N = 8), subcutaneous emphysema (N = 3), pneumocardium (N = 2), pneumoperitoneum (N = 1), or pneumothorax (N = 1). Pneumopericardium was not seen. Sixteen (52%) of the 31 patients had pulmonary infiltrates. Radiographic evidence of barotrauma was on occasion subtle, and in four cases was overlooked. Evidence of barotrauma (i.e., extra-alveolar air) was often identified along the left cardiac border, aortic arch, descending aorta, and hilar vessels. Subtle findings of ectopic air can confirm the clinical diagnosis of AGE; however, radiographic evidence of concomitant near drowning occurs more frequently.

Effect of radiologic stage III substage on nonsurgical therapy of non-small cell lung cancer

Background. Patients with Stage III non–small cell lung cancer (NSCLC) whose cases are staged or treated surgically have different prognoses, depending on the substage (IIIa, IIIb). It is not known whether the prognostic differences apply to clinically staged nonsurgical cases. The authors wanted to determine whether radiologic Stage III substages, determined by computerized axial tomography (CT) scans, are prognostically important in these patients with NSCLC. In addition, they wanted to determine whether the observed superior survival of selected patients with Stage III NSCLC receiving chemotherapy in addition to radiation therapy (chemo‐RT) (Cancer and Leukemia Group B protocol 8433: N Engl J Med 1990; 323:940–5) was influenced by an imbalance in the radiologic Stage III substage.

Quantitative volumetric breast imaging with 3D inverse scatter computed tomography

A method was developed to map tissue properties of the entire breast including sound speed and attenuation using fully 3D nonlinear inverse-scattering tomography. Clinical measurements suggest that in breast tissue benign and cancerous lesions may be identified in part by these inherent acoustic parameters. Sound speed accuracy and linearity are very high over a wide range (1325-1700 m/sec) with ~1.5 mm resolution at 2 MHz in transmission mode. Attenuation tomograms provide image contrast over a wide range (0-4 dB/cm/MHz) and assist classification of masses. High resolution 0.6 mm volumetric reflection tomograms are acquired with bandwidth 2-8 MHz, are refraction-corrected with the transmission tissue data and are precisely registered in 3D with the transmission volumes. USCT promises an automated whole-breast scan providing a global view of the entire breast in 3D, facilitating comparison to prior exams in a reproducible geometry. Scanner design, automated operation and results of our trial with over 125 subjects with confirmed breast masses will be presented with detailed comparison to conventional sonography and MRI.

Echocardiographic evidence of pericardial effusion in severe chronic pulmonary hypertension

Abstract We have frequently observed pericardial effusions in patients with severe chronic pulmonary hypertension. In this study, we retrospectively reviewed all echocardiographic data from 66 patients with chronic severe pulmonary hypertension for evidence of pericardial effusion and, if present, whether it was associated with particular hemodynamic characteristics.

Accelerated Partial Breast Irradiation and Posttreatment Imaging Evaluation

Accelerated partial breast irradiation (APBI) is a technique that allows irradiation of only that part of the breast that is at greatest risk for recurrence of breast cancer. Because only a portion of the breast is irradiated, APBI can be performed in a relatively short period of time, usually in 5 days rather than the traditional 6 weeks. When used in carefully selected patients, APBI also allows normal portions of the breast parenchyma and regional vital organs to be spared from unnecessary irradiation. Common post-APBI imaging findings include focal skin thickening, seroma, scar, and skin retraction. Studies are underway that will compare a cohort of patients who underwent whole-breast irradiation with a cohort who underwent APBI to help determine whether the two techniques lead to significantly different imaging findings. Additional multicenter studies will be needed to document and analyze any such differences. In the future, APBI may play a significant role in selected patients, with pretherapy dynamic contrast material-enhanced magnetic resonance imaging of the breast possibly aiding in the selection process.

Abdominal wall CT: A pictorial essay

Abdominal CT demonstrates clearly the anatomy of the abdominal wall. This radiographic technique may provide valuable information when pathology is suspected in this region or in the adjacent peritoneum. The muscles, subcutaneous tissues and vascular structures of the abdominal wall should be examined thoroughly when reading routine abdominal CT films. This paper reviews abnormalities identified involving the abdominal wall including hernias, masses, vessels, hematomas, abscesses, ascites, neuromuscular diseases and miscellaneous entities.

Furosemide during sustained left atrial hypertension in functionally anephric dogs: Intravascular and extravascular pulmonary fluid volumes. V☆

The response of intravascular (PBV) and extravascular (EVLW) pulmonary fluid volume was examined using double-indicator techniques (thermal-green dye) in 11 open-chest anesthetized dogs during the production of sustained left atrial (LA) hypertension by a LA balloon over a period of 195 min. In 6 of these animals data were also acquired after the intravenous administration of furosemide (1 mg/kg). The renal effects of the diuretic were blocked by tying off the ureters and the vascular supply of both kidneys. Left atrial pressure (N = 11) was abruptly increased from 2.2 +/- 2.1 mm Hg to 30.2 +/- 4.0 mm Hg (P less than 0.01) and maintained at that level for 120 min. Data were obtained prior to pressure elevation, immediately upon pressure elevation, and then every 60 min for a total of 120 min. At that point EVLW had increased (8.1 +/- 0.8 cc/kg at control to 21.7 +/- 2.0 cc/kg at 120 min, P less than 0.001), as had PBV (6.2 +/- 2.1 cc/kg to 9.1 +/- 3.1 cc/kg P less than 0.01). After furosemide injection (N = 6), LA pressure declined (mean peak reduction of approximately 6 mm Hg at 60-75 min, P less than 0.01), aortic and pulmonary arterial pressure both declined (P less than 0.01). However, EVLW remained unchanged, though PBV decreased significantly (peak decrease at 75 min after furosemide administration of 2.0 +/- 0.4 cc/kg, P less than 0.01). In the untreated dogs, EVLW continued to climb (P less than 0.05 vs treated dogs at 75 min postfurosemide).(ABSTRACT TRUNCATED AT 250 WORDS)

WE‐D‐304A‐04: Performance of a Method to Aid Breast Ultrasound Interpretation Using Image Processing and Case‐Based Reasoning

Purpose: To examine factors that may impact accuracy, reproducibility of Breast UltrasoundCADxsoftware. Goal for CADx is standardized reporting of findings using well‐defined descriptors and to aid accuracy and reproducibility of interpretation by radiologists.Method and Materials: Breast Companion® (BC, Almen Laboratories and UCSD) provides tools to analyze breast masses. It computes 9 features of the mass, compares these to images in Reference Library of masses with known findings. Using Relative Similarity it retrieves instantaneously a cluster of the most similar cases and outputs numerical data including Computerized Lesion Assessment (CLA) following the ACR BI‐RADS assessment category (1 through 5). Results: On 596 cases with known findings BC achieved ROC Area 0.98±0.02, Sensitivity 99.7%, Specificity 96.1%, significantly higher than four experienced radiologists who read the same cases (ROC Areas 0.88 to 0.90±0.02). Increasing the number of cases in the Reference Library from 41–331 and the number Test Set cases from 20–924 keeping mix same, ROC varied from 0.90±0.07 to 0.98±0.02 (NS). In 55 cases (40% malignant) with confirmed findings BC calculated CLAs for radial and anti‐radial images that were highly correlated, not significantly different by two‐tailed t‐test (p>.5). CLA for simple cysts was 2.0, mean for complicated cysts was 2.5, 3.0 for solid benign and 4.5 for malignants. 28 subjects (40% malignant) were analyzed who had exams of the mass on two different occasions within 3 weeks on GE and Siemens (NS difference). Simulated masses of were imaged over 3 months at 9, 10, 13 MHz with varying gain, dynamic range, focal depth post‐processing. CLA was stable and independent of or linearly scaled to machine parameters. Conclusion: The BC system accuracy is high, stable over range of conditions. Measured parameters are dimensionless, relative to their backgrounds so it appears normalization achieves mitigation in machine effects.

Investigation of a method to assess breast ultrasound level of suspicion

Research studies indicate that careful application of breast ultrasound is capable of reducing the number of unnecessary biopsies by 40% with potential cost savings of as much as

Intravascular and extravascular pulmonary fluid volumes during chronic experimental left ventricular dysfunction

1 billion per year in the U.S. A well-defined rule-based system has been developed for scoring the Level of Suspicion (LOS) based on parameters describing the ultrasound appearance of breast lesion. Acceptance and utilization of LOS is increasing but it has proven difficult to teach the method and many radiologists have felt uncomfortable with the number of benign and malignant masses that overlap in appearance. In practice, the quality of breast ultrasound is highly operator dependent, it is often difficult to reproduce a finding and there is high variability of lesion description and assessment between radiologists. The goal of this research is to improve the uniformity and accuracy of applying the LOS scheme by automatically detecting, analyzing and comparing breast masses using sophisticated software developed for satellite imagery applications. The aim is to reduce biopsies on the masses with lower levels of suspicion, rather that increasing the accuracy of diagnosis of cancers, which will require biopsy anyway. In this paper we present our approach to develop a system to process, segment, analyze and classify medical images based on information content. A feasibility study was completed in a digital database of biopsy-proven image files from 46 women retrieved chronologically from our image library. Segmentation and classification were sufficiently accurate to correctly group all benign cystic masses, all benign solid masses and all solid malignant masses. The image analysis, computer-aided detection and image classification software system Image Companion developed by Almen Laboratories, Inc. was used to achieve the presented results.