Pamela M Otto

How well can the chest radiograph diagnose left ventricular dysfunction

OBJECTIVES: To review the diagnostic utility of the chest radiograph for left ventricular dysfunction.DATA SOURCES: Structured MEDLINE searches, citation reviews of relevant primary research, review articles, and textbooks, personal files, and data from experts.STUDY SELECTION: Studies of patients without valvular disease that allowed calculation of the sensitivity and specificity of selected radiographic signs compared with a criterion standard of increased left ventricular preload or reduced ejection fraction.DATA EXTRACTION: Two independent readers reviewed 29 studies. Studies were pooled after stratification by radiographic finding, criterion standard, and clinical setting.MAIN RESULTS: Redistribution best diagnosed increased preload with a sensitivity of 65% (95% confidence interval [CI] 55%, 75%) and specificity 67% (95% CI 53%, 79%). Cardiomegaly best diagnosed decreased ejection fraction with a sensitivity of 51% (95% CI 43%, 60%) and specificity of 79% (95% CI 71%, 85%). Interrater reliability was fair to moderate for redistribution and moderate for cardiomegaly. The clinical setting affected results by decreasing the specificity of cardiomegaly to 8% in detecting increased preload in patients with severe systolic dysfunction. The absence of redistribution could only exclude increased preload in situations in which the suspicion (pretest probability) of disease was less than 9%, whereas redistribution could confirm increased preload when the pretest probability was greater than 91%. The absence of cardiomegaly could only exclude a reduced ejection fraction if the pretest probability was less than 8%, whereas cardiomegaly could confirm a reduced ejection fraction if the pretest probability was greater than 87%.CONCLUSIONS: Redistribution and cardiomegaly are the best chest radiographic findings for diagnosing increased preload and reduced ejection fraction, respectively. Unfortunately, neither finding alone can adequately exclude or confirm left ventricular dysfunction in usual clinical settings. Redistribution is not always reliably interpreted.

Pathologic review of atypical hyperplasia identified by image-guided breast needle core biopsy: Correlation with excision specimen

CONTEXT Management of breast needle core biopsies diagnosed as atypical ductal hyperplasia, atypical lobular hyperplasia, and lobular carcinoma in situ is controversial. Current recommendations involve excisional biopsy to rule out ductal carcinoma in situ and/or invasive carcinoma, which have been reported in more than 50% of cases in some series. OBJECTIVE To determine how frequently these diagnoses made on needle core biopsy are ultimately found to represent in situ or invasive carcinoma based on excisional biopsy specimens, in order to identify predictive factors. DESIGN One thousand eight hundred thirty-six image-guided needle core biopsies were performed between January 1, 1995 and May 1, 2001. Fifty-four (2.9%) patients diagnosed with atypical ductal hyperplasia (n = 36), atypical lobular hyperplasia (n = 12), atypical ductal hyperplasia + atypical lobular hyperplasia (n = 3), or lobular carcinoma in situ (n = 3) subsequently underwent breast excisions. Pathologic features were reviewed in each of the needle core biopsies using Pages criteria and were then correlated with excision specimens. SETTING University medical center. RESULTS Review of the needle core biopsy cases with either ductal carcinoma in situ or invasive carcinoma + ductal carcinoma in situ on final excision showed that nucleoli were evident in most of the needle core cases, with foci of nuclear pleomorphism and individual cell necrosis or apoptosis. CONCLUSION A more precise diagnosis can be made by using strict criteria for atypical ductal hyperplasia versus ductal carcinoma in situ on needle core biopsy. Cytologic atypia, even if in a small area, particularly when there is apoptosis/individual cell necrosis, correlates with the finding of a more serious lesion on excision.

Development of laser optoacoustic and ultrasonic imaging system for breast cancer utilizing handheld array probes

We describe two laser optoacoustic imaging systems for breast cancer detection based on arrays of acoustic detectors operated manually in a way similar to standard ultrasonic breast imaging. The systems have the advantages of standard light illumination (regardless of the interrogated part of the breast), the ability to visualize any part of the breast, and convenience in operation. The first system could work in both ultrasonic and optoacoustic mode, and was developed based on a linear ultrasonic breast imaging probe with two parallel rectangular optical bundles. We used it in a pilot clinical study to provide for the first time demonstration that the boundaries of the tumors visualized on the optoacoustic and ultrasonic images matched. Such correlation of coregistered images proves that the objects on both images represented indeed the same tumor. In the optoacoustic mode we were also able to visualize blood vessels located in the neighborhood of the tumor. The second system was proposed as a circular array of acoustic transducers with an axisymmetric laser beam in the center. It was capable of 3D optoacoustic imaging with minimized optoacoustic artifacts caused by the distribution of the absorbed optical energy within the breast tissue. The distribution of optical energy absorbed in the bulk tissue of the breast was removed from the image by implementing the principal component analysis on the measured signals. The computer models for optoacoustic imaging using these two handheld probes were developed. The models included three steps: (1) Monte Carlo simulations of the light distribution within the breast tissue, (2) generation of optoacoustic signals by convolving N-shaped pressure signals from spherical voxels with the shape of individual transducers, and (3) back-projecting processed optoacoustic signals onto spherical surfaces for image reconstruction. Using the developed models we demonstrated the importance of the included spatial impulse response of the optoacoustic imaging system.

Detection and noninvasive diagnostics of breast cancer with two-color laser optoacoustic imaging system

We have designed, fabricated and tested a new laser optoacoustic imaging system (LOIS-64/16) for quantitative optoacoustic tomography of breast cancer. The system was designed to create a single slice of an optoacoustic image of the breast with 64 ultrawide band acoustic transducers. Other 16 transducers on the back of the acoustic probe were used to reconstruct the light distribution inside the breast. The system resolution was at least 0.5 mm for high-aspect-ratio objects. Maximum system sensitivity was 4.8 mV/Pa and the RMS noise of 3.1 mV, which allowed imaging of small (less than 1 cm) tumors at depths over 3 cm. The directivity of the optoacoustic transducers used in LOIS-64/16 assured that the signal detection was better than 70% of the maximum for about 75% of the imaging slice and reduced quickly for signals coming from out of the imaging slice. Implemented signal processing allowed significant reduction of the low-frequency acoustic noise and localizing the small OA signals. The system was able to differentiate phantoms mimicking tumors and malformations visualized in clinics based on the contrast and morphology of their images obtained at 1064 nm and 757 nm.

Recognition of abnormalities on computed scout images in CT examinations of the head and spine

SummaryWe investigated the information which can be obtained from the computer-generated digital radiographs (“scout images”) performed for CT examinations. One hundred CT examinations of the head and one hundred of the spine were randomly selected and retrospectively reviewed: the head scout images were acquired in the lateral projection, and those of the spine in the lateral and/or anteroposterior projections. In 122 patients with demonstrable pathology on the CT sections or the scout image, a total of 154 abnormalities was found, of which 31 (20%) were identified only on the scout images. Eight (25.8% of this number) required additional clinico-radiologic study and were therefore designated as clinically pertinent positives. This study demonstrates that the CT scout image may contain considerable, clinically relevant information which is not available on, or is complementary to, the CT sections.

Screening test for detection of metallic foreign objects in the orbit before magnetic resonance imaging

RATIONALE AND OBJECTIVES A study was designed to determine whether plain films, used as a screening modality for magnetic resonance imaging (MRI), could reliably detect intraorbital metallic foreign objects. METHODS In the first experiment, 20 metal particles were placed in five human cadaver orbits. Routine orbital plain film series and computed tomography (CT) were obtained, randomized, and interpreted blinded by three experienced radiologists. RESULTS The threshold size of particle detection for CT (0.07 mm3) was lower than for plain films (0.12 mm3). Placing metal particles in artificial and true vitreous demonstrated that all particles moved under a magnetic field at 1.5 T. When human globes were exposed to industrial tools (grinder, bandsaw, air hose, etc.), no metal objects penetrated the sclera. CONCLUSIONS Plain films can be used as a low-cost, low-radiation screening procedure for high-risk patients with occupations involving metal work. CT should be used for patients with a history of eye trauma from other causes.

Morphologic and immunophenotypic markers as surrogate endpoints of tamoxifen effect for prevention of breast cancer.

SummaryPrevention trials using incidence or mortality as endpoints require a large number of participants and long follow-up. Trials using biomarkers as endpoints would potentially require fewer participants, less time, and significantly less resources to test promising new agents for breast cancer prevention. To test this idea, a randomized trial of tamoxifen for 1 year versus observation for 1 year was conducted to determine whether tamoxifen can cause regression of hyperplastic breast tissue, whether it changes the biomarker phenotype of premalignant disease or normal breast epithelium, and if biomarkers can be used as early surrogate indicators of response to tamoxifen. Women were identified by having an abnormal mammogram and ductal hyperplasia diagnosed by core needle biopsy. Image-directed needle biopsy was repeated in the same site of the breast after 1 year. Approximately 3000 women were screened, and 265 were eligible. Sixty-three women were randomized and paired biopsies from 45 subjects were available for analysis. There was no evidence of substantial regression of hyperplasia – fewer samples showed hyperplasia at 1 year follow-up, but this was seen in both untreated and tamoxifen-treated women. There were trends for reductions in ER and PgR and trends for increases in bcl-2 in normal and hyperplastic tissue in the tamoxifen-treated arm, though these changes did not reach statistical significance. Proliferation, determined by Ki67 staining, was not significantly changed. Clinical trials of this type are difficult to carry out and modifications in trial design are needed to make this process more efficient.

Real-time optoacoustic imaging of breast cancer using an interleaved two-laser imaging system coregistered with ultrasound.

We present results from a clinical case study on imaging breast cancer using a real-time interleaved two laser optoacoustic imaging system co-registered with ultrasound. The present version of Laser Optoacoustic Ultrasonic Imaging System (LOUIS) utilizes a commercial linear ultrasonic transducer array, which has been modified to include two parallel rectangular optical bundles, to operate in both ultrasonic (US) and optoacoustic (OA) modes. In OA mode, the images from two optical wavelengths (755 nm and 1064 nm) that provide opposite contrasts for optical absorption of oxygenated vs deoxygenated blood can be displayed simultaneously at a maximum rate of 20 Hz. The real-time aspect of the system permits probe manipulations that can assist in the detection of the lesion. The results show the ability of LOUIS to co-register regions of high absorption seen in OA images with US images collected at the same location with the dual modality probe. The dual wavelength results demonstrate that LOUIS can potentially provide breast cancer diagnostics based on different intensities of OA images of the lesion obtained at 755 nm and 1064 nm. We also present new data processing based on deconvolution of the LOUIS impulse response that helps recover original optoacoustic pressure profiles. Finally, we demonstrate the image analysis tool that provides automatic detection of the tumor boundary and quantitative metrics of the optoacoustic image quality. Using a blood vessel phantom submerged in a tissue-like milky background solution we show that the image contrast is minimally affected by the phantom distance from the LOUIS probe until about 60-65 mm. We suggest using the image contrast for quantitative assessment of an OA image of a breast lesion, as a part of the breast cancer diagnostics procedure.

Clinical Feasibility Study of Combined Optoacoustic and Ultrasonic Imaging Modality Providing Coregistered Functional and Anatomical Maps of Breast Tumors

We report on findings from the clinical feasibility study of the ImagioTM. Breast Imaging System, which acquires two-dimensional opto-acoustic (OA) images co-registered with conventional ultrasound using a specialized duplex hand-held probe. Dual-wavelength opto-acoustic technology is used to generate parametric maps based upon total hemoglobin and its oxygen saturation in breast tissues. This may provide functional diagnostic information pertaining to tumor metabolism and microvasculature, which is complementary to morphological information obtained with conventional gray-scale ultrasound. We present co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical feasibility study. The clinical results illustrate that the technology may have the capability to improve the efficacy of breast tumor diagnosis. In doing so, it may have the potential to reduce biopsies and to characterize cancers that were not seen well with conventional gray-scale ultrasound alone.

Postlumpectomy focal brachytherapy for simultaneous treatment of surgical cavity and draining lymph nodes

PURPOSE The primary objective was to investigate a novel focal brachytherapy technique using lipid nanoparticle (liposome)-carried β-emitting radionuclides (rhenium-186 [(186)Re]/rhenium-188 [(188)Re]) to simultaneously treat the postlumpectomy surgical cavity and draining lymph nodes. METHODS AND MATERIALS Cumulative activity distributions in the lumpectomy cavity and lymph nodes were extrapolated from small animal imaging and human lymphoscintigraphy data. Absorbed dose calculations were performed for lumpectomy cavities with spherical and ellipsoidal shapes and lymph nodes within human subjects by use of the dose point kernel convolution method. RESULTS Dose calculations showed that therapeutic dose levels within the lumpectomy cavity wall can cover 2- and 5-mm depths for (186)Re and (188)Re liposomes, respectively. The absorbed doses at 1 cm sharply decreased to only 1.3% to 3.7% of the doses at 2 mm for (186)Re liposomes and 5 mm for (188)Re liposomes. Concurrently, the draining sentinel lymph nodes would receive a high focal therapeutic absorbed dose, whereas the average dose to 1 cm of surrounding tissue received less than 1% of that within the nodes. CONCLUSIONS Focal brachytherapy by use of (186)Re/(188)Re liposomes was theoretically shown to be capable of simultaneously treating the lumpectomy cavity wall and draining sentinel lymph nodes with high absorbed doses while significantly lowering dose to surrounding healthy tissue. In turn, this allows for dose escalation to regions of higher probability of containing residual tumor cells after lumpectomy while reducing normal tissue complications.