Risk screening in a medicare/medicaid population administrative data versus self report.

OBJECTIVE: To compare the abilities of two validated indices, one survey-based and the other database-derived, to prospectively identify high-cost, dual-eligible Medicare/Medicaid members. DESIGN: A longitudinal cohort study. SETTING: A Medicaid health maintenance organization in Philadelphia, Pa. PARTICIPANTS: HMO enrollees (N = 558) 65 years and older eligible for both Medicare and Medicaid. MEASUREMENTS AND MAIN RESULTS: Two hundred ninety six patients responded to a survey containing the Probability of Repeat Admission Questionnaire (Pra) between October and November 1998. Using readily available administrative data, we created an administrative proxy for the Pra. Choosing a cut point of 0.40 for both indices maximized sensitivity at 55% for the administrative proxy and 50% for the survey Pra. This classification yielded 103 high-risk patients by administrative proxy and 73 by survey Pra. High-cost patients averaged at least 2.3 times the resource utilization during the 6-month follow-up. Correlation between the two scores was 0.53, and the scales disagreed on high-cost risk in 78 patients (54 high-cost by administrative proxy only, and 24 high-cost by survey Pra only). These two discordant groups utilized intermediate levels of resources, $2,171 and $2,794, that were not statistically significantly different between the two groups (probability > chi2 =.66). Receiver operating characteristic curve areas (0.68 for survey Pra and administrative proxy for respondents, and 0.67 by administrative proxy for nonrespondents) revealed similar overall discriminative abilities for the two instruments for costs. CONCLUSIONS: The Medicaid/Medicare dual-eligible population responded to the survey Pra at a rate of 53%, limiting its practical utility as a screening instrument. Using a cut point of 0.40, the administrative proxy performed as well as the survey Pra in this population and was equally applicable to nonrespondents. The time lag inherent in database screening limits its applicability for new patients, but combining database-driven and survey-based approaches holds promise for targeting patients who might benefit from case management intervention.

Cultural identity and health lifestyles among African Americans: a new direction for health intervention research?

OBJECTIVES: To assess associations of cultural and personal identity variables with socioeconomic status (SES) and health lifestyle in African Americans. DESIGN: Cross-sectional. METHODS: A questionnaire administered to 333 African Americans, ages 40-70 years, at enrollment in a nutrition education study assessed: African-American cultural identity (15 items scored 1 [low] to 4 [high]); reference group (two questions about perceived success in the Black or White way of life-scored as bi-cultural if "yes" to both); personal identity (4 items on: self-concept as attractive, self-confident, satisfied and friendly-scored 1 [no/not sure] or 2 [yes]); and selected demographic and lifestyle variables. RESULTS: Cultural identity factors reflecting participation in and belonging to African-American culture and bi-cultural reference group were related to higher SES, lower fat diets, not smoking, current drinking, and higher leisure time physical activity (cultural identity only), particularly in women (P<.001 to P = .06). Associations of cultural identity with physical activity and of bi-cultural reference group with low-fat eating and not smoking (females) remained significant at P<.05 after adjustment for SES. CONCLUSIONS: A greater emphasis is needed on aspects of cultural identity that are positively related to health lifestyles as distinct from aspects that might act as barriers.

Detection of Björk-Shiley convexo-concave heart valve outlet strut single leg separations: consensus image acquisition and interpretation using two different cineradiographic imaging technologies.

BACKGROUND: Conventional cineradiology has been used clinically to detect partially broken outlet struts (single leg separations, SLSs) in normally functioning Björk-Shiley convexo-concave (C/C) heart valves. The value of radiographic screening has, however, been debated in the medical literature. This study uses the same radiographic technique in sheep implanted with known-status C/C valves in combination with a newly developed geometric image magnification radiography system. This study was designed to test whether sensitivity and specificity of radiographic screening of C/C valves in detecting SLSs could be improved through the combination of readers and imaging modalities. METHODS: Twenty-one sheep with mitral C/C valves were studied on both systems. Five were used for extensive scanning training. When operators were expert on both systems, 16 blinded study valves (4 intact and 12 with outlet strut SLSs) were scanned twice on both systems, first on a modified conventional and then a prototype geometric image magnification (Feinfocus(TM)) cineradiographic system by two expert physicians working together. RESULTS: Among the 32 scanned valves, the two combined expert physicians were required to evaluate 40 intact legs and 24 with an SLS. For all SLS valves, the conventional and Feinfocus systems separately detected 50 (12/24) and 54% (13/24), respectively. When the two systems were combined, the final consensus score was correct in 67% (16/24) of all SLS valves. CONCLUSIONS: Combined modality, paired expert physicians detected 67% of all SLSs. The Feinfocus system might be best reserved for those patients in whom the Siemens screening study demonstrates in minimally suspicious (grade 2) or suspicious (grade 3) appearance of a C/C valve outlet strut leg.

CT bronchoscopy: optimization of imaging parameters.

The authors evaluated the relative importance of the following scanning parameters at computed tomographic bronchoscopy in an anesthetized adult sheep's thorax: section thickness (2, 4, 8 mm), pitch (1.0, 1.5, 2.0), milliampere setting (100, 175, 250 mA), and overlap of reconstructed sections (0%, 25%, 50%, 75%). Five blinded readers ranked the images twice in comparison with photographs of the mounted specimen. Differences in image quality were significant (P < .001) with section thickness of 2 mm and a pitch of 1.0. The milliampere setting had only a minor effect on image quality, and a 50% overlap of reconstructed sections was best.

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.

The readability of currently used surgical/procedure consent forms in the United States.

BACKGROUND: Informed consent forms are universally used by hospitals throughout the United States before surgery or invasive procedures. This survey was undertaken to determine the content of these forms and their ability to be understood by individuals with differing reading comprehension levels. METHODS: Ten percent of all U.S. hospitals were requested to forward a copy of their current surgical/procedural informed consent form. The forms received were digitized and computer assessed for readability. In addition, each form was evaluated for a variety of items with respect to content. RESULTS: Of the 2194 requests mailed, 681 responses were received including 616 with surgical/procedural consent forms. The mean grade level required to understand these consent forms was 12.6 (+/- 3.1). There was no variability in readability scores on the basis of hospital bed size. Of the 616 consent forms reviewed, 29, 146, 347, and 461 forms could be understood by individuals reading at a grade level of less than 8 and at least 8, 10, and 12 years of education, respectively. Although most required the name of the patient, physician, and procedure, the majority did not describe or provide a full-in blank for the specific benefits, risks, and alternatives to the procedure. CONCLUSIONS: The majority of surgical/procedural informed consent forms currently used by U.S. hospitals are complex and are not easily understood by the average patient. In addition, the majority of reviewed consent forms do not list specific benefits or potential complications of the planned surgery/procedure.

In vivo accuracy of two radiographic systems in the detection of Björk-Shiley convexo-concave heart valve outlet strut single leg separations.

OBJECTIVE: Modified cineradiographic systems have been used clinically to detect partially broken outlet struts in normally functioning Björk-Shiley convexo-concave heart valves. Almost all such valves were explanted, presuming that full failure would likely follow. Inasmuch as the clinical setting only rarely permits examination of normally rated valves, the accuracy of radiographic detection cannot be clinically defined. This study uses the clinical radiographic technique in sheep implanted with known-status convexo-concave valves, comparing its accuracy and that of a newly developed, geometric image magnification radiography system. METHODS: Twenty-one sheep with mitral convexo-concave valves were studied on both systems. Five were used for extensive training. When operators were expert with both systems, images of four intact valves and 12 valves with outlet strut single leg separations, along with a seventeenth single leg separation valve used for calibration, were integrated into 112 image sets organized into a balanced incomplete block design for evaluation by eight trained, blinded reviewers. RESULTS: Cineradiography sensitivity was 24% versus 31% for direct image magnification. The odds ratio for detection of single leg separation by direct image magnification versus cineradiography was 2.0 (95% confidence interval, 0.76 to 5.9; p = 0.13). Cineradiography specificity was 93% versus 90% for direct image magnification. Sensitivity and specificity varied markedly by reviewer, with sensitivity ranging from 8% to 55% and specificity from 51% to 100% for the combined technologies. CONCLUSIONS: The data support the need for more intensive training for convexo-concave valve imaging and further investigation of unconventional radiographic technologies. Clinical cineradiography of convexo-concave valves may detect as little as 25% of valves having a single leg separation, underestimating the prevalence of single leg separations and thereby implying more rapid progression to full fracture than is actually the case.

Utility of low mA 1.5 pitch helical versus conventional high mA abdominal CT.

The objective of this study was to evaluate the utility of a low mA 1.5 pitch helical versus conventional high mA conventional technique in abdominal computed tomography (CT). Twenty-five patients who had both a conventional high mA (> 300) and a 1.5 pitch low mA (80-125) helical CT within 3 months were selected for inclusion in the study. Patients were excluded who had a significant change in pathology between the two studies. The other parameters (injection rate, contrast type and volume, and filming window/level) were constant. The studies were randomized and blinded to five separate experienced readers who graded the studies by a variety of normal anatomical structures and pathological criteria. Overview questions also assessed noise, resolution, contrast, and overall quality. The abdominal wall/retroperitoneum and hiatal hernias were statistically better visualized on the conventional high mA studies. However, for all other normal anatomical and pathological sites, there was equivalent or better visualization on the helical versus the conventional CT examinations. The resolution of the helical studies was graded statistically better than the high mA conventional CT scans as was the amount of noise present on the images. While there was some advantage for conventional high mA CT with respect to contrast enhancement and low contrast sensitivity, these differences were not statistically significant. It appears from the data of this study that a low mA technique in evaluating the abdomen may be a useful option in performing routine abdominal CT. The radiation dose savings to the patient is significant and there appears to be little degradation of image quality using a low mA 1.5 helical versus mA conventional CT technique.

Extended pitch thoracic helical CT 47.

The objective of this study was to test whether extended 1.5 pitch helical computed tomography (CT) can be used for routine thoracic CT without a significant loss of clinical scan quality. Thirty consecutive patients presenting for contrast thoracic CT were computer randomized into one of three groups: conventional, 1.0 pitch helical, and 1.5 pitch helical. All other variables, including kV, mA, slice thickness and reconstruction interval, and contrast administration, were kept constant. The studies were randomized to five independent, blinded, experienced radiologists who rated visualization 25 normal structures, and up to five pathologic findings per patient. In addition, each reader evaluated the studies' contrast enhancement, low contrast sensitivity, linear resolution, motion artifact, noise, and overall quality. The visualization score for all normal and overall for pathological lesions did not vary between groups. The three groups were not equivalent for several individual pathologic categories. However, these differences were not consistently in favor of one technique over the other two. The overall score for scan quality was not significantly different between the three groups. Extended 1.5 pitch thoracic helical CT provides equivalent quality versus either 1.0 pitch helical or conventional CT. The use of 1.5 pitch helical thoracic CT allows faster scanning, greater patient coverage, and the use of reduced amounts of intravenous contrast.

Comparison of 1.0-, 1.5-, and 2.0-pitch abdominal helical computed tomography in evaluation of normal structures and pathologic lesions.

RATIONALE AND OBJECTIVES: The authors performed a comprehensive prospective clinical trial comparing 1.0-, 1.5-, and 2.0-pitch abdominal helical computed tomography (CT) in the evaluation of normal and pathologic structures/lesions. METHODS: Seventy-five consecutive patients were randomized by computer into one of three equal groups: helical CT pitch 1.0, 1.5, and 2.0. The imaging parameters and contrast enhancement of all 75 patients were kept constant. The 75 studies were masked, placed into a randomized order, and evaluated by five separate experienced radiologists who rated visualization of 25 normal structures and up to five pathologic findings per patient using a scale of 1 (not seen) to 5 (very well seen/very sharp margins). RESULTS: There were no statistical differences in 1.0- and 1.5-pitch abdominal CT scans when assessing the display of normal and pathologic lesions. In addition, helical pitch 1.0 and 1.5 studies were equivalent for both normal and pathologic structures/lesions, whereas equivalency was not demonstrated for helical pitch 2.0 studies. Overall study assessment questions again found equivalency between helical 1.0- and 1.5-pitch studies. CONCLUSIONS: Abdominal CT performed with pitches of 1.0 and 1.5 are equivalent. Because of its advantages, we advocate the routine use of an extended pitch (1.5) in routine abdominal CT. Further studies are required to evaluate the usefulness of the helical 2.0-pitch technique.

The breast: in-plane x-ray protection during diagnostic thoracic CT--shielding with bismuth radioprotective garments.

PURPOSE: To evaluate the ability of thin overlying bismuth radioprotective shielding to reduce the x-ray dose to radiosensitive superficial organs during diagnostic computed tomography (CT). MATERIALS AND METHODS: A variety of patient and phantom studies were performed with four thicknesses of bismuth radioprotective latex over the breast. Dose savings were determined with thermoluminescent dosimeters. A prototype and then a final manufactured radioprotective brassiere was constructed and tested for radiation dose savings to the breast during diagnostic chest CT. Preliminary studies were also performed to evaluate shielding of the thyroid, orbit, and testes. RESULTS: The use of bismuth radioprotective latex saved an average 57% of the radiation dose to the breast from thoracic CT, decreasing the radiation level from an average 2.2 rad (0.022 Gy) to 1.0 rad (0.010 Gy) (P < .001). Preliminary tests of shielding other superficial radiosensitive organs frequently included at diagnostic CT (eyes, thyroid gland, and testes) were performed with the same thickness of overlying bismuth radioprotective latex, with similar results. Radiation to the thyroid gland was reduced by 60% (from 0.0573 to 0.0229 Gy) and radiation to the eye and testes was reduced by 40% (from 0.0256 to 0.0154 Gy) and 51% (from 0.0463 to 0.0229 Gy), respectively. CONCLUSION: The use of in-plane overlying bismuth radioprotective latex manufactured into form-fitting garments did not affect the diagnostic CT image but reduced the amount of radiation to radiosensitive superficial structures.

Gel tubes: a method of core-specimen retrieval and transport.

The utility of saving core biopsy specimens in sterile gel tubes was evaluated with 30 liver and 30 kidney core specimens obtained at open biopsy with an 18-gauge needle during autopsy. The core specimens were saved with one of three methods: gel tube, formalin swirl, or scalpel retrieval. The combined-organ mean time for the radiologist to save core specimens was not statistically significantly different with gel tubes (3.8 seconds) and the formalin-swirl method (4.5 seconds). Both of these methods, however, were significantly faster than the scalpel-retrieval method (11.2 seconds) (P < .001). The combined radiologist and cytotechnologist time was greatest with the gel tubes (35.1 seconds vs 14.7 and 21.2 seconds, respectively). Core specimens were broken with the formalin-swirl and scalpel-retrieval methods but not with the gel-tube method.

Thoracic spiral CT: delivery of contrast material pushed with injectable saline solution in a power injector.

A method of power injection of contrast material pushed with injectable saline solution during thoracic computed tomography (CT) was evaluated in 75 patients to help decrease the amount of contrast material necessary. Patients received 50-125 mL of 60% nonionic contrast material alone or pushed with 50 mL of saline. A volume of 75 mL of contrast material pushed with saline provided enhancement of the thoracic vasculature equal to that provided by a 125-mL volume of contrast material administered alone (P < .001) and caused significantly less beam-hardening artifact (P < .01).

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.

Literacy assessment in a cardiovascular nutrition education setting.

We assessed functional literacy of hypercholesterolemic or hypertensive African Americans (n = 339) prior to their participation in a nutrition education program. A word pronunciation and recognition test using 20 common cardiovascular or nutrition terms was first developed based on correlations with standardized reading achievement test scores, then administered to program participants. Nearly half (48%) had word recognition scores equivalent to a < or = 8th grade reading level. Lower scores were associated with less education, lower income, unemployment, heavier work activity if employed, less healthy diets, history of heart disease or diabetes, and higher depression scores (all P < 0.01); several of these associations were independent of education. The educational materials were geared to a 5th to 8th grade reading level. However, when both audiotaped and printed instruction were provided, individuals with reading scores < or = 8th grade preferentially used the tapes. This brief and relatively unobtrusive literacy assessment may help to identify persons who can benefit most from audiovisual approaches to cardiovascular nutrition education.

The public release of hospital and physician mortality data in Pennsylvania. A case study.

OBJECTIVES: Using the public reports of the Pennsylvania Health Care Cost Containment Council on coronary artery bypass graft surgery for 1990 to 1992 as a case study, the authors assess the sensitivity of results to the choice of data and statistical methodology. METHODS: Using the Council's public-release data, surgical mortality and utilization were reanalyzed by standard linear models, empirical Bayes methods, Monte Carlo simulations, and hierarchical statistical models. RESULTS: Statistical power calculations demonstrate that the annual volume of bypass surgery for many hospitals and for most surgeons is too small for meaningful mortality comparisons. The number of hospitals and physicians designated as mortality "outliers" in the Council's reports results in part from a failure to adjust critical P values for multiple comparisons. Hierarchical statistical models implemented by mixed effects logistic regression, by contrast, can detect true differences in performance without producing false outliers. Mortality analyses are sensitive to the choice of comorbidities used for severity adjustment of a mortality model. Small-area analyses indicate large differences in the rates of bypass surgery across Pennsylvania, with lower population-based rates of surgery associated with higher population-based inpatient mortality. CONCLUSIONS: Analyses of mortality by operative procedure, rather than by patient diagnosis, should consider the potential for selection bias caused by the decision to elect surgery. The clinical and statistical issues of operative mortality are sufficiently complex to merit review by independent experts before public release of hospital and physician performance measures.

The effect of helical CT on X-ray attenuation.

PURPOSE: Conventional CT has been shown to have wide variability in measured CT attenuation, both temporally within the same scanner and between different scanners. Many radiologists have raised the concern that the increased noise and multiple variables associated with helical CT may lead to degradation in resolution, specifically causing errors in CT number values. This study was designed to specifically evaluate the performance of both types of CT scanning in this regard. METHOD: A Picker PQ2000 helical CT scanner was used to scan a phantom containing multiple tissue-equivalent densities, allowing the measurement of CT attenuation of soft tissue, distilled water, cortical bone, medullary bone, air, and fat with a variety of techniques. A Catphan phantom was imaged with a variety of slice thicknesses (2, 4, and 8 mm), phantom positions (isocenter, y = +20 cm), and pitches (1.0, 1.5, 2.0) using both conventional and helical sequences. The entire image set was repeated with two additional annuli placed around the Catphan phantom to simulate the abdomen and the calvarium. The attenuation measurements of the same imaging parameters for helical versus conventional CT were statistically compared. RESULTS: No statistical differences were found for the CT numbers based on scan type (conventional versus helical) for all sequences and gantry positions tested, including helical CT with pitches > 1.0. Greater CT number variability was found with the extremes of tissue density such as with air and especially cortical bone, but were not statistically significant. The addition of the abdominal and calvarial annuli created a greater variation in CT attenuation values, but again were not statistically significant. CONCLUSION: The measurement of X-ray attenuation does not vary significantly with the use of the helical technique.

The impact of 2D versus 3D quantitation of tumor bulk determination on current methods of assessing response to treatment.

PURPOSE: Measurements from sequential axial "2D" data in cancer patients are commonly used to assess treatment response or disease progression. This study compares the volume of tumor bulk calculated with 3D reconstructions with that calculated by conventional methods to determine if it might change patient classification. METHOD: All medical, gynecologic, and pediatric oncology patients under treatment who were evaluated with serial CT scans between January 1, 1992, and July 31, 1994, for whom the digital data were available were included in this study. For each tumor site, the maximum diameter and its perpendicular were measured and multiplied together to yield an area. The sum of areas of the measured lesions was used as an approximation of overall 2D tumor volume. In addition, the 2D area of each site was multiplied by its height, yielding a 2D volume. Last, the digital data were loaded into a 3D computer system and total 3D tumor volumes determined. All medical and gynecologic oncology patients were treated based upon the 2D area of tumor. The pediatric oncology patients were treated based upon the 2D volume of tumor measured as per standard practice. The members of each treating oncologic service assessed their patients as to how the other two methods would have changed their classification of the patients' response category. RESULTS: Four hundred thirty-three CT scans were performed in 139 patients, which included 204 baseline and 294 follow-up CT examinations. Seventy patients had new tumor foci and would have been classified as failure by all three methods of tumor bulk measurement. The 3D volume versus the 2D area method of tumor bulk assessment would have changed response categories in 52 of the 294 follow-up CT examinations (p < 0.0001). Thirty-five patients were recategorized from either "no response" to "failure" (21 patients) or "no response" to "response" (14 patients) categories. If only those follow-up studies without new metastatic foci are considered, the 3D volume versus the 2D area methods of tumor assessment would have changed the treatment response category in 23.2%. The use of the 2D volume method of calculating tumor volume of bulk tended to overestimate the overall tumor size by an average of 244 cm3 (p = 0.001). CONCLUSION: The 3D method of tumor volume measurement differs significantly from conventional 2D methods of tumor volume determination. Large prospective studies analyzing the usefulness of 3D tumor volume measurements and assessing possible changes in patient response categories would be required for full utilization of this more accurate method of following disease bulk.

Analysis of interobserver and intraobserver variability in CT tumor measurements.

OBJECTIVE: The purpose of this study was to evaluate the variability between radiologists interpreting thoracic and abdominal/pelvic CT scans in selecting specific sites of metastatic tumor for measurement (indicator lesions) and to assess interobserver and intraobserver variability in tumor measurement. MATERIALS AND METHODS: Three separate experienced radiologists were asked to review 24 combined thoracic and abdominal CT scans in patients with metastatic tumor. Each radiologist was asked to identify the indicator lesions representative of each patient's tumor bulk. In the second phase of the study, 105 specific foci on 26 combined thoracic and abdominal CT studies (including the original 24) were reviewed twice by the same three radiologists. Up to eight foci were randomly identified per patient, and each observer was asked to determine the slice with the maximum diameter for each tumor focus and to measure it in three dimensions (maximum diameter, its perpendicular, and length). RESULTS: A total of 132 tumor sites were present on the CT studies in phase I, all of which were chosen by at least one observer as an indicator lesion. Of the 116 of these that were separate and nonoverlapped, 57 (49%) were measured by only one observer, whereas 32 (28%) and 27 (23%) were measured by two or all three observers, respectively. Observers were more inclined to pick round or defined/well-defined lesions rather than irregular, oval, or poorly defined ones, although this tendency was not statistically significant. The second phase of the study showed considerable interobserver variability (15%) in CT tumor measurement, which was worse for poorly defined and irregular lesions. Intraobserver variability in measuring individual foci was less (6%). CONCLUSION: Radiologists interpreting thoracic and/or abdominal/pelvic CT scans for metastatic cancer should measure and report a significant number of each patient's tumor sites, especially larger ones in different anatomic areas. When interpreting a follow-up CT scan of a patient with metastatic cancer, the interpreting radiologist should remeasure the indicator lesions on the previous and on the follow-up CT scans, especially when the results will change the patient's treatment response category.

Routine use of a higher order interpolator and bone algorithm in thoracic CT.

OBJECTIVE: This study was designed to evaluate the utility of the routine use of high spatial frequency algorithms and higher order helical interpolators for imaging lung parenchyma during routine thoracic CT. SUBJECTS AND METHODS: We evaluated 50 consecutive patients undergoing clinically indicated thoracic CT using the same imaging parameters and scanner. The helical volume was reconstructed three separate times using standard and higher order (180 degrees linear with double-sided lobes) interpolators and standard and high spatial frequency (bone) algorithms. The images were photographed and given to five separate readers who were kept unaware of the interpolator and algorithm and who were asked to evaluate simultaneously each patient's three sets of images for best, in-between, and worst images of the lung interstitium, pathology, and normal anatomy. RESULTS: All five readers rated the standard interpolator and algorithm images as the worst (p < .01). All five readers consistently rated the double-sided lobe interpolator and bone algorithm images as the best (p < .01). CONCLUSION: A second reconstruction of routine thoracic helical CT data using higher order helical interpolators and a bone algorithm significantly improves interstitial detail of lung parenchyma and overall visualization of normal anatomy and pathologic processes.