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Purpose: To perform external validation of a computer-assisted registration algorithm for prone and supine computed tomographic (CT) colonography and to compare the results with those of an existing centerline method., Materials and Methods: All contributing centers had institutional review board approval; participants provided informed consent. A validation sample of CT colonographic examinations of 51 patients with 68 polyps (6-55 mm) was selected from a publicly available, HIPAA compliant, anonymized archive. No patients were excluded because of poor preparation or inadequate distension. Corresponding prone and supine polyp coordinates were recorded, and endoluminal surfaces were registered automatically by using a computer algorithm. Two observers independently scored three-dimensional endoluminal polyp registration success. Results were compared with those obtained by using the normalized distance along the colonic centerline (NDACC) method. Pairwise Wilcoxon signed rank tests were used to compare gross registration error and McNemar tests were used to compare polyp conspicuity., Results: Registration was possible in all 51 patients, and 136 paired polyp coordinates were generated (68 polyps) to test the algorithm. Overall mean three-dimensional polyp registration error (mean ± standard deviation, 19.9 mm ± 20.4) was significantly less than that for the NDACC method (mean, 27.4 mm ± 15.1; P = .001). Accuracy was unaffected by colonic segment (P = .76) or luminal collapse (P = .066). During endoluminal review by two observers (272 matching tasks, 68 polyps, prone to supine and supine to prone coordinates), 223 (82%) polyp matches were visible (120° field of view) compared with just 129 (47%) when the NDACC method was used (P < .001). By using multiplanar visualization, 48 (70%) polyps were visible after scrolling ± 15 mm in any multiplanar axis compared with 16 (24%) for NDACC (P < .001)., Conclusion: Computer-assisted registration is more accurate than the NDACC method for mapping the endoluminal surface and matching the location of polyps in corresponding prone and supine CT colonographic acquisitions.

Purpose: Computed tomographic (CT) colonography is a relatively new technique for detecting bowel cancer or potentially precancerous polyps. CT scanning is combined with three-dimensional (3D) image reconstruction to produce a virtual endoluminal representation similar to optical colonoscopy. Because retained fluid and stool can mimic pathology, CT data are acquired with the bowel cleansed and insufflated with gas and patient in both prone and supine positions. Radiologists then match visually endoluminal locations between the two acquisitions in order to determine whether apparent pathology is real or not. This process is hindered by the fact that the colon, essentially a long tube, can undergo considerable deformation between acquisitions. The authors present a novel approach to automatically establish spatial correspondence between prone and supine endoluminal colonic surfaces after surface parameterization, even in the case of local colon collapse., Methods: The complexity of the registration task was reduced from a 3D to a 2D problem by mapping the surfaces extracted from prone and supine CT colonography onto a cylindrical parameterization. A nonrigid cylindrical registration was then performed to align the full colonic surfaces. The curvature information from the original 3D surfaces was used to determine correspondence. The method can also be applied to cases with regions of local colonic collapse by ignoring the collapsed regions during the registration., Results: Using a development set, suitable parameters were found to constrain the cylindrical registration method. Then, the same registration parameters were applied to a different set of 13 validation cases, consisting of 8 fully distended cases and 5 cases exhibiting multiple colonic collapses. All polyps present were well aligned, with a mean (+/- std. dev.) registration error of 5.7 (+/- 3.4) mm. An additional set of 1175 reference points on haustral folds spread over the full endoluminal colon surfaces resulted in an error of 7.7 (+/- 7.4) mm. Here, 82% of folds were aligned correctly after registration with a further 15% misregistered by just onefold., Conclusions: The proposed method reduces the 3D registration task to a cylindrical registration representing the endoluminal surface of the colon. Our algorithm uses surface curvature information as a similarity measure to drive registration to compensate for the large colorectal deformations that occur between prone and supine data acquisitions. The method has the potential to both enhance polyp detection and decrease the radiologist's interpretation time.

The role of health system laboratories is critical to the appropriate clinical integration of personalized medicine. We conducted semistructured interviews with experts and opinion leaders representing laboratory medicine, health policy and the diagnostics industry, to examine what is known about the real-world effectiveness of health laboratories as organizations. We describe and encourage the wider use of an evidence-based, novel Transformation Model© to prepare for the future and set goals for a better health system. A collaborative approach appropriately integrates the efficiency and high-quality expertise of the health laboratory system with the transformative vision of the personalized medicine community.

Background: Diagnostic errors occur in laboratory medicine resulting from an error or delay in diagnosis, a failure to employ indicated tests, and the use of outmoded tests. Since laboratory tests provide essential information used by physicians to make medical decisions, it is important to determine how often laboratory testing mistakes occur, whether they cause patient harm, where they are most likely to occur in the testing process, and how to prevent them from occurring., Methods: The US Quality Institute Conference in 2003 and the Institute for Quality in Laboratory Medicine in 2005 brought together providers of, users of, and payers for laboratory services to explore how working together they could help to reduce laboratory testing errors and enhance patient safety., Results and Conclusions: Users of and payers for laboratory services must become partners in the laboratory's efforts to reduce laboratory testing errors and enhance patient safety. They must be linked to a laboratory information system that provides assistance in decisions on test ordering, patient preparation, and test interpretation. Laboratory quality assessment efforts need to be expanded to encompass the detection of non-analytical mistakes. Healthcare institutions need to adopt a culture of safety that is implemented at all levels of the organization.

Purpose: To provide a summary of the outcomes of two working conferences organized by the Centers for Disease Control and Prevention (CDC), to develop recommendations for practical, sustainable mechanisms to make quality control (QC) materials available to the genetic testing community., Methods: Participants were selected to include experts in genetic testing and molecular diagnostics from professional organizations, government agencies, industry, laboratories, academic institutions, cell repositories, and proficiency testing (PT)/external Quality Assessment (EQA) programs. Current efforts to develop QC materials for genetic tests were reviewed; key issues and areas of need were identified; and workgroups were formed to address each area of need and to formulate recommendations and next steps., Results: Recommendations were developed toward establishing a sustainable process to improve the availability of appropriate QC materials for genetic testing, with an emphasis on molecular genetic testing as an initial step., Conclusions: Improving the availability of appropriate QC materials is of critical importance for assuring the quality of genetic testing, enhancing performance evaluation and PT/EQA programs, and facilitating new test development. To meet the needs of the rapidly expanding capacity of genetic testing in clinical and public health settings, a comprehensive, coordinated program should be developed. A Genetic Testing Quality Control Materials Program has therefore been established by CDC in March 2005 to serve these needs.

Objective: To examine the frequency and characteristics of problems in laboratory testing in primary care physicians's offices and their impact on health care., Design: Prospective descriptive study in which participating office-based primary care clinicians reported each occurrence of any laboratory incident during a 6-month study. Each identified problem was reported on a structured data collection instrument with an open-ended description of the problem., Setting: Primary care physicians' offices in North America., Participants: One hundred twenty-four primary care clinicians in 49 practices of the Ambulatory Sentinel Practice Network (ASPN)., Main Results: A total of 180 problems were reported, yielding a crude rate of 1.1 problems per 1000 patient visits. Problems involving test ordering and specimen handling were the most common (56%), while those attributable to the test analysis itself accounted for 13% of the total. In the judgment of the practice staff, 27% of the reported problems had an impact on patient care. Of the 24 cases for which the specific impact was known and reported, half of the impacts were minor and about half were significant, as judged by whether or not the diagnosis and/or treatment of the patient was measurably affected., Conclusions: Clinically apparent problems with laboratory testing in primary care were found at a rate of 1.1 problems per 1000 patient visits. Of the laboratory problems that occurred in this study, 27% were judged by the physician to have an effect on patient care.

Objective: To evaluate the reasons (indications) for and immediate intraoperative surgical results (outcomes) associated with pathology intraoperative consultation., Design: In 1992 and 1993, surgeons collaborated with pathologists in 472 voluntarily participating institutions from the United States (462), Canada (7), Australia (2), and New Zealand (1) in a study jointly sponsored by the College of American Pathologists and the Centers for Disease Control and Prevention. Pathologists selected 20 consecutive intraoperative consultations and assembled a cover letter, a checklist questionnaire, and a copy of the corresponding surgical pathology report, all of which were sent to the surgeon(s) for retrospective evaluation., Participants: The study was distributed to participants in the College of American Pathologists voluntary Q-Probes quality improvement and Surgical Pathology Performance Improvement programs and to Canadian and Australian hospitals with more than 200 beds., Results: Evaluation of 9164 cases established the five most common indications for intraoperative consultation: (1) establish or confirm diagnosis to determine type or extent of operation (51%), (2) confirm adequacy of margins (16%), (3) confirm nature of tissue to direct sampling for immediate culture or other laboratory study (10%), (4) expedite obtaining diagnosis to inform family or patient (8%), and (5) confirm sufficient tissue submitted to secure diagnosis in permanent section (8%). The information provided by the intraoperative consultation resulted in changed surgical procedures that were either modified, terminated, or newly initiated in 47%, 30%, 6%, 9%, and 28% of cases, corresponding respectively to each of the above five common indications. Rarely cited reasons for intraoperative consultation were to expedite obtaining diagnosis for surgeon's knowledge (3%), to facilitate patient management, other professional communication or discharge planning prior to permanent section availability (3%), academic protocol (< 1%), and consultation not needed or no reason for request (< 1%)., Conclusions: This multi-institutional, interdisciplinary database confirms that pathology intraoperative consultations, regardless of the initial indications, influence immediate patient care decisions, resulting in changed surgical procedures in an average of 39% of all operative cases.

Objective: To survey transfusion medicine practices in 1990, to determine the distribution of defects in the transfusion process, to examine the relationship between defects and complications, and to recommend improvements in the transfusion process., Design: A mail survey that divided the transfusion process into 24 risk-prone steps and gathered defect rates on each step, along with incidence data for eight known complications of transfusions and other demographic information., Settings: Hospitals, independent laboratories, and blood centers that provide transfusion medicine services., Other Participants: Respondents were 1365 participants in the College of American Pathologists 1991 Blood Bank Quality Assurance Survey., Results: While processing 6.2 million units of blood and blood products, respondents reported detecting over 88,000 defects: 41% in the preanalytic phase of testing, 55% in the postanalytic phase, and only 4% in the analytic phase, the phase to which most monitoring efforts were devoted. A median of eight steps were actively monitored by survey participants overall, whereas 96 facilities sought defects in all 24 steps., Conclusions: Analysis of the data showed several monitoring steps provide similar information. Although monitoring of the transfusion process could not be linked with prevention of the complications studied, active surveillance does focus attention on defect-prone steps and allows testing of strategies to improve the transfusion process. We describe how defect detection systems may be improved.

The Centers for Disease Control and Prevention (CDC) was delegated authority to conduct the studies mandated in the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Since that time, the CDC has been planning and implementing a research program, Evaluation of Quality of Laboratory Practices and Standards (EQLPS), aimed at demonstrating a clear linkage between patient outcome and laboratory practices and standards such as proficiency testing, quality assurance, and personnel standards. The goal of EQLPS is to improve the quality of laboratory medicine by providing a scientific and technical basis for laboratory practices and standards. In October 1995, the CDC will sponsor an Institute entitled "Frontiers in Laboratory Practice Research," during which strategies for conducting laboratory practice research will be discussed. The Institute should help identify research strategies that will eventually provide the information necessary to develop appropriate practice guidelines for laboratory medicine.

The quality of laboratory analytical performance required to support medical decision-making has been defined in four major ways: (a) by the analytical variance of the state of the practice; (b) by the total variance, including analytical and biological variability; (c) by the loss of diagnostic efficiency attributable to analytical error; and (d) by medical-usefulness criteria. From the federal government's perspective, the answer to the question "How good must a laboratory test result be to be medically relevant?" must take into account the clinical context of the test, with accompanying concerns about access, timeliness, and cost, as well as limits for precision and accuracy in the analytical process and the frequency and potential patient-care impact of error in the pre- and postanalytical steps of the total testing process. Therefore, medically relevant goals should encompass not only analytical precision and accuracy but also goals to provide access to clinically effective tests and to reduce errors in the total testing process that can lead to medically misleading information. Development of more appropriate regulatory requirements for laboratories, as well as any needed improvements in instrumentation and methodology, should focus on ensuring that goals for medically relevant results are met by appropriate design and management of the entire process of laboratory testing.

In conjunction with a 1990 Report to Congress on the studies required by the Clinical Laboratory Improvement Amendments of 1988 (CLIA '88), the Centers for Disease Control, Atlanta, Ga, prepared a summary of the existing scientific literature related to the five studies listed in Section 4 of the Act. Over 800 articles were identified that, by title, seemed to deal with subjects that have been assumed to be associated with the quality of clinical laboratory testing. Although our search was not exhaustive, we believe that the articles included in our search are representative of the scientific evidence that exists. Most of the articles collected in our initial search were later eliminated from additional review because they were determined to be evaluations of laboratory analytic methods, contained only anecdotal evidence, were primarily descriptions of methods or programs, or were opinion articles without specific scientific data to support the opinions. This review reports the conclusions drawn by the research investigators of the 90 referenced articles; it does not analyze each article to assess the scientific validity of the research nor does it critique each article that is included. The review points to the need for additional research to answer questions raised by CLIA '88.

Historically, the quality of laboratory performance that must be provided to adequately support medical decision-making has been defined in three major ways: by the analytical variance of the state of the practice; by the total variance, including the expected analytical and biological variability; and by medical-usefulness criteria. Quality goals defined by these approaches have influenced instrument manufacturers, professional societies, governmental agencies, and even the precision and accuracy of medical practice. Despite past efforts, a consensus has not emerged on a scientifically and medically supportable set of laboratory performance requirements. Medically relevant goals for analytic performance would help avoid costly and unnecessary regulatory requirements and permit steady improvement in instrumentation and methods.

More than 300 laboratories participated in an interlaboratory survey of creatine kinase (CK, EC 2.7.3.2) determinations in which they analyzed seven lyophilized samples for total CK and CK isoenzymes and furnished information about their methodology. The samples were not necessarily intended to mimic typical patients' specimens but rather to determine the analytical ability of the laboratories to distinguish isoenzyme fraction CK-MB from CK-BB and to detect small but abnormal amounts of CK-BB. For total CK measurement, most laboratories used an NADP+ reduction method monitored at 340 nm (89%), and reported results in units per liter (U/L) (99%) at either 30 degrees C (34%) or 37 degrees C (60%). Despite the variety of analytical conditions, most laboratories (89%) correctly reported results within their normal range for all samples. The 287 laboratories that reported isoenzyme distributions in the samples used either cellulose acetate (37%) or agarose (44%) electrophoresis, ion-exchange chromatography (9%), or immunoinhibition (7%). Results from laboratories that used nonspecific CK-MB immunoinhibition techniques were biased when a significant amount of CK-BB isoenzyme was present.

Using data from the Centers for Disease Control (CDC) Proficiency Testing (PT) Surveys, we obtained estimates of repeatability (intralaboratory variability between results on the same material) and reproducibility (interlaboratory variability between results on the same material) for the Technicon SMA 6 (or 12/60) and SMAC 1 (or II) systems used with cresolphthalein complexone methodology to measure serum calcium. The two systems were comparable in terms of short-term (within-day) repeatability, long-term (three to six months) repeatability, short-term (one to two weeks) reproducibility, and long-term (three to six months) reproducibility. The long-term repeatability was essentially the same as the long-term reproducibility. Short-term repeatability, long-term repeatability, and long-term reproducibility increased linearly with increased calcium concentration over the range 1.75 to 2.95 mmol/L; short-term reproducibility showed no significant change over this range. The effect of analytical variance on the definition of a reference change in semiannual calcium measurements was demonstrated.

Experimental evidence is presented that the determination of gamma-glutamyl transferase (GGT) activity in serum is useful in the assessment of alcohol-induced liver disease and for demonstrating to patients the toxic effects of their drinking habits on the liver. Serial measurements of GGT activity in serum have also proved valuable in monitoring the progress of therapy as well as alleged abstention from alcohol in the known alcoholic.

In response to questions about the reliability of the results of screening urine for drugs, we evaluated the performance of 13 laboratories, which serve a total of 262 methadone treatment facilities, by submitting prereferenced samples through the treatment facilities as patient samples (blind testing). Error rates for the 13 laboratories on samples containing barbiturates, amphetamines, methadone, cocaine, codeine, and morphine ranged from 11% to 94%, 19% to 100%, 0% to 33%, 0% to 100%, 0% to 100%, and 5% to 100%, respectively. Similarly, error rates on samples not containing these drugs (false-positives) ranged from 0% to 6%, 0% to 37%, 0% to 66%, 0% to 6%, 0% to 7%, and 0% to 10%, respectively. These blind tests indicate that greater care is taken with known evaluation samples than with routine samples, laboratories are often unable to detect drugs at concentrations called for by their contracts, and the observed underreporting of drugs may threaten the treatment process. Drug treatment facilities should monitor the performance of their contract laboratories with quality-control samples, preferably through blind testing.