Impact of a quality assessment program on radiologist performance in ultrasound-guided renal transplant biopsy.

PURPOSE: The purpose of this study was to analyze the impact of a quality assessment (QA) program on radiologist performance in ultrasound-guided renal transplant biopsy. METHODS: The numbers of glomeruli and small arteries obtained during ultrasound-guided renal transplant biopsy of all consecutive patients performed by any of 8 radiologists in an ultrasound section between September 1, 2007, and May 31, 2010, were recorded. Procedural success was assessed using Banff 97 criteria. Two subgroups were defined on the basis of each radiologist's approximate fractional full-time equivalent effort in the section, with 2 radiologists who were engaged 100% of their clinical noncall time in the ultrasound section constituting the primary ultrasound subgroup and 6 radiologists who were engaged <25% of their clinical noncall time in the ultrasound section constituting the secondary ultrasound subgroup. The biopsy success rate for individuals, subgroups, and the entire section for 9 months before (pre-QA) and 24 months after (post-QA) the onset of quarterly dissemination of the QA data was analyzed. RESULTS: Of 339 biopsies in the pre-QA period, 90.5% were successful. Of 1,063 biopsies in the post-QA period, 96.0% were successful (P < .001). The pre-QA individual radiologist success rates ranged between 71.4% and 96.7% (mean, 86.2 ± 10.3%). The post-QA individual radiologist success rates ranged between 80.0% and 97.9% (mean, 92.5 ± 6.6%). The primary ultrasound subgroup success rate increased from 93.4% to 97.5% (P = .005). The secondary ultrasound subgroup success rate increased from 85.7% to 93.8% (P = .004). CONCLUSIONS: A renal transplant biopsy QA program improves operator performance.

Informatics in radiology: Efficiency metrics for imaging device productivity.

Acute awareness of the costs associated with medical imaging equipment is an ever-present aspect of the current healthcare debate. However, the monitoring of productivity associated with expensive imaging devices is likely to be labor intensive, relies on summary statistics, and lacks accepted and standardized benchmarks of efficiency. In the context of the general Six Sigma DMAIC (design, measure, analyze, improve, and control) process, a World Wide Web-based productivity tool called the Imaging Exam Time Monitor was developed to accurately and remotely monitor imaging efficiency with use of Digital Imaging and Communications in Medicine (DICOM) combined with a picture archiving and communication system. Five device efficiency metrics-examination duration, table utilization, interpatient time, appointment interval time, and interseries time-were derived from DICOM values. These metrics allow the standardized measurement of productivity, to facilitate the comparative evaluation of imaging equipment use and ongoing efforts to improve efficiency. A relational database was constructed to store patient imaging data, along with device- and examination-related data. The database provides full access to ad hoc queries and can automatically generate detailed reports for administrative and business use, thereby allowing staff to monitor data for trends and to better identify possible changes that could lead to improved productivity and reduced costs in association with imaging services. © RSNA, 2011.

The vascular groove sign: a new CT finding associated with osteoid osteomas.

OBJECTIVE: We have observed that osteoid osteomas are frequently surrounded by thin curvilinear or serpiginous low-density grooves in the surrounding bone on CT examinations. We believe that these grooves represent prominent enlarged feeding arterioles, corresponding to recently published histologic findings. This study was performed to assess the sensitivity and specificity of this vascular groove sign for differentiating osteoid osteomas from other radiolucent bone lesions. MATERIALS AND METHODS: The study group consisted of 42 patients with pathologically proven osteoid osteomas. The control group included 29 patients with radiolucent bone lesions other than osteoid osteomas. Two readers scored CT examinations of these lesions for the presence of the vascular groove sign, defined as one or more radiolucent linear or serpiginous grooves extending from the periosteal surface of bone down to the radiolucent tumor. Sensitivity and specificity values were calculated for each reader. Positive and negative predictive values, p values, and interobserver agreement values were calculated. RESULTS: The sensitivity of the vascular groove sign for detection of osteoid osteoma was 73.8% for reader 1 and 76.2% for reader 2, specificity was 96.6% for reader 1 and 89.7% for reader 2, positive predictive value was 96.9% for reader 1 and 91.4% for reader 2, and negative predictive value was 71.8% for reader 1 and 72.2% for reader 2. The p value was less than 0.0001 for both readers. The interobserver agreement was very good, with a kappa value of 0.85. CONCLUSION: The vascular groove sign is a moderately sensitive but highly specific sign for distinguishing osteoid osteomas from other radiolucent bone tumors on CT.

A reference standard-based quality assurance program for radiology.

The authors have developed a comprehensive radiology quality assurance (QA) program that evaluates radiology interpretations and procedures by comparing them with reference standards. Performance metrics are calculated and then compared with benchmarks or goals on the basis of published multicenter data and meta-analyses. Additional workload for physicians is kept to a minimum by having trained allied health staff members perform the comparisons of radiology reports with the reference standards. The performance metrics tracked by the QA program include the accuracy of CT colonography for detecting polyps, the false-negative rate for mammographic detection of breast cancer, the accuracy of CT angiography detection of coronary artery stenosis, the accuracy of meniscal tear detection on MRI, the accuracy of carotid artery stenosis detection on MR angiography, the accuracy of parathyroid adenoma detection by parathyroid scintigraphy, the success rate for obtaining cortical tissue on ultrasound-guided core biopsies of pelvic renal transplants, and the technical success rate for peripheral arterial angioplasty procedures. In contrast with peer-review programs, this reference standard-based QA program minimizes the possibilities of reviewer bias and erroneous second reviewer interpretations. The more objective assessment of performance afforded by the QA program will provide data that can easily be used for education and management conferences, research projects, and multicenter evaluations. Additionally, such performance data could be used by radiology departments to demonstrate their value over nonradiology competitors to referring clinicians, hospitals, patients, and third-party payers.

Early experience with percutaneous cryoablation of extra-abdominal desmoid tumors.

OBJECTIVE: Surgical resection, radiation therapy and chemotherapy are all accepted as standard treatments for extra-abdominal desmoid (EAD) tumors, but their effectiveness has been limited by frequent local recurrence. The purpose of this article is to describe our early experiences with using percutaneous cryoablation for local control of extra-abdominal desmoid tumors in five patients whose tumors had failed to respond to standard therapy. MATERIAL AND METHODS: In a retrospective search of our institution's radiology database for patients who had undergone percutaneous cryoablation for treatment of EAD tumors between June 2004 and July 2007, we identified five patients (three female and two male). No patients were excluded from this review. Three of these patients had been referred for cryoablation for local tumor control, and two had been referred for palliation of inoperable tumors. The age range of the patients at the time of cryoablation was 9-41 years. The treated EAD tumors were located in the neck, shoulders and trunk and ranged in size from 3.0 cm to 10.0 cm. Medical records were reviewed for short-term and long-term follow-up, and patients were contacted for additional follow-up. Patients were asked to rate their pain as absent, mild, moderate or severe, and to compare it with their levels before cryoablation, describing it as improved, unchanged or worsened. Radiology records were reviewed to follow the size of the EAD tumors before and after cryotherapy. RESULTS: For the three patients referred for local control of EAD tumors, complete tumor coverage with the ablation zones was achieved. Two of these patients, with masses 3.0 cm and 4.9 cm in diameter, reported complete absence of pain at both short-term and long-term follow-up at 13 months and 49 months. Their tumors had completely resolved on long-term imaging follow-up at 19 months and 43 months. The third patient, with a 6.1 cm mass, reported improved mild pain at 6 months, and imaging showed a moderate decrease of tumor size. For the two patients referred for palliative therapy, initial partial pain relief was felt 2 weeks after the procedure, At long-term (58 months) follow-up of one patient with a 9.1 cm mass, the tumor was still present although reduced in size, and local pain had returned to its former moderate level. In the other patient who underwent only partial treatment of a 10.0 cm mass, at long-term follow-up (36 months) the mass had enlarged and pain had returned to the pretreatment, moderate level. CONCLUSION: Cryoablation appears to be an effective alternative treatment for the achievement of local control of small and moderately sized EAD tumors, but it is likely of limited use in patients with larger tumors that have untreatable regions due to involvement of vital structures. Continued research evaluating cryoablation for the treatment of EAD tumors is needed.

Musculoskeletal tumor imaging, biopsy, and therapies: self-assessment module.

OBJECTIVE: The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of musculoskeletal tumor imaging, biopsy, and therapies. CONCLUSION: The solutions in this activity review the imaging characteristics of musculoskeletal tumors, biopsy approaches, and therapies.

Imaging spectrum of bites, stings, and their complications: pictorial review.

OBJECTIVE: Soft-tissue injuries from animal bites and insect stings are frequent causes of emergency department visits. Although many cases follow a short and benign clinical course, life-threatening complications can occur. Imaging can play an important role in guiding clinical care by revealing the scope of the injury and associated complications. The purpose of this article is to provide a brief overview of the epidemiology of animal-related injuries, with a focus on imaging manifestations of soft-tissue injury using multiple techniques in a pictorial review format. CONCLUSION: This article reviews the imaging manifestations of soft-tissue injuries caused by animal bites and insect stings. After completing this article, the reader should have an improved ability to recognize complications of soft-tissue injuries and the role of advanced imaging in select cases.

Imaging spectrum of bites, stings, and their complications: self-assessment module.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging spectrum of bites, stings, and their complications.

Metal artifact reduction image reconstruction algorithm for CT of implanted metal orthopedic devices: a work in progress.

INTRODUCTION: Despite recent advances in CT technology, metal orthopedic implants continue to cause significant artifacts on many CT exams, often obscuring diagnostic information. We performed this prospective study to evaluate the effectiveness of an experimental metal artifact reduction (MAR) image reconstruction program for CT. MATERIALS AND METHODS: We examined image quality on CT exams performed in patients with hip arthroplasties as well as other types of implanted metal orthopedic devices. The exam raw data were reconstructed using two different methods, the standard filtered backprojection (FBP) program and the MAR program. Images were evaluated for quality of the metal-cement-bone interfaces, trabeculae < or = 1 cm from the metal, trabeculae 5 cm apart from the metal, streak artifact, and overall soft tissue detail. The Wilcoxon Rank Sum test was used to compare the image scores from the large and small prostheses. Interobserver agreement was calculated. RESULTS: When all patients were grouped together, the MAR images showed mild to moderate improvement over the FBP images. However, when the cases were divided by implant size, the MAR images consistently received higher image quality scores than the FBP images for large metal implants (total hip prostheses). For small metal implants (screws, plates, staples), conversely, the MAR images received lower image quality scores than the FBP images due to blurring artifact. The difference of image scores for the large and small implants was significant (p = 0.002). Interobserver agreement was found to be high for all measures of image quality (k > 0.9). CONCLUSION: The experimental MAR reconstruction algorithm significantly improved CT image quality for patients with large metal implants. However, the MAR algorithm introduced blurring artifact that reduced image quality with small metal implants.

Correlation of arthrodesis stability with degree of joint fusion on MDCT.

OBJECTIVE: The purpose of our study was to correlate clinically determined joint stability with the degree of bone fusion in the ankle or subtalar joint on MDCT examinations after arthrodesis. MATERIALS AND METHODS: We performed a retrospective review of 42 consecutive MDCT examinations from 29 patients. All patients had previously undergone arthrodesis of their ankle or subtalar joints and had persistent or recurrent hindfoot or ankle pain. Two musculoskeletal radiologists examined in consensus sagittal 2-mm-thick reformatted slices, measuring on each image the length of the joint surface and the length of the fused portion of the joint space. The sum of the lengths of the fused segments on all slices was then divided by the sum of the lengths of the joint surfaces to calculate the fusion ratio. For the standard of reference, the medical records were reviewed and operative reports, diagnostic injections, and physical examinations were used to classify the joints as stable or unstable. RESULTS: Twelve clinically unstable joints had fusion ratios of 0-32.8%, whereas 30 clinically stable joints had fusion ratios of 33.2-100%. Using receiver operating characteristic analysis, we selected the cutoff level that maximized Youden's index (the sum of sensitivity and specificity). Using a 33% fusion ratio as the lower limit cutoff for joint stability, the sensitivity was 100%; specificity, 100%; and accuracy, 100%. CONCLUSION: After arthrodesis of the ankle or subtalar joint, MDCT scans can be used to determine whether that joint is likely to be stable if > 33% of the joint has visible bone fusion on sagittal MDCT images.

Imaging evaluation of foot and ankle pathology: self-assessment module.

The educational objectives of this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of foot and ankle pathology.

MRI of the foot for suspected osteomyelitis: improving radiology reports for orthopaedic surgeons.

Of all the available imaging modalities, magnetic resonance imaging (MRI) is the best test for evaluation of possible osteomyelitis because of its high sensitivity for bone marrow abnormalities, soft tissue contrast, and depiction of anatomic detail. In this article we review the literature on MRI of pedal osteomyelitis, focusing on how radiologists can be most helpful to the orthopaedic surgeon if they review the pretest probability of disease, examine for secondary signs as well as primary signs of osteomyelitis, and grade their degree of suspicion when reporting these cases.

Radiological reasoning: Acutely painful swollen finger.

OBJECTIVE: The purpose of this article is to review the differential diagnosis of finger masses and their imaging appearances. CONCLUSION: Giant cell tumor of the tendon sheath is a slowly growing, benign tumor of the synovium that commonly presents as a painless nodular mass in the hand or wrist. Also termed "localized nodular tenosynovitis," these tumors are the most common soft-tissue tumors of the hand. Occasionally, these tumors can present with pain when traumatized, and they should be suspected when a firm, rubbery mass is found at the location of a tendon sheath.

Radiologic assessment of reverse shoulder arthroplasty.

The reverse shoulder prosthesis was approved for clinical use in the United States in March 2004. This new prosthesis reverses the normal ball-and-socket relationship of the shoulder joint. As a result of replacement of the glenoid component with a ball and of the humeral head with a socket, the center of rotation is moved distally and medially, allowing more control of shoulder motion by the deltoid muscle. This improved geometric configuration allows shoulder reconstruction in patients who have irreparable rotator cuff damage with secondary arthropathy, pain, and "pseudoparalysis" (ie, inability to lift the arm above the horizontal). Patients experience a significant improvement in range of motion and markedly decreased pain after undergoing reverse shoulder arthroplasty; however, the procedure is associated with a relatively high rate of complications, including dislocation, infection, loosening, malpositioning of the glenoid component or fixation screws, disassembly of the humeral component, periprosthetic fracture, and inferior glenoid impingement leading to scapular erosion. Therefore, it is important that the radiologist be familiar with the normal and abnormal imaging appearances of this new prosthesis.

Anatomically based guidelines for core needle biopsy of bone tumors: implications for limb-sparing surgery.

Diagnostic image-guided needle biopsy plays a vital role in the work-up and treatment of patients with extremity bone tumors. The radiologist and the orthopedic oncologic surgeon should take a team approach to this procedure, especially when the bone lesion might be a primary sarcoma for which limb-sparing surgery (LSS) would be considered. A set of anatomically based guidelines were developed that can be used by the radiologist, in combination with case-by-case consultation with the surgeon, to plan image-guided core needle biopsies of extremity long bone lesions that may be treatable with LSS. By using these guidelines, along with the aforementioned consultation, the radiologist will be able to preserve the patient's chances of receiving optimal surgical treatment.

Imaging evaluation of tendon sheath disease: self-assessment module.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of tendon sheath disease.

Chronic expanding hematoma of the thigh simulating neoplasm on gadolinium-enhanced MRI.

Patients who present with slowly growing extremity masses are often imaged with MRI to be examined for possible tumors. In addition to cysts and neoplasms, chronic expanding hematomas should be considered in the differential diagnosis if the patient has a history of remote trauma. The presence or absence of internal contrast enhancement is often used to distinguish between hematomas and hemorrhagic neoplasms on MRI and CT. We present the unusual case of a patient who had a chronic expanding hematoma of the calf that demonstrated nodular internal enhancement on gadolinium-enhanced MRI, simulating a neoplasm.