Steven E. Seltzer

The production and evaluation of contrast-carrying liposomes made with an automatic high-pressure system.

An automatic, high-pressure system (Microfluidizer) has been found useful for producing contrast-carrying liposomes on an industrial scale. The goal of this investigation was to determine the feasibility of using this new microemulsification process to manufacture contrast-carrying microemulsified liposomes (MELs). Seven contrast media (three ionic, four nonionic) were encapsulated into the MELs. Light and electron microscopy, light scattering, radioisotope, and CT scan techniques were used to characterize these MELs, and the contrast entrapments among the studied media were compared. The contrast-carrying MELs had good properties for imaging normal reticuloendothelial tissues, selectively. They had a narrow size range (0.1-3.0 micron), a single bilayer wall, high liver and spleen upake, and low leakage rates. The nonionic media were significantly more effectively entrapped in the MELs than the ionic media (P less than .05). The iodine-to-lipid weight ratio was about 1:16 for ionic media and 1:4 for nonionic media. Physical properties of the contrast media such as osmotic pressure and charge appeared to affect contrast entrapment. It was concluded that the microemulsification process is a useful system for producing contrast-carrying liposomes continuously, on a large scale and in a reproducible manner.

Arthrosonography--technique, sonographic anatomy, and pathology.

Ultrasound scanning of the hips, shoulders, and elbows was investigated as a noninvasive technique for the diagnosis of joint disorders. Sixteen patients with known intra-articular fluid collections, loose bodies, or periarticular abnormalities were studied. Ultrasound images clearly demonstrated the contours of bony surfaces, normal muscles, and other soft-tissue structures around joints. Intra-articular fluid collections were seen as sonolucent halos around the femoral neck and humeral head and as an oval, sonolucent area anterior to the distal humerus. Collections of fluid as small as 10 ml in the hip and 16 ml in the shoulder were visualized. Intra-articular loose bodies and para-articular fluid collections were also demonstrated. It is concluded that gray-scale ultrasound can demonstrate some of the basic pathologic processes in joint disorders. Further evaluation of its scope and applicability is indicated.

Radiation Exposure from CT Scans: How to Close Our Knowledge Gaps, Monitor and Safeguard Exposure—Proceedings and Recommendations of the Radiation Dose Summit, Sponsored by NIBIB, February 24–25, 2011

This article summarizes the proceedings of a portion of the Radiation Dose Summit, which was organized by the National Institute of Biomedical Imaging and Bioengineering and held in Bethesda, Maryland, in February 2011. The current understandings of ways to optimize the benefit-risk ratio of computed tomography (CT) examinations are summarized and recommendations are made for priority areas of research to close existing gaps in our knowledge. The prospects of achieving a submillisievert effective dose CT examination routinely are assessed.

Is Terminology Used Effectively to Convey Diagnostic Certainty in Radiology Reports

RATIONALE AND OBJECTIVES This study was performed to assess the extent of agreement among radiologists and nonradiologists in perception of diagnostic certainty conveyed by words and phrases commonly used in radiology reports. MATERIALS AND METHODS The study was performed in a large academic radiology department. To determine the commonly used terminology for conveying diagnostic certainty in radiology reports, 12 randomly selected radiologists from six different subspecialties were interviewed. The authors identified the 15 most commonly used words and phrases and included these in random order in a questionnaire sent to all staff radiologists (n = 45) and to 158 referring physicians. Physicians were asked to rank the 15 phrases in order of the diagnostic certainty conveyed by each, from 1 (most certain) to 15 (least certain), using each number only once. The kappa statistic was used to assess agreement in rank order among physicians. RESULTS The questionnaire response rate was 76% (n = 34) for radiologists and 49% (n = 78) for nonradiologists. There was excellent agreement among radiologists (kappa = 0.95) and nonradiologists (kappa = 0.93) in the rank order for the phrase diagnostic of. Although there was good agreement (kappa = 0.45) among radiologists for the word unlikely, agreement among nonradiologists was poor (kappa = 0.27). There was very poor agreement among all physicians for the rank order of the other 13 phrases. CONCLUSION Among radiologists and nonradiologists, concordance was poor regarding the diagnostic certainty associated with phrases commonly used in radiology reports. Because poor agreement could lead to suboptimal quality of care, the standardization of terminology would benefit all parties.

Three-dimensional imaging and displayof renal tumors using spiral CT a potential aid to partial nephrectomy

OBJECTIVE A new technique for creating three-dimensional (3D) images of renal tumors using contrast-enhanced spiral computed tomography (CT) is described and preliminarily investigated. METHODS 3D spiral CT was employed in 2 patients before radical nephrectomy and in 5 patients before partial nephrectomy. Preoperative and postoperative image analyses were conducted to evaluate the ability of the images to depict key anatomic relationships in planning partial nephrectomies. RESULTS 3D spiral CT defined the tumors location and relationship to the kidney surface better than the tumors proximity to renal hilar vessels and collecting system. Negative surgical margins were obtained in all 4 patients with renal cell carcinoma, and post-operative serum creatinine remained less than 2 mg/dL in all 5 patients after partial nephrectomy. CONCLUSIONS This early experience suggests that 3D spiral CT can help in the planning of partial nephrectomy and in attaining complete resection of renal cell carcinoma while conserving normal renal tissue.

In vivo 19F NMR imaging of liver, tumor, and abscess in rats. Preliminary results.

In vivo magnetic resonance imaging (MRI) has employed almost exclusively the proton because of its high gyromagnetic ratio and natural abundance relative to other nuclei. Recent research has focused on imaging using nuclei other than 1H, but has been limited by the decreased sensitivity and/or low biologic concentrations of the nuclei. Fluorine (19F), with a gyromagnetic ratio second only to that of hydrogen, is a theoretically attractive nucleus for MRI, but fluorine is present in only minute amounts in most tissues. Perfluorochemical emulsions (PFC), developed as blood replacement agents, appear to be safe vehicles for fluorine administration. We report our initial results of in vivo 19F magnetic resonance imaging of liver, tumor, and abscess in rats given exogenous fluorine.

Spiral CT in the evaluation of flank pain: overall accuracy and feature analysis.

PURPOSE Our goal was to assess test reliability and identify those features that have the strongest positive and negative predictive values in the diagnosis of renal colic using spiral CT. METHOD Fifty non-contrast-enhanced CT scans (5 mm slice thickness) obtained in patients presenting with flank pain were reviewed by three radiologists blinded to the final diagnoses. The sensitivity, specificity, and positive and negative predictive values for nine pertinent findings were determined as compared to clinical follow-up. RESULTS Twenty-nine cases had findings of ureteral obstruction. Findings with the strongest positive predictive values (> 0.90) were ureteral stone, hydronephrosis, hydroureter, periureteral stranding, and ureterovesical junction edema. Findings with the strongest negative predictive values (> 0.89) were absence of hydronephrosis and hydroureter. The areas under the receiver operating curves for Readers 1, 2, and 3 were 0.970 +/- 0.030, 0.942 +/- 0.036, and 0.982 +/- 0.020. CONCLUSION Absence of hydroureter and hydronephrosis on spiral CT images should prompt a search for a diagnosis other than an obstructing ureteral stone.

Safety and efficacy of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. multicenter phase III clinical trials (safety).

The short‐term1 safety of mangafodipir trisodium (MnDPDP) injection was studied in 546 adults with known or suspected focal liver lesions. An initial contrast‐enhanced computed tomography examination was followed by unenhanced magnetic resonance imaging (MRI), injection of MnDPDP (5 μmol/kg), and enhanced MRI. Adverse events were reported for 23% of the patients; most were mild to moderate in intensity, did not require treatment, and were not drug related. The most commonly reported adverse events were nausea (7%) and headache (4%). The incidence of serious adverse events was low (nine events in six patients) and not drug related. Injection‐associated discomfort was reported for 69% of the patients, and the most commonly reported discomforts included heat (49%) and flushing (33%). Changes in laboratory values and vital signs were generally transient, were not clinically significant, and did not require treatment. There were no clinically significant short‐term risks from exposure to MnDPDP. J. Magn. Reson. Imaging 2000;12:186–197.

Impact of a 4-year Quality Improvement Initiative to Improve Communication of Critical Imaging Test Results

PURPOSE To evaluate the impact of a 4-year initiative to develop, implement, monitor, and reinforce a communication of critical test results policy by using continuous-process improvement methods. MATERIALS AND METHODS This HIPAA-compliant quality-improvement initiative was performed between February 2006 and January 2010. Institutional review board approval was received with waiver of informed consent for medical record reviews. A critical results policy for radiology was developed that was based on recommendations from the Joint Commission, American College of Radiology, and Massachusetts Coalition for the Prevention of Medical Errors. It defined types of findings (critical or discrepant), urgency level (red, orange, or yellow), timelines for notification, acceptable communication and documentation methods, and a communication escalation process. The primary outcome measure, adherence to the communication of critical results policy, was measured by periodic review of radiology reports with feedback of results to staff radiologists. The χ(2) statistic was used to assess for trends. RESULTS During 21 quality reviews, 16,983 of 1,489,951 (1.14%) total radiology reports were reviewed, 1628 (9.6%) of which were assessed to contain critical results according to policy. Adherence to critical results policy increased from 28.6% (12 of 42) in February 2006 to 90.4% (122 of 135) by the end of the study period (P < .001), with most of the gains occurring in the first 2 years. CONCLUSION Review and feedback of performance in regard to a policy on communication of critical imaging test results allowed significant improvement and sustained adherence to policy. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101396/-/DC1.

Arthrosonography: Gray-Scale Ultrasound Evaluation of the Shoulder

Gray-scale ultrasound images of the shoulders of 6 rhesus monkeys were obtained before and after fluid instillation to assess the ability of ultrasound to diagnose joint disorders. The normal bony landmarks and muscular structures were shown. After the fluid was introduced, fluid collections were identified in the axillary pouch and subscapular bursa. Ultrasound is a promising new method of detecting intra-articular effusions of the shoulder.