Portrayal of radiology in a major medical television series: How does it influence the perception of radiology among patients and radiology professionals?

OBJECTIVES: To assess how the portrayal of Radiology on medical TV shows is perceived by patients and radiology professionals. METHODS: In this IRB-approved study with patient consent waived, surveys were conducted among adult patients scheduled for radiological examinations and radiology professionals. The questionnaire investigated medical TV watching habits including interest in medical TV shows, appearance of radiological examination/staff, radiology's role in diagnosis-making, and rating of the shows' accuracy in portraying radiology relative to reality. RESULTS: One hundred and twenty-six patients and 240 professionals (133 technologists, 107 radiologists) participated. 63.5 % patients and 63.2 % technologists rated interest in medical TV shows ≥5 (scale 1-10) versus 38.3 % of radiologists. All groups noted regular (every 2nd/3rd show) to >1/show appearance of radiological examinations in 58.5-88.2 % compared to 21.0-46.2 % for radiological staff appearance. Radiology played a role in diagnosis-making regularly to >1/show in 45.3-52.6 %. There is a positive correlation for interest in medical TV and the perception that radiology is accurately portrayed for patients (r = 0.49; P = 0.001) and technologists (r = 0.38; P = 0.001) but not for radiologists (r = 0.01). CONCLUSIONS: The majority of patients perceive the portrayed content as accurate. Radiologists should be aware of this cultivation effect to understand their patients' behaviour which may create false expectations towards radiological examinations and potential safety hazards. KEY POINTS: • Radiology in medical TV shows is conveyed as important in diagnosis making • Presence of radiological staff is less frequent compared to examinations shown • Positive correlation for interest in medical TV and radiology perceived as accurate • TV experience may create false expectations and potential safety hazards.

Minimally invasive techniques for the treatment of liver tumors.

Recently, several minimally invasive, image-guided therapies have been developed for the local treatment of hepatocellular carcinoma (HCC) and hepatic metastases in patients who are considered poor candidates for surgical resection. Radio-frequency ablation, microwave ablation, and laser ablation all destroy tumor by creating a hyperthermic injury. Cryoablation and ethanol ablation achieve cellular death through freezing and direct toxicity, respectively. Chemoembolization is unique in that the entire liver can be treated over time with a combination of cytotoxic drugs and embolic agents, potentially reducing the rate of recurrence from radiologically occult tumor. Outcomes for minimally invasive therapy have approached the success rate of surgical resection in some series with considerably fewer complications. However, a paucity of randomized trials and variability in reporting limit assessment of the relative role of these techniques in clinical practice. With a few exceptions, the indications, contraindications, and complications associated with the different techniques are similar, and success with HCC has exceeded that for metastatic disease independent of technique.

Tumor recurrence after radiofrequency thermal ablation of hepatic tumors: spectrum of findings on dual-phase contrast-enhanced CT.

OBJECTIVE: We conducted this study to determine the spectrum of CT findings of tumor recurrence after radiofrequency ablation of primary and secondary malignant hepatic tumors. MATERIALS AND METHODS: Twenty-five patients, 10 with hepatocellular carcinoma (HCC) and 15 patients with metastases who developed tumor recurrence after radiofrequency ablation of hepatic neoplasms, formed the study population. Three observers reviewed the CT scans of these patients and evaluated the location (local intrahepatic, remote intrahepatic, or extrahepatic) of all recurrent lesions and the morphology and enhancement characteristics of local intrahepatic recurrences. RESULTS: Local intrahepatic recurrences were seen in nine patients (90%) and 11 patients (73%); remote intrahepatic recurrences, in five patients (50%) and seven patients (45%); and extrahepatic recurrences, in zero and six patients (40%) with recurrent HCC and recurrent metastases, respectively. Of the 12 nodules of local intrahepatic recurrences in HCC and the 24 in metastases, the patterns of local intrahepatic recurrences were of nodular, halo, and gross enlargement types in eight (67%) and nine (38%), four (33%) and six (38%), and zero and nine (37%) nodules in HCC and hepatic metastases, respectively. The number of local intrahepatic recurrent lesions enhancing in the arterial phase was significantly greater in HCC. CONCLUSION: Tumor recurrences occurred at intra- and extrahepatic sites after radiofrequency ablation of hepatic neoplasms. The local intrahepatic recurrences appeared in three patterns: nodular, halo, or gross enlargement. The sites of recurrence and the morphologic patterns of local intrahepatic tumor recurrence differed between primary and secondary hepatic neoplasms.

Single institution prospective evaluation of the over-the-wire Greenfield vena caval filter.

PURPOSE: To assess the technical and clinical success of the over-the-wire (OTW) Greenfield inferior vena caval (IVC) filter. MATERIALS AND METHODS: Prospective evaluation of the OTW Greenfield filter in 47 patients was performed during the course of 18 months. Technical success and deployment problems were documented. Caval perforation, leg asymmetry, and tilt were evaluated with a postprocedure, noncontrast computed tomographic (CT) scan. Follow-up was performed at 6- and 12-month intervals after the procedure and included a clinical history, chart review, and magnetic resonance (MR) imaging examination of the IVC. RESULTS: Ninety-one percent of filters were placed without technical difficulties and 100% were successfully deployed. Technical difficulties included sheath kinking prior to deployment (n = 3), initial incomplete filter opening (n = 1), and wire entrapment within the filter (n = 1). Of 38 patients evaluated with CT, there was no case of caval perforation. Twenty-one patients (55%) demonstrated tilt and 14 (37%) had leg asymmetry. Tilting occurred more frequently when the filter was placed from a femoral approach (51%) than from a jugular approach (12%). Of patients with leg asymmetry, the vena cava was narrow in anteroposterior (AP) dimension in five (36%). Of 13 deaths, none were attributed to pulmonary embolism. One patient (2%) had a recurrent pulmonary embolus. Two of 16 patients (12%) with MR imaging follow-up had documented IVC thrombosis. CONCLUSIONS: The OTW Greenfield filter has an effective delivery system, with few difficulties encountered during deployment. Filter tilt and leg asymmetry are common. The etiology of leg asymmetry is likely multifactorial but is often associated with a cava with a small AP diameter. Because OTW deployment appears to offer no benefit in centering the filter, the authors have elected to remove the wire prior to filter deployment to avoid possible entanglement. MR imaging follow-up reveals an acceptable incidence of IVC thrombosis.

Effect of anatomic distribution of pulmonary emboli on interobserver agreement in the interpretation of pulmonary angiography.

OBJECTIVE: This study examines the anatomic distribution of emboli on pulmonary angiography and attempts to determine the relationship of vessel size to interobserver agreement, two factors having important implications in comparing pulmonary angiography with cross-sectional imaging for pulmonary embolism. MATERIALS AND METHODS: One hundred twenty-five consecutive pulmonary angiograms were reviewed retrospectively by three interventional radiologists. Initial interpretations were recorded and compared to determine interobserver agreement on a per-patient and per-embolus basis. Discordant interpretations were reviewed by all radiologists for a consensus interpretation. RESULTS: Unanimous per-patient agreement occurred in 91% (114/125) of initial interpretations. The largest artery containing acute pulmonary embolism was segmental or larger in 24 patients (83% of patients with acute positive findings, 19% of all patients) and subsegmental in only five patients (17% and 4%, respectively). On a per-patient basis, initial interobserver agreement averaged 45% and unanimous consensus agreement was achieved for 79% of patients having isolated subsegmental pulmonary embolism. Consensus readings altered initial per-patient interpretations for 30% of patients having only subsegmental pulmonary embolism; per-embolus interpretations were altered for 37% of all subsegmental emboli. CONCLUSION: Subsegmental emboli occurring as isolated findings are relatively rare. Approximately one third of subsegmental emboli and one third of patients having isolated subsegmental emboli may be initially misdiagnosed on pulmonary angiography. Objections to cross-sectional imaging for pulmonary embolism based on the inability to detect subsegmental pulmonary embolism when compared with pulmonary angiography should be reexamined with this data in mind.

The role of infrapopliteal MR angiography in patients undergoing optimal contrast angiography for chronic limb-threatening ischemia.

PURPOSE: To determine the benefit of infrapopliteal magnetic resonance angiography (MRA) in patients with chronic limb-threatening ischemia who have undergone optimal contrast angiography (CA). PATIENTS AND METHODS: Thirty-four patients (37 limbs) with limb-threatening chronic lower extremity ischemia underwent MRA and CA of the symptomatic extremity. Selective, vasodilator-enhanced digital subtraction angiography of the infrapopliteal vessels was possible for 34 limbs. Two vascular surgeons retrospectively formulated treatment plans based on CA. They then formulated treatment plans based on CA and MRA together. RESULTS: CA clearly visualized 495 of 888 vascular segments as patent, while MRA clearly visualized 412 of 888 segments. Treatment plans differed for at least one of two surgeons in eight limbs, but MRA would possibly have improved clinical outcome in only one. The amount of inflow disease did not appear to influence segment visualization or treatment planning. In eight of 11 limbs that eventually required below- or above-knee amputation, CA clearly visualized more vascular segments than MRA. One patient developed renal insufficiency after CA. CONCLUSION: Most patients undergoing optimal CA for chronic limb-threatening ischemia will not benefit from the addition of MRA. However, MRA should be considered when CA is suboptimal and when it is necessary to conserve contrast material.

MR angiography of the portal venous system: techniques, interpretation, and clinical applications.

Magnetic resonance (MR) angiography is a noninvasive means of assessing the portal venous system that has potential advantages over currently used modalities. Time-of-flight and phase-contrast MR angiography are useful techniques that differ fundamentally in their means of data acquisition but are comparable in their ability to demonstrate normal anatomy as well as abnormalities of the portal venous system. Occasionally, artifacts caused by respiratory motion, implanted metallic devices or surgical clips, in-plane saturation, or areas of complex flow are seen at MR angiography of the portal venous system. However, most artifacts can easily be identified as such and either remedied or ignored. In addition, the suppression of signal from surrounding soft tissues may result in poor detection of parenchymal lesions. The utility of standard projection angiograms and source images can be increased through the use of intravenously administered contrast material and postprocessing techniques such as partial-volume maximum intensity projection reconstructions and shaded surface renderings. In addition to providing information on portal venous anatomy and portosystemic collateral vessels, MR angiography of the portal vein has clinical application in portal venous thrombosis and stenosis, liver transplantation, and the evaluation and planning of surgical and transjugular intrahepatic portosystemic shunts.

Time-of-flight MR arteriography of below-knee arteries with maximum-intensity-projection reconstruction: is interpretation of the axial source images helpful?

OBJECTIVE: We evaluated the extent to which detailed review of axial source images enhances the interpretation of projectional reconstructions of two-dimensional time-of-flight MR arteriograms of the tibial vessels. SUBJECTS AND METHODS: Thirty-one patients (34 limbs) with limb-threatening ischemia underwent two-dimensional time-of-flight imaging and contrast-enhanced angiography of the below-knee arteries. Maximum-intensity-projection (MIP) reconstructions of the MR arteriograms were independently interpreted by three observers. The studies were then reinterpreted after detailed review of the axial source images. A consensus reading of each study was performed as well. The observers commented on the patency of 816 vascular segments and graded the extent of disease for 272 vessels. Interobserver agreement and correlation with contrast-enhanced angiography were determined. RESULTS: On average, the addition of axial images altered the observers' interpretation of MR arteriograms in 13% of segments for patency and in 18% of vessels for grading of disease severity. For determining the patency of vascular segments, mean interobserver agreement was 0.79 without and 0.80 with axial image interpretation, and mean agreement with contrast-enhanced angiography improved from 0.69 to 0.72 with the addition of axial images. When evaluating the extent of disease, correlation between observers improved for all combinations of observers with the addition of axial images, and correlation with contrast-enhanced angiography improved for two of three observers. Based on the consensus interpretation of the MR arteriograms, review of axial images was found to improve agreement with contrast-enhanced angiography in 34 vascular segments. In addition, axial image review correctly altered the number of stenoses identified in 12 vessels. When consensus interpretation identified a vessel as patent without significant stenosis on the MIP images, the MIP-based interpretation was found to be correct in all cases. CONCLUSION: Review of axial source images provides limited benefit to interpretation of MR arteriograms of the distal lower extremity in patients with peripheral vascular disease. Although selective review of axial source images may be appropriate, axial images can improve interpretation when MIP images are complicated by the presence of patient motion, difficult anatomy, or artifacts. Axial image review may also be appropriate when a significant stenosis is identified on the MIP images.

Stent deformation and intimal hyperplasia complicating treatment of a post-carotid endarterectomy intimal flap with a Palmaz stent.

We report a case of common carotid artery Palmaz stent placement for treatment of an intimal flap after surgical endarterectomy. Despite technical success with an excellent immediate result, a significant stenosis detected by duplex sonographic examination developed at 10 months. This stenosis, the result of stent compression and intimal hyperplasia, illustrates the previously theoretic risk associated with placement of the balloon-expandable stent in a compressible site such as the cervical carotid artery. In addition, we demonstrate that significant intimal hyperplasia may occur after carotid artery stent placement, potentially limiting long-term patency.

Transjugular portosystemic shunts in pediatric patients awaiting liver transplantation.

Three pediatric patients from 6 to 11 years of age awaiting liver transplantation for end stage liver disease underwent transjugular intrahepatic portosystemic shunt (TIPS) placement for control of variceal bleeding. Two of the three procedures were performed emergently after endoscopic sclerotherapy failed to stop active bleeding. One procedure was performed electively after multiple prior bleeding episodes. The shunts were created from the middle or left hepatic vein to the left portal vein, and none of the subsequent transplant surgeries was complicated by the presence of the stents. No major or minor complications were related to TIPS placement. Two patients underwent concomitant variceal embolization. Bleeding was successfully controlled in each patient. We conclude that TIPS placement in children is technically feasible, does not complicate subsequent surgery, and is useful treating acute variceal hemorrhage in pediatric patients awaiting liver transplantation.

Three-dimensional displays of left ventricular epicardial surface from standard cardiac SPECT perfusion quantification techniques.

UNLABELLED: Two methods for generating left ventricular epicardial surface from SPECT perfusion tomograms are described and validated. Both methods use the locations of the maximal reconstructed count values determined from a perfusion quantification procedure as a basis for generating surfaces. METHODS: The first method fits circular contours, which are perpendicular to the long-axis, to the points obtained from perfusion quantification. The second method applies median and linear filters to the points to remove noise but maintain the basic shape of the surface. Both models are validated against an automatic technique and against the user-traced surfaces of both the perfusion image and an MR image of the same patient. RESULTS: The median-filtered model was found to be closer to the standard surfaces than the circular model in all cases, and 85% of the points on the median-filtered surfaces were within one SPECT pixel length of the hand-traced MR surfaces. CONCLUSION: Accurate, three-dimensional left ventricular epicardial surfaces can be generated quickly and easily from already existing perfusion quantification software. The resulting images may be useful for realistic displays of ventricular size, shape and the three-dimensional distribution of perfusion.

Genetic control of susceptibility to streptozotocin diabetes in inbred mice: effect of testosterone and H-2 haplotype.

Males of certain mouse strains are more susceptible than females to the diabetogenic effect of multiple low doses of streptozotocin (MSZ, 40 mg/kg BW.day X 5). Several investigators linked sensitivity to the potentiating action of androgens and genes of the major histocompatibility (H-2) complex. Our studies were designed to investigate the role of testosterone in MSZ-diabetes induction in males of three C3H stocks: C3H X SW/SnJ (H-2b), C3HeB/FeJ (H-2k), and C3H/OuJ (H-2k). Serum testosterone levels in gonad-intact animals correlated inversely with SZ sensitivity, the more resistant C3HeB/FeJ males having a higher mean level than the other two stocks. Males from each group were castrated at 4 weeks of age and implanted with either testosterone or cholesterol; 4 weeks later they were given MSZ. C3H.SW/SnJ and C3H/OuJ castrates implanted with either testosterone or cholesterol were as sensitive to the hyperglycemic effect of MSZ as the intact controls, whereas C3HeB/FeJ castrates implanted with cholesterol lost sensitivity; this sensitivity could be fully restored by testosterone implants. Surprisingly, there was no difference in the residual pancreatic insulin content (90% reduced) between the SZ-resistant cholesterol-implanted vs. the SZ-sensitive testosterone-implanted C3HeB/FeJ castrates. This demonstrated that the androgen was not potentiating SZ destruction of the beta-cells, but rather was antagonizing the ability of the residual insulin to maintain glycemic control. The present study also indicated that the H-2 complex was not a significant factor predisposing to SZ sensitivity as reflected by marked sensitivity of the C3H/OuJ and C3H.SW/SnJ males vs. the relative resistance of C3HeB/FeJ males sharing the same H-2 haplotype as C3H/OuJ.