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Cystic renal cell carcinoma (RCC) is almost certainly overdiagnosed and overtreated. Efforts to diagnose and treat RCC at a curable stage result in many benign neoplasms and indolent cancers being resected without clear benefit. This is especially true for cystic masses, which compared with solid masses are more likely to be benign and, when malignant, less aggressive. For more than 30 years, the Bosniak classification has been used to stratify the risk of malignancy in cystic renal masses. Although it is widely used and still effective, the classification does not formally incorporate masses identified at MRI or US or masses that are incompletely characterized but are highly likely to be benign, and it is affected by interreader variability and variable reported malignancy rates. The Bosniak classification system cannot fully differentiate aggressive from indolent cancers and results in many benign masses being resected. This proposed update to the Bosniak classification addresses some of these shortcomings. The primary modifications incorporate MRI, establish definitions for previously vague imaging terms, and enable a greater proportion of masses to enter lower-risk classes. Although the update will require validation, it aims to expand the number of cystic masses to which the Bosniak classification can be applied while improving its precision and accuracy for the likelihood of cancer in each class.

Gadolinium-based contrast agents (GBCAs) have revolutionized MRI, enabling physicians to obtain crucial life-saving medical information that often cannot be obtained with other imaging modalities. Since initial approval in 1988, over 450 million intravenous GBCA doses have been administered worldwide, with an extremely favorable pharmacologic safety profile; however, recent information has raised new concerns over the safety of GBCAs. Mounting evidence has shown there is long-term retention of gadolinium in human tissues. Further, a small subset of patients have attributed a constellation of symptoms to GBCA exposure, although the association of these symptoms with GBCA administration or gadolinium retention has not been proven by scientific investigation. Despite evidence that macrocyclic GBCAs show less gadolinium retention than linear GBCAs, the safety implications of gadolinium retention are unknown. The mechanism and chemical forms of gadolinium retention, as well as the biologic activity and clinical importance of these retained gadolinium species, remain poorly understood and underscore the need for additional research. In February 2018, an international meeting was held in Bethesda, Md, at the National Institutes of Health to discuss the current literature and knowledge gaps about gadolinium retention, to prioritize future research initiatives to better understand this phenomenon, and to foster collaborative standardized studies. The greatest priorities are to determine (a) if gadolinium retention adversely affects the function of human tissues, (b) if retention is causally associated with short- or long-term clinical manifestations of disease, and (c) if vulnerable populations, such as children, are at greater risk for experiencing clinical disease. The purpose of the research roadmap is to highlight important information that is not known and to identify and prioritize needed research. ©RSNA, 2018 Online supplemental material is available for this article .

Purpose To determine if the allergic-like breakthrough reaction rate of intravenous corticosteroid prophylaxis administered 5 hours before contrast material-enhanced computed tomography (CT) is noninferior to that of a traditional 13-hour oral regimen. Materials and Methods Institutional review board approval was obtained and informed consent waived for this retrospective noninferiority cohort study. Subjects (n = 202) who completed an accelerated 5-hour intravenous corticosteroid premedication regimen before low-osmolality contrast-enhanced CT for a prior allergic-like or unknown-type reaction to iodine-based contrast material from June 1, 2008, to June 30, 2016, were identified. The breakthrough reaction rate was compared by using the Farrington and Manning noninferiority likelihood score to test subjects premedicated with a traditional 13-hour oral regimen (2.1% [13 of 626]). All subjects were premedicated for a prior allergic-like or unknown-type reaction to iodine-based contrast material. A noninferiority margin of 4.0% was selected to allow for no more than a clinically negligible 6.0% breakthrough reaction rate in the cohort that received 5-hour intravenous corticosteroid prophylaxis. Results The breakthrough reaction rate for 5-hour intravenous prophylaxis was 2.5% (five of 202 patients; 95% confidence interval: 0.8%, 5.7%), which was noninferior to the 2.1% (13 of 626 patients; 95% confidence interval: 1.1%, 3.5%) rate for the 13-hour regimen (P = .0181). The upper limits of the confidence interval for the difference between the two rates was 3.7% (0.4%; 95% confidence interval: -1.6%, 3.7%), which was within the 4.0% noninferiority margin. All breakthrough reactions were of equal or lesser severity to those of the index reactions (two severe, one moderate, and one mild reaction). Conclusion Accelerated intravenous premedication with corticosteroids beginning 5 hours before contrast-enhanced CT has a breakthrough reaction rate noninferior to that of a 13-hour oral premedication regimen. © RSNA, 2017.

To estimate the effect of an oral 13-hour inpatient corticosteroid premedication regimen on length of stay, hospital cost, and hospital-acquired infections (HAIs) by using a combination of real and hypothetical study populations.Institutional review board approval was obtained and informed consent waived for this HIPAA-compliant retrospective study. Inpatients who received an oral 13-hour corticosteroid premedication regimen before contrast material-enhanced CT (n = 1424) from 2008 to 2013 were matched by age, sex, and year when CT was performed to a control cohort (n = 1425) of patients who underwent contrast-enhanced CT without premedication and who had similar rates of 13 comorbid diseases. Length of stay in the hospital and time from admission to CT were compared by using the Mann-Whitney U test. Rates of prospectively reported HAIs were compared by using χ(2) tests. The indirect cost and risk of HAI with premedication were estimated by using published data.Premedicated inpatients had a significantly longer median length of stay (+25 hours; 158 vs 133 hours, P.001), a significantly longer median time to CT (+25 hours, 42 vs 17 hours, respectively; P.001), and a significantly greater risk of HAI (5.1% [72 of 1424] vs 3.1% [44 of 1424], respectively; P = .008) compared with nonpremedicated control subjects. On the basis of these data and existing references, the prolonged length of stay was estimated to result in 0.04 HAI-related deaths and a cost of $159 131 (in U.S. dollars) for each prevented reaction of any severity and 32 HAI-related deaths and a cost of $131 211 400 for each prevented reaction-related death.Oral 13-hour inpatient corticosteroid prophylaxis is associated with substantial cost relative to its modest benefit, and may cause more indirect harm than the direct harm that it prevents.

Purpose To identify computed tomographic (CT) findings that are predictive of recurrence of colonic diverticulitis. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant, retrospective cohort study. Six abdominal fellowship-trained radiologists reviewed the CT studies of 440 consecutive subjects diagnosed with acute colonic diverticulitis between January 2004 and May 2008 to determine the involved segments, maximum wall thickness in the inflamed segment, severity of diverticulosis, presence of complications (abscess, fistula, stricture, or perforation), and severity of the inflammation. Electronic medical records were reviewed for a 5-year period after the patients' first CT study to determine clinical outcomes. Predictors of diverticulitis recurrence were assessed with univariate and multiple Cox proportional hazard regression models. Results Colonic diverticulitis most commonly involved the rectosigmoid (70%, 309 of 440) and descending (30%, 133 of 440) colon segments. Complicated diverticulitis was present in 22% (98 of 440) of patients. On the basis of the results of univariate analysis, significant predictors of diverticulitis recurrence were determined to be maximum colonic wall thickness in the inflamed segment (hazard ratio [HR], 1.07 per every millimeter of increase in wall thickness; P < .001), presence of a complication (HR, 1.75; P = .002), and subjective severity of inflammation (HR, 1.36 for every increase in severity category; P value for linear trend = .003). The difference in maximum wall thickness in the inflamed segment (HR, 1.05 per millimeter; P = .016) and subjective inflammation severity (HR, 1.29 per category; P = .018)remained statistically significant in a Cox multiple regression model. Conclusion Maximum colonic wall thickness and subjective severity of acute diverticulitis allow prediction of recurrent diverticulitis and may be useful for stratifying patients according to the need for elective partial colectomy. © RSNA, 2017 Online supplemental material is available for this article.

To compare serum creatinine (SCr) level- and estimated glomerular filtration rate (eGFR)-based screening methods for identifying adult inpatients at risk for contrast medium-induced nephrotoxicity (CIN).Institutional review board approval was obtained; informed consent was waived for this HIPAA-compliant retrospective study. Computed tomographic examinations performed during 10 years in adult inpatients with stable renal function were identified (n = 28 390). The proportion of inpatients meeting various eGFR (≥60,60,45,30, 30-44, 45-59 mL/min/1.73 m(2)) and SCr (1.5, ≥1.5, ≥1.6, ≥1.7, ≥1.8, ≥1.9, ≥2.0 mg/dL) thresholds were contrasted with each other and with published guidelines (≥2.0 mg/dL [SCr] and45 mL/min/1.73 m(2) [eGFR]) using McNemar and binomial tests.Most inpatients were considered low risk for CIN with commonly used thresholds: 92.6% (26 285 of 28 390) had SCr1.5 mg/dL; 91.3% (25 922 of 28 390) had eGFR of ≥45 mL/min/1.73 m(2). Using SCr threshold of ≥1.5 mg/dL, identified inpatients had the following eGFRs: 19.6% (413 of 2105), 45-59 mL/min/1.73 m(2); 51.1% (1075 of 2105), 30-44 mL/min/1.73 m(2); 28.6% (603 of 2105),30 mL/min/1.73 m(2); and 0.7% (14 of 2105), ≥60 mL/min/1.73 m(2) . Using SCr threshold of ≥2.0 mg/dL, identified inpatients had the following eGFRs: 100% (658 of 658),45 mL/min/1.73 m(2); 74.6% (491 of 658),30 mL/min/1.73 m(2). Threshold of SCr ≥2.0 mg/dL could not be used to identify eGFR30 mL/min/1.73 m(2) in 0.4% (112 of 28 390) and45 mL/min/1.73 m(2) in 6.4% (1810 of 28 390) of all inpatients. Using eGFR45 mL/min/1.73 m(2) instead of SCr of ≥1.5 mg/dL would result in a significant but small increase in identified inpatients (8.7% [2468 of 28 390; 95% confidence interval: 8.4%, 9.0%] vs 7.4% [2105 of 28 390; 95% confidence interval: 7.1%, 7.7%]; P.0001).Screening using eGFR45 mL/min/1.73 m(2) instead of common SCr thresholds would significantly increase the number of inpatients identified to be at risk for CIN but would reduce misidentification of a large number of inpatients at low risk according to eGFR criteria.

To evaluate multi-detector row computed tomographic (CT) urography for detection of urinary tract abnormalities.Sixty-five patients referred from the urology service, in whom urinary tract abnormalities were strongly suspected, underwent multi-detector row CT urography. The technique included unenhanced, nephrographic, compression, and excretory-phase images through the abdomen and pelvis. Transverse images and three-dimensional reformations were reviewed by one of two radiologists. Findings were retrospectively compared with results of urinalysis, cystoscopy and/or ureteroscopy, and/or surgery.Multi-detector row CT urography depicted many clinically diagnosed urinary tract abnormalities, including 15 of 16 uroepithelial malignancies, five congenital anomalies, five urinary tract calculi, and 18 calyceal and/or papillary, 30 renal pelvic and/or ureteral, and 25 bladder abnormalities. All abnormalities were detected on transverse images. These abnormalities included diffuse urothelial wall thickening in four patients (three of whom had transitional cell carcinoma), a renal abscess, a colovesical fistula, and incidentally detected extrarenal disease (a liver mass, hepatic metastases, lymph node metastases, an aortic dissection, and a pheochromocytoma; each of these findings was seen in one patient).Multi-detector row CT urography is a useful method for detecting urinary tract abnormalities.

To determine the optimal imaging modality for diagnosis and staging of ovarian cancer.Two hundred eighty women suspected to have ovarian cancer were enrolled in a prospective study before surgery. Doppler ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging were used to evaluate the mass; conventional US, CT, and MR imaging were used to stage spread.All three modalities had high accuracy (0.91) for the overall diagnosis of malignancy. In the ovaries, the accuracy of MR imaging (0.91) was higher than that of CT and significantly higher than that of Doppler US (0.78). In the extraovarian pelvis and in the abdomen, conventional US, CT, and MR imaging had similar accuracies (0.87-0.95). In differentiation of disease confined to the pelvis from abdominal spread, the specificity of conventional US (96%) was higher than that of CT and significantly higher than that of MR imaging (88%), whereas the sensitivities of MR imaging (98%) and CT (92%) were significantly higher than that of conventional US (75%).MR imaging is superior to Doppler US and CT in diagnosis of malignant ovarian masses. There is little variation among conventional US, CT, and MR imaging as regards staging.

To determine the effect of intravenous (IV) low-osmolality iodinated contrast material (LOCM) on the development of post-computed tomography (CT) acute kidney injury (AKI), stratified by pre-CT estimated glomerular filtration rate (eGFR), in patients with stable renal function.Institutional review board approval was obtained and patient consent waived for this HIPAA-compliant, retrospective study. CT examinations performed over a 10-year period on unique adult inpatients with sufficient serum creatinine (SCr) data and stable renal function (difference between baseline and pre-CT SCr within 0.3 mg/dL and 50% of baseline) were identified. A 1:1 propensity score matched cohort analysis with multivariate analysis of effects was performed with post-CT AKI as the primary outcome measure (8826 nonenhanced and 8826 IV contrast agent-enhanced CT studies in 17 652 patients). Propensity matching was performed with respect to likelihood of receiving IV contrast material (19 tested covariates). Post-CT AKI with Acute Kidney Injury Network SCr criteria was the primary endpoint. A stepwise multivariate conditional logistic regression model was performed to identify the effect of IV LOCM on post-CT AKI.After 1:1 propensity matching, IV LOCM had a significant effect on the development of post-CT AKI (P = .04). This risk increased with decreases in pre-CT eGFR (≥ 60 mL/min/1.73 m(2): odds ratio, 1.00; 95% confidence interval: 0.86, 1.16; 45-59 mL/min/1.73 m(2): odds ratio, 1.06; 95% confidence interval: 0.82, 1.38; 30-44 mL/min/1.73 m(2): odds ratio, 1.40; 95% confidence interval: 1.00, 1.97;30 mL/min/1.73 m(2): odds ratio, 2.96; 95% confidence interval: 1.22, 7.17).IV LOCM is a nephrotoxic risk factor in patients with a stable eGFR less than 30 mL/min/1.73 m(2), with a trend toward significance at 30-44 mL/min/1.73 m(2). IV LOCM does not appear to be a nephrotoxic risk factor in patients with a pre-CT eGFR of 45 mL/min/1.73 m(2) or greater.

To determine whether the intravenous administration of low-osmolality contrast material is associated with exacerbation of disease-related symptoms in patients with myasthenia gravis.This HIPAA-compliant, retrospective cohort study was approved by the institutional review board. The requirement to obtain patient consent was waived. Computed tomography (CT) was performed in 267 patients with clinically confirmed myasthenia gravis between January 1, 1995, and December 31, 2011. CT was performed without intravenous administration of contrast material in 155 patients and with intravenous administration of low-osmolality contrast material in 112. Electronic medical records were searched to identify myasthenia gravis-related symptoms before (≤ 14 days) and after (≤ 45 days) each CT examination. The Mantel-Cox log-rank test was used to compare the time to symptom progression between the two groups. The Fisher exact test was used to compare rates of disease-related symptoms during three time periods: (a) 0-1 day after CT, (b) 2-7 days after CT, and (c) 8-45 days after CT.The unenhanced and contrast-enhanced CT groups had similar thymectomy rates (P = .97) and disease-related symptom trends before CT (P = .58). The contrast-enhanced CT group was associated with a significant reduction in time to disease-related symptom progression following CT (median time to onset of symptom progression, 2.5 days with contrast-enhanced CT vs 14.0 days with unenhanced CT; P = .05). There were significantly more disease-related symptom exacerbations within 1 day of CT in the contrast-enhanced CT group compared with the unenhanced CT group (6.3% [seven of 112 patients] vs 0.6% [one of 155 patients], respectively; P = .01). Acute exacerbations were primarily respiratory (five patients with new-onset dyspnea [four in contrast-enhanced CT group and one in unenhanced CT group], two patients with progressive dyspnea [both in the contrast-enhanced CT group], and one patient with progressive weakness [in contrast-enhanced CT group]). There was no difference in symptoms between groups at 2-7 days (P = .70) or 8-45 days (P = .99).Intravenous administration of low-osmolality contrast material is significantly associated with exacerbation of myasthenia gravis-related symptoms. Exacerbations most commonly manifest as new or progressive acute respiratory compromise.

To assess the effects of oral computed tomography (CT) contrast agents on hepatic hemodynamics with duplex Doppler ultrasound (US).Thirty healthy subjects who fasted underwent duplex Doppler US of the hepatic artery and portal vein both before and after administration of oral CT contrast agents. Resistive indexes were determined for the hepatic arteries. Peak and mean velocity (centimeters per second) and mean diameter were calculated for the main portal vein.Statistically significant elevation of the resistive index (P.01) of the hepatic arteries was observed after ingestion of oral CT contrast agents. Increase in the mean resistive index at 15 minutes was 12% in the proper hepatic arteries and 20% in the intrahepatic arteries. There was a postprandial increase in mean portal venous flow compared with baseline levels (1,110 mL/min +/- 210 vs 940 mL/min +/- 140) (P.05).An elevation of hepatic artery resistance that is probably due to arterial vasoconstriction after ingestion of oral CT contrast agents can be observed with Doppler US. Hemodynamic changes in liver vasculature after ingestion of oral CT contrast agents may have as yet unknown implications for CT scanning of the liver.

To evaluate the effect of abruptly substituting gadobenate dimeglumine for gadopentetate dimeglumine on allergic-like reactions.The institutional review board approved and waived patient consent for this HIPAA-compliant retrospective study. Allergic-like reactions related to gadolinium-based contrast media were assessed 2 years before and 3.5 years after gadobenate dimeglumine was substituted for gadopentetate dimeglumine. Reaction rates and severity were compared by using χ(2) tests, Fisher exact tests, odds ratios (ORs), and confidence intervals (CIs).Allergic-like reactions (137 mild, 19 moderate, and six severe) occurred in 162 (0.15%) of 105 607 injections of gadolinium-based contrast media (gadopentetate dimeglumine, 31 540; gadobenate dimeglumine, 66 152; other, 7915). Gadobenate dimeglumine was associated with significantly more overall (0.19% [123 of 66 152] vs 0.08% [24 of 31 540]; OR, 2.4; 95% CI: 1.6, 3.8; P.0001) and mild (0.16% [107 of 66 152] vs 0.06% [18 of 31 540]; OR, 2.8; 95% CI: 1.7, 4.7; P.0001) allergic-like reactions than was gadopentetate dimeglumine. The reaction rate for gadobenate dimeglumine peaked (maximum per quarter, 0.38% [16 of 4262]; minimum per quarter, 0.07% [three of 4237]) in the 2nd year after it replaced gadopentetate dimeglumine (maximum per quarter, 0.10% [four of 4122]; minimum per quarter, 0.05% [two of 4222]) and then declined in the 3rd year. The final gadobenate dimeglumine reaction rate (last 3 quarters, 0.12% [17 of 14 387]) did not significantly differ from the original baseline reaction rate with gadopentetate dimeglumine.After gadobenate dimeglumine was substituted for gadopentetate dimeglumine, a significant transient increase occurred in the frequency of reported allergic-like reactions that demonstrated a temporal pattern suggestive of the Weber effect (a transient increase in adverse event reporting that tends to peak in the 2nd year after a new agent or indication is introduced). © RSNA, 2012.

PURPOSE: To assess fasting and postprandial resistive index (RI) in subjects with healthy and diseased livers. MATERIALS AND METHODS: Subjects with healthy (n = 10) and diseased (n = 33) livers underwent fasting and postprandial Doppler ultrasonography of the hepatic artery. Findings were compared with parameters for liver disease and Child class A-C and Child score of 5-15. RESULTS: The mean postprandial RI increase in healthy subjects was 42% (all, > or = 20%) and in patients with liver disease was 7% (six, > or = 20%). Patients with class A disease (n = 12) had a significantly greater increase in post-prandial RI (13%) than those with class B or C disease (3%) (P < .05). All patients with class C disease (n = 9) had an increased postprandial RI of less than 10%. The 13 patients with at least 10% increase in postprandial RI had less severe liver disease (Child score, 6.1 +/- 1.3 [standard deviation]) than the 20 patients with less than 10% increase (Child score, 8.4 +/- 1.7) (P < .01). CONCLUSION: A nor...

To assess the decisions made by uroradiologists regarding choice of type of intravenous contrast material (low-osmolar contrast media [LOCM] vs conventional ionic agents) and frequency of use of corticosteroid prophylaxis.A questionnaire was mailed to 158 members of the Society of Uroradiology. There were 108 responses received, yielding a response rate of 68%. Results from 76 represented institutions were tabulated.Most respondents practice at institutions in which LOCM are used selectively rather than universally. Corticosteroid prophylaxis in patients at risk is used with similar frequency at both types of institutions. There is considerable diversity in pretreatment regimens (ie, type and dose of corticosteroid used). Although antihistamines are used by many uroradiologists (almost always in conjunction with corticosteroids), H2 receptor antagonists are used at only a few institutions.At institutions in which LOCM are used selectively, the majority of respondents use LOCM quite liberally, with most choosing these agents in patients at risk. Corticosteroid prophylaxis is widely used by respondents. There is much variation in the type of pretreatment regimen and its use in specific clinical settings.

To compare Doppler ultrasonography (US) with conventional clinical and laboratory tests in evaluation of diabetic renal disease.Ninety-eight patients with diabetes mellitus underwent renal Doppler (resistive index [RI] measurement) US examination. US data were compared with clinical variables and follow-up data.Thirty-four diabetic patients without nephropathy had a mean RI of 0.62 +/- 0.09, which was not significantly different from the mean RI of 0.64 +/- 0.09 in 23 patients with early diabetic nephropathy. Patients with established nephropathy had a mean RI of 0.83 +/- 0.11, which was significantly (P.001) higher than in the other two groups. Renal RI correlated highly with serum creatinine concentration (r = .64) and creatinine clearance rate (r = .80). An elevated RI (or = 0.70) was associated with impaired renal function, increased proteinuria at 24 hours, and poor outcome. Absent diastole (RI = 1.0), observed in 7% of patients, was an ominous sign: Five of seven patients underwent dialysis or transplantation shortly after US.RI is typically elevated in established nephropathy but is often normal in the early clinical stages of disease. Renal Doppler US provides an accurate indication of renal function in diabetic nephropathy but does not offer a great advantage over conventional tests.

To evaluate duplex Doppler ultrasound (US) in acute renal obstruction, bilateral intrarenal Doppler US was performed in 23 patients with unilateral renal obstruction (proved by means of intravenous urography) of 36 hours duration or less. A mean renal resistive index (RI) was calculated for each obstructed and normal contralateral kidney and compared with findings on conventional US scans. The mean RI in the obstructed kidneys was elevated (.77 +/- .07 [standard deviation]) and was higher than the mean RI in the normal contralateral kidney (.60 +/- .04) (P.001). RIs in the obstructed kidneys were as follows: .75 or greater in 15 kidneys, .70-.74 (mild RI elevation) in five kidneys (butor = .10 higher than the RI in the normal contralateral kidney), and less than .70 in three kidneys (two of these three patients had pyelosinus extravasation and one patient had clinical obstruction for only 4-5 hours). RI elevation occurred before collecting-system dilatation in four patients (17%). RI elevation occurs by 6 hours of clinical acute renal obstruction and may precede pyelocaliectasis. Renal duplex Doppler US contributes useful clinical information, especially when US is the first modality used to evaluate acute renal colic.

To determine the frequency, type, and severity of breakthrough and repeat breakthrough reactions to iodinated low-osmolality contrast medium (LOCM) in patients who were premedicated with corticosteroids and antihistamines.Institutional review board approval was obtained, and informed consent was waived for this retrospective HIPAA-compliant analysis. One hundred ninety breakthrough allergic-like reactions to intravenous LOCM in 175 patients with a history of contrast medium reactions were reviewed. The repeat breakthrough reactions that resulted from 197 additional LOCM-enhanced examinations performed in 58 patients after the initial breakthrough reaction were also reviewed. The Fisher exact test was used to determine if certain risk factors were associated with an increased risk of a moderate or severe breakthrough reaction. Subgroup analysis was performed to determine if the contrast medium type, contrast medium volume, and/or time between the initial (index) and breakthrough reactions affected the breakthrough reaction severity.Of 128 breakthrough reactions in which the index reaction severity was known, 103 (81%) were of a severity similar to that of the index reaction, 15 (12%) were less severe, and 10 (8%) were more severe. The severity of the breakthrough reactions in the patients with a mild index reaction was usually (in 94 [91%] of 103 reactions) mild. When the index reaction was severe, the breakthrough reaction was usually moderate or severe (in eight [42%] of 19 cases and four [67%] of six cases, respectively). The majority (174 [88%] of 197) of LOCM injections after the initial breakthrough reaction did not result in a repeat breakthrough reaction. Breakthrough reactions were significantly more likely to be moderate or severe in patients with a history of chronic oral corticosteroid use (P = .01), drug (P = .04) or severe (P.001) allergies, or allergies to four or more allergens (P = .01).Breakthrough reactions are usually similar in severity to the index reaction, and subsequent contrast medium injections usually do not induce repeat breakthrough reactions. Breakthrough reactions are more likely to be moderate or severe in patients with certain risk factors.

To distinguish the obstructed from the nonobstructed dilated collecting system of transplanted kidneys without interventional diagnostic measures, the authors prospectively evaluated duplex Doppler analysis (determination of resistive index [RI]) in 35 renal transplant patients with pyelocaliectasis. Proof of the presence or absence of obstruction was obtained at interventional procedures in 18 patients and at clinical follow-up in 17. Thirteen kidneys were obstructed (mean RI, .81 +/- .06), while 22 had nonobstructive dilatation (mean RI, .66 +/- .07). The RI difference was statistically significant (P less than or equal to .01). Of 21 kidneys with a normal RI, only two had obstruction. In both of these, the obstruction was associated with a significant peritransplant collection of fluid due to a ureteral leak. In the seven obstructed transplanted kidneys with follow-up, the mean RI was .82 +/- .06 before nephrostomy and .67 +/- .05 after nephrostomy. Obstruction was a common cause of an elevated RI (greater than or equal to .75). Other causes of transplant dysfunction can be associated with an elevated RI and nonobstructed dilatation. More important, a normal RI should strongly argue against obstruction unless a ureteral leak is also present.

Ultrasonography (US) of the native kidneys is commonly requested for acute renal failure (ARF), although in most cases the examination results are negative. To detect changes in the Doppler waveform associated with ARF and determine whether Doppler US can provide significant diagnostic information not available with standard US, 91 patients with ARF were studied to determine a mean resistive index (RI) for each patient. Forty-six patients had acute tubular necrosis (ATN) with a mean RI +/- 1 standard deviation of .85 +/- .06, which was significantly higher than the mean RI of .67 +/- .09 in 30 patients with prerenal ARF (P less than .01). Fifteen patients had ARF due to non-ATN intrinsic renal disease (mean RI, .74 +/- .13). An elevated RI (greater than or equal to .75) occurred in 91% of patients with ATN versus only 20% of patients with prerenal azotemia. Patients with severe liver disease (hepatorenal syndrome) are a subset of those with prerenal ARF that accounted for most of the elevated RIs in this group. The study demonstrates that intrarenal Doppler US allows detection of changes associated with ARF far more often than standard US. More important, Doppler US may be helpful in distinguishing ATN from prerenal azotemia.

To determine the prevalence of protected health information (PHI) in PowerPoint presentations available for downloading from the Internet.No institutional review board approval was needed for this project, which involved no patient subjects. Two Google searches, each limited to PowerPoint files, were performed by using the criteria "Cardiac CT" and "Magnetic Resonance Imaging." The first 100 hits of each search were downloaded from the source Web site. The presentations were examined for the PHI contained on any images, links, or notes pages.Two hundred presentations were evaluated. There were 143 presentations with images, image links, or notes, and 52 (36%) of these contained PHI. There were 129 presentations containing radiologic images; 51 (40%) of these contained PHI, and 31 (24%) showed the patient's name. At least 132 (66%) of the 200 presentations originated from the United States. Thirty-five (37%) of 94 presentations with images, image links, or notes contained PHI. Eighty-six U.S. presentations contained radiologic images; 34 (40%) of these contained PHI, and 19 (22%) showed the patient's name.Online or other distributions of PowerPoint presentations that contain radiologic images often contain PHI, and this may violate laws, including the U.S. Health Insurance Portability and Accountability Act.

To determine retrospectively the frequency, management, and outcomes of extravasations of intravenously injected nonionic iodinated contrast medium.Institutional review board approval was obtained, and the requirement for informed consent was waived. The study was HIPAA compliant. For 69,657 intravenous injections of nonionic iodinated contrast medium for computed tomographic examinations between January 1, 2000, and March 31, 2005, the incident reports, radiology reports, and medical records of patients in whom contrast medium extravasations occurred were reviewed. Data collected included patient age, catheter gauge, injection site, volume extravasated, patient symptoms, severity of injury, treatment, whether or not the plastic surgery service was consulted and any additional treatment that service instituted, and patient outcome.Extravasations occurred in 475 (0.7%) of 69 657 patients, and follow-up information was available for 442 adults (280 women, 162 men; mean age, 57 years) and 17 children (nine girls, eight boys; mean age, 6 years). Extravasated volumes ranged from 3 to 150 mL. Symptoms usually consisted of swelling and/or pain. The plastic surgery service was consulted for 38 adults and six children and provided additional treatment in eight patients (seven adults, one child). Among adults, 432 had minimal or no adverse effects, nine had moderate adverse effects, and one had a severe complication (75 mL of contrast material extravasated into the hand, causing compartment syndrome). Only one moderate or severe complication in an adult resulted from an extravasation of less than 50 mL. Fifteen children had minimal or no adverse effects, one had moderate adverse effects, and one had a severe complication (18 mL of contrast material extravasated into the arm, causing brachial plexopathy).Extravasation of nonionic iodinated contrast medium results only rarely in moderate or severe adverse effects, and these usually occur only when large volumes of contrast medium are involved.

To retrospectively compare the effects of abdominal compression, intravenous saline hydration, and two imaging delays on both distention and opacification of the intrarenal collecting system and ureter during multi-detector row computed tomographic (CT) urography.Institutional review board approval for reviewing images and medical records of the patients was obtained; informed patient consent was not required. Excretory phase images obtained from multi-detector row CT urography in 85 patients (57 men, 28 women) were reviewed. Examinations were performed by using one of four techniques: abdominal compression and intravenous hydration with 250 mL of normal saline, compression only, intravenous hydration with saline only, and neither compression nor saline hydration. Excretory phase imaging was performed at 300 and 450 seconds for each patient. Two reviewers measured urinary tract distention on transverse images and graded opacification and image quality on volume-rendered images. Effects were compared by using statistical mixed models with repeated-measures analysis of variance.Saline hydration significantly improved opacification (P = .02) and overall image quality (P.001) of the intrarenal collecting system and proximal ureter. Delayed excretory phase image acquisition of 450 seconds significantly increased distention of the intrarenal collecting system and proximal ureter (P.001). No significant effects involving the lower segment of the ureter were seen with any technique; however, there were fewer nonvisualized distal ureteral segments with the longer imaging delay.Compression does not significantly improve distention or opacification of the urinary tract. Saline hydration is effective in improving opacification of the proximal urinary tract. Longer imaging delays improve distention of the proximal urinary tract and may aid in visualization of the lower segment of the ureter.

To describe positional variation in the outcome of the Whitaker test.The authors retrospectively reviewed the cases of six patients in whom the pressure gradient during Whitaker testing varied by at least 10 cm of water and changed from normal (or = 13 cm of water) to abnormal (13 cm of water) when patients were placed in different positions.Four patients had obstruction only in nonstandard positions. All had intermittent symptoms, and three had ureteral kinks at fluoroscopy. Two patients with ileal conduits had abnormal results in the standard position but normal results at repositioning related to compression of the conduits (seen as conduit distention at fluoroscopy). All six had undergone urinary tract surgery. Gradient differences with positional change ranged from 10 to38 cm of water.Whitaker testing in different positions may help identify intermittent obstructions that might otherwise go undetected or prevent inappropriate diagnosis of obstruction. Intermittent or unexplained symptoms, tortuous ureters, malpositioned kidneys, or previous surgery are indications for provocative positional testing.

To assess whether contrast material enhancement findings on computed tomographic (CT) scans are useful in determination of the risk for development of hepatic metastases.Dual-phase helical CT scans were obtained in 80 patients with nonhepatic cancer and no hepatic metastases visible at CT. Attenuation was measured on scans obtained at 25 and 40 seconds. Peak liver attenuation was determined in all cases. Unenhanced scans were obtained in 35 patients. The ratio of liver attenuation at 25 and 40 seconds to peak liver attenuation, liver enhancement values at 25 and 40 seconds, and ratio of liver enhancement at 25 and 40 seconds to peak liver enhancement were determined.Liver metastases developed during 18-month follow-up in 22 patients. The 25- and 40-second liver enhancement values and the liver enhancement and attenuation ratios were higher in these patients than in those who did not develop metastases (P.01). Enhancement values and ratios were more accurate than densitometric measurements for predicting development of metastases. Use of an optimal threshold (0.40 or greater) for the 40-second enhancement ratio resulted in a sensitivity of 75%, specificity of 96%, and overall accuracy of 89%.CT measurements may help in the prediction of risk for subsequent development of hepatic metastases.

To compare conventional and Doppler ultrasound (US) with clinical and biopsy parameters used to assess disease activity and outcome in lupus nephritis and to assess the predictive value of US.Thirty-four patients with lupus nephritis prospectively underwent laboratory and US analysis at the time of renal biopsy. US parameters were renal length, relative echogenicity, and resistive index (RI). Laboratory parameters were serum creatinine level, urinary protein level, and serum markers of disease activity. Biopsy parameters were activity index, chronicity index, and assessment of the tubulointerstitium of the kidney. Follow-up data were obtained in all patients for at least 1 year.Ten patients with elevated RI (0.70) had significantly (P.05) higher chronicity indexes and creatinine levels than the 24 patients with a more normal RI. RI correlated significantly (P.05) with creatinine level, chronicity index, and presence of interstitial disease. Only RI and chronicity index were statistically significant predictors of a poor renal outcome. Abnormalities at conventional US were not predictive of renal outcome. A normal RI predicted a better renal outcome whether or not creatinine level was elevated.Renal Doppler US may be of greatest clinical utility when its results are apparently discordant with renal functional assessment by allowing identification of patients with higher likelihood of subsequent improvement or worsening of renal status.

PURPOSE: To assess helical computed tomography (CT) as a potential substitute for intravenous urography and renal angiography in the evaluation of living potential renal donors. MATERIALS AND METHODS: Helical CT was performed in 32 potential donors both before and after administration of contrast material. Scans were reconstructed at 1.5-mm intervals for three-dimensional reconstructions. Helical CT images were blindly compared with urograms (n = 32) and renal angiograms (n = 24). RESULTS: One small accessory artery was not depicted with helical CT, and angiography did not depict an accessory artery arising in proximity to the origin of the main renal artery. All eight kidneys with early dividing main arteries were identified with both helical CT and angiography. Three renal venous anomalies were depicted only with helical CT. Helical CT and urography equally depicted nonvascular findings. CONCLUSION: Renal helical CT is a suitable replacement for intravenous urography and angiography in the assessment of...

PURPOSE: To determine if portal vein thrombosis (PVT) is associated with changes in the hepatic artery resistive index (RI) at Doppler ultrasonography (US). MATERIALS AND METHODS: In 35 patients with findings suspicious for PVT, prospective hepatic artery RIs were obtained before angiographic proof of portal vein status. RIs were also obtained from 27 age-matched patients with liver disease (without PVT) and from eight patients with PVT (without occlusion). RESULTS: Twenty-seven of the 35 patients had proved PVT and a significantly lower (P < .01) mean hepatic artery RI than did patients in any other group studied. Twelve of these 27 patients had RI values of .50 or less, while none of the patients in any other group studied had an RI value this low (specificity, 100%). CONCLUSION: A reduction in hepatic artery RI accompanies PVT and may be a helpful secondary sign to determine this venous abnormality.

To assess accuracy of three different magnetic resonance (MR) imaging techniques, including the endorectal coil, in staging prostate cancer.MR imaging was performed in 213 patients with prostate cancer with a conventional body coil, with fat suppression and a body coil, and with an endorectal coil. Radiologists identified tumor invasion into periprostatic tissues, neurovascular bundles, and seminal vesicles. Each technique was evaluated separately, and in a subset of 74 patients the three techniques were evaluated together. Images obtained with the two body-coil techniques were read in combination with images obtained with the endorectal coil (combination A) and alone (combination B).Overall accuracy for conventional body-coil, fat-suppressed body-coil, and endorectal-coil MR was 61%, 64%, and 54%, respectively. Overall group accuracy for combinations A and B was 57% and 61%. Considerable interreader variability was found for combination A.No technique was highly accurate for staging early prostate cancer. Individual radiologists did achieve a high degree of staging accuracy with the endorectal-coil and body-coil combination.

A superelastic guide wire was used (after failure of other methods) as a loop snare to retrieve a foreign body from the ureter in three patients. In vitro comparison of the expansion capability of the superelastic guide wire and that of the standard retrieval wire showed that the superelastic wire forms larger loops within an elastic space. Also, because of less frictional resistance and its ability to be formed into stiffer loops, the superelastic wire resists kinking and is easier to manipulate than the standard wire.

To improve early detection of renal dysfunction in patients who undergo liver transplantation, a prospective study was performed with intrarenal duplex Doppler sonography before and after liver transplantation in 42 patients. The duplex Doppler findings were compared with multiple clinical and laboratory findings; patients were grouped on the basis of preoperative renal resistive index (RI) and serum creatinine level. The mean initial renal RI was elevated (.73 +/- .07 [standard deviation]); after transplantation, it was lower (.60 +/- .06) (P less than .001). Thirty-six patients had a normal serum creatinine level at the preoperative Doppler examination. Patients with an elevated renal RI (n = 19) had a greater chance of subsequent renal dysfunction (P less than .001), hemodialysis (P less than .01), longer stays in the intensive care unit (P less than .05), and longer hospital stays after surgery (P less than .05) than those with a normal renal RI (n = 17). In 34 patients the RI fell 10% or more after surgery and none died, whereas five of eight patients (62%) whose RI fell less than 10% died. Doppler analysis enabled identification of patients without azotemia whose course of disease before and after surgery was similar to that of patients with clinically recognized renal disease.

There are few data in the literature on the abdominal manifestations of sarcoidosis at computed tomography (CT). To determine whether differences in nodal distribution and appearance can be reliably used to distinguish between sarcoidosis and non-Hodgkin lymphoma (NHL), the authors retrospectively reviewed the abdominal and pelvic CT scans of 16 patients with biopsy-proved sarcoidosis and 20 patients with biopsy-proved NHL. Eleven of the 16 patients with sarcoidosis had abdominal and/or pelvic lymphadenopathy, which was common at all nodal sites except for the retrocrural and pelvic locations. There was a statistically significant lower frequency of retrocrual adenopathy in sarcoidosis than in NHL. Mean nodal size was significantly greater in NHL. Nodes tended to be confluent in NHL and discrete in sarcoidosis. Hepatomegaly was seen in six of the 16 patients (38%) with sarcoidosis and splenomegaly was present in nine of 15 (60%). CT depicted hepatic lesions in only three of eight patients (38%) with biopsy-proved hepatic involvement. Splenic lesions were seen at CT in five of the 15 patients (33%). The authors believe that the overlap in nodal appearance and distribution poses a limitation for use of these criteria in accurate disease characterization.

Distinction of the obstructed from the nonobstructed dilated renal collecting system is a difficult problem often requiring interventional procedures and pressure measurements. The authors prospectively performed duplex Doppler ultrasound (US) evaluations in 21 kidneys (obstructed, n = 14; nonobstructed, n = 7) immediately before percutaneous nephrostomy. In addition, ten of the obstructed kidneys were evaluated with follow-up Doppler US after percutaneous nephrostomy. Renal obstruction caused a change in the Doppler waveform detected by means of the resistive index (RI). Thirteen of the 14 obstructed kidneys had a RI value greater than .70, while none of the nonobstructed kidneys had a RI value exceeding .70. Relief of the obstruction resulted in a reduced RI; in nine of ten kidneys, the RI was less than or equal to .70 (similar to that of the nonobstructed kidneys). When a dilated collecting system is being imaged, additional evaluation with duplex Doppler US may help distinguish obstructed from nonobstructed dilatation, which may be of particular benefit in patients with conditions that usually predispose them to collecting system dilatation.

Magnetic resonance (MR) imaging of the cervical spine was employed in 18 patients with rheumatoid arthritis and suspected cervical involvement. Fifteen patients had symptoms referable to the cervical spine, and seven had neurologic deficits. In three patients who were asymptomatic with regard to the neck, MR imaging was performed because of abnormal cervical radiographs. Cervical radiographs were available for all patients; bone erosion was evident in 14, subluxation in 17, and no abnormalities in one. MR imaging demonstrated indentation or abnormal signal in the caudal brain stem and/or cervical spinal cord in ten patients, including the seven with related neurologic deficits; discrete indentation or distortion of the dura without visible morphologic effect on the underlying neuraxis was observed in five other patients. In all patients with neurologic symptoms, cord or brain-stem abnormalities were seen on MR images. MR imaging therefore appears to provide valuable information regarding the status of the spinal cord and dura in patients with rheumatoid arthritis.

In two patients examined with magnetic resonance (MR) imaging after lymphangiography, opacified pelvic lymph nodes could not be distinguished from subcutaneous or retroperitoneal fat because of the short T1 and long T2 relaxation times of lymphangiographic contrast media. Opacified nodes removed from one patient had relaxation times similar to those of fat. Thus, assessment of lymphadenopathy with MR imaging should be performed before lymphangiography to obviate this potential pitfall.