Visual Assessment of the Intensity and Pattern of T1 Hyperintensity on MRI to Differentiate Hemorrhagic Renal Cysts From Renal Cell Carcinoma.

OBJECTIVE: The purpose of this study was to apply a visual assessment of the intensity and pattern of T1 hyperintensity at MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma (RCC). MATERIALS AND METHODS: A total of 144 T1-hyperintense renal lesions (62 cysts, all showing no enhancement on subtracted contrast-enhanced images and either 2-year stability or unenhanced CT density > 70 HU, and 82 histologically confirmed RCCs) in 144 patients were included. Two radiologists independently characterized qualitative features of the T1 hyperintensity in each lesion on unenhanced T1-weighted images. An additional radiologist placed ROIs to measure lesions' T1 signal intensity normalized to that of the psoas muscle. Chi-square and unpaired t tests were performed to compare the pattern of T1 hyperintensity between groups. RESULTS: The T1 hyperintensity was considered marked in 62.9% of cysts and 17.1% of RCCs for reader 1 and in 46.8% of cysts and 8.5% of RCCs for reader 2 (p < 0.001). The T1 hyperintensity exhibited a diffusely homogeneous distribution in 88.7% of cysts and 7.3% of RCCs for reader 1 and in 72.6% of cysts and 4.9% of RCCs for reader 2 (p < 0.001). The combination of both diffusely homogeneous distribution and marked degree of T1 hyperintensity achieved sensitivities of 40.3-56.5%, specificities of 97.6-98.8%, and accuracies of 73.6-79.9% for the diagnosis of T1-hyperintense cysts. The two cases of RCC exhibiting this imaging pattern for at least one reader were both papillary RCCs. Normalized signal intensity was 2.39 ± 0.99 in T1-hyperintense cysts versus 2.12 ± 0.84 in T1-hyperintense RCCs (p = 0.088). CONCLUSION: Diffuse T1 hyperintensity, particularly when marked, strongly indicates a hemorrhagic cyst rather than an RCC. Deferral of follow-up imaging may be considered when this imaging appearance is encountered at unenhanced MRI.

Coronary Computed Tomography Angiography Versus Radionuclide Myocardial Perfusion Imaging in Patients With Chest Pain Admitted to Telemetry: A Randomized Trial.

BACKGROUND: The role of coronary computed tomography angiography (CCTA) in the management of symptomatic patients suspected of having coronary artery disease is expanding. However, prospective intermediate-term outcomes are lacking. OBJECTIVE: To compare CCTA with conventional noninvasive testing. DESIGN: Randomized, controlled comparative effectiveness trial. (ClinicalTrials.gov: NCT00705458). SETTING: Telemetry-monitored wards of an inner-city medical center. PATIENTS: 400 patients with acute chest pain (mean age, 57 years); 63% women; 54% Hispanic and 37% African-American; and low socioeconomic status. INTERVENTION: CCTA or radionuclide stress myocardial perfusion imaging (MPI). MEASUREMENTS: The primary outcome was cardiac catheterization not leading to revascularization within 1 year. Secondary outcomes included length of stay, resource utilization, and patient experience. Safety outcomes included death, major cardiovascular events, and radiation exposure. RESULTS: Thirty (15%) patients who had CCTA and 32 (16%) who had MPI underwent cardiac catheterization within 1 year. Fifteen (7.5%) and 20 (10%) of these patients, respectively, did not undergo revascularization (difference, -2.5 percentage points [95% CI, -8.6 to 3.5 percentage points]; hazard ratio, 0.77 [CI, 0.40 to 1.49]; P = 0.44). Median length of stay was 28.9 hours for the CCTA group and 30.4 hours for the MPI group (P = 0.057). Median follow-up was 40.4 months. For the CCTA and MPI groups, the incidence of death (0.5% versus 3%; P = 0.12), nonfatal cardiovascular events (4.5% versus 4.5%), rehospitalization (43% versus 49%), emergency department visit (63% versus 58%), and outpatient cardiology visit (23% versus 21%) did not differ. Long-term, all-cause radiation exposure was lower for the CCTA group (24 versus 29 mSv; P < 0.001). More patients in the CCTA group graded their experience favorably (P = 0.001) and would undergo the examination again (P = 0.003). LIMITATION: This was a single-site study, and the primary outcome depended on clinical management decisions. CONCLUSION: The CCTA and MPI groups did not significantly differ in outcomes or resource utilization over 40 months. Compared with MPI, CCTA was associated with less radiation exposure and with a more positive patient experience. PRIMARY FUNDING SOURCE: American Heart Association.

Characteristic CT Findings After Percutaneous Cryoablation Treatment of Malignant Lung Nodules.

Assess computed tomography (CT) imaging characteristics after percutaneous cryotherapy for lung cancer.A retrospective IRB-approved analysis of 40 patients who underwent nonsurgical treatment for primary stage 1 lung cancer performed from January 2007 to March 2011 was included in this study. All procedures were performed using general anesthesia and CT guidance. Follow-up imaging with CT of the chest was obtained at 1 month, 3 months, 6 months, and 12 months postprocedure to evaluate the ablated lung nodule. Nodule surface area, density (in Hounsfield units), and presence or absence of cavitations were recorded. In addition, the degree of nodule enhancement was also recorded. Patients who were unable to obtain the aforementioned follow-up were excluded from the study.Thirty-six patients underwent percutaneous cryoablation with men to women ratio of 75% with mean age for men 74.6 and mean age for women 74.3 years of age. The average nodule surface area preablation and postcryoablation at 1-, 3-, 6-, and 12-month follow-ups were 2.99, 7.86, 3.89, 3.18 and 3.07[REPLACEMENT CHARACTER]cm, respectively. The average precontrast nodule density before cryoablation was 8.9 and average precontrast nodule density postprocedure at 1, 3, 6, and 12 months follow-ups were 8.5, -5.9, -9.4, and -3.8 HU, respectively. There is increased attenuation of lung nodules over time with an average postcontrast enhancement of 11.4, 18.5, 16.1, and 25.7 HU at the aforementioned time intervals. Cavitations occurred in the cryoablation zone in 53% (19/36) of patients. 80.6% (29/36) of the cavitations in the cryoablation zone resolved within 12 months. Four patients (11%) had recurrence of tumor at the site of cryoablation and none of the patients had satellite or distant metastasis.Our study shows that patients who underwent cryotherapy for lung nodules treatment had characteristic changes on follow-up CT including. The surface area of the nodule increases at the 1-month follow-up with subsequent gradual decrease in the surface area. Decreased nodule density (Hounsfield units) at each interval follow-up is associated with complete ablation of the lung cancer whereas increasing nodule density was suggestive of recurrence. Cavity formation within the region of the ablated nodule, most of which typically resolved within the first 3 to 6 months. Nodule enhancement is difficult to assess because of the limited data sets that are available.

Postlobectomy chest radiographic changes: a quantitative analysis.

PURPOSE: To provide a quantitative analysis of postlobectomy chest radiographic changes and to evaluate whether the scarring from prior sternotomy affects the size of the hemithorax and the duration of air leak in patients with subsequent lobectomy. METHODS: In this retrospective case-controlled series, 10 consecutive patients who had a lobectomy after a prior sternotomy and 30 controls, 3 for each case, matched for lobectomy site were identified. Pre- and postoperative chest radiographs were quantitatively analysed for diaphragmic elevation, size of each hemithorax, mediastinal shift, and the presence of pneumothorax. Charts were reviewed for air-leak duration, surgical complications, and duration of hospitalization. RESULTS: There was no difference between patients with lobectomy and with and without prior sternotomy for the following variables expressed as mean (SD): hemidiaphragm elevation (1.5 ± 2.5 vs 0.5 ± 2.0 cm; P = .2), change of hemithorax size (mean transverse, 0.99 ± 0.05 vs 0.97 ± 0.07; P = .5; craniocaudal, 0.93 ± 0.08 vs 0.91 ± 0.08; P = .4) and mediastinal shift (upper, 1.2 ± 0.4 vs 1.3 ± 0.6; P = .5; lower, 1.2 ± 0.4 vs 1.2 ± 0.3; P = .8), the latter 2 were expressed as the ratio of post- to preoperative measurements. These postlobectomy radiographic findings varied, depending on the resected lobe, and became progressively more pronounced during the first 12 months after surgery. There was no difference in pneumothorax duration (mean [SD]) (9.5 ± 21 days vs 6.4 ± 7.5 days; P = .5), air leak duration (mean [SD]) (0.7 ± 0.8 days vs 1.3 ± 3.9 days; P = .6), complication rate (20% vs 30%; P = .5), or hospital stay (mean [SD]) (6.0 ± 1.7 days vs 6.9 ± 4.7 days; P = .6). CONCLUSION: There are specific patterns of volume loss, mediastinal shift, and hemidiaphragm displacement that can be quantified on postlobectomy chest radiographs. Prior sternotomy did not affect postlobectomy radiographic changes or patient outcome.

Efficacy of coronary CT angiography: where we are, where we are going, and where we want to be.

Over the decade since its earliest introduction, coronary CT angiography has spread rapidly, despite the fact that its validation base is smaller than that of alternative imaging examinations. Consensus statements have issued a call for improvement of coronary CT angiography's knowledge base. This article reviews recent progress in validating the efficacy of coronary CT angiography in the detection of coronary artery disease, with a focus on clinical decision making, management, and outcomes. We discuss the rationale for comparative effectiveness research and a framework for assessment of levels of efficacy. Comparison is made with radionuclide myocardial perfusion imaging, which serves as a model noninvasive examination. The potential roles of coronary CT angiography in screening, early triage, and as a gatekeeper for catheterization are discussed. Although few randomized controlled trials have been performed to date, we review the pivotal publications and mention ongoing and future efforts. Cardiovascular event rates provide the basis for estimating the success of potential study designs. The rigorous validation of coronary CT angiography may serve as a model for other noninvasive diagnostics.