Depiction of normal gastrointestinal anatomy with MDCT: comparison of low- and high-attenuation oral contrast media.

PURPOSE: To compare low- and high-attenuation oral contrast media for depiction of normal gastrointestinal anatomy with multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: A prospective, randomized study of 90 consecutive patients without known or suspected gastrointestinal disease was conducted after the approval of our Institutional Review Board. All patients underwent IV contrast-enhanced abdominal and pelvic CT scans after oral administration of 900 ml of either low- or high-attenuation barium sulphate suspension. Using a five-point scale, two radiologists independently graded distention and wall visualization of stomach, duodenum, jejunum, and ileum. The degree of distention and wall visualization was compared using Mann-Whitney U-test. RESULTS: Duodenal, jejunal and ileal distention (p<0.05, <0.001, <0.001, respectively) and wall visualization (p<0.05, <0.01, <0.05, respectively) scores with low-attenuation contrast medium were significantly higher than those with high-attenuation barium sulphate preparation, for reader 1. Duodenal and jejunal wall visualization scores with low-attenuation contrast medium (p<0.05, <0.01, respectively) were significantly higher than those with high-attenuation contrast medium, for reader 2. Interobserver agreement was fair to good for both distention (kappa-range: 0.41-0.74) and wall visualization (kappa-range: 0.48-0.71). CONCLUSION: MDCT with low-attenuation contrast medium provides distention and wall visualization of the GI tract that is equal or better than high-attenuation contrast medium.

FDG-PET/CT tumor segmentation-derived indices of metabolic activity to assess response to neoadjuvant therapy and progression-free survival in esophageal cancer: correlation with histopathology results.

PURPOSE: To evaluate the diagnostic and prognostic abilities of PET tumor segmentation-derived indices of metabolic activity for the assessment of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer. METHODS: Twenty-five patients with histologically confirmed esophageal cancer were retrospectively evaluated. The patients underwent PET-CT imaging before and after completion of neoadjuvant therapy. Images were evaluated visually and quantitatively with a three-dimensional threshold-based region-growing program, which calculates SUVm, SUVa of the entire tumor, metabolic tumor length (Lm) and volume (Vm) before and after therapy (SUVm1, SUVm2, SUVa1, SUVa2, Lm1, Lm2, Vm1, and Vm2, respectively). Percentage changes in these metabolic variables before and after therapy were also calculated (%SUVm, %SUVa, %Lm, %Vm, respectively). RESULTS: SUVm1 (P = 0.018), SUVa1 (P = 0.019), Lm1 (P = 0.016), and Vm1 (P = 0.016) correlated with T-status. Advanced stage tumors (T3 + T4) had significantly higher glucose metabolism, metabolic length, and volume. Moreover, Lm1 >47.4 mm and Vm1 >29 cm3 were the best predictors of the level of tumor invasiveness. SUVm1 >12.7 and SUVa1 >5.9 could differentiate patients with positive lymph nodes from those without at presentation. %SUVa >32.3% and the SUVa1 >5.5 proved to be reliable predictors of pathologic response. SUVa2 >3.55 and SUVm2 >4.35 were the best predictors of disease progression during follow-up, with the latter having the best prognostic value. CONCLUSIONS: This study showed that FDG-PET tumor segmentation-derived indices of metabolic activity play a definite role in the evaluation of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer.

Carcinoma de células renais de células claras e papilares tipos 1 e 2: achados nas imagens por ressonância magnética e correlação histopatológica / Clear cell, type 1 and type 2 papillary renal cell carcinomas: retrospective analyses of magnetic resonance imaging findings and histopathologic correlation

Objetivou-se descrever os padrões de sinal nos exames de ressonância magnética (RM) dos carcinomas de células renais (CCR) de células claras e papilares tipos 1 e 2, correlacionando-os com os achados histopatológicos, bem como avaliar o realce dos tumores após a administração intravenosa do meio de contraste paramagnético. Pesquisa no banco de dados da patologia nos últimos 5 anos identificou 49 CCR avaliados com imagens por ressonância magnética (RM), dos quais 37 (17 CCR papilares tipo 1, 4 CCR papilares tipo 2 e 16 CCR de células claras) tinham espécimes patológica disponíveis para avaliação. A intensidade do sinal (IS) dos CCR comparados ao córtex renal, qualitativamente e quantitativamente (IS do tumor/IS do córtex renal x 100), nas imagens por RM ponderadas em T1 e T2, assim como o realce do tumor (qualitativamente e quantitativamente) foram avaliados por 2 radiologistas independentes. Um patologista avaliou as características das células tumorais e achados associados como a presença de hemosiderina, ferritina, sangue fresco, necrose, fibrose e calcificação. Os três subtipos de CCR avaliados tinham padrão diverso nas imagens ponderadas em T1 (p>0.05)...

The purpose of this study is to describe magnetic resonance imaging (MRI) tumor signal intensity (SI) of clear cell, and types 1 and 2 papillary renal cell carcinomas (RCC), correlating with histopathologic findings, as well as to evaluate tumor enhancement after intravenous administration of paramagnetic contrast. A query on our pathology database for the past 5 years identified 49 RCC, which were evaluated with MRI. Of these, 37 (17 papillary type 1, 4 papillary type 2, and 16 clear cell) pathology specimens were available for review. Two independent radiologists assessed tumor SI compared to renal cortex, both qualitatively and quantitatively (tumor SI/renal cortex SI x 100), on T1 and T2 weighted MRI, as well as tumor enhancement. A pathologist evaluated tumor cell characteristics and associated findings, such as the presence of hemosiderin, ferritin, fresh blood, necrosis, fibrosis, and calcification. T1 tumor SI varied among RCC subtypes. On T2-weighted images, most types 1 and 2 papillary RCC had hypo signal, whereas hyper signal was only seen among clear cell RCC (p<0.05); which was confirmed with a quantitative assessment (type 1 papillary RCC= 71% ±16%, type 2 papillary RCC= 54% ±23%, and clear cell RCC= 141% ±44%, p<0.01). Tumor T2 SI of 96% or less had a sensitivity of 96% and specificity of 89% for papillary RCC, when compared to clear cell RCC; and tumor SI of 66.2% or less had a sensitivity of 54% and specificity of 100%. Tumor predominant architecture, papillary for tumors with hypo signal and nested for tumors with hyper signal, was the only histopathologic finding to correlate with tumor SI on T2 weighted MRI (p<0.05)...

CT features of hepatic venoocclusive disease and hepatic graft-versus-host disease in patients after hematopoietic stem cell transplantation.

OBJECTIVE: We conducted this study to evaluate whether CT scans could be used to differentiate hepatic venoocclusive disease from hepatic graft-versus-host disease in patients treated with hematopoietic stem cell transplantation. SUBJECTS AND METHODS: We retrospectively evaluated 18 patients (eight women, 10 men; mean age, 42.4 years) after hematopoietic stem cell transplantation with biopsy-proven hepatic venoocclusive disease (n = 5), hepatic graft-versus-host disease (n = 6), or both (n = 7). Two radiologists reviewed abdominal and pelvic CT scans for hepatomegaly (> 18 cm), splenomegaly (> 13 cm), size of main portal and right hepatic veins, presence of periportal edema, gallbladder wall edema, hydropic gallbladder, ascites, and small-bowel wall thickening. CT and histopathology findings were correlated using analysis of variance and Fisher-Free-man-Holton tests. RESULTS: Ascites and periportal edema were present in all five patients with venoocclusive disease, but of six patients with graft-versus-host disease, ascites was seen in two (p < 0.05) and periportal edema in only one (p < 0.05). Small-bowel wall thickening was encountered in five patients with graft-versus-host disease and in none with venoocclusive disease (p < 0.05). The right hepatic vein diameter in patients with venoocclusive disease (mean, 0.27 cm) was significantly smaller than the right hepatic vein diameter in patients with graft-versus-host disease (mean, 0.87 cm; p < 0.05). CONCLUSION: In patients treated with hematopoietic stem cell transplantation, CT findings of periportal edema, ascites, and a narrow right hepatic vein suggest venoocclusive disease rather than graft-versus-host disease. Small-bowel wall thickening suggests graft-versus-host disease.

Universal use of nonionic iodinated contrast medium for CT: evaluation of safety in a large urban teaching hospital.

OBJECTIVE: We evaluated the safety of the universal use of the nonionic iodinated contrast agent iopromide in patients undergoing CT in a large urban teaching hospital. SUBJECTS AND METHODS: For 2 years, we prospectively recorded all adverse events temporally associated with the administration of iopromide in 29,508 consecutive patients undergoing contrast-enhanced CT at our institution. The types, intensities, treatments, and outcomes of adverse events were recorded along with relevant patient history, including risk factors. Descriptive analyses of the variables, comparisons of means, and proportions using Student's t and chi-square tests, and logistic regressions were conducted. RESULTS: Adverse events were observed in 211 patients (0.7%) and were categorized as follows: urticaria (n = 161), facial or laryngeal edema (n = 13), bronchospasm (n = 8), severe nausea or vomiting (n = 10), or other (n = 19). One hundred eighty-eight adverse events (89%) were rated mild, 19 moderate (9%), and four severe (2%), including one fatality. Adverse events required treatment in 89 patients (42%). A history of allergy was present in 92 patients (44%), and 29 (14%) had a prior contrast reaction. Other relevant risk factors were identified in 63 patients (30%). No relationship existed between the occurrence of adverse events and any of the following: patient age, dose of iodine administered, or time of study (i.e., month, season, and year). Women (p < 0.001) and outpatients (p < 0.001) had a statistically significant higher incidence of adverse events. CONCLUSION: The universal use of iopromide as an IV CT contrast agent has a favorable safety profile.

Liver cancer imaging: role of CT, MRI, US and PET.

Liver imaging in patients with a history of known or suspected malignancy is important because the liver is a common site of metastatic spread, especially tumours from the colon, lung, pancreas and stomach, and in patients with chronic liver disease who are at risk for developing hepatocellular carcinoma. Since benign liver lesions are common, liverimaging strategies should incorporate liver lesion detection and characterisation. Survey examination in patients with a known extra-hepatic malignancy to exclude the presence of hepatic and extra-hepatic involvement is normally undertaken with a contrast-enhanced computed tomography examination. When patients with hepatic metastases are being considered for metastasesectomy, they undergo a staging examination with contrast-enhanced magnetic resonance imaging (MRI) using tissue-specific contrast agents. Patients with chronic liver disease who are at risk for hepatocellular carcinoma undergo periodic liver screening for focal liver detection, usually with ultrasonography (US) with MRI being used when US is equivocal. Finally, contrast-enhanced MRI with extra-cellular gadolinium chelates is preferred for characterisation of indeterminate hepatic masses with liver biopsy used when tissue diagnosis is needed.