The purpose of our study was to evaluate quantitative multiphasic CT enhancement patterns of malignant renal neoplasms to enable lesion differentiation by their enhancement characteristics. We used a ...new method to standardize enhancement measurement in lesions on multiphasic CT not being influenced by intrinsic factors like cardiac output.
The new correction method is a simple tool for excluding intrinsic influences on the enhancement of lesions. Quantitative enhancement evaluation with this method of the influence of intrinsic factors enables accurate differentiation between renal clear cell carcinoma and renal papillary carcinoma.
Differences of attenuation and enhancement patterns in focal nodular hyperplasia and hepatocellular adenoma were evaluated and quantified using triphasic single-slice helical CT.
Forty-five ...histologically proven focal nodular hyperplasias in 27 patients and 18 hepatocellular adenomas in six patients were examined with helical CT. Quantitative evaluation included the following: attenuation of lesions, scar, and liver parenchyma during unenhanced, arterial (20 sec after injection), and portal venous phases (70 sec after injection); relative enhancement of lesions and liver (the ratio between attenuation in arterial phase and portal venous phase, respectively, and attenuation in unenhanced phase); and the prevalence of scar and its central vessel in focal nodular hyperplasia.
The study showed no significant difference between mean attenuation values of focal nodular hyperplasia (mean +/- SD, 51.2 +/- 5.9 H) and hepatocellular adenoma (mean +/- SD, 56.3 +/- 7.8 H) in the unenhanced phase. In the arterial phase attenuation values were significantly higher in focal nodular hyperplasia (mean +/- SD, 117.9 +/- 15.1 H) than in hepatocellular adenoma (mean +/- SD, 80.1 +/- 10.5 H). In the portal venous phase no significant differences in attenuation values were detected between focal nodular hyperplasia (mean +/- SD, 112.1 +/- 20.4 H) and hepatocellular adenoma (mean +/- SD, 110.2 +/- 12.9 H). For enhancement parameter thresholds separating focal nodular hyperplasia from hepatocellular adenoma, the following were found: the relative enhancement was higher in 100% of the focal nodular hyperplasias and lower than or equal to 1.6 (accuracy, 96%) in 87% of the hepatocellular adenomas.
Triphasic helical CT combined with quantitative evaluation of liver lesions offers the possibility of detecting differences in liver lesions that are visually similar on CT. The attenuation and relative enhancement in the arterial phase show significant differences that make accurate differentiation between focal nodular hyperplasia and hepatocellular adenoma possible.
The aim of this study was to evaluate the feasibility and diagnostic potential of dynamic MR urography (MRU) in neonates and infants with sonographically detected abnormalities of the upper urinary ...tract. Thirty infants (age range 5 days to 3 years, mean age 7.9 months; male:female: 22:8) underwent MRU using T2 and contrast-enhanced dynamic T1-weighted sequences. The results were compared with the findings of ultrasound ( n=30), intravenous urography (IVU, n=19) and/or scintigraphy ( n=25) based on the criteria suggestive of obstructive uropathy. Oral sedation was sufficient to perform MRU with diagnostic quality in 20 of 21 patients younger than 1 year; 9 older patients needed intravenous sedation. Diagnosis of the 66 renal units (58 kidneys, 29 successful examinations) included normal systems (contralateral units), duplex systems, vesico-ureteral reflux, obstructive megaureter, ureteropelvic junction obstruction and accompanying renal parenchymal disease, with complex pathology in 10 patients. Magnetic resonance urography demonstrated anatomy better than IVU, particularly the renal parenchyma, (ectopic) ureters, and poorly functioning dilated systems. Magnetic resonance urography was superior to US in showing ureteral pathology. Tiny cysts in dysplastic kidneys were better seen by US. Gadolinium-enhanced dynamic MRU allowed accurate assessment of obstruction applying IVU criteria. Here MRU matched IVU results, and most of the scintigraphic findings. Magnetic resonance urography can be performed in young infants with diagnostic quality using oral sedation. Magnetic resonance urography correctly depicts anatomy and allows assessment of the urinary tract better than US and IVU, with additional functional information. Magnetic resonance urography thus has the potential to replace IVU for many indications.
This case of an esophageal liposarcoma illustrates a polypoid lesion within the esophagus that extended from the left pyriform sinus to the distal esophagus above the gastric cardia. ...Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) showed an inhomogenously-enhancing intraluminal mass, while video-fluoroscopy revealed that the mass was adherent to the esophageal wall and was associated with esophageal dilatation and diminished peristalsis. This ninth reported case of esophageal liposarcoma is the first described where preoperative radiologic studies and endoscopy showed broad fixation of the tumor to the esophageal wall.
We assessed the usefulness of helical computed tomography (CT) with a negative oral contrast material for detecting Crohn disease.
Thirty-eight patients with proven Crohn disease were examined. We ...administered a large volume of a new negative oral contrast material (Mucofalk suspended in water) and then proceeded with helical CT scanning. This technique is an alternative to CT and conventional enteroclyses that use a nasojejunal tube. Two radiologists interpreted the scans, and patients were interviewed about their tolerance of the procedure. We created multiplanar reformatted images in all cases. Potential of small bowel distention by Mucofalk was evaluated by two observers on a three-point scale, and interobserver agreement was calculated with kappa statistics.
All patients who underwent enteroclysis stated that CT was the more comfortable method, the taste of the peroral contrast medium was considered good by 52.6% and acceptable by 47.4%. Small bowel distention was excellent in 55% of cases, moderate in 26%, and poor in 19%, with an interoberserver agreement of 78%. CT findings correlated with enteroclysis in 27 patients who underwent both methods. Analysis of CT versus enteroclysis showed a sensitivity of 89% for CT versus 78% for small bowel enteroclysis.
Mucofalk CT is a simple, rapid, noninvasive, and accurate method of evaluating extramucosal manifestations of Crohn disease. The tubeless procedure improved patients' comfort and decreased time, cost, and radiation exposure.
Pedestrian-car collisions are in motorised countries one of the leading causes of unintentional-injury-related death and morbidity among children. The objective of this study was to assess ...correlations between the mode and the severity or post-traumatic sequels of the injury. A 12-year (1989-2001) retrospective study of children aged 0-16 years injured in pedestrian-motor-vehicle collisions was undertaken. An anonymous survey with questionnaires completed by families was conducted. In this time period, 501 children (average age: 7.9 years) were injured. The lack of visibility of the vehicle (45%) and/or the pedestrian (39%) was the leading cause of injury. The mean injury severity score was 6.0 (1-75) and the mortality rate was 0.8% ( n=4, injury severity scores 47, 75, 75, 75). In this study, 217 questionnaires were analysed. When the children were injured, 37% of them were alone, 32.3% were in the presence of accompanying adults, and 24.0% were in the presence of other children. The latter group suffered the highest injury severity score ( P=0.016). Positive correlations were noted between injury severity score and impact speed ( r=0.31, P<0.001) and the distances that the children were thrown off or transported on the vehicle front ( r=0.29, P<0.001). Physical sequels were reported by 27% of the families, and 23% noted psychological disturbances. A positive correlation was noted between impact speed and the occurrence of physical sequels ( P<0.001). The number of deformed parts per vehicle was correlated to the occurrence of behavioural disturbances ( P<0.004).
The incidence of post-traumatic sequels seems to be associated with higher speed at impact, lack of braking attempts, and higher numbers of vehicle parts deformed.
Lesions of focal nodular hyperplasia are hypervascular, benign focal liver lesions whose differentiation from other focal liver lesions is of significant clinical relevance. The purpose of this study ...was to investigate the echo‐enhancing agent SHU 508A (Levovist) in the evaluation of focal nodular hyperplasia with Doppler sonography. We examined 49 patients with 71 lesions of focal nodular hyperplasia in the liver with gray scale and power Doppler sonography. In all patients Levovist was administered intravenously in a concentration of 300 to 400 mg galactose per milliliter. Visualization of the feeding vessels and the vascularity of the lesions were evaluated, and the resistive indices in the feeders and the hepatic arteries were assessed. In comparison with unenhanced power Doppler sonography, echo‐enhanced power Doppler sonography yields a higher sensitivity in the detection of the feeding artery (97% versus 82%) in focal nodular hyperplasia and in the depiction of the radial vascular architecture in such lesions, especially those located in the left lobe of the liver. Lesions less than 3 cm in diameter do not consistently show a characteristic vascular architecture with echo‐enhanced Doppler sonography. The resistive index of the tumor‐feeding artery (mean, 0.51 +/‐ 0.09) is significantly (P < 0.0001) lower than that of the hepatic artery (mean, 0.65 +/‐ 0.06) and decreases as the size of the focal nodular hyperplasia increases. The administration of Levovist may improve the signal‐to‐noise ratio and thus visualization of the vascular architecture in focal nodular hyperplasia. Lesions located in the left lobe of the liver, which commonly are subject to disturbing motion artifacts in color Doppler sonography, will significantly benefit from the administration of Levovist. Echo‐enhanced power Doppler sonography, however, is not capable of depicting a characteristic vascular pattern in small (< or = 3 cm) lesions of focal nodular hyperplasia that would guarantee a specific diagnosis.
Multidetector computed tomography (MDCT) possesses distinct advantages for examination of the kidneys. It carries the potential of becoming the gold standard of diagnostic work-up and surgical ...planning for most renal diseases and replacing conventional methods such as i.v. urography and angiography. The most outstanding improvements, in comparison to single slice spiral CT, are the speedier image acquisition and enhanced z-axis resolution, which aids particularly in visualization of the urinary tract as it aligns along the axis of the body. Respiratory artifacts are few or nonexistent even in patients who cannot hold their breath. This overview presents a strategy for prudent management of MDCT examinations and describes examination of the most important and frequent renal diseases using MDCT.
To evaluate the diagnostic accuracy of thin collimated unenhanced spiral-CT in patients with clinically suspected acute appendicitis and to determine the impact on patient management and overall ...costs.
Unenhanced focussed appendiceal spiral-CT was performed in 56 patients (23 women and 33 men) with clinically suspected acute appendicitis. Scans were obtained from the L4 level to the symphysis pubis using 5 mm collimation, 7.5 mm table feed (pitch 1.5) and 4 mm increment without i.v., oral, or rectal contrast material. Prospective diagnoses based on CT findings were compared with surgical (and histopathological) results and clinical follow-up. The effect of spiral-CT on patient management and clinical resources was assessed.
29 patients (10 women and 19 men) underwent appendectomy. Unenhanced spiral-CT was an accurate imaging technique for the initial examination of patients with suspected acute appendicitis with a sensitivity of 95.4% and a specificity 100%, an accuracy of 98.2%, a positive predictive value of 100%, and a negative predictive value of 97.1%. In 27 patients with no evidence of acute appendicitis, an alternative diagnosis could be made in 24 patients by unenhanced spiral-CT.
Unenhanced spiral-CT is an accurate test to diagnose or to exclude acute appendicitis. Routine appendiceal spiral-CT can improve medical care and reduce the overall costs for patients suspected of having acute appendicitis.
