Perfusion CT in childhood stroke--initial observations and review of the literature.

INTRODUCTION: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. PATIENTS AND METHODS: Within the last two years emergency perfusion CT was performed in ten children (age: 8-17 years, male:female=3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. RESULTS: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. CONCLUSIONS: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs' diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

Pleural and pericardial morbidity after minimal access repair of pectus excavatum.

PURPOSE: The aim of this study was to evaluate the pleural and pericardial morbidity in patients that had undergone pectus excavatum corrections using minimal access repair of pectus excavatum (MARPE) at a single center. MATERIALS AND METHODS: Data from patients after MARPE from 2000 to 2007 were prospectively collected. Patients with pneumothorax and pleural and pericardial effusions were identified. RESULTS: One hundred eighty patients were corrected by MARPE. Eighty-four were identified to have pleural or pericardial morbidities. Pneumothorax was documented in 33 patients and five required placement of a chest tube. Pleural effusions were recorded in 53 and were found to recur in four patients. Drainage was necessary in 18 patients. Pericardial effusions were observed in five patients; in two cases, they were associated with recurring pleural effusions, suggesting postcardiomyotomy syndrome. CONCLUSIONS: MARPE is associated with a high rate of pleural and pericardial morbidities, but only a small number requires interventions.

The reverse target sign in liver disease: a potential ultrasound feature in cirrhotic liver nodules characterization.

In patients with suspected liver disease, ultrasound is the most commonly performed initial imaging modality. We report a patient who had previously undiagnosed liver cirrhosis with target-shaped lesions interspersed throughout the liver parenchyma on ultrasound seen as multiple uniform round shaped lesions with varying isoechoic to hyperechoic centres surrounded by a hyperechoic rim. We have termed this the "reverse" target sign as there is inversion of the typical echoic pattern that is normally seen in metastatic liver disease. We suggest this ultrasound sign may represent a method for differentiating cirrhotic liver nodules from other nodular liver lesions.

Focal nodular hyperplasia and hepatocellular adenoma of the liver: differentiation with multiphasic helical CT.

OBJECTIVE: Differences of attenuation and enhancement patterns in focal nodular hyperplasia and hepatocellular adenoma were evaluated and quantified using triphasic single-slice helical CT. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Vehicles reversing or rolling backwards: an underestimated hazard.

OBJECTIVES: A retrospective analysis of injuries caused by vehicles that were reversing or rolling backwards to establish guidelines for prevention was performed. PATIENTS AND METHODS: Medical records and questionnaires completed by parents for 32 children admitted to the Department of Pediatric Surgery, Graz, within the past eight years, were analysed. RESULTS: The median age was 2.1 years (1.0-14.0 years). Fourteen of 32 of the cars were driven by family members (43.8%); three were rolling backwards without a driver (9.4%). The median injury severity score was 3 (1-27) and the most common injuries were contusions (40.6%), fractures (31.3%), and lacerations/burns (21.9%). Most incidents occurred in driveways (37.5%) or farmyards (21.9%). Altogether 70.3% of children sustained "run-over" injuries, 29.6% were hit by the rear bumper or injured by a breaking window. CONCLUSIONS: Toddlers playing in driveways or farmyards are at risk of a injury caused by reversing vehicles/vehicles rolling backwards.

[Radiologic staging of renal cell carcinoma]. / Radiologisches Staging des Nierenzellkarzinoms.

The routine staging work-up for renal cancer includes a contrast-enhanced multiphasic spiral CT and a chest radiograph. If there is doubt regarding the presence and extent of (supradiaphragmatic) IVC thrombus, MR imaging should be performed. Dynamic contrast-enhanced MR imaging should be used in place of CT in any patient with severe renal dysfunction, symptomatic polycystic kidney disease, or a history of allergy to iodinated contrast media. Cavography is no longer needed in the era of (adaptive array detector) spiral CT and MR venography.

[Criteria for ultrasound differentiation of small angiomyolipomas (< or = 3 cm) and renal cell carcinomas]. / Sonographische Differenzierungskriterien von kleinen Angiomyolipomen (< or = 3 cm) und Nierenzellkarzinomen.

PURPOSE: The purpose of this prospective study was to analyze whether ultrasound (US) features are helpful for the differentiation and characterization of small solid (< or = 3 cm) renal masses. MATERIALS AND METHODS: 70 small solid (< or = 3 cm) renal masses were evaluated sonographically with respect to size, location, echogenicity, homogeneity, shadowing, hypoechoic rim, and cystic regions. In addition, all masses were evaluated with spiral-computed tomography (CT). A diagnosis of angiomyolipoma (AML) was made when a lesion contained components with attenuation of fat (> -10 HU). The amount of fat and soft tissue of an AML detected on CT was correlated with the presence of shadowing seen on sonography. RESULTS: 10 (29%) of the 35 renal cell carcinomas (RCC) were hyperechoic to renal parenchyma, but no RCC was as echogenic as the renal sinus fat. Acoustic shadowing was only observed in AML. 11 (34%) AML with shadowing tended to have a larger amount of soft tissue. A hypoechoic rim and cystic regions were only found in RCC. 14 of 35 (40%) RCC showed a hypoechoic rim. Cystic regions were found in 12 of the 35 RCC (34%). CONCLUSIONS: Renal cell carcinomas display a broad range of echogenicities indicating that small RCC (< or = 3 cm) and AML are not definitely distinguishable by their type of echogenicity. The presence of shadowing, a hypoechoic rim, and cystic regions enable differentiation of small (< or = 3 cm) AML from RCC with a high specificity. Accordingly, sonography has the potential to characterize small (< or = 3 cm) hyperechoic renal masses, with high specificity. However, the low sensitivity of these US features may require a CT for accurate diagnosis.