[Spontaneous rupture of an adrenal angiomyolipoma]

Retroperitoneal haemorrhages mostly occur as a result of trauma. Besides a traumatic origin of retroperitoneal haemorrhage, the other most common cause is an anticoagulation therapy. Further potential sources of retroperitoneal hematoma are benign and malignant tumours of the adrenal gland.

[CT Venography and CT Angiography of the Pulmonary Arteries in Acute Pulmonary Embolism]

OBJECTIVES

To determine the diagnostic value of CT venography after CT angiography of the pulmonary arteries using multislice helical CT in the diagnosis of acute pulmonary embolism.

METHODS

Between September 1999 and April 2001 252 patients with clinically suspected pulmonary embolism were examined. CT angiography of the pulmonary arteries was followed by CT venography of the inferior vena cava, the iliac veins and the proximal femoral veins; after April 2000 the popliteal veins and the proximal lower leg veins were additionally investigated. The examinations were performed with a double detector and a multidetector scanner (Elscint Twin and GE Lightspeed).

RESULTS

Pulmonary embolism was found in 79/252 patients (40 central and 39 segmental/subsegmental PE). In 38/40 patients with central PE and in 22/39 patients with segmental/subsegmental PE in CT venography a deep venous thrombosis was detected, in 1/79 patient a doubled inferior vena cava could be found. In 5 patients with thrombosis of the inferior vena cava a transjugular cava filter placement was performed. In 13/173 patients without pulmonary embolism CT venography showed deep venous thrombosis.

CONCLUSION

CT venography of the lower extremities is a practical and efficient additional examination to CT angiography in clinical suspected pulmonary embolism. It can detect the causing venous thrombosis with a high sensitivity.

High-resolution blood oxygen-level dependent MR venography (HRBV): a new technique

Our purpose of this study was to demonstrate the clinical potential and spatial resolution of a new MRI technique: high-resolution blood oxygen-level dependent venography (HRBV), in well-known intracranial vascular lesions, such as cavernous and venous angiomas, and venous sinus thrombosis. HRBV provides unique high-resolution information on veins without administration of contrast medium. The data are independent of conventional findings on MRI and potentially useful in characterising and demonstrating the architecture of vascular lesions of the brain.

Hemodynamic assessment of acute stroke using dynamic single-slice computed tomographic perfusion imaging

BACKGROUND

Stroke management would benefit from a broadly available imaging tool that detects perfusion deficits in patients with acute stroke.

OBJECTIVE

To determine the role of dynamic, single-slice computed tomographic (CT) perfusion imaging (CTP) in the assessment of acute middle cerebral artery stroke.

DESIGN AND PATIENTS

Imaging with CTP and CT within the first 6 hours of symptom onset and before the start of treatment in a consecutive clinical series of 22 patients (mean age, 68.3 years; 14 women; studied within 143 +/- 96 minutes of stroke onset).

SETTING

A stroke unit in a university hospital.

MAIN OUTCOME MEASURES

Area of the perfusion deficit (nAP(0)) from time-to-peak maps, hemispheric lesion area from follow-up CT (HLA(F)), final infarct volume, and stroke recovery (National Institutes of Health Stroke Scale scores).

RESULTS

Eighteen patients had perfusion deficits in the middle cerebral artery territory and corresponding hypoattenuation in follow-up CT. Three patients with normal CTP findings showed lacunar infarctions or normal findings on follow-up CT. In 1 patient, CTP did not reveal a territorial deficit above the imaging slice. The overall sensitivity and specificity of CTP for the detection of perfusion deficits in patients with proven territorial infarction (n = 18) on follow-up CT were 95% and 100%, respectively. The nAP(0) was significantly correlated with the National Institutes of Health Stroke Scale score at admission (P<.003) and the HLA(F) (P<.001). Different stroke patterns were identified in patients with follow-up CTP (n = 10): (1) initial perfusion deficit and partial nutritional reperfusion (nAP(0)>HLA(F); n = 6), (2) initial perfusion deficit and nonnutritional reperfusion (nAP( 0)>/=HLA(F); n = 2), and (3) initial perfusion deficit without reperfusion (nAP(0)>/=HLA(F); n = 2).

CONCLUSIONS

Computed tomographic perfusion imaging detects major perfusion deficits in the middle cerebral artery territory. Because CTP is broadly available, it may play a role in acute stroke management. Arch Neurol. 2000;57:1161-1166

Acute stroke evaluated by time-to-peak mapping during initial and early follow-up perfusion CT studies

BACKGROUND AND PURPOSE

Early diagnosis of perfusion deficits in patients with acute stroke could guide treatment decisions and improve prognosis. We investigated the sensitivity of perfusion CT studies using parametric time-to-peak maps to assess ischemic brain tissue with respect to early infarct signs on native CT scans.

METHODS

First-pass, single-section perfusion CT was performed in 20 patients who presented with symptoms of acute stroke within 6 hours of onset. Initial CT perfusion studies were compared with follow-up studies within 30 hours in 10 patients. A manual, region of interest (ROI)-based, local evaluation procedure was performed to determine delayed time-to-peak values and diminished peak amplitudes. In addition, time-to-peak parameter maps were processed off-line from the dynamic CT data sets to identify areas of perfusion deficits, which were expressed as hemispheric lesion areas (HLAs). Evolution of the ischemic regions was assessed by comparing the HLA on the initial and follow-up studies as well as on the native CT scan of the follow-up studies.

RESULTS

Diagnostic time-to-peak maps were generated in 19 of 20 initial and in nine of 10 follow-up perfusion CT studies. The initial time-to-peak map showed perfusion deficits in 14 of 20 patients. Hemispheric territorial infarcts were diagnosed with a sensitivity of 93%. Perfusion deficits in two patients with brain stem infarctions and three patients with lacunar strokes were missed. Follow-up time-to-peak maps showed the extent of reperfusion after various therapeutic strategies.

CONCLUSION

Perfusion CT is potentially useful for detecting cerebral perfusion deficits in acute ischemic stroke before morphologic changes are observable on native CT scans. Compared with a locally restricted ROI-based evaluation, time-to-peak maps provide sensitive, global indications of malperfused brain areas, facilitate lesion localization, and allow assessment of the evolution of the infarction during follow-up.

[The reduction of the radiation dosage by means of storage phosphor-film radiography compared to a conventional film-screen system with a grid cassette on a skull phantom]

PURPOSE

How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette?

METHODS AND MATERIALS

A skull phantom (3M) was x-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhöfer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast.

RESULTS

The surface entrance dose at 73 kV/22 mAs was 0.432 mGy in conventional screen film system and 0.435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0.308 mGy; SD 0.050); sufficient images were obtained down to an average dose of 31% (0.136 mGy; SD 0.065). The resolution of the line pairs were reduced down to 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resulted in an improvement of the assessment of bone structures and contrast in higher dose ranges only.

CONCLUSION

For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement of the skull the dose can be reduced to at least 56% (phi 31%; SD 14.9%)/40% (phi 27%; SD 9.3%)/18% (phi 14%; SD 4.4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12.5 mAs and to skull measurement 73 kV/4 mAs.

Establishment of reference ranges for cortisol in neonates, infants, children and adolescents

Cortisol was determined in the sera of 687 normal, healthy probands between the ages of 5 days and 18 years (neonates, infants, children and adolescents), using a fluorescence polarization immunoassay (FPIA) on the TDx from Abbott Laboratories. The proband collective was divided into 9 age groups and each group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. Only a few reference groups showed a normal Gaussian distribution. In addition to the 50th percentile, the 2.5th and 97.5th percentiles were determined for all reference groups. Minimal and maximal values were also determined. The U-test of Mann & Whitney was used to test for significant differences between the individual reference groups. Groups showing no significant differences were combined, and reference ranges were finally calculated for cortisol in the serum of normal, healthy neonates, infants, children and adolescents. The serum cortisol concentration showed a significant increase with age. In the 14-15 years age group, there was also a significant difference between males and females.

Establishment of reference ranges for prolactin in neonates, infants, children and adolescents

Prolactin was determined in the sera of 686 healthy neonates, infants, children and adolescents (age range 5 days to 18 years), using the IMx from Abbott Laboratories. The applied test was a microparticle enzyme immunoassay (MEIA). The proband collective was divided into 9 age groups, and each age group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. Only a few reference groups showed a normal Gaussian distribution. In addition to the 50th percentile, the 2.5th and 97.5th percentile were calculated for all reference groups, and the minimal and maximal values were also reported. From the age of 12 years onwards, significant differences were found between males and females. The U-test of Mann & Whitney was used to test for significant differences between individual reference groups. Groups showing no significant differences were combined, and the corresponding reference ranges for serum prolactin were then calculated.

Establishment of reference ranges for ferritin in neonates, infants, children and adolescents

Ferritin was determined in the sera of 631 healthy neonates, infants, children and adolescents (age range 5 days to 18 years), using the IMx from Abbott Laboratories. The applied test was a microparticle enzyme immunoassay (MEIA). The proband collective was divided into 9 age groups, and each group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. Only a few reference groups showed a normal Gaussian distribution. In addition to the 50th percentile, the 2.5th and 97.5th percentile were calculated for all reference groups, and the minimal and maximal values were also reported. Significantly different reference ranges were found for males and females in the age group 16-18 years. The U-test of Mann & Whitney was used to test for significant differences between individual reference groups. Groups showing no significant differences were combined, and the corresponding reference ranges for serum ferritin were then calculated.

Establishment of reference ranges for follitropin and lutropin in neonates, infants, children and adolescents

Follitropin was determined in the sera of 645 probands, and lutropin in the sera of 649 probands between the ages of 5 days and 18 years (neonates, infants, children and adolescents), using microparticle-enzyme-immunoassays (MEIA) on the IMx from Abbott Laboratories. The proband collective was divided into 9 age groups and each group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. In some age groups, the ranges for individual hormones showed a significant sex difference. Age groups without significant sex differences were combined and evaluated statistically as a single group. Only a few reference groups showed a normal Gaussian distribution. In addition to the 50th percentile, the 2.5th and 97.5th, or the zero and 95th percentiles were determined for all reference groups. Minimal and maximal values were also determined. The U-test of Mann & Whitney was used to test for significant differences between the individual reference groups. Groups showing no significant differences were combined, and reference ranges were finally calculated for follitropin and lutropin in the serum of healthy neonates, infants, children and adolescents.

Establishment of reference ranges for thyrotropin, triiodothyronine, thyroxine and free thyroxine in neonates, infants, children and adolescents

Thyrotropin, triiodothyronine, thyroxine and free thyroxine were determined in the sera of 714 euthyreotic neonates, infants, children and adolescents (age range 5 days to 18 years), using the IMx from Abbott Laboratories. Thyrotropin, triiodothyronine and free thyroxine were determined with microparticle enzyme immunoassays (MEIA). Thyroxine was determined with a fluorescence polarization immunoassay (FPIA). The proband collective was divided into 9 age groups, and each age group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. In the different age groups, the ranges of some hormones showed significant differences between males and females. When no significant difference existed between the sexes, the results for males and females were evaluated statistically as a single group. Only a few reference groups showed normal Gaussian distributions. Therefore, in addition to the 50th percentile, the 2.5th and 97.5th percentiles were also calculated for all reference groups. Minimal and maximal values were also determined. The U-test of Mann & Whitney was used to test for significant differences between individual reference groups, and groups showing no significant differences were combined. The corresponding references ranges were then calculated.

Reference ranges for thyrotropin in the serum of full-term neonates--compared with the ranges for full-term neonates with various post-partal adaptation disorders, and premature neonates

The "IMx hTSH ultrasensitive test" from Abbott Laboratories is a new method for the determination of thyrotropin. Its introduction for the purpose of hypothyreosis screening led to the present investigation of the reference ranges in full-term and premature neonates. In a total of 1712 healthy neonates, the reference range for serum thyrotropin on the 5th day post partum was 0.4-9.05 mU/l (median value 1.90 mU/l). In contrast, 64 full-term neonates with various post-partal adaptation disorders showed a significantly lower serum thyrotropin concentration on the 5th day post partum (0.14-6.39 mU/l; median value 1.60 mU/l). Serum thyrotropin was also determined on the 7th and 14th day post partum in 131 premature neonates with birth-weights below 2500 g. In the birth-weight range 1500- < 2500 g, the median values for serum thyrotropin were 2.35 and 2.12 mU/l, respectively. A negative correlation (r = -0.3019) was found between the birth-weight and the serum thyrotropin concentration on the 14th day post partum. In two premature neonates with birth-weights less than 800 g, the serum thyrotropin concentrations were conspicuously high (18.6 and 28.0 mU/l) on the 14th day post partum.