Effect of tumor size and tumor-to-liver contrast of hypovascular liver tumors on the diagnostic performance of hepatic CT imaging

To assess the effect of tumor size and tumor-to-liver contrast of simulated hypovascular liver tumors on the diagnostic accuracy of hepatic computed tomography (CT).

CT-based intravenous thrombolysis 3-4.5 hours after acute ischemic stroke in clinical practice

Outcome of stroke patients selected with cerebral computed tomography for intravenous thrombolysis administered in clinical routine from 3 to 4.5 hours after symptoms onset is not well investigated. Aim of this single-center, prospective, observational study was to compare the safety and efficacy of intravenous alteplase given in routine clinical praxis 181-270 minutes (late) and within 180 minutes (early) after stroke onset in patients selected with cerebral computed tomography.

Direct Quantitative Assessment of the Peripheral Artery Collateral Circulation in Patients Undergoing Angiography

Despite the fact that numerous studies pursued the strategy of improving collateral function in patients with peripheral artery disease (PAD), there is currently no method available to quantify collateral arterial function of the lower limb.

Post-mortem angiography after vascular perfusion with diesel oil and a lipophilic contrast agent

OBJECTIVE: The objective of our study was to establish optimal perfusion conditions for high-resolution postmortem angiography that would permit dynamic visualization of the arterial and venous systems. MATERIALS AND METHODS: Cadavers of two dogs and one cat were perfused with diesel oil through a peristaltic pump. The lipophilic contrast agent Lipiodol Ultra Fluide was then injected, and angiography was performed. The efficiency of perfusion was evaluated in the chick chorioallantoic membrane. RESULTS: Vessels could be seen up to the level of the smaller supplying and draining vessels. Hence, both the arterial and the venous sides of the vascular system could be distinguished. The chorioallantoic membrane assay revealed that diesel oil enters microvessels up to 50 microm in diameter and that it does not penetrate the capillary network. CONCLUSION: After establishing a postmortem circulation by diesel oil perfusion, angiography can be performed by injection of Lipiodol Ultra Fluide. The resolution of the images obtained up to 3 days after death is comparable to that achieved in clinical angiography.

Detection of regional blood perfusion changes in epileptic seizures with dynamic brain perfusion CT--a pilot study

BACKGROUND AND PURPOSE: Perfusion CT (P-CT) is used for acute stroke management, not, however, for evaluating epilepsy. To test the hypothesis that P-CT may identify patients with increased regional cerebral blood flow during subtle status epilepticus (SSE), we compared P-CT in SSE to different postictal conditions. METHODS: Fifteen patients (mean age 47 years, range 21-74) underwent P-CT immediately after evaluation in our emergency room. Asymmetry indices between affected and unaffected hemispheres were calculated for regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and mean transit time (MTT). Regional perfusion changes were compared to EEG findings. RESULTS: Three patients in subtle status epilepticus (group 1) had increased regional perfusion with electro-clinical correlate. Six patients showed postictal slowing on EEG corresponding to an area of regional hypoperfusion (group 2). CT and EEG were normal in six patients with a first epileptic seizure (group 3). Cluster analysis of asymmetry indices separated SSE from the other two groups in all three parameters, while rCBF helped to distinguish between chronic focal epilepsies and single events. CONCLUSION: Preliminary results indicate that P-CT may help to identify patients with SSE during emergency workup. This technique provides important information to neurologists or emergency physicians in the difficult clinical differential diagnosis of altered mental status due to subtle status epilepticus.

A novel multiple-trauma CT-scanning protocol using patient repositioning

Emergency CT examination is considered to be a trade-off between a short scan time and the acceptance of artifacts. This study evaluates the influence of patient repositioning on artifacts and scan time. Eighty-three consecutive multiple-trauma patients were included in this prospective study. Patients were examined without repositioning (group 1, n=39) or with patient rotation to feet-first with arms raised for scanning the chest and abdomen/pelvis (group 2, n=44). The mean scan time was 21 min in group 1 and 25 min in group 2 (P=0.01). The mean repositioning time in group 2 was 8 min. Significantly, more artifacts were observed in group 1 (with a repeated scan in 7%) than in group 2 (P=0.0001). This novel multiple- trauma CT-scanning protocol with patient repositioning achieves a higher image quality with significantly fewer artifacts than without repositioning but increases scan time slightly.

Patients with mild traumatic brain injury: immediate and long-term outcome compared to intra-cranial injuries on CT scan

BACKGROUND: Mild traumatic brain injury (MTBI) defined as Glasgow Coma Scale (GCS) 14 or 15 has shown contradictory short- and long-term outcomes. The objective of this study was to correlate intra-cranial injuries (ICI) on CT scan to neurocognitive tests at admission and to complaints after 1 year. METHODS: Two hundred and five patients with MTBI underwent a CT scan and were examined with neurocognitive tests. After 1 year complaints were assessed by phone interviews. RESULTS: The neurocognitive tests in 51% of the patients showed significant deficits; there was no difference for patients with GCS 14-15, nor was there a difference between patients with ICI to patients without. After 1 year patients with ICI had significantly more complaints than patients without ICI, the most frequent complaint was headache and memory deficits. CONCLUSIONS: No correlation was found between GCS or ICI and the neurocognitive tests upon admission. After 1 year, patients with ICI have significantly more complaints than patients without ICI. No cost savings resulted by doing immediate CT scan on all.

Extended CT scale overcomes restoration caused streak artifacts for dental identification in CT--3D color encoded automatic discrimination of dental restorations

OBJECTIVE: Besides DNA, dental radiographs play a major role in the identification of victims in mass casualties or in corpses with major postmortem alterations. Computed tomography (CT) is increasingly applied in forensic investigations and is used to scan the dentition of deceased persons within minutes. We investigated different restoration materials concerning their radiopacity in CT for dental identification purposes. METHODS: Extracted teeth with different filling materials (composite, amalgam, ceramic, temporary fillings) were CT scanned. Radiopacities of the filling materials were analyzed in extended CT scale images. RESULTS: Radiopacity values ranged from 6000-8500HU (temporary fillings), 4500-17000HU (composite fillings) and >30710HU (Amalgam and Gold). The values were used to define presets for a 3D colored volume rendering software. CONCLUSIONS: The effects of filling material caused streak artifacts could be distinctively reduced for the assessment of the dental status and a postprocessing algorithm was introduced that allows for 3D color encoded visualization and discrimination of different dental restorations based on postmortem CT data.

Dental CT imaging as a screening tool for dental profiling: advantages and limitations

The use of dental processing software for computed tomography (CT) data (Dentascan) is described on postmortem (pm) CT data for the purpose of pm identification. The software allows reconstructing reformatted images comparable to conventional panoramic dental radiographs by defining a curved reconstruction line along the teeth on oblique images. Three corpses that have been scanned within the virtopsy project were used to test the software for the purpose of dental identification. In every case, dental panoramic images could be reconstructed and compared to antemortem radiographs. The images showed the basic component of teeth (enamel, dentin, and pulp), the anatomic structure of the alveolar bone, missing or unerupted teeth as well as restorations of the teeth that could be used for identification. When streak artifacts due to metal-containing dental work reduced image quality, it was still necessary to perform pm conventional radiographs for comparison of the detailed shape of the restoration. Dental identification or a dental profiling seems to become possible in a noninvasive manner using the Dentascan software.