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Despite clinically available high-resolution CT, the detection and classification of gallstones remains a challenge in some cases. This pilot study examines whether noninvasive characterization of gallstones in vitro is possible using dual-energy analysis (DECT) of dual source CT datasets.A total of 43 gallstones (0.4 - 1.5 cm) were examined at 80 kV, 140 kV and in the dual-energy mode. The monoenergetic datasets were examined by two independent examiners and classified as calcium, cholesterol or pigment stones. The results were compared with the pathological classification as the clinical gold standard. After creating reference images for each group via dual-energy analysis, the classification was repeated and compared with the gold standard again.Using the monoenergetic analysis at 80 kV, the sensitivity and specificity were 100 / 84 % and 100 / 88 % for calcium stones. For cholesterol stones the values were 54 / 89 % and 54 / 85 % and for pigment stones 70 / 80 % for both examiners. At 140 kV, the sensitivity and specificity for calcium stones were 100 / 84 % for both examiners, 46 / 92 % for cholesterol stones for both examiners and the sensitivity and specificity were 80 / 75 % and 80 / 80 % for pigment stones. Using the reference images established by DECT, both examiners were able to correctly classify all gallstones.The present data indicates that DECT is able to correctly classify Gallstones according to the clinical gold standard in vitro. Clinical studies have to demonstrate whether these results lead to optimized clinical decision making.

Spiral CT angiography (CTA) of the coronaries using low-pitch scanning and ECG-gated image reconstruction is a robust method for detecting or excluding relevant coronary plaque. However, the resulting dose exposure is considerable. The aim of the present study was to evaluate image quality and artifacts as well as to record dose values for sequential coronary CTA using a 128-slice scanner with a temporal resolution of 150 ms.20 patients with a regular heart rate and without contraindications for oral/I.V. beta blockers, who were referred for CTA of the coronaries for exclusion or detection of relevant plaques, were examined by sequential CTA with the following parameters: 120 kV, 200 ref mAs, collimation 2 x 64 x 0.6, table feed of 34.5 mm at a detector width of 38.4 mm. A total acquisition time of 380 ms per table position allowed for mild shifting of the reconstruction window within the cardiac cycle of +/- 5 %. 50 ml of contrast agent were injected at 5 ml/s followed by a 50 ml split bolus (20 % contrast). The individual start delay was determined by a test bolus scan (10 ml contrast + 50 ml saline flush at 5 ml/s). The image quality for each segment, coronary artery, and patient was determined on a 4-point scale. Dose values were estimated based on the individual dose length product as provided by the scanner's patient protocol. Artifacts were evaluated to determine the cause (calcium vs. motion).All patients received beta blocker pretreatment. The mean heart rate was 62 +/- 5 beats/min. 5 % (13 / 286) of all segments in 5 / 20 patients were rated as non-diagnostic. The mean dose length product was 213 mGy x cm, and the mean effective dose was 3.6 mSv. Calcifications were the major cause of non-diagnostic images. However breathing or other motion artifacts occurred as well.In select patients with effective heart rate control and thorough instruction for breath hold compliance, sequential CTA of the coronaries using a 128-slice scanner with a temporal resolution of 150 ms is technically feasible. The resulting effective dose values are clearly below those of spiral coronary CT scans.

Due to the technical advance of multislice cardiac CT and the recently introduced dual source CT, the acquisition times for cardiac CT exams are10 sec. At the same time the assessment of left ventricular function is possible. However, in many patients a complete right ventricular outwash is noted, leading to insufficient septal delineation. Studies were able to demonstrate that contrast media (CM) mixed in the saline chaser bolus is sufficient for significantly better visualization of septal structures. The aim of this study was to investigate whether this dual flow concept works as well for 64-slice and dual source CT angiography using only 20 % CM in the saline chaser bolus.97 patients were included in this prospective study. 47 patients underwent 64-slice CT coronary angiography. 80 cc were administered at 5 cc/sec as the main bolus followed by a 50 cc saline chaser bolus containing 20 % contrast media. The other 50 patients were examined using dual source CT. They received a CM protocol adapted for the scan time with the identical saline/CM chaser bolus. The datasets were quantitatively examined in defined ROIs along the septum and in the right ventricle with respect to the density. The septal delineation was qualitatively analyzed and both groups were compared. In a final step the density was measured in the proximal and distal RCA as well as in the LAD and also compared.Using the protocol adapted for the scan time, significantly less CM was used. No significant difference was able to be found regarding the septal delineation or coronary enhancement.The study shows that the dual flow concept allows for robust septal delineation regardless of the CM injection protocol used as long as a 20 % saline chaser bolus is used. A CM protocol adapted for the scan time also leads to significant CM reduction at equal image quality.

The incidence of degenerative changes and osteoarthritis is lower in the ankle than in the knee joints. This cannot be explained exclusively with differences in anatomy and biomechanical properties of these two synovial joints. Previous studies have indicated distinct differences in the biochemical composition of the extracellular matrix of articular cartilage from knee and ankle joints. The aim of this study was to identify potential metabolic differences between knee and ankle joint chondrocytes using isolated cells to distinguish the secondary effects of the resident extracellular matrix from the primary matrix-independent effects of cellular differentiation.Isolated knee and ankle chondrocytes from the same human donor were cultured in alginate beads and subsequently exposed to a three-day pulse of the catabolic cytokine interleukin-1 (IL-1) as a model of an inflammatory episode. The metabolism of proteoglycans (PG's) was analyzed as expressed changes in 35S-sulfate incorporation into glycosaminoglycans (GAG's).The presence of IL-1 induced an inhibition of PG synthesis in knee and ankle articular chondrocytes. The 50% inhibitory concentration (IC50) of IL-1 was about 5 times lower for knee than for ankle chondrocytes.Ankle chondrocytes are more resistant to IL-1 induced inhibition of PG synthesis than chondrocytes from the knee.

The endovascular occlusion of symptomatic carotid cavernous fistulae (CCF) via the transfemoral approach is safe and effective. Due to anatomical variations or after unsuccessful transarterial therapy, a direct surgical approach to the superior ophthalmic vein (SOV) may be necessary.In two patients with acute ophthalmologic symptoms coil occlusion of the CCF was performed after palpebral incision and cannulation of the SOV.In both patients preparation of the SOV was performed successfully and without complications. After coil embolization of the CCF both patients had complete resolution of symptoms within several weeks. During a follow-up of 12 months there were no recurrences, but both patients exhibited moderate blepharoptosis.Embolization of CCF via a surgically created approach is an effective procedure in selected cases when standard interventional treatment is not possible.

Due to technical improvements, multislice spiral computed tomography (MSCT) has become available for the noninvasive visualization of human coronary arteries. The current scanner generation provides 16 detector slices. The aim of the present study was to evaluate the influence of a careful patient selection on the diagnostic accuracy of noninvasive angiography.Out of a study population of 60 patients, 36 with mild coronary calcifications (Agatston score500) were selected for the present retrospective analysis. In addition to conventional coronary angiography (CCA), all patients underwent a noninvasive MSCT examination of the coronary arteries. All coronary segments were assessed with respect to image quality and presence of severe lesions with a diameter stenosisor = 50%. The MSCT examinations were performed using a Sensation 16 scanner (Siemens Medical Systems, Forchheim, Germany).The Agatston score of the study population was 83.3 +/- 125.4 (0-491.3), calcium mass 14.7 +/- 21.4 (0-83) mg CaHA (calcium hydroxyapatite). Diagnostic image quality could be obtained in 391/455 coronary segments (86%). 26 lesionsor = 50% could be detected by MSCT, CCA confirmed the presence of 21 lesions. No false-negative results were obtained (sensitivity: 100%, specificity: 99%, positive predictive value: 0.81, negative predictive value: 1.0).The new MSCT generation with 16 detector slices permits a noninvasive visualization of the coronary arteries with good image quality. It could be shown that a careful patient selection is of major importance for the diagnostic accuracy of MSCT imaging. It appears to be useful to perform a stepwise imaging, starting with a native scan to rule out severe calcifications. Prospective multicenter trials with larger patient numbers are required to confirm these initial results.

Teratomas of the oropharynx are quite rare congenital tumors. Even more rare than oropharyngeal teratomas are those with additional intracranial extension. Reviewing the literature the prognosis of these cases has been poor. In the majority stillbirth or immediate postpartum death following respiratory obstruction is reported. We present a case of a congenital teratoma of the oral cavity with intracranial extension in a female neonate. After several intraoral tumor resections to establish secure airway in the postpartum period the total tumor resection had to be performed at the age of 6 month via a lateral transmandibular approach to the skull base. By using extraoral distaction devices the operation related microsomia of the mandible could be corrected at the age of 5 years. At 7 years follow-up the girl presented free of recurrence and without any neurological or functional deficits.

Malignant change in the epithelium of an odontogenic cyst and growth of an invasive squamous cell carcinoma is rare. The diagnosis of malignant disease is mostly only established by histological evaluation of excised tissue because the initial clinical appearance does not differ much from that of odontogenic cysts. The clinical course of one patient after removal of an impacted canine and adjacent cystic tissue is presented. Histological evaluation of the specimen led to diagnosis of a squamous cell carcinoma arising from the cystic epithelium. Partial resection of the maxilla was performed subsequently and 1 year postoperatively the patient was free from recurrence or metastasis. This case report underlines the importance of submitting any soft tissue excised in the treatment of odontogenic cysts to histologic evaluation.

Successful and cartilage-specific cultivation of chondrocytes requires a stable phenotype during the in vitro culture period. This is based on a differentiated extracellular matrix synthesis. The alginate system as a three-dimensional support is a useful system to culture chondrocytes and to analyze the biochemical processes in this system. Talar cartilage from the talocrural joints of 40 different donors were obtained through the Regional Organ Bank of Illinois within 24 hours of death. In 65% of the tissues the cartilage was classified as being undamaged. In these studies we were interested in the results of short-term culture over 14 days. Cell proliferation, total collagen content and total proteoglycan content were measured in the different matrix compartments and were visualized by histology and immunohistochemistry. Already after 7 days in culture the adult human chondroctes looked intact and formed a stable and cell-associated cartilage-specific extracellular matrix in the presence of 10% calf serum. This could be also demonstrated in the presence of IGF-I. With regards to the collagen content IGF-I at a concentration of 50 ng/ml seemed to induce an equal effect to 10% serum; with regards to the proteoglycan content IGF-I at a concentration of 20 ng/ml was equivalent. These encouraging preliminary results may lead to a new approach in tissue engineering for chondrocyte transplantation in combination with their extracellular matrix.

von F. Küttner Teilw. in Fraktur