Diagnostic value of ex-vivo three-dimensional micro-computed tomography imaging of primary nonhematopoietic human bone tumors: osteosarcoma versus chondrosarcoma.

BACKGROUND: Osteosarcoma and chondrosarcoma are the most common nonhematopoietic primary malignancies of bone. However, unusual radiographic appearances can lead to delay in diagnosis and confusion with benign diseases. PURPOSE: To evaluate the feasibility of micro-computed tomography (CT) for the analysis of primary, nonhematopoietic human bone tumors ex vivo. MATERIAL AND METHODS: Samples from 12 human bone specimens (osteosarcoma, n=6; chondrosarcoma, n=6) obtained for diagnostic purposes were scanned using industrial X-ray film without amplifier foil and scanned with micro-CT (7- and 12-microm-cubic voxels). Trabecular bone CT "density" and tumor matrix CT "density" were determined, and results were compared with those obtained from a detailed conventional histopathologic analysis of corresponding cross-sections. The significance of differences in grayscale measurements was tested with analysis of variance. RESULTS: Micro-CT provided quantitative information on bone morphology equivalent to histopathological analysis. We established grayscale measurements by which tumor matrices of chondrosarcoma and osteosarcoma could be radiographically categorized following histological classifications (P<0.001). CONCLUSION: Micro-CT is feasible for the analysis and differentiation of human osteosarcoma and chondrosarcoma.

The imaging of root canal obturation using micro-CT.

AIM: To examine the potential and accuracy of micro-computed tomography (micro-CT) for imaging of filled root canals. METHODOLOGY: The root canals of five extracted maxillary teeth were shaped manually with K-files. After irrigation and drying, the root canals were filled by lateral condensation using gutta-percha cones and AH plus (Dentsply Maillefer, Ballaigues, Switzerland) as sealer. The filled root canals were examined by micro-CT at resolutions <11 microm. Three-dimensional reconstructions of the root canal fillings were made. The roots were sectioned histologically and standard photographs of the sectioned surfaces were taken. Digitized photographic images and the corresponding micro-CT sections were correlated qualitatively by superimposition. Quantitative morphometric data were obtained with respect to the surface area of the root canal filling and the individual gutta-percha points of the histological and the micro-CT sections. Pearson correlation coefficients were calculated. RESULTS: There was a good qualitative correlation between the images from the histological and the micro-CT sections. The fillings were clearly differentiated from the root canal walls. Individual gutta-percha cones and sealer were discernable. Pearson correlation coefficients showed a highly significant correlation between the two methods (P < 0.001) with respect to the area of the complete root canal filling (r = 0.992) and the gutta-percha cones (r = 0.968). CONCLUSIONS: The micro-CT technique was a highly accurate and nondestructive method for the evaluation of root canal fillings and its constituents. Qualitative and quantitative correlation between histological and micro-CT examination of root canal fillings was high.

Quantification of in-stent restenosis parameters in rabbits by Micro-CT.

PURPOSE: The well-defined model of angioplasty and stent implantation in the rabbit aorta is useful in experimental studies of restenosis. This study was performed to evaluate the feasibility of Micro-CT for quantification of in-stent restenosis in a rabbit aortic in-stent-restenosis model. MATERIAL AND METHODS: To induce in-stent restenosis seven female New Zealand rabbits underwent balloon dilation and denudation prior to stenting the abdominal aorta. After six weeks on atherogenic diet, animals were killed and the aorta was perfused with contrast agent. Micro-CT morphometric analysis of balloon and stent injured arteries obtained by 700 transverse sections (voxel size 10 microm) was compared to conventional histological analysis. RESULTS: Intimal hyperplasia was present in stented and balloon injured arteries with a moderate intimal area assessed by Micro-CT and conventional histology (3.91 +/- 0.5 mm(2) vs. 4.18 +/- 0.42; r = 0.9). High significant correlations between Micro-CT image analysis and conventional histomorphometry were obtained for lesion size, size of media, size of lumen and stent area (r = 0.84 to 0.96). CONCLUSION: Micro-CT is feasible for quantitative information about restenosis following balloon angioplasty and stent implantation and has the potential to become a standard technique in many laboratories which will augment serial histology as the reference method for ex-vivo studies of restenosis.

Systemic aspergillosis with predominant genitourinary manifestations in an immunocompetent man: what we can learn from a disastrous follow-up.

Prostatic aspergillosis is a rare finding with only ten cases reported previously. We report the first case of systemic aspergillosis predominantly presenting with prostatic involvement and, clinically, with urinary retention in an immunocompetent host. Routine transurethral resection was performed due to benign prostatic hyperplasia with subvesical obstruction. Concomitant prostatic aspergillosis was diagnosed without signs of systemic infection. In the clinical follow-up systemic aspergillosis became rapidly progressive requiring complex surgical interventions and long-term antifungal therapy. The current literature is reviewed, and diagnostic and management options are discussed.

[Biochemical bone marrow markers and their significance in postmenopausal osteoporosis--a new method in the diagnosis of osteoporosis?]. / Biochemische Knochenmarker und deren Bedeutung bei der postmenopausalen Osteoporose--Eine neue Methode in der Osteoporosediagnostik?

This study analyzes the qualification of biochemical markers in the diagnosis of osteoporosis and evaluates the potential of a multiparametric classification of premenopausal and non-osteoporotic as well as osteoporotic postmenopausal women, which is based on biochemical marker profiles. For this evaluation data of 29 women in the age between 28-74 years were used. The classification of osteoporosis was done by the trabecular density of the lumbar spine using qCT-measurements. The biochemical markers of formation and resorption AP, bAP, OC, ucOC, PICP, PYD, DPD, NTX, BSP and vitamin K were analyzed on day 1 and 42 in all patients. For vitamin K we found significant distribution differences between non-osteoporotic and osteoporotic women (p<0.005). The crosslinks PYD and DPD showed weakly significant differences. All other parameters exhibited non-significant results. Vitamin K acted with a sensitivity of 64% and a specificity of 82%. The used multiparameter classification process improved sensitivity and specificity considerably. The parameter profiles of OC/PYD, vitamin K/PYD and vitamin K/bAP revealed the highest sensitivities with specificities of more than 82%.

[Micro-computed tomography of the vasculature in parenchymal organs and lung alveoli]. / Mikro-Computertomographie von Blutgefässen parenchymatöser Organe und von Lungenalveolen.

Micro-CT has become a powerful technique in non-destructive 3D imaging and morphometric analysis. First results were limited to the investigation of osteoporosis in cancellous bone. But the availability of systems with almost microscopic resolution and sufficient soft tissue contrast has opened up entirely new applications for laboratory investigation of blood vessels and soft tissues. This article gives an overview of micro-CT technology and the potential of three-dimensional imaging of the vessel wall and soft-tissue architecture imaging in different organs using different contrast perfusion and staining techniques. Micro-CT provides quantitative information on human plaque morphology equivalent to histomorphometric analysis. Based on differences in grey-scale attenuations, micro-CT also correctly identifies atherosclerotic lesions that are histologically classified as fibrous plaques, calcified lesions, fibroatheroma, and lipid rich lesions. Micro-CT is a promising method to visualize the architecture of the renal vasculature and, importantly, to separate cortex and medulla for the visualization of glomeruli and their afferent and efferent arterioles. Micro-CT can determine the vascular surface in a defined placental volume. Combining of micro-CT data and total placental volume enables an estimation of the approximate surface of the placental vasculature. The diameter of opacified vessels in the investigated samples ranged from 2 mm (chorion plate artery) to 14 micro m (smallest vessel diameter, terminal loop). Recognizing that lung parenchyma can only be visualized if the alveoli are completely expanded and the contrast of the thin alveolar walls is enhanced, we tested two preparation methods: (1) fixation of lung tissue with formalin vapour and staining with silver nitrate, and (2) intravenous injection of a barium sulfate-gelatine-thymol mixture in vivo in the anesthetized animal. We evaluated the ability of this mixture to enter the pulmonary microcirculation and the technical feasibility of micro-CT to assess lung micro-architecture.

[MRI in the follow-up of matrix-supported autologous chondrocyte transplantation (MACI) and microfracture]. / Die MRT in der Verlaufskontrolle nach matrixgestützer autologer Chondrozytenimplantation (MACI) und Mikrofrakturierung.

AIM: Matrix-guided autologous chondrocyte implantation (MACI) was compared with microfracture (MFX) to demonstrate the reconstitution of cartilage over a two-year period using the morphological capabilities of MRI. PATIENTS AND METHODS: 27 patients (9 females and 18 males, mean age 33 years) underwent MACI on the knee joint. The defects originated from trauma (15 cases), osteochondritis dissecans (8 cases) and chronic repetitive trauma (4 cases) and were localized at the condyles (24 cases) or patella (3 cases). All patients were examined postoperatively after 1, 3, 6, 12 and 24 months with a 1,5 T unit (Gyroscan, Philips) using proton- and T2w spinecho and T1w fatsuppressed 3D gradientecho sequences. We measured the signal intensities of the implant and neighbouring cartilage to calculate the contrast-to-noise ratio (CNR), and the thickness of cartilage and implant layers to define the defect filling rate. Finally, partial and complete remission was defined on MRI and compared with clinical data and morphology on MRI. Additionally, 7 patients were treated with MFX and, subsequently examined on MRI with the same protocol. RESULTS: After MACI, MRI showed a partial but no complete equilibration of signal intensities of implant and adjacent cartilage over the 1 and 2 year follow-up periods which was shown by reduction of CNR from 21 to 10 on 3D-GE and from 26 to 9 on T2w SE sequences. Continuous growth of the implants resulted in an increased filling of the defects starting at 40% after 0.5 year to 85% after 1 or 2 years. Complete remission was found on MRI in 17/27 cases, and remission rate was influenced by etiology of cartilage defect but not by age and gender of patients or size and location of defects. The Lysholm-Gillquist score improved from 49.7 to 97.3. After MFX equilibration of signal intensities and growth of the regenerating fibrous cartilage was less pronounced and complete remission was found in only 2/7 cases. In addition, the clinical score improved from 45.5 to 74.2. CONCLUSION: Direct imaging of cartilage with MRI and assessment of clinical scores allowed improved documentation of the outcome after MACI and MFX. MRI showed that MACI is superior to MFX concerning rate of complete remissions and filling of the defect with regenerating tissue. Clinical examinations showed better scores for MACI than for MFX.

Disseminated periportal fatty degeneration after allogeneic intraportal islet transplantation in a patient with type 1 diabetes mellitus: a case report.

Insulin independence after islet transplantation has been significantly improved by using new steroid-free immunosuppressive protocols and increased islet mass. Only little is known about the influence on the morphology of the liver of intraportally transplanted islets. We describe a case of disseminated periportal fatty degeneration after allogeneic intraportal islet transplantation (ITx). A 35-year-old patient with type-1 diabetes mellitus who was suffering from repeated severe hypoglycemic episodes received two sequential intraportal islet grafts. Liver structure was normal before the first ITx, based upon ultrasound and magnetic resonance imaging (MRI). One week after the first ITx, ultrasound demonstrated normal liver morphology. Four months later, at the second ITx, we detected small, disseminated, and hypodense hepatic lesions (1 to 3 mm) by ultrasound, which were confirmed by MRI and interpreted to be fatty degenerations. Histologically we found focal drop-shaped fatty degenerations with signs of mild periportal chronic inflammation. These liver alterations without clinical symptoms or pathological liver function tests matched the predicted distribution of infused islets. Glucose metabolism markedly improved after the first ITx, namely 58.6% reduction of daily insulin requirements, 1.4% decrease in HbA1c, basal C-peptide of 0.8 to 1.3 ng/dl with no severe hypoglycemia. We interpreted these benign changes in liver morphology as reactions to a local hyperinsulinemia in the neighborhood of the transplanted islets. We hypothesized that a steroid-free immunosuppression with rapamycin and tacrolimus may have contributed to changes in the portal microenvironment.