Influence of extracorporeal shock-wave application on normal bone in an animal model in vivo. Scintigraphy, MRI and histopathology.

There is little information about the effects of extracorporeal shock-wave application (ESWA) on normal bone physiology. We have therefore investigated the effects of ESWA on intact distal rabbit femora in vivo. The animals received 1500 shock-wave pulses each of different energy flux densities (EFD) on either the left or right femur or remained untreated. The effects were studied by bone scintigraphy, MRI and histopathological examination. Ten days after ESWA (0.5 mJ/mm2 and 0.9 mJ/mm2 EFD), local blood flow and bone metabolism were decreased, but were increased 28 days after ESWA (0.9 mJ/mm2). One day after ESWA with 0.9 mJ/mm2 EFD but not with 0.5 mJ/mm2, there were signs of soft-tissue oedema, epiperiosteal fluid and bone-marrow oedema on MRI. In addition, deposits of haemosiderin were found epiperiosteally and within the marrow cavity ten days after ESWA. We conclude that ESWA with both 0.5 mJ/mm2 and 0.9 mJ/mm2 EFD affected the normal bone physiology in the distal rabbit femur. Considerable damaging side-effects were observed with 0.9 mJ/mm2 EFD on periosteal soft tissue and tissue within the bone-marrow cavity.

The use of [18 F]fluorodeoxyglucose positron emission tomography to differentiate between synovitis, loosening and infection of hip and knee prostheses.

Pain is a common unspecific symptom in orthopaedic prosthetics. The accurate differentiation between synovitis, loosening or infection is often difficult with conventional X-rays, arthrography or bone scintigraphy. Because of the high glucose uptake of inflammatory cells, [18F]fluorodeoxyglucose (18F-FDG) is an appropriate tracer for the evaluation of suspected inflammation or infection. In this preliminary study we describe 18F-FDG PET findings in patients referred for evaluation of painful hip or knee prostheses. We studied 23 patients with 28 prostheses, 14 hip and 14 knee prostheses, who had a complete operative or clinical follow-up. 18F-FDG PET scans were obtained with an ECAT EXACT HR+ PET scanner. High glucose uptake in the bone prostheses interface was considered as positive for infection, an intermediate uptake as suspect for loosening, and uptake only in the synovia was considered as synovitis. The imaging results were compared with operative findings or clinical outcome. PET correctly identified three hip and one knee prostheses as infected, two hip and two knee prostheses as loosening, four hip and nine knee prostheses as synovitis, and two hip and one knee prostheses as unsuspected for loosening or infection. In three patients covered with an expander after explantation of an infected prosthesis PET revealed no further evidence of infection in concordance with the clinical follow-up. PET was false negative for loosening in one case. Our preliminary results suggest that FDG PET could be a useful tool for differentiating between infected and loose orthopaedic prostheses as well as for detecting only inflammatory tissue such as synovitis.

3-phase bone imaging and SPECT in the follow up of patients with allogenic vascularized knee joint transplants.

UNLABELLED: Vascularized allotransplantation of knee joints under immunosuppression is a novel approach in orthopedic surgery. During the postoperative course immunosuppressive management depends on perfusion and viability of the graft. AIM: Evaluation of different diagnostic tools in regard to their usefulness and reliability to provide information about microvascularity and viability of vascularized knee joint allografts. METHODS: Four patients with allogenic knee joint transplants were studied up to 26 months after transplantation with 3-phase bone scans and SPECT. The results were compared with duplex sonography, angiography, and histology. RESULTS: Two cases without complications were characterized by adequate perfusion in duplex sonography, angiography and early bone scans. Late bone scans demonstrated increased bone metabolism of the transplant. Corresponding biopsy revealed viable bone cells. In one case with partial thrombosis and one case with complete thrombosis of the transplant vessels rapidly decreasing or missing perfusion was detected by duplex sonography, angiography, and bloodpool scintigraphy. Late bone scans showed reduced or absent bone metabolism. Biopsy demonstrated necrotic bone tissue. Due to the advantage of a tomographic technique SPECT allowed a more reliable assessment of graft viability as compared to planar imaging. CONCLUSION: Our findings confirm bone scintigraphy as a valuable diagnostic tool in patients with allogenic vascularized knee joint transplants. In contrast to other diagnostic approaches, scintigraphy provides reliable information on both viability and perfusion of the transplant within a single non-invasive clinical investigation.

[Advantages and limitations of whole-body bone marrow MRI using Turbo-STIR sequences in comparison to planar bone scans] . / Vorzüge und Limitationen der Ganzkörper-Knochenmark-MRT mit Turbo-STIR-Sequenzen im Vergleich zur planaren Skelettszintigraphie.

UNLABELLED: At modern MRI tomographs the whole body can be screened for bone marrow metastases within 45 min. AIM of this study was to evaluate the diagnostic advantages and disadvantages of a whole-body bone marrow MRI protocol using Turbo Short Tau Inversion Recovery [STIR] sequences in comparison to planar bone scintigraphy (SZ). PATIENTS AND METHODS: In order to screen for bone metastases within two weeks SZ and whole-body MRI with Turbo-STIR-sequences were performed in 20 patients with known breast cancer. For further evaluation five regions were defined: skull, spine including the pelvis, femora, humeri and ribs including scapulae and sternum. RESULTS: In 9/20 patients neither with SZ nor with MRI bone metastases were detected (staging M0). Among the remaining 11 patients SZ detected 109 and MRI 150 lesions which were typical for bone metastases. All of these 11 patients were staged M1 correspondingly with both methods. Within the thorax (ribs, sternum, scapulae) MRI discovered only 6/17 and within the skull 0/6 lesions which were suspicious for metastases in SZ. Inversely MRI identified much more metastatic lesions than SZ within the femora (20/16), the humeri (14/12) and the spine including the pelvis (110/58). CONCLUSIONS: Susceptibility-, truncation-, chemical-shift-, third arm- and particularly pulsation artifacts along with the impossibility to chose slice orientation equally advantageous for all regions of the body cause impaired image quality of MRI whole body scanning. Therefore, concerning the detection rate of bone metastases within the thorax (ribs, sternum and scapulae) and the skull, conventional Turbo-STIR-MRI whole-body scans are even less accurate than conventional planar bone scintigraphy in those regions.

Influence of thyroid-stimulating hormone levels on uptake of FDG in recurrent and metastatic differentiated thyroid carcinoma.

UNLABELLED: The objective of this prospective study was to determine the extent to which the levels of thyroid-stimulating hormone (TSH) influence the uptake of FDG by thyroid carcinoma tumors METHODS: Ten patients with follicular (n = 7) or papillary (n = 3) thyroid carcinoma underwent FDG PET during TSH suppression (<0.05 microU/mL) and TSH stimulation (>22 microU/mL) within an average interval of 42 d (range, 28-73 d). The findings were evaluated by visual criteria. In addition, a tumor-to-background ratio (TBR) was determined for 17 lesions that were visualized. RESULTS: In 15 of 17 lesions with positive FDG uptake, TSH stimulation was associated with an increase in the TBR from 3.85 +/- 2.53 (mean +/- SD) to 5.84 +/- 4.84, corresponding to an average increase of 63.1% (P < 0.001). Determination of absolute counting rates indicated that this increase was the result of a decrease in FDG metabolism in the background together with an increase in the tumor tissue. No relationship was found between the presence or absence of iodine storage capacity (5 versus 12/17 lesions) and increase in FDG accumulation. Seven of 10 patients had additional iodine-positive metastases that showed no accumulation of FDG. CONCLUSION: Most locally recurrent and metastatic follicular and papillary thyroid carcinomas exhibited a significant increase in FDG uptake on TSH stimulation. In 3 of 10 patients, TSH stimulation resulted in either detection of new lesions or classification of the FDG uptake pattern as typical for malignancy. These findings suggest that FDG uptake in recurrent and metastatic thyroid carcinoma depends on the TSH level. Therefore, we recommend that PET examinations be performed in patients with thyroid carcinoma under TSH stimulation and follow-up examinations be performed under identical TSH conditions to prevent erroneous interpretation.

Use of three-phase bone scans and SPET in the follow-up of patients with allogenic vascularized femur transplants.

The vascularized allotransplantation of femoral diaphyses under immunosuppression is a novel approach in orthopaedic surgery. To evaluate which method provides the best information about microvascularity and viability of the transplant, we compared different diagnostic approaches used in transplant surgery. Three patients were investigated four times over a period of 1 month (on days 2, 7, 15 and 30 post-transplantation) and 6 and 12 months later with planar 99Tcm-MDP three-phase bone scintigraphy and SPET. The results were compared with duplex sonography, angiography and intraoperative biopsies. Rejection and thrombosis of the transplant were associated with decreased or missing perfusion detected by duplex sonography, angiography and blood pool scintigraphy. In these cases, late bone scans showed reduced or absent bone metabolism while biopsy revealed necrotic bone tissue. In cases without complications, blood pool scans revealed hyperaemia of the graft indicating excellent perfusion and patency of vascular anastomoses and transplant vessels. Late bone scans demonstrated increased bone metabolism. The corresponding biopsies showed viable bone cells. We conclude that bone scintigraphy is a valuable diagnostic tool in vascularized femur allotransplantation, since it provides reliable information on both viability and perfusion of the transplant within a single non-invasive investigation.

Changes in self-concept and body image during alopecia induced cancer chemotherapy.

Alopecia as a result of cancer chemotherapy has been reported to cause changes to the self-concept and body image. In a prospective longitudinal study, self-concept and body image were analysed in 29 patients after histological confirmation of gynaecological malignancy, mainly ovarian cancer, who were assigned to receive a complete-alopecia-inducing PEC combination chemotherapy (cisplatin 50 mg/m2, epirubicin 60 mg/m2, and cyclophosphamide 500 mg/m2 in 1 day every 28 days). The analysis was performed before the commencement of treatment and repeated when alopoecia was complete and after completion of therapy when patients had already experienced regrowth of hair, using the Frankfurt self-concept scales (FSKN) and Frankfurt body concept scales (FKKS). Significant differences were observed in the various evaluation scales FSAP (general ability to solve problems), FSSW (general self-esteem), SGKB (state of health), and SKEF (physical fitness). For all scales the results worsened during chemotherapy but did not return to normal or improve when patients experienced regrowth of hair. It was found that 73.3% of the patients did not feel as self-confident as before treatment and that for 46.6% alopecia was the most traumatic side effect of chemotherapy. Since there is no chemotherapeutic regimen or any other effective treatment that can prevent alopecia, either of the following conclusions can be drawn: the observed differences may not be related exclusively to alopecia, but also associated with coping processes initiated by chemotherapy and perhaps enhanced by alopecia; or the changes persist even after the discontinuation of chemotherapy. Regrowth of hair and other adaptive processes do not normalize or improve the impaired body image and self-concept.