Three-dimensional bone scintigraphy using volume-rendering technique and SPECT.

UNLABELLED: Three-dimensional bone scintigraphic images were made and their usefulness and limitations discussed. METHODS: After usual bone scan procedures, single-photon emission computed tomography (SPECT) data were taken and reconstructed into three-dimensional images. Volume rendering methods were used. RESULTS: Three cases of three-dimensional bone scintigraphy were obtained; one of a normal patient, one of a case of transplanted kidney and incomplete fracture of the left femoral head, and one of a case of degenerative joint disease (DJD) on the left temporomandibular joint (TMJ). The three-dimensional structure of the skeletal system was depicted more clearly by the three-dimensional images than by a conventional bone scan. CONCLUSION: Three-dimensional bone scintigraphs were thought to provide additional information for better understanding of the nature of bone lesions. Some technical improvements including automated threshold level determination and feature extraction for detecting abnormal high uptake are required before routine use can be envisaged.

Age-related change of technetium-99m-HMDP distribution in the skeleton.

UNLABELLED: To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolism. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers. METHODS: The whole-body skeletal uptake (WBSU) and tracer distribution pattern were studied in men and women by bone scintigraphy using 99mTc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers. RESULTS: WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites. CONCLUSION: These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone metabolism.

Relationship between skeletal uptake of 99mTc-HMDP and bone mineral density in elderly women.

The relationship between bone mineral density in elderly women and the pattern of skeletal uptake of 99mTc-HMDP, especially in regard to skull uptake, was investigated. The whole-body skeletal uptake (WBSU) and whole-body skeletal tracer distribution patterns were studied in 86 disease-free women on bone scintigraphy with 99mTc-hydroxy-methylene-diphosphonate (HMDP). Bone scans were quantified by setting regions of interest (ROI) and bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry in all patients. WBSU and the skeletal distribution pattern were compared with bone mineral densities of the entire skeleton as well as selected regions. WBSU was high in the elderly and negatively correlated with regional bone mineral densities (r = -0.403 to -0.534). Among the regions, uptake by the skull increased with age more than in other regions in women and had the highest negative correlation with the bone mineral density. The skull uptake correlated negatively with total body BMD (r = -0.583) and with lumbar BMD (r = -0.561, p < 0.0001). Our results show that increased radionuclide uptake in bone scintigraphy, especially skull uptake was associated with decreased bone mineral density in elderly women, so that, increased skull uptake in elderly women would be a scintigraphic sign of post-menopausal or senile osteopenia.

Angiographic retrieval of foreign bodies in pulmonary artery: a report of three cases.

Three cases of percutaneous retrieval of foreign bodies that migrated into the pulmonary artery are described in this paper. All of the intravascular foreign bodies were attributed to SVC catheters for intravenous hyperalimentation (IVH) therapy, an accidentally cut strip of indwelling SVC catheter in two patients and a fragment of guide wire used for the insertion of the SVC catheter in one patient. They were all successfully removed by fluoroscopic angiographic procedures using a snare loop retriever and grasping forceps. The technical aspects of the procedures are discussed here.

[Measurement of circulating 1,25-dihydroxyvitamin D employing radioimmunoassay].

Measurement of serum 1,25-dihydroxyvitamin D levels is important for diagnosis of various calcium metabolism disorders. Conventional assays for 1,25-dihydroxyvitamin D employed specific 1,25-dihydroxyvitamin D receptor as binding site for the ligand and thus, biologically active 1,25-dihydroxyvitamin D ligand, which is labeled with 3H, was required. Usage of 3H made assays cumbersome works. A new assay which uses specific antibody as the binding site and the radioligand labeled with 125I is now available as a commercial kit. Using these kits, we first studied basically the reproducibility, recovery, cross-reactivity and comparison with conventional assays. All of those results were satisfactory. Secondly, we measured clinically in 111 healthy adults and in patients with various disorders such as renal failure, primary hyperparathyroidism, hypoparathyroidism and sarcoidosis. This newly available kit for measurement of circulating 1,25-dihydroxyvitamin D is proved to be useful in clinical evaluation of calcium metabolic disorders.

[Radioimmunoassay for the pyridinoline cross-linked carboxy-terminal telopeptide of type 1 collagen (1CTP)--some basic aspects of the RIA kit and clinical evaluation in various bone diseases].

A radioimmunoassay for circulating levels of the pyridinoline cross-linked carboxy-terminal telopeptide of type 1 collagen (1CTP) was developed and can be available as a kit on a commercial base. Using the kits, we evaluated basically and clinically the assay. The assayed values were reproducible and the assay can detect as low as 0.5 ng/ml of 1CTP. In healthy volunteers, circulating level was high under age 24 and over age 46. In patients with bone metastasis, serum levels elevated even in its early stage and correlated well with clinical status. In other bone diseases, such as primary hyperparathyroidism, hyperthyroidism, post-gastrectomy, hypercalcemia of malignancy and myeloma, serum levels elevated according to their clinical conditions. In patients with chronic renal failure, serum levels were high, suggesting decrease of renal clearance of 1CTP. The circulating 1CTP levels seemed to reflect well clinical bone destructive status. A high correlation between serum 1CTP level and urinary pyridinoline (r = 0.884) was shown, whereas essentially no correlation was observed between bone formation markers such as osteocalcin and alkaline phosphatase. Thus, the measurement of circulating 1CTP seems to be a simple and sensitive method to monitor bone destruction.

[Detection of bone metastasis by serial measurement of C-terminal telopeptide of type I collagen in patients with malignancy].

Measurements of biochemical markers specific to bone resorption are known to be useful in evaluation of skeletal metastasis. However, most of previous studies were performed cross-sectionally and sensitivity for detection of early bone metastasis was not satisfactory. Since basal levels of bone markers differ significantly individually, longitudinal studies would be preferable to evaluate small metabolic changes such as in early skeletal metastasis. Thus, we performed serial measurements of serum c-terminal telopeptide of type I collagen (ICTP), a bone resorption marker, in patients with malignancy and evaluated its clinical significances for detection of bone metastasis, comparing with measurements of propeptide of type I procollagen (PICP) and tumor markers. In total, 43 patients (41 of them are breast cancer), serial serum samples were obtained during 0.5 to 2.4 years (mean 1.4 years). In all of nine patients, who developed bone metastasis, serum ICTP level increased, and by successful treatment to the metastatic lesions, ICTP level decreased, while in some cases, tumor markers remained to be elevated. PICP was less sensitive and specific for detection of bone metastasis. Thus, serial measurement of ICTP is suggested to be useful for detection and evaluation of therapeutic responses in patients with bone metastasis.

Primary splenic malignant lymphoma associated with hepatitis C virus infection.

We present two cases of primary splenic malignant lymphoma associated with chronic hepatitis C virus infection detected early by routine follow-up imaging studies. Septumlike structures were seen on postcontrast computed tomography or magnetic resonance imaging, which presented characteristic gross findings. These findings may suggest primary splenic malignant lymphoma during the course of chronic hepatitis C.

Chronic intramedullary infusion of prostaglandin E2 stimulates bone formation both in the bone marrow and in the periosteum.

Prostaglandin E2 (PGE2) has a potent bone resorbing activity in vitro, but some recent studies have shown that PGE2 stimulates bone formation in vivo. The effects of PGE2 on the bone are therefore still controversial. We attempted to reveal the effects of PGE2 on bone in vivo more directly; we injected PGE2 continuously into the bone marrow and onto the periosteum and examined the local effects of PGE2 histologically or by bone densitometry. Following PGE2 infusion into the bone marrow, new bone was formed in the bone marrow around the infused site and following PGE2 infusion onto the periosteum, extensive periosteal bone formation was observed. Bone mineral content was also increased significantly in the PGE2 infused bones. The administration of cyclic AMP did not mimic the effects of PGE2. In contrast to in vitro experiments, the in vivo effect of PGE2 is predominantly to produce bone.

Estimation of bone mineral density and bone loss by means of bone metabolic markers in postmenopausal women.

We have examined healthy women (51 premenopausal women and 30 postmenopausal women; age 28-59) for lumbar bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) and assessed metabolic bone markers, such as type I procollagen carboxy-terminal propeptide (P1CP), pyridinoline (PYR), deoxypyridinoline (DPYR), osteocalcin (BGP) and alkaline phosphatase (ALP). BMD was assessed once a year in three consecutive years. Correlations among the BMD, BMD changes and levels of bone markers in samples at the first DXA assessment were studied. In pre-menopausal women, none of the biochemical markers were correlated with the BMD or changes in BMD. In contrast, BMD in post-menopausal women correlated (negatively) well with levels of P1CP, DPYR, PYR and ALP declining in this order, and a significant positive correlation was observed between the rate of bone loss in postmenopausal women and the P1CP concentration. PYR and DPYR also had a tendency to correlate. Combinations of several bone markers improved the correlation. These results show that by measuring several bone specific biochemical markers in postmenopausal women, one can estimate their rates of bone loss as well as their present BMDs. The measurement of biochemical bone markers will therefore be very useful in evaluating bone status and would be applicable in screening postmenopausal osteopenia.

Diagnostic validity of bone metabolic markers for bone metastasis.

We measured bone resorption markers in tumor patients with and without bone metastases and evaluated the diagnostic validity of these biochemical parameters in the diagnosis of neoplastic bone involvement. On the basis of radiography and bone scintigraphy findings, subjects were divided into 3 groups, 83 patients without bone metastases (META(-)), 22 patients with 1 or 2 bone metastases (META(+)) and 22 patients with more than 3 bone metastases (META(++)). Among the biochemical markers, urinary pyridinoline (PYR), circulating C-terminal telopeptide of type I collagen (ICTP) and urinary N-terminal telopeptide of type I collagen (NTx) were especially sensitive and specific and increased significantly not only in META(++) but also even in META(+). The efficacy of several bone metabolic markers in differentiating between patients with and without bone metastases was evaluated by receiver-operating characteristic (ROC) analysis, and PYR, ICTP and NTx were proved to have high diagnostic validity (area under the ROC curve; 0.75 for PYR, 0.77 for ICTP and 0.77 for NTx). Furthermore, their odds ratios showed significantly high values for both META(+) and META(++)(to META(++); 7.91 for PYR, 5.33 for ICTP and 5.70 for NTx). On the other hand, urinary deoxypyridinoline (DPYR) and serum total alkaline phosphatase (ALP) showed relatively low sensitivities, the odds ratio of ALP in particular being insignificant. In conclusion, several bone metabolic markers were proved to be useful in the diagnosis of bone metastases in patients with malignancies, particularly PYR, ICTP and NTx had rather high diagnostic validities among all markers examined in this study.

[Clinical utility of Gd-DTPA subtraction MR imaging for spinal bone metastasis].

Based on reports that Gd-DTPA contributes to the detection of tumors, we used it in 31 cases (97 lesions) of spinal bone metastases. The result was that Gd-DTPA increased the intensity of tumors and the surrounding bone marrow to almost the same level in 53%. To show the metastases clearly, an existing subtraction command system was utilized. The technique included the pixel-by-pixel method, to obtain a Gd-DTPA T1-weighted image (T1WI) subtracted by the original T1WI. The detectability of the subtraction image was improved up to 96%, but was less than the original T1WI (99%). Because of the different imaging rationale between two methods, a means to assess the quality of diagnosis must be proposed. To check the normal background, the same kind of postprocessing was performed in 21 patients without malignancy. Gd-DTPA perfusion was highest in the paravertebral veins, moderate in muscles and epidural fat, and lowest in the spinal cord, intervertebral disk and bone cortex. Gd-DTPA enhanced subtraction MR imaging provides a new diagnostic tool to detect and to assess bone metastasis.