Vertebral Bone Mineral Density Measured with Dual Photon Absorptiometry Using a Gamma Camera: Clinical Application to Metabolic Bone Diseases

Dual photon absorptiometry (DPA) with a gamma camera, instead of a rectilinear scanner, has been developed for vertebral bone mineral density (BMD) measurement. The system consists of 50 mCi (1,850 MBq) 153-Gd as the emitting source, and an Anger-type gamma camera with a rectangular Nal (Tl) crystal and 22 photomultiplier tubes. The effective field of a view was enough to cover more than 3 vertebrae. With the patient sitting, data acquisition was performed. The spatial resolution and uniformity of the gamma camera were good. With the introduction of a correction equation, the error in calculated BMD due to body thickness was reduced. A data acquisition of 7.5 to 15 min led to a satisfactory C.V. value (less than 2.0%). The precision (1.63% of C.V. in vitro and 3.53% in vivo) and accuracy (r=0.999) of the BMD measurements were also good. Vertebral BMD values in 300 normal Japanese females decreased with aging. Although in involutional osteoporosis and secondary hyperparathyroidism both vertebral and radial % BMDs decreased, in steroid-induced osteoporosis and primary hyperparathyroidism, disproportionate bone loss (relatively lower in vertebral bone) was demonstrated. Thus, it was shown that a newly developed DPA system using a gamma camera provided sufficient precision and accuracy to quantificaticn of vertebral BMD, and its application should provide reliable information for clarification of the pathophysiology of metabolic bone diseases

A Newly Developed Instrument of Dual Photon Absorptiometry for Bone Mineral Analysis of the Lumbar Vertebra: Study in Control and Aged Females

In order to determine the quantitatively bone mass, dual photon absorptiometry instrument using a scintillation camera was newly developed, and its basic performance was described. Furthermore, with this instrument, bone mineral at 3rd lumbar vertebra was measured in 57 women (31 controls: age 29.9±6.4 yrs., and 16 seniles: age 67.7±6.6 yrs.). The aged females, compared with the young control females, showed significantly low the all parameters of bone mineral such as bone mineral content (BMC), bone mineral density and total BMC at 3rd lumbar vertebra. Thus, it was shown that assessment of bone mineral with this instrument provided a useful information in the diagnosis of osteoporosis

散乱X線除去用グリッドの縞目像に対する空間周波数画像処理

X線撮影時に被写体から発生する散乱X線はX線画像の写真コントラスト等の画質を低下させるため,通常は散乱X線除去用グリッドを用いた撮影が行われるが,X線グリッドを用いた撮影では,グリッドの鉛箔が画像上に縞目模様となって現れるため,診断や画像解析の障害となることがある.そこで我々は,コンピュータ画像処理の空間周波数処理を用いて,X線グリッドによってX線画像上に生じた縞目模様を除去することを検討した.その結果,X線グリッドによってX線画像上に生じた縞目模様をLow passフィルタなどの空間周波数処理を用いて除去することが可能であった.また指骨では2.0 cycles/mmまでの高周波数成分の削除が可能であると考えられた

Scintigraphic Findings of Bone and Bone-Marrow and Determination of Bone Mineral Density Using Photon Absorptiometry in Osteopetrosis

On a 15-year-old girl with osteopetrosis, bone and bonemarrow scintigraphy were performed. Also, bone mineral density (BMD) with quantitative CT (QCT), single photon absorptiometry (SPA) and dual photon absorptiometry (DPA) were measured. On bone scintigraphy the diffusely increased skeletal uptake and relatively diminished renal uptake were noted. On the other hand, on bone marrow scintigraphy poor accumulation in central marrow and peripheral expansion were shown. BMD value by QCT and DPA (mainly trabecular bone) was markedly high, while BMD by SPA (mainly cortical bone) was within normal range. Thus, it was shown that bone and bone-marrow scintigraphy combined with BMD measurement by photon absorptiometry were useful and essential in evaluating the pathophysiology of osteosclerosis

CT画像を用いて算出したHip Structural Analysis(HSA)指標の検討

骨粗鬆症に伴う脆弱性骨折を起こすか否かは,骨量,骨構造,骨の石灰化,ダメージの蓄積および骨代謝などに依存するとされているが,近年,骨量測定に臨床で広く用いられているDXA装置に大腿骨近位部の構造力学的解析が可能なHip Structural Analysis (HSA) のプログラムが組み込まれ,骨強度の評価に用いられている.そこで我々は,CT画像からHSA指標の算出が可能か否か,また,その手法による指標の計算精度について,DXA装置で得られた指標と比較することによって検討した.その結果,CT画像からHSA指標の算出は可能であったが,その計算精度に若干の問題があり,撮影時の整位および計算位置の解剖学的なズレ等を補正する必要があることがわかった

The Usefulness of Bone Scintigraphy in the Detection of Hypertrophic Pulmonary Osteoarthropathy

In a patient with lung cancer, increased accumulation in both lower legs on bone scintigraphy with 99mTc-hydroxymethylene diphosphonate was confirmed radiographically to be hypertrophic pulmonary osteoarthropathy. A characteristic scintigraphic pattern of radionuclide accumulation could be distinguished from bone metastasis

Serial Cerebral Perfusion Imaging in a Case with Herpes Simplex Encephalitis

To evaluate cerebral blood flow, single photon emission computed tomographies (SPECTs) were serially performed in a case with herpes simplex encephalitis (HSE). Increased accumulation of N-ispropyl-I-123-p-iodoamphetamine (I-123-IMP) and Tc - 99m - hexamethylpropyleneamine oxime (Tc - 99m - HM - PAO) were noticed in the acute phase, and continued for seven weeks after the onset of the disease. In the third week, regional cerebral blood flow (rCBF) was estimated with I-123-IMP SPECT, and rCBF showed a high value in the affected temporal and occipital lobes of 60 to 70 ml/100 g/min (normal value; 40-50 ml/100 g/min), reflecting high accumulation of the tracer. After the twelfth week, when chinical symptoms and laboratory data had improved, the increased accumulation of these tracers was converted to a decreased accumulation

A Study of Cases with Rib Metastasis Difficult to Distinguish from Microfractures on Bone Scintigraphy

A retrospective study of about 10,000 cases at Kawasaki Medical School Hospital on whom bone scans were performed over a six year period revealed five cases in which metastasis was mistaken for a benign rib lesion. This mistake occurred because the accumulation pattern of the radionuclide in the rib region on the bone scan indicated a so-called "hot spot" observed with microfractures rather than the rod-like increased accumulation along costal bones that is coincident with the finding of bone metastasis. This experience suggests that solitary hot spots in the rib region on bone scans should be diagnosed carefully, as such an accumulation is most frequently associated with a benign etiology but rarely may be a malignant lesion