Abnormally high diffuse activity on bone scintigram the importance of exposure time for its recognition

When the bone scintigram reveals high diffuse skeletal activity, it may be misinterpreted as normal. Some authors have reported such scintigrams in articles entitled Significance of absent or faint kidney sign on bone scan and False negative bone scintigram. Three cases with bone metastasis showing high diffuse skeletal activity are presented in this paper. The recognition of abnormally high diffuse skeletal activity on bone scintigrams is discussed. The exposure time of all three cases was short when compared with normal cases, when the bone image was taken with a preset count. Therefore, exposure time is very important for objective differentiation between the cases showing high diffuse skeletal activity and normal cases.     

Infrabladder "cup defect" following prostatectomy: recognition on bone scintigram

Seventeen bone scintigrams, made after prostatectomy for proven or suspected carcinoma, showed a "cup defect" below the bladder. This defect was likely related to the volume of tissue removed at the time of transurethral prostatectomy. In two cases, the defect was not present on images made before prostatectomy but was clearly seen after the operation. The time of persistence of the "cup defect" is discussed, as well as the differential diagnosis of the finding.     

Analysis of bone scintigram data using speech recognition reporting system--data analysis with speech recognition system

Five hundred eighty bone scintigram reports were stored using a voice pattern recognition system in a general-purpose, middle-sized computer (ACOS-650). Bone scintigraphy carried out in our institute was examined by analyzing these data. The results of the examination showed that the introduction of this system made it possible to analyze all the data quickly. Before the introduction of this system, the data able to be analyzed had been restricted because of their complexity. The results also showed that this system would be useful for understanding the examinations carried out in the whole hospital as well as for analyzing metastatic tumors and the number of patients receiving examinations. Furthermore, this system would be helpful in the logical analysis of reports prepared by doctors.     

Detection of extensive melorheostosis on bone scintigram performed for suspected metastases

Melorheostosis is a rare but benign disorder characterized by asymmetric osteosclerotic dysplasia. Radiographic appearances are characteristic and described as "melting wax flowing down a candle." This disorder may involve more than one bone contiguously across the joints following a sclerotomal distribution. It is often asymptomatic but occasionally presents with pain and contractures. The authors report accidental detection of bilateral upper and lower limb melorheostosis in an elderly woman with the history of breast cancer and recent onset of low back pain, which was referred for a bone scintigram for suspected metastases. The images showed bilateral femoral and tibial melorheostosis, which was subsequently confirmed on plain radiograph and by clinical follow-up.     

Solitary phalangeal metastasis of renal cell carcinoma on bone scintigram

Renal cell carcinoma is known to cause lytic metastasis at various sites including axial and appendicular skeleton. However, it is unusual to find an isolated metastasis of renal cell carcinoma in the distal extremity on bone scintigraphy. A 70-year-old woman with renal cell carcinoma was referred to the Nuclear Medicine Department for a bone scintigram to exclude metastasis. The whole-body planar images were unremarkable, but the local views of the hands demonstrated a solitary metastasis in the middle phalanx of the finger. This rare experience illustrates the need for including local views of extremities in a standard whole-body study.     

The importance of bone marrow examination for hemoblastoses]

Morphological bone marrow evaluation is an integral component in staging patients with hematological malignancies. In acute leukemias or myelodysplastic syndromes cytologic examination is crucial since it allows precise analysis on the individual cell level. Histological examination of an iliac crest trephine biopsy is mandatory in malignant lymphomas because of the frequent nodular involvement of bone marrow in these diseases. In recent years magnetic resonance tomography (MRT) has been shown to be a sensitive method for detecting marrow infiltration in a variety of marrow diseases. In malignancies with focal marrow involvement, such as malignant lymphoma, MRT is today a useful complement to morphological bone marrow evaluation.     

The effect of iatrogenic trauma on the bone scintigram: an animal study: concise communication

An animal study was performed to assess the effect on the Tc-99m phosphate bone scintigram of injury by needle aspiration or drill hole to metaphyseal and diaphyseal areas in immature and mature bones. Results showed that in 12 immature rabbits such trauma to metaphyseal regions had no effect on the bone image. Similar metaphyseal trauma in two mature dogs showed definite abnormalities on the bone image, but in one mature rabbit, no abnormality could be identified by scintigram. Diaphyseal trauma always gave a definitely abnormal bone image. Extrapolation of these results to humans should be cautious, but it suggests that needling or drilling in metaphyseal regions in neonates or young children probably does not affect later bone images.     

Comparison between visual assessment and quantitative measurement of radioactivity on the bone scintigram in Paget's disease of bone

Two methods of evaluating bone scintigrams in Paget's disease of bone were compared. Bone scintigraphy was performed after IV injection of 20 mCi 99mTc-Sn-EHDP. Qualitative evaluation was carried out by visual assessment of the photographs of the oscilloscope of the gamma camera, using a scale of six well-defined scores. Quantitative evaluation of uptake of radionuclide was obtained by calculating the ratio of the number of counts per pixel in pagetoid bone with that in comparable normal bone; measurements were performed by a computer interfaced to the gamma camera, after marking the regions of interest with a light-pen. In 42 patients with untreated Paget's disease there was a linear relationship between the visually assessed score and the logarithm of the computer-measured ratio. In 27 patients treated with APD a decrease in uptake was measured in all lesions and was usually also detected visually; however, in 14% of these lesions the changes (ranging from 9% to 70%) were not visible to the eye. Here too, visual estimation of the changes corresponded to the logarithm of the measured changes. In conclusion, there is a semilogarithmic relationship between the visual and the physical methods.     

Comparison between visual assessment and quantitative measurement of radioactivity on the bone scintigram in Paget's disease of bone

Two methods of evaluating bone scintigrams in Paget's disease of bone were compared. Bone scintigraphy was performed after IV injection of 20 mCi ^99mTc-Sn-EHDP. Qualitative evaluation was carried out by visual assessment of the photographs of the oscilloscope of the gamma camera, using a scale of six well-defined scores. Quantitative evaluation of uptake of radionuclide was obtained by calculating the ratio of the number of counts per pixel in pagetoid bone with that in comparable normal bone; measurements were performed by a computer interfaced to the gamma camera, after marking the regions of interest with a light-pen. In 42 patients with untreated Paget's disease there was a linear relationship between the visually assessed score and the logarithm of the computermeasured ratio. In 27 patients treated with APD a decrease in uptake was measured in all lesions and was usually also detected visually; however, in 14% of these lesions the changes (ranging from 9% to 70%) were not visible to the eye. Here too, visual estimation of the changes corresponded to the logarithm of the measured changes. In conclusion, there is a semilogarithmic relationship between the visual and the physical methods.     

The value of pretreatment clinical and biochemical parameters in patients with newly diagnosed untreated prostate carcinoma and no indications for bone metastases on the bone scintigram

Between 10% and 25% of patients with newly diagnosed prostate cancer without bone metastases at the time of diagnosis will develop metastases during follow-up. To determine the value of clinical and biochemical parameters for assessment of prognosis at the time of diagnosis, a retrospective study was performed in 124 consecutive patients with newly diagnosed prostate cancer without bone metastases. The mean follow-up was 41 months, during which time 36 patients died and 15 patients developed metastases. Bone scans were classified from 0 (=normal) through 2 (=abnormal, but not typical for metastases) and were correlated with age, alkaline phosphatase (AP), prostate-specific antigen (PSA), tumour grade, T-stage and N-stage. In patients with a class 2 scan, additional roentgenograms and follow-up were used to exclude metastases at initial stage. All parameters, including therapy, were finally correlated with the development of metastases and survival. For survival 38 patients with proven metastases were used as controls. For all parameters tested, no statistically significant differences were found between the three bone scan classifications. The interval between diagnosis and the development of metastases ranged from 12 to 72 months. For the risk of development of metastases only PSA was found to be a significant correlate (P=0.0075). However, when tumour stages were clustered in limited disease (T0–2) and extensive disease (T3–4), the incidence of metastases was significantly higher in patients with extensive disease than in those with limited disease (P=0.0021). Finally, age, PSA and Anderson classification were found to be significant correlates of survival, but in stepwise analysis PSA was selected as the most prognostic variable (P<0.0001). In contrast with a typical pattern of metastases on bone scintigraphy, an abnormal scan (class 1 and 2) at the time of diagnosis is not a poor prognostic parameter of the risk of death. In conclusion, in patients with prostate cancer without bone metastases at the time of diagnosis, pretreatment PSA and tumour stage can be used for the assessment of risk of development of metastases during follow-up and survival. For this purpose, tumour stage should be clustered in limited and extensive disease. Received 14 April and in revised form 9 June 1997     

A new look at pattern recognition of diffuse pulmonary disease.

The common practice of describing the histologic distribution of pulmonary lesions from their radiographic patterns is often inaccurate. Recognition of disease entities is more successful if a given pattern is analyzed for its probable causes, rather than by attempting to predict its microscopic distribution. This represents a change in attitude toward the correlation of the radiographic and pathologic findings in disseminated diseases of the lung. The objective of this communication is to enable radiologists to become more secure in recognizing diffuse pulmonary patterns, to understand the shortcomings of this approach, and to stop trying to predict microscopic distribution from the chest radiograph.     

Multiple level spinal injuries: importance of early recognition.

Patients with severe trauma may simultaneously sustain more than one level of spinal injury. Often, the second or third levels of injury are not recognized early enough to prevent clinically significant extension of the neurologic deficit, pain pattern, spinal instability, and/or deformity. A review of 710 spinal injury patients admitted to the Midwest Regional Spinal Cord Injury Care System yielded 4.5% multiple noncontiguous vertebral injuries. Thirty cases were studied in respect to location and type of primary and secondary injury. Of the secondary lesions, 40% occurred above and 60% below the primary lesion. In half of the patients, there was a mean of 52.6 days delay in diagnosis of the secondary lesion. Three major patterns of injury emerged from this analysis. Knowledge of these patterns and careful total spine radiography in patients with severe trauma may be a significant aid in early recognition of multiple level injuries and possible prevention of their complication.     

Effects of intermittent exposure to high altitude on blood volume and erythropoietic activity

The purpose of this review is to describe changes in blood volume and erythropoietic activity occurring under different types of intermittent exposure to hypoxia. These hypoxic episodes can vary from a few seconds or minutes to hours, days, or even weeks. Short hypoxic episodes like sleep apnea only lead to a small increase in hemoglobin concentration, which is mainly due to a hormonal-mediated decrease in plasma volume. In most of these cases the cumulative time spent under hypoxia does not exceed the critical threshold of about 90 min. Endurance athletes and mountaineers who voluntarily expose themselves to hypoxia for some hours or during the night while spending the day at normoxia ("sleep high-train low" concept) do improve their physical performance. Despite raising erythropoietic activity, indicated by elevated plasma concentrations of EPO and the transferrin receptor, the postulated increase in red cell volume has not satisfactorily been proved. Frequent changes between low and high altitudes, which are usual in some South American and Asian countries, provoke similar adaptations in red cell mass as occur in high altitude residents. However, the plasma volume decreases at altitude and increases again when staying at sea level. Even after more than 20 yr of regular moving between low and high altitude, the total blood volume, hemoglobin concentration and hematocrit, as well as the plasma EPO concentration, noticeably oscillate during every hypoxic-normoxic cycle. We assume these changes to be an optimal rapid adaptation of the oxygen transport system to the prevailing hypoxic or normoxic environment. However, possible risks for the organism cannot be excluded.