Jan Fogh

Interobserver variation in the detection of metastases on liver scans

Two specialists in nuclear medicine and two trainees independently read 106 liver scans for abnormalities suggestive of metastases. The four observers made a positive diagnosis with a significantly different frequency. The overall agreement between pairs of observers was 0.83-0.87. After adjusting for the expected chance agreement, kappa-values between 0.66 and 0.74 were obtained. No difference was found in the level of agreement between the two specialists or between the two trainees. After a consensus conference where the observers tried to unify their diagnostic interpretation, another 106 scans were read for abnormalities suggestive of metastases. The conference did not increase the level of agreement. Scintigraphic lesions that especially imply a risk of disagreement are pointed out.

Primary hemangiosarcoma of the spleen with angioscintigraphic demonstration of metastases

A case of primary hemangiosarcoma of the spleen in a 48‐year‐old woman is presented. Twenty‐eight months after splenectomy the patient developed a severe anemia of the microangiopathic type, thrombocytopenia, and a leukoerythroblastic peripheral blood picture. In contrast to x‐ray and conventional 99mTc‐methylene‐diphosphonate (MDP) bone scintigraphy, which showed only a few minor focal changes in the spine and ribs, angioscintigraphy with in vitro labeled 99mTc‐erythrocytes revealed extensive pathologic accumulations throughout the spine, femurs, and the liver, indicating the presence of extremely vascular metastases. Autopsy 15 months later confirmed the scintigraphic findings. Angiography with 99mTc‐labeled erythrocytes seems to be useful for monitoring metastases from hemangiosarcomas.

Scintigraphic control of pulmonary embolism.

Pulmonary embolism was diagnosed by combined perfusion and ventilation scintigraphy in 30 patients. A control examination 6 months later revealed pulmonary embolism or infarction in 8, in spite of conventional treatment. Therefore, patients treated for pulmonary embolism should be reexamined 3 to 6 months after diagnosis.

In vivo stability of in vitro labelled 99Tcm-red blood cells for radionuclide determination of left ventricular ejection fractions and volumes

Serial determination of radionuclide left ventricular ejection fraction and volumes require a label that remains highly stable after introduction into the human circulation. We have evaluated the in vivo stability of 99Tcm-red blood cells (99Tcm-RBC) labelled in vitro by preparation with small amounts of a stannous agent in 19 patients with coronary artery disease. The distribution volume of 99Tcm-RBC was virtually identical to that of RBC labelled with Cr. Labelling efficiency expressed as the cell bound/total activity was more than 95% and remained high throughout 1 h after injection of the label. The effective in vivo half-times (T1/2) calculated from venous blood activity and externally recorded left ventricular end-diastolic frame activity were 342±103 min (mean±S.D.) and 306±92 min, respectively.A significant correlation, r = 0.86 (p < 0.01) was found between the T1/2 values calculated from the two methods. Thus, a high in vivo stability of the label was demonstrated with considerable inter-patient variation. The labelling procedure seems suitable for serial performance of radionuclide cardiography within an hour after injection of 99Tcm-RBC. However, serial volume determination necessitates individual calculation of in vivo tracer decay from either venous blood or externally recorded activity in the left ventricular area during steady conditions.

Persistent impairment of liver function caused by a pendulated accessory liver lobe

A large pendulated accessory liver lobe and complete absence of the left lobe were discovered by liver scintigraphy and ultrasound scanning in a patient suspected of having an ovarian tumor. The patient had a history of fluctuating impaired liver function tests for many years, probably caused by intermittent torsion of the peduncle. Pedunculated accessory liver lobes are extremely rare and seldom diagnosed in vivo. Our patient seems to be the 11th published case, and the only 1 in which longstanding fluctuating impaired liver function tests have been observed.

Evidence against erythropoietin production by the carotid body

Abstract It has been suggested that the carotid bodies produce erythropoietin. We have investigated this proposition by examining in cats whether removal of the carotid bodies affects the magnitude of the increase in erythropoietin concentration in blood following 6 hr of hypoxia. We also determined whether extracts prepared from homogenized carotid bodies contained measurable amounts of erythropoietin. Furthermore we examined histochemically whether the carotid bodies contained glycoproteins, as erythropoietin is a glyeoprotein. We found: 1) The erythropoietin concentration in serum following 6 hr of hypoxia was significantly higher in cats who had their carotid bodies removed. 2) Carotid body extract did not contain measurable amounts of erythropoietin. 3) Histochemically we were not able to detect erythropoietin in the carotid bodies. We must therefore reject the suggestion that the carotid produce erythropoietin.

Studies on the method of intrauterine transfusion: I. Question of erythrocyte absorption from amniotic fluid☆

Abstract 1. 1. Four women had the intraamniotic injection of red cells followed by measurement of such cells in the fetus. 2. 2. Active inspiration and ingestion of amniotic fluid takes place as early as 14 to 16 weeks of gestation. 3. 3. Erythrocytes are apparently not absorbed from the amniotic fluid into the fetal circulation at an early stage of gestation.

In vitro labeling of human polymorphonuclear leukocytes with 99mTc

Preliminary experience with 99mTc labeling of isolated polymorphonuclear leukocytes is reported. Leukocytes efficiently purified from 100 ml peripheral blood were labeled in vitro with 99mTc after pretreatment with small amounts of a stannous agent to reduce pertechnetate. A labeling yield of 1.3 mCi equivalent to 12.5% of the added dose of 99mTc and a cell binding efficiency of more than 90% was achieved under sterile conditions. Viability assays showed no influence of the labeling procedure on cell function. The technique may prove a valuable alternative for assessment of local leukocyte accumulation by scintigraphy.

Scintigraphic demonstration of subcutaneous abscesses with 99mTc-labeled leukocytes

Our initial experience with the clinical application of autologous leukocytes labeled in vitro with technetium 99m is reported. An injection of 3.6×108 leukocytes (83% of which were polymorphonuclear) labeled with 6.4 mCi 99mTc was administered to a patient with subcutaneous abscesses in order to evaluate the in vivo stability of the labeling and cellular function. Scintigraphic examinations demonstrated marked accumulations of radioactivity at the sites of inflammation, suggesting that 99mTc was efficiently bound to the cells and that the migration of polymorphonuclear leukocytes was not disturbed by the labeling procedure.