The purposes of this study were to determine the origin and nature of normal lower limb venous Doppler flow phasicity and to assess normal and respiratory variations. SUBJECTS AND METHODS. The common femoral veins of 12 healthy volunteers (three men and nine women; age range. 21-50 years; mean. 29 years) were evaluated by detailed spectral Doppler examinations with simultaneous ECG and respirometric tracings. The examinations were performed using a 5-or 7-MHz linear-array transducer with breath held in mid respiration. at the end of deep expiration, at the end of deep inspiration. during Valsalva's

Tl 201 imaging offers more specificity with a higher positive predictive value in the diagnosis of Hodgkin's disease. The Ga 67 study is more sensitive than Tl 201 in the detection of disease. There is no significant difference in accuracy and negative predictive value between the two studies. Therefore, we recommend Tl 201 imaging in the initial evaluation and assessment of patients' response to radiation therapy and/or chemotherapy.