Cystic lymphangiomatosis of the spleen is an extremely rare pathologic entity. We report the radiologic, sonographic, and scintigraphic findings in two cases of splenic cystic lymphangiomatosis. In both patients echograms demonstrated multiloculated cystic lesions in the intra-abdominal masses, which were identified on radiocolloid scans as abnormal spleens. The gross and microscopic findings of the excised spleens were characteristic of cystic lymphangiomatosis. The findings on echograms and scintigrams correlated well with the abnormal splenic morphology. The clinical presentation, the findings on diagnostic imaging, and the gross and microscopic appearances of the pathologic spleens in our patients were remarkably similar. When a massively enlarged spleen with a multicystic appearance is encountered during a diagnostic workup, awareness of the scintiscan and sonographic findings might aid in the noninvasive preoperative recognition of cystic lymphangiomatosis.

Metastatic calcification involving the lungs and stomach was demonstrated in 3 patients by bone scans. In one patient, postmortem studied five days later confirmed the findings. Follow-up scans in 2 patients, demonstrating improvement in one and worsening in another, paralleled the clinical course.

A technic for visualization of inflamed joints using intravenously injected technetium-99m as pertechnetate and an Anger (scintillation) camera for detection will be described. Contrast between inflamed and normal tissue was usually greatest in the first few minutes after isotope injection, presumably, at the time of maximal difference in concentration of 99mTc between blood and extravascular tissue. Inflamed joints with moderate to large effusions were often visualized best 1-2 hr after injection. The extensive binding of pertechnetate by plasma and joint fluid proteins found in equilibrium dialysis experiments was evoked as an explanation of this phenomenon.Technetium-99m ("9mTc) scheme for 99M0 is given in Fig 1.4 Many clinical uses of 99mTc have been developed, including joint scans.6-7 A technic for the visualization of diseased joints using 9 s m T~ and a scintillation (Anger) camera is the subject of this report. The data are interpreted in terms of isotope kinetics. MATERIALS AND METHODSSubjects. T h e optimal time of exposure was determined after scintiphotographs of the hands and wrists of 6 patients without joint disease had demonstrated a nearly uniform distribution of radioactivity (Fig 2). The "normals" were individuals receiving intravenous pertechnetate-99m for other diagnostic studies such as brain tumor localization. The hand, "wrist" and knee joints of patients with classical rheumatoid arthritis (RA) were then examined serially. Serial frontal images (ie, patella to collimator) were obtained of an inflamed knee containing a large effusion in patient E.M.Podtfonlng. Five mc lomTc, as sodium pertechnetate (NaTcO,) , were given intravenously. The

A new technique that requires neither arterial blood sampling nor prior knowledge of the indicator's tissue-blood partition coefficient has been developed for quantitation of local CBF. This technique arises from an existing method that uses the inert, freely diffusible gaseous tracer [18F]methyl fluoride (CH3(18)F) and positron computed tomography. The shape of the arterial blood curve is derived from continuous sampling of expired air. The concentration of CH3(18)F in the arterial blood is assumed to be proportional to the expired gas curve interpolated between end-tidal values. The absolute scale of the blood curve is determined by fitting a series of venous blood samples to a multicompartment model. Four validation studies were performed to compare values derived using the venous scaled expired breath input function with those derived using direct arterial samples. The proposed method gave higher flow values than the standard arterial sampling method by an average of 4.4%. These validation studies and data from both normal and patient scans suggest that the method provides the quantitation necessary for interstudy comparisons yet avoids the trauma of an arterial puncture.

Technetium-99m scintiphotography of the hands, wrists and knee joints of 24 patients with rheumatoid arthritis (RA) showed abnormal localization of isotope in one or more synovial structures in 96% of hands, in 94% of wrists and in 74% of knees. The results of scintiphotography correlated well with clinical assessment of synovial thickening and tenderness in the proximal interphalangeal and metacarpophalangeal joints of 9 consecutive RA patients. Scintiphotography proved more sensitive than clinical examination only in knee joints; in 2 patients clinical involvement was antedated by positive scintiphotos. Joint visualization after intravenous pertechnetate was nonspecific, and positive scintigrams were obtained in other diseases associated with increased articular or periarticular vascularity. The technic is definitely useful in the serial evaluation of the results of local medical and surgical treatment of arthritis and as an aid in the diagnosis of psychogenic rheumatism.A technic for visualization of inflamed joints using DDmTechnetiurn as the pertechnetate (NaTcO,) and an Anger (scintillation) camera is described in an accompanyFrom the Section of Arthritis and Metabolism.