Focal Pulmonary Uptake Research Articles

Focal pulmonary uptake on myocardial perfusion scintigraphy due to iatrogenic microembolism

Focal pulmonary uptake on myocardial perfusion scintigraphy due to iatrogenic microembolism

Usefulness of 18 F-Labeled Fluorodeoxyglucose-Positron Emission Tomography for the Diagnosis of Lymphoma in Primary Sjögren's Syndrome.

The usefulness of positron emission tomography-computed tomography (PET-CT) with 18 F-labeled fluorodeoxyglucose (18 F-FDG) for the diagnosis of lymphoma in patients with primary Sjögren's syndrome (SS) is unclear, since the abnormalities it reveals may be due to systemic manifestations of SS. This study was undertaken to compare 18 F-FDG-PET-CT in patients with primary SS with lymphoma and those without lymphoma in order to identify patterns associated with lymphoma. A retrospective study was conducted in 2 centers and included patients who met the American College of Rheumatology/European League Against Rheumatism 2016 criteria for primary SS and had undergone PET-CT. Two independent readers who were blinded with regard to lymphoma diagnosis analyzed PET-CT scans. Abnormalities were compared between patients with and those without lymphoma. Of the 45 patients included, 15 had lymphoma. Compared to patients without lymphoma, the mean size (P = 0.048) and maximum standardized uptake value (SUVmax) (P = 0.001) of the parotid glands were higher in patients with lymphoma. FDG uptake in the lymph nodes was observed in 53.3% of the patients with lymphoma and 43.3% of the patients without lymphoma, with no difference in the number of sites, uptake pattern, or mean SUVmax. Focal pulmonary uptake (nodules or condensations) was observed in 5 of the patients with lymphoma (33.3%) but only 1 patient without lymphoma (3.3%) (P = 0.01). Having an SUVmax in the parotid gland of ≥4.7 and/or the presence of focal pulmonary lesions was highly suggestive of lymphoma (sensitivity 80%, specificity 83.3%). Some systemic manifestations of primary SS (lymphadenopathy, pulmonary involvement, and salivary gland involvement) can be visualized by PET-CT. Involvement of the lymph nodes and parotid glands is commonly observed with a similar frequency in SS patients with and those without lymphoma. An SUVmax in the parotid glands of ≥4.7 and/or the presence of focal lung lesions are associated with the diagnosis of lymphoma.

Incidental Detection of Rounded Atelectasis During Tc-99m MIBI Scintimammography

Focal pulmonary uptake resembling a malignant tumor was incidentally detected in a 37-year-old woman with recurrent breast cancer during Tc-99m MIBI scintimammography. The lesion had the characteristic computed tomography (CT) features of rounded atelectasis with a relatively low uptake on FDG-PET. The lesion was unchanged on follow-up CT and scintimammography performed 1 year later.

Pulmonary activity on labeled leukocyte images: physiologic, pathologic, and imaging correlation.

Accurate interpretation of labeled leukocyte images requires knowledge of pulmonary labeled leukocyte uptake: its prevalence and patterns and its correlation with technical, physiologic, and pathologic conditions as well as with other imaging findings. Images obtained shortly after injection of labeled cells are characterized by diffuse pulmonary activity, which decreases over time, until about 4 hours after injection when it becomes indistinguishable from background activity, remaining constant thereafter. Focal pulmonary uptake that is segmental or lobar in appearance is most often associated with bacterial pneumonia. Focal pulmonary uptake that is not segmental or lobar results from technical problems during labeling or reinfusion and is not usually associated with infection. Diffuse pulmonary uptake on images obtained more than 4 hours after reinjection of labeled cells is associated with a variety of pathologic conditions, some of the more common being opportunistic infection, radiation pneumonitis, pulmonary drug toxicity, adult respiratory distress syndrome, and sepsis. However, this pattern is almost never seen in bacterial pneumonia. When pulmonary uptake patterns are analyzed and correlated with the clinical situation, labeled leukocyte scintigraphy can provide useful information about pulmonary disease.

Intrathoracic and intra-abdominal Tl-201 abnormalities seen on rotating raw cine data on dual radionuclide myocardial perfusion and gated SPECT.

The lower thorax and upper abdomen are visualized during cardiac acquisition of rest Tl-201 and stress Tc-99m tetrofosmin gated SPECT. Thus, abnormal Tl-201 localization in these areas and in organs such as parts of the lungs, liver, spleen, and kidneys can be observed, including rotating raw cine data. Other than cardiac images, the authors retrospectively reviewed Tl-201 rotating (raw data) images of 235 patients. Abnormal findings in the lungs, liver, spleen, and kidneys were identified that correlated with the patients' clinical information; radiographic findings, including computed tomography and ultrasonography of the abdomen; other scintigraphic studies; and laboratory findings. In 53 patients, 54 abnormalities were detected. Intrathoracic abnormalities included focal areas of increased uptake, one in the right lower lung and another in the right upper lung that confirmed lung cancer, in 2 patients; diffuse uptake in both lungs in 11 patients; photopenia in the lung bases, which had resulted from pleural effusions, in 3 patients; and abnormal right liver configuration caused by elevation of the right hemidiaphragm in 1 patient. Of the intra-abdominal abnormalities, 12 patients with splenomegaly were identified. Six patients had focal areas of increased uptake in the gastric area. Nonvisualization of one kidney resulted from a congenitally absent right kidney in 1 patient, from right nephrectomy in 1 patient, from end-stage renal disease in another, and from a lower position of the left or right kidneys in 5 patients. Small and decreased uptake of both kidneys resulted from end-stage renal disease in 1 patient. Small and decreased uptake of one kidney was noted in 1 patient with renal scarring, in 1 patient with a renal stone, in 3 patients with chronic pyelonephritis, and in 5 patients with renal cyst(s). Discernible intrathoracic and intra-abdominal abnormalities using rotating raw cine data from imaging in three-dimensional displays include diffuse or focal pulmonary uptake, pleural effusion, elevation of a hemidiaphragm, splenomegaly, increased uptake in the gastric area, renal abnormalities including absent or small kidneys, end-stage renal disease, renal scarring, renal cyst(s), and lower position of a kidney. The incidental finding of such abnormalities may prompt further clinical investigation.

Focal pulmonary uptake during Tc-99m myocardial perfusion SPECT imaging.

To evaluate the incidence and origin of abnormal focal pulmonary uptake during myocardial perfusion SPECT imaging (MSPECT). For evaluation of chest pain, 790 men and 581 women (mean age, 56 +/- 13 years) underwent MSPECT. All of them received adenosine for pharmacologic stress and Tc-99m tetrofosmin (TF, n = 817) or Tc-99m sestamibi (MIBI, n = 554) for myocardial perfusion imaging. Review of chest radiography with or without computed tomography revealed 111 (8.1%) focal pulmonary diseases. Among them, 38 (34.2%) showed focal pulmonary uptake (TF, 22; MIBI, 16); 27 (30.7%) of 88 showed previous pulmonary tuberculosis; 2 of 10 (20%) benign pulmonary nodules; 4 of 5 (80%) metastatic lung cancers; 2 of 4 (50%) primary lung cancers; and 3 of 4 (75%) pneumonias. No difference in uptake was noted for the two imaging agents. Intensity of uptake did not vary with origin of the uptake. Focal abnormal pulmonary uptake was found in 2.8% of patients undergoing MSPECT and in 34.2% of patients in whom radiological examinations showed regional pulmonary disease. In patients with abnormal pulmonary uptake on MSPECT, 16% had a malignant lesion, whereas 75% of patients with a pulmonary nodule shown on radiography and focal pulmonary uptake on MSPECT had a malignant lesion. Although the incidence of abnormal pulmonary uptake during MSPECT was very low, the incidence of malignant lesions in the patients with nodular pulmonary uptake was relatively high.

13.41 Focal pulmonary uptake during myocardial perfusion SPELT imaging

13.41 Focal pulmonary uptake during myocardial perfusion SPELT imaging