A. Fuat Yapar

Gastroesophageal scintigraphy in children: a comparison of posterior and anterior imaging

The purpose of this study was to compare the posterior dynamic imaging with the anterior imaging in the evaluation of children with gastroesophageal reflux (GER). Sixty-eight children (26 female, 42 male; age range 4 months to 7 years, median 21 months) were studied. After 4-hour fasting, all the subjects underwent gastroesophageal scintigraphy. Synchronous dynamic imaging in the anterior and posterior projections was performed with the subject in the supine position with a dual-head gamma camera equipped with low-energy general-purpose collimators at a rate of 30 s/frame for 40 min. The anterior and posterior images were visually evaluated for the presence of gastroesophageal reflux by two nuclear medicine physicians. The anterior and posterior images were correlated by Pearson correlation analysis, and inter-observer variability was evaluated by paired t-test and kappa value. There was a good correlation between the two projections with r-values of 0.906–0.990. The inter-observer agreement for interpretation of the anterior and posterior imaging was excellent (k: 0.83). In conclusion, anterior and posterior dynamic imaging showed excellent correlation in detection of GER in children. Posterior imaging is superior to anterior imaging in that it is more comfortable, and it reduces motion artifacts, especially for infants and anxious children; thus, it may be preferred over anterior imaging.

The conditions for which the geometric mean method revealed a more accurate calculation of relative renal function in 99mTc-DMSA scintigraphy

Aims(1) To compare the results of calculating relative renal function (RRF) by using only posterior images (POST) with the geometric mean (GM) through both anterior and posterior imaging on dimercaptosuccinic acid (DMSA) scintigraphy. (2) To determine whether there was an age-related difference between them and whether some renal pathologies or asymmetrical renal function cause an error in the RRF calculation by using posterior images only. MethodsEight hundred and ninety-one DMSA scans were studied retrospectively. The patients were divided into five age groups: group I, ≤2 years; group II, >2 to ≤5 years; group III, >5 to ≤10 years; group IV, >10 to ≤18 years; and group V, >18 years. The RRF of the right kidney (RKF) was calculated from the POST and GM counts. The differences between RKFGM and RKFPOST were calculated in all the patients. ResultsAmong the 891 patients, nine had malrotated or malpositioned kidneys, 373 had renal pathologies of pyelonephritis, hydronephrosis, cortical scarring and atrophy, 247 had asymmetrically functioning kidneys and 509 had normal kidneys. When the patients were analysed according to different age groups, significant differences were found between all groups (P<0.05) except groups I–II and IV–V (P>0.05) with the F-test. The clinically meaningful RRF variance (≥5% difference between two methods) rate differed significantly between groups I, II and III, and groups IV and V (chi-squared test, P<0.05). In patients aged ≤10 years, a clinically meaningful RRF variance (≥5%) rate was significantly higher in the groups with pathological or asymmetrically low (≤40% RRF) functioning kidneys than in the groups without pathological or asymmetrically low functioning kidneys, respectively (P<0.05). ConclusionsAccording to our findings, the calculation of RRF using the GM method differs significantly from that using posterior images. Calculation of the GM can effectively correct the RRF measurement not in only adults, but also in the patient population ♯10 years of age. In addition, a significant correction can be made in patients aged ♯10 years who have a renal pathology or an asymmetrically low functioning kidney.

Diffuse splenic tc-99m mdp uptake in hypersplenic patient

A 52-year-old woman with nonspecific left leg pain was examined by Tc-99m methylene diphosphonate (MDP) bone scintigraphy. The patient had been a marble quarry worker for 10 years and had developed chronic congestive heart failure secondary to pneumoconiosis. Her hemoglobin analysis and hematologic findings were interpreted as being consistent with sickle cell beta+ thalassemia and also hypersplenism. Bone scintigraphy showed intense and diffuse MDP accumulation in the enlarged spleen without ultrasonographic or radiologic evidence of calcification.

Sonographic Diagnosis of a Tracheal Extramedullary Plasmacytoma

Solitary extramedullary plasmacytoma (EMP) is a rare tumor constituting 4% of all plasma cell neoplasms. It may occur in any reticuloendothelial system containing organs but is found most frequently in the head and neck regions, which are rich in lymphoid tissue. The most common sites of origin are the subepithelial tissues of mucous membranes of the oronasopharynx and paranasal sinuses.1-5 Sonography has no role in the evaluation of tracheal lesions. We report a case of tracheal plasmacytoma that was discovered during a sonographic examination of the neck for goiter. The interesting aspect of this case is the presentation of a rare tracheal tumor diagnosed by a sonographic examination.

The value of Tc-99m-tetrofosmin scintigraphy in the assessment of P-glycoprotein in patients with malignant bone and soft-tissue tumors

P-glycoprotein (Pgp) overexpression has been shown to be correlated with resistance to chemotherapy in patients with malignant bone and soft-tissue tumors. The aim of our study was to investigate the role of99mTc-tetrofosmin as a functional imaging agent reflecting Pgp expression in these tumors.Methods: Twenty eight patients with various malignant bone and soft-tissue tumors were studied. Radionuclide angiography with99mTc-tetrofosmin was done first and planar images were acquired at 15 min and 90 min postinjection. Vascular phase was evaluated visually on dynamic images, metabolic state was evaluated both visually and quantitatively on planar images. Quantitative analysis was performed by the calculation of tetrofosmin uptake in the lesion against background and percent washout rate (WR%) of the tracer. Immunohistochemical analysis of Pgp was performed on biopsy specimens and the degree of expression was graded from 0 to 3.Results: There was a positive correlation between the Pgp score and the washout rate of tetrofosmin (r=0.73, p=0.000). The mean washout rate of tetrofosmin from the lesions with Pgp expression (31.81±6.72) was found to be significantly higher than those of without Pgp expression (21±3.49) (p=0.000). No statistically significant correlation was found between 15 min and 90 min uptake, ratios (UR) of tetrofosmin and Pgp score (r=−0.10, p=0.7 and r=−0.21, p=0.2, respectively). When the cut-off value of 24.5 (according to ROC-analysis) for the washout rate was used to discriminate the lesions with and without Pgp expression, the test yielded a sensitivity value, of 87.5% with a specificity of 100%.Conclusions: In malignant bone and soft-tissue tumors,99mTc-tetrofosmin uptake were not related to Pgp overexpression. Pgp overexpression was found to be correlated with the washout rate of the tracer.99mTc-tetrofosmin scintigraphy with washout analysis may not only be a useful method for evaluating Pgp overexpression but also, its function.

Assessment of the optimal time interval and background region of interest in the measurement of differential renal function in Tc-99m-EC renography

BackgroundDifferential renal function (DRF) measurements are routinely corrected for back-ground, which mainly affects the reproducibility and accuracy of the measurement. The present study was conducted to identify the most appropriate background ROI and optimal time interval in the calculation of DRF for EC renographyMaterials and MethodsNineteen patients were studied.For determination of DRF in EC renography, the selected time intervals were 0.5-1.5; 0.5-2; 1-2; 1.5-2.5; 2-3 min, and the background ROI types were inferolateral crescent, lateral crescent, and perirenal shaped. The reference DRF was obtained through DMSA study. For low functioning kidney of each patient, relative uptake differences between the DMSA and EC scans were calculated. Then, the mean differences and the standard deviations were found.ResultsThe highest correlation was between the DRF values obtained using inferolateral background ROI in 0.5-2 minutes of EC scintigraphy and the DRF values obtained through posterior DMSA images (r = 0.9889). However, there were no statistically significant differences between the mean DRF values obtained for each time interval with each ROI type (p > 0.05). For all the time intervals and background ROIs, the mean of the differences was <0.9%. In conclusion, in obtaining comparable DRF values from EC and DMSA studies, none of the background types proved superior. Also our research for optimal time interval showed that EC scintigraphy underestimates the DRF when compared to DRF obtained from DMSA study. The DRF has a tendency to decrease as the later time intervals are used. The time intervals less than 2.5 minutes show lower underestimation of DRF values.

Scintigraphic diagnosis of jejunoileal duplication

A 10-month-old male infant was hospitalized with a history of chronic intermittent gastrointestinal bleeding. A tentative diagnosis of Meckels diverticulum was made, and Tc-99m pertechnetate scintigraphy demonstrated extensive uptake in the abdomen. At laparotomy, a 65-cm long jejunoileal tubular duplication was resected. Pathologic examination of the specimen revealed extensive gastric mucosal lining and hemorrhagic areas. In this report, the importance of Tc-99m pertechnetate scans for the diagnosis of jejunoileal duplication with heterotopic gastric mucosa is highlighted.