Darlene Fink-Bennett

The Sensitivity of Renal Scintigraphy and Sonography in Detecting Nonobstructive Acute Pyelonephritis

Recently it has been demonstrated that any child with proved acute pyelonephritis may be at risk for parenchymal scarring, whether or not reflux is present. Since cortical renal scintigraphy has been shown to detect accurately renal inflammation, we compared cortical scintigraphy with renal sonography in 46 children with documented acute pyelonephritis to determine which modality is best to detect patients at risk for renal injury. Cortical scintigraphy was abnormal in 36 children (78%) and renal ultrasonography was abnormal in 5 (11%). Reflux was demonstrated in only 20 cases (43%). We conclude that cortical scintigraphy is the preferred imaging technique for diagnosing renal inflammation, and it should be used routinely in every child with suspected acute pyelonephritis. A new imaging protocol is proposed.

Suspected acute cholecystitis. Comparison of hepatobiliary scintigraphy versus ultrasonography

One hundred ninety-fine patients with suspected acute cholecystitis (AC) underwent both hepatobiliary scintigraphy (HBS) and static gray-scale ultrasonography (US) to assess the relative value of each imaging modality in this clinical setting. HBS was performed after the intravenous injection of 5 mCi Tc-99m iprofenin. Abnormal HBS indicative of AC visualized the common bile duct, but not the gallbladder, within 1 to 4 hours after tracer administration. Abnormal US indicative of AC demonstrated cholelithiasis and/or gallbladder wall edema. In this series, HBS surpassed US in sensitivity (98.3% versus 81.4%), specificity (90.2% versus 60.2%), predictive value of an abnormal test (91.4% versus 51.6%), and predictive value of a normal test (100% versus 92%), HBS should be the procedure of choice for the rapid detection of AC.

Indium-111 OncoScint CR/OV and F-18 FDG in colorectal and ovarian carcinoma recurrences. Early observations.

lndlum-111 satumomab pendetide (ln-111 OncoScint) planar and SPECT imaging and F-18 FDG positron emission tomography (PET) have been found individually to be helpful in the detection of recurrent colorectal and ovarian cancer, but have not been compared. Twelve patients who were examined for recurrent colorectal or ovarian carcinoma underwent both ln-111 OncoScint imaging and F-18 FDG PET imaging. All had normal or equivocal results of CT or MR studies. Tumor detection abilities were similar in most cases. However, Oncoscint demonstrated an advantage in the detection of carcinomatosls. PET demonstrated an advantage in detecting focal tumor recurrence in one case and, not unexpectedly, In detecting liver metastases. All positive nuclear studies for tumor were found to be true-positives at pathology (7 patients), or by diagnostic new CT changes (1 patient). Finally, unreported, bone marrow, bowel, and colostomy sites appear to be normal sites of localization of F-18 FDG 1 hour after injection.

Patterns of abnormal FDG uptake by various histological types of non-small cell lung cancer at initial staging by PET

Abstract. The aim of this study was to identify useful patterns of abnormal fluorine-18 fluorodeoxyglucose (FDG) uptake by different types of non-small cell (NSC) lung cancer and to assess their clinical implications. One hundred and three sequential patients with newly diagnosed, pathology-proven NSC lung cancer were included. FDG positron emission tomography (PET) images were acquired using a dedicated PET scanner. There were 35 squamous cell carcinomas (SQC), 17 large cell cancers (LGC), 38 adenocarcinomas (ADC), 1 bronchioloalveolar carcinoma (BAC) and 12 non-classified NSC cancers. PET images were categorized into detectable patterns of necrotic center in the primary tumor, satellite lesions (T4), hilar lymph nodes (N1), and N2, N3, and M1 lesions by visual interpretation of PET images for SQC, LGC, and ADC (n=90; BAC and non-classified NSC cancers were excluded). The PET lesions were correlated with surgical pathology and with CT findings in inoperable cases. Necrosis was more commonly present in the primary tumors of LGC (53%) and SQC (43%) than in those of ADC (26%) (P<0.0001 and <0.01, respectively). The frequencies of nodal uptake in ADC, SQC and LGC were similar (71%, 60%, and 59%, respectively). However, M1 lesions were present significantly more often in LGC (41%) and ADC (34%) than in SQC (3%) (both P<0.0001). Significantly more surgically inoperable cases were found by PET (T4, N3, M1) in ADC (50%) and LGC (41%) than in SQC (26%) (P<0.001 and <0.02, respectively). Our results suggest a wide variation of PET findings for different types of NSC lung cancer. Identification of these patterns is useful in clinical PET interpretation, in that knowledge of the most probable association between the PET patterns and the histological types will facilitate initial staging and planning of management.

Correlating metabolic and anatomic responses of primary lung cancers to radiotherapy by combined F-18 FDG PET-CT imaging

BackgroundTo correlate the metabolic changes with size changes for tumor response by concomitant PET-CT evaluation of lung cancers after radiotherapy.Methods36 patients were studied pre- and post-radiotherapy with18FDG PET-CT scans at a median interval of 71 days. All of the patients were followed clinically and radiographically after a mean period of 342 days for assessment of local control or failure rates. Change in size (sum of maximum orthogonal diameters) was correlated with that of maximum standard uptake value (SUV) of the primary lung cancer before and after conventional radiotherapy.ResultsThere was a significant reduction in both SUV and size of the primary cancer after radiotherapy (p < 0.00005). Among the 20 surviving patients, the sensitivity, specificity, and accuracy using PET (SUV) were 94%, 50%, 90% respectively and the corresponding values using and CT (size criteria) were 67%, 50%, and 65% respectively. The metabolic change (SUV) was highly correlated with the change in size by a quadratic function. In addition, the mean percentage metabolic change was significantly larger than that of size change (62.3 ± 32.7% vs 47.1 ± 26.1% respectively, p = 0.03)ConclusionCorrelating and incorporating metabolic change by PET into size change by concomitant CT is more sensitive in assessing therapeutic response than CT alone.

Augmented cholescintigraphy: Its role in detecting acute and chronic disorders of the hepatobiliary tree

Cholecystagogue cholescintigraphy can be employed as a means of (1) confirming the surgeons and/or gastroenterologists clinical impression of symptomatic chronic acalculous biliary disease, (2) better understanding the pathophysiology of gallbladder disease, (3) preparing patients for hepatobiliary scintigraphy who have fasted for longer than 24-48 hours and who are suspected of acute cholecystitis, and (4) reducing the time required to confirm the clinical impression of acute cholecystitis. Morphine-augmented cholescintigraphy is also used to decrease the time required to determine cystic duct patency. Phenobarbital-augmented cholescintigraphy is used as a means of increasing the accuracy of hepatobiliary scintigraphy in differentiating neonatal hepatitis from biliary atresia. Nonpharmacological interventions and augmentations have been employed to maintain the high degree of accuracy of cholescintigraphy in confirming the clinical impression of acute cholecystitis. The efficacy of these modalities in detecting acute and chronic disorders of the hepatobiliary tree as well as how and why they are performed comprise the contents of this article.

A statistical investigation of normal regional intra-subject heterogeneity of brain metabolism and perfusion by F-18 FDG and O-15 H2O PET imaging

BackgroundThe definite evaluation of the regional cerebral heterogeneity using perfusion and metabolism by a single modality of PET imaging has not been well addressed. Thus a statistical analysis of voxel variables from identical brain regions on metabolic and perfusion PET images was carried out to determine characteristics of the regional heterogeneity of F-18 FDG and O-15 H2O cerebral uptake in normal subjects.MethodsFourteen normal subjects with normal CT and/or MRI and physical examination including MMSE were scanned by both F-18 FDG and O-15 H2O PET within same day with head-holder and facemask. The images were co-registered and each individual voxel counts (Q) were normalized by the gloabl maximal voxel counts (M) as R = Q/M. The voxel counts were also converted to z-score map by z = (Q - mean)/SD. Twelve pairs of ROIs (24 total) were systematically placed on the z-score map at cortical locations 15-degree apart and identically for metabolism and perfusion. Inter- and intra-subject correlation coefficients (r) were computed, both globally and hemispherically, from metabolism and perfusion: between regions for the same tracer and between tracers for the same region. Moments of means and histograms were computed globally along with asymmetric indices as their hemispherical differences.ResultsStatistical investigations verified with data showed that, for a given scan, correlation analyses are expectedly alike regardless of variables (Q, R, z) used. The varieties of correlation (rs) of normal subjects, showing symmetry, were mostly around 0.8 and with coefficient of variations near 10%. Analyses of histograms showed non-Gaussian behavior (skew = -0.3 and kurtosis = 0.4) of metabolism on average, in contrast to near Gaussian perfusion.ConclusionThe co-registered cerebral metabolism and perfusion z maps demonstrated regional heterogeneity but with attractively low coefficient of variations in the correlation markers.

Detection of heterotopic gastric mucosa in the upper esophagus with 99mTc-pertechnetate scintigraphy

Five patients with patches of gastric fundal type columnar epithelium in the proximal esophagus at the level of the upper esophageal sphincter diagnosed by upper endoscopy underwent 99mTc-pertechnetate scintigraphy (TcO4-). In all instances, the patches contained both chief cells and mucus-secreting cells. One patient had dysphagia localized to the area of columnar epithelium. Two cases of heterotopic gastric mucosa in the upper esophagus (HGM-UE) were demonstrated by TcO4-. In both, thyroid uptake was absent due to complete suppression of thyroid function by thyroid hormone supplements. TcO4- accumulated in thyroid glands of the other three patients, causing overlapping activity between the thyroid gland and HGM-UE. TcO4- scintigraphy is suitable for the detection of HGM-UE only in those patients who have had a total thyroidectomy or are on suppressive thyroid therapy.

Bile ascites in adults. Diagnosis using hepatobiliary scintigraphy and paracentesis.

Hepatobiliary scintigraphy has been recognized as a useful diagnostic tool in detecting the presence and site of bile leaks. The authors report a case of bile ascites secondary to a postsurgical biliary leak, the scintigraphic findings in bile ascites, and the potential use of paracentesis, in combination with hepatobiliary scintigraphy, in confirming the presence of bile ascites and a bile leak.

Granulomatous disease: is it a nuisance or an asset during PET/computed tomography evaluation of lung cancers?

ObjectivesTo evaluate combined PET-computed tomography (CT) criteria for differentiating between granulomatous disease (GD) and malignancy (CA) in oncologic PET–CT studies. MethodsSixty-two patients who were referred for fluoro-2-deoxyglucose (FDG) PET–CT evaluation of pulmonary lesion(s) without a history of concurrent infection were studied. PET–CT was performed 1.5 h after intravenous administration of 555 MBq 18F-FDG in the fasting state with oral contrast. Combined PET–CT criteria including (i) calcifications (Ca2+) within lymph nodes, (ii) Ca2+ in lung nodules, (iii) liver and/or spleen Ca2+, (iv) locations of lung lesion(s), (v) hilar FDG uptake, (vi) comparison of lung versus maximum mediastinal FDG uptake, (vii) lymph node uptake not in the most probable lymphatic drainage pathway from a particular lung lesion, and (viii) extra pulmonary abnormal FDG uptake were each assigned a numerical score (0–3) with progressively higher score and sum of scores toward the increasing likelihood of GD. These patients either had pathological confirmation by biopsy/resection or were followed radiographically for a period of 2 years (CA=13; GD=49). Discriminant analysis was performed on all the above criteria with this gold standard. Simple t-test and box plot analysis were also performed on the summation of the scores (from 0 in CA to 13 in GD). ResultsWhen all eight criteria were entered into discriminant analysis, the combined PET–CT criteria classified correctly 71% of patients with a sensitivity of 65% and specificity of 92% for GD. The most significant discriminating criterion was FDG uptake in the lung lesion(s) less than maximum mediastinal uptake (P=0.01). The sum scores in GD and CA were significantly different (4.9±2.4 vs. 3.2±1.5, respectively, P=0.014). Box plots showed a clear separation at a cut-off value of around 3.5. ConclusionResults show that the set of combined PET–CT criteria are highly specific for GD, which is not necessarily a nuisance during oncologic evaluation. Knowledge of these criteria may attribute some of the abnormal PET findings to GD, which is a useful asset for quick recognition and clinical interpretation.