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Eosinophilic enterocolitis diagnosed by means of technetium-99m albumin scintigraphy and treated with budesonide (CIR).

A patient with a 15 year history of diarrhoea of unknown origin is described. Scintigraphy with technetium-99m labelled albumin suggested albumin loss at the terminal ileum and caecum; subsequent colonoscopic biopsies of these macroscopically normal looking areas showed abundant infiltration with eosinophils. A diagnosis of eosinophilic enterocolitis was made. Treatment with prednisolone had good results, but had to be stopped because of severe side effects. Oral cromoglycate and mesalazine were not effective. Budesonide (CIR), a new topically active corticosteroid with very little systemic effects, was at least as effective as prednisolone without producing side effects.

Adult↗

Quantification of inflammatory bowel disease activity using technetium-99m HMPAO labelled leucocyte single photon emission computerised tomography (SPECT).

Technetium-99m HMPAO labelled white cell bowel uptake was quantified in 23 patients with suspected colitis by means of the novel technique of single photon emission computerised tomography (SPECT) using a standard gamma-camera. Uptake in colon segments was quantified on transaxial images and expressed as a fraction of marrow uptake (SPECT score). Segmental histological disease activity was assessed at colonoscopy (20) or at surgery (3). Segmental histology score correlated with SPECT score r = 0.79 (p < 0.001). Overall SPECT score for all affected segments correlated with Crohn's disease activity index (CDAI) r = 0.66, p = 0.001 and with laboratory activity indices; erythrocyte sedimentation rate r = 0.44, p = 0.03, C reactive protein r = 0.38, p = 0.05, and albumin r = -0.46, p = 0.03. Small bowel SPECT score in 13 patients correlated with CDAI r = 0.65, p < 0.01 but not with erythrocyte sedimentation rate or C reactive protein. Five patients with positive small bowel white cell uptake had normal C reactive protein and erythrocyte sedimentation rate. Overall SPECT score for disease at all sites correlated with both CDAI and with laboratory indices of inflammation. 99mTc HMPAO SPECT provides non-invasive and accurate quantification of inflammatory bowel disease activity in both large and small bowel and may be useful in the objective evaluation of treatment for inflammatory bowel disease.

Adult↗

Quantitative assessment of overall inflammatory bowel disease activity using labelled leucocytes: a direct comparison between indium-111 and technetium-99m HMPAO methods.

The ideal imaging method in inflammatory bowel disease would reliably detect inflammation, identify the correct intestinal location, and assess the severity of the disease. The aim of this study was to compare scintigraphic methods of quantifying overall disease activity using both indium-111 (111In) and technetium-99M (99mTc) HMPAO labelled leucocyte scans. The four day faecal excretion of 111In was measured after 111In scintigraphy in 24 patients known to have inflammatory bowel disease. The same patients also underwent 99mTc HMPAO scanning. The scans were performed 10 days or less apart with no changes in treatment between scans. Bowel activity on the 99mTc HMPAO scans was assessed using a computer based method (scan score) and a visual grading method in a further 54 99mTc HMPAO. The results showed a close correlation between inflammatory activity defined by faecal 111In excretion and the scan score generated from the computer analysis of the 99mTc HMPAO image (Spearman rank correlation: rs = 0.78; p < 0.001). Accurate information to localise inflammatory activity could be obtained by simple visual assessment of both types of scan images, although image quality was superior with 99mTc HMPAO. Qualification of disease activity from 99mTc HMPAO images by visual grading was associated with a large variability, only 69% of scans had similar scores when graded by three observers. Computer generated image analysis was more reproducible. In conclusion, in inflammatory bowel disease 99mTc HMPAO scintigraphy and faecal 111In excretion correlated well. Either method can quantify and localise the inflammation. As 99mTc HMPAO scanning provides a quicker result, with a lower radiation dose, and avoids faecal collection, it may be the preferred method.

Adolescent↗

Dobutamine stress echocardiography versus quantitative technetium-99m sestamibi SPECT for detecting residual stenosis and multivessel disease after myocardial infarction.

OBJECTIVE: To compare the relative accuracy of dobutamine stress echocardiography (DSE) and quantitative technetium-99m sestamibi single photon emission computed tomography (mibi SPECT) for detecting infarct related artery stenosis and multivessel disease early after acute myocardial infarction. DESIGN: Prospective study. SETTING: University hospital. METHODS: 75 patients underwent simultaneous DSE and mibi SPECT at (mean (SD)) 5 (2) days after a first acute myocardial infarct. Quantitative coronary angiography was performed in all patients after imaging studies. RESULTS: Significant stenosis (> 50%) of the infarct related artery was detected in 69 patients. Residual ischaemia was identified by DSE in 55 patients and by quantitative mibi SPECT in 49. The sensitivity of DSE and mibi SPECT for detecting significant infarct related artery stenosis was 78% and 70%, respectively, with a specificity of 83% for both tests. The combination of DSE and mibi SPECT did not change the specificity (83%) but increased the sensitivity to 94%. Mibi SPECT was more sensitive than DSE for detecting mild stenosis (73% v 9%; p = 0.008). The sensitivity of DSE for detecting moderate or severe stenosis was greater than mibi SPECT (97% v 74%; p = 0.007). Wall motion abnormalities with DSE and transient perfusion defects with mibi SPECT outside the infarction zone were sensitive (80% v 67%; NS) and highly specific (95% v 93%; NS) for multivessel disease. CONCLUSIONS: DSE and mibi SPECT have equivalent accuracy for detecting residual infarct related artery stenosis of >/= 50% and multivessel disease early after acute myocardial infarction. DSE is more predictive of moderate or severe infarct related artery stenosis. Combined imaging only improves the detection of mild stenosis.

Adult↗

Assessment of infarcted myocardium with real time myocardial contrast echocardiography: comparison with technetium-99m sestamibi single photon emission computed tomography.

BACKGROUND: Little is known about the relation between the extent of microvascular damage and infarct size in patients after successful mechanical reperfusion of acute myocardial infarction. OBJECTIVE: To compare the spatial extent of reduced myocardial signal between real time myocardial contrast echocardiography (MCE) and single photon emission computed tomography (SPECT) after successful mechanical reperfusion of acute myocardial infarction and to test the hypothesis that MCE can be used for clinical infarct size assessment. METHODS: 10 days after successful mechanical reperfusion of acute myocardial infarction, 117 patients underwent MCE (power pulse inversion technique, slow contrast bolus injection) and SPECT (technetium-99m sestamibi). Location and number of segments with normal myocardial signal intensity and with mild and severe reduction were registered and the concordance between the techniques was calculated. RESULTS: Segmental concordance between MCE and SPECT was 83% (kappa = 0.64). On average, the difference in the number of segments with reduced myocardial signal intensity between MCE and SPECT did not exceed one segment (p < 0.001). Sensitivity and specificity of MCE for the detection of an abnormal segment on SPECT were 87% and 91%, respectively. Intraobserver and interobserver agreement were 94% (kappa = 0.84) and 92% (kappa = 0.83), respectively. CONCLUSIONS: Real time MCE is a promising technique for infarct size assessment after successful mechanical reperfusion of acute myocardial infarction.

Echocardiography↗

Clinical experience with technetium-99m stannous polyphosphate for myocardial imaging.

Myocardial imaging with technetium-99m stannous polyphosphate was performed on 46 patients. Eleven patients had no cardiac disease, 22 had acute myocardial infarction, and 13 had stable arteriosclerotic heart disease. Distinct patterns of myocardial activity were noted: (1) the patients with no obvious cardiac disease showed no cardiac activity; (2) stable arteriosclerotic heart disease showed faint, ill-defined cardiac activity, primarily in the anterior or inferior aspect of the left ventricle; (3) acute myocardial infarction showed intense, focal, well-defined activity, with a shape that characterized the location of the infarct.

Acute Disease↗

Assessment of diagnostic value of technetium-99m pyrophosphate myocardial scintigraphy in 80 patients with possible acute myocardial infarction.

The diagnostic value of technetium-99m-pyrophosphate (Tc-pyrophosphate) myocardial scintigraphy was determined in 80 consecutive patients who had been admitted to the coronary care unit in order to rule out an acute myocardial infarction. Scintigraphic findings obtained within 5 days of admission were correlated with the final cardiac diagnosis determined for each patient. Significant myocardial uptake of Tc-pyrophosphate (positive scans) occurred in 13 of 22 patients (59%) who had enzyme and/or electrocardiographic proven acute myocardial infarct: 3 out of 5 with transmural myocardial infarct, 9 of 16 with nontransmural myocardial infarct, and 1 patient with left bundle-branch block. Of 58 patients who showed no evidence of acute myocardial infarction, positive scans occurred in 14 of 33 patients who had unstable angina pectoris (42%), 0 of 6 who had congestive heart failure, 6 of 9 who had other acute cardiac syndromes, and in 0 of 10 who had noncardiac chest pain. In the patients with unstable angina pectoris positive scans could not be predicted on the basis of the history, electrocardiographic findings or the arteriographically determined severity of the coronary artery disease. Blood levels of Tc-99m activity measured in 21 cardiac patients and in 6 volunteers did not correlate with the uptake intensity of Tc-pyrophosphate. These findings suggest caution in the use of this imaging method for the diagnosis of acute myocardial infarct in patients admitted with 'rule out myocardial infarction'.

Acute Disease↗

Technetium-99m stannous pyrophosphate scintigraphy in patients with calcification within the cardiac silhouette.

Technetium-99m stannous pyrophosphate scintiscanning was performed in 22 patients with radiographically detected calcification within the cardiac silhouette. All but one of these scintigrams showed a localised area of increased activity similar to that ordinarily seen in acute myocardial infarction. Scintiscans in 3 patients after removal of the calcified aortic valve reverted to negative. It was concluded that this technique for acute infarct detection may yield false positive results in the presence of cardiac calcification.

Calcinosis↗

Advantages of technetium pyrophosphate scintigraphy over plasma enzyme analysis in estimation of anterior myocardial infarct size.

Infarct size was estimated by cumulative creatine kinase MB isoenzyme (CKMB-r) release and by technetium 99m stannous pyrophosphate (TcPYP) scintigraphy in 27 patients with acute anterior myocardial infarction. In eight patients, scintigraphy showed a central area of reduced tracer uptake surrounded by a peripheral rim of increased TcPYP accumulation ("doughnut" pattern). This appearance occurred only in large infarcts and the maximal scintigraphic area (51.3 +/- 2.8 cm2, mean +/- SEM) in this group was significantly greater than that in the remainder (28.1 +/- 2.5 cm2). Correlation between CKMB-r and maximal scintigraphic infarct area was moderate in the whole group. Exclusion of patients, however, with "doughnut" scintigrams in which correlation was very poor, resulted in substantial improvement in the remainder. It is suggested that in the central regions of large "doughnut" infarcts, reduced blood flow hinders the efflux of CKMB from the centre causing an underestimate of infarct size. Pyrophosphate scintigraphy appears to be more accurate than CKMB release in measuring the size of these large anterior infarcts.

Adult↗

Additive effects of exposure to silica dust and smoking on pulmonary epithelial permeability: a radioaerosol study with technetium-99m labelled DTPA.

BACKGROUND: Increased pulmonary epithelial permeability evaluated by the rate of clearance from lung to blood of the radioaerosol solute technetium-99m labelled diethylenetriamine pentaacetate (99mTc-DTPA) has been reported in smokers and in workers exposed to silica dust. A study was carried out to determine whether there are additive effects of cigarette smoke and exposure to silica dust on clearance rates of 99mTc-DTPA in ceramic workers. METHODS: Thirty one subjects with silicosis were studied, of whom 18 smoked cigarettes and 13 were non-smokers. They had similar histories of exposure to silica dust, and radiological alterations consistent with silicosis. The results from these patients were compared with those from normal subjects and smokers previously studied by the authors. RESULTS: Pulmonary function values were normal in most patients and not significantly different among groups. The median (range) rate of clearance of 99mTc-DTPA in smokers with silicosis was 4.1 (1.9-12.7) %/minute, which was higher than the rates in non-smoking patients with silicosis of 2.2 (1.1-6.6) %/minute and in smokers without exposure to silica dust of 2.9 (1.6-4.5) %/minute. These differences were more evident and significant when the clearance rates of the lower lobes of the three groups were compared. Clearance rates higher than 3%/minute were much more frequent in smokers with silicosis (85%) than in non-smoking patients with silicosis (15%) and in smokers (40%). CONCLUSION: In ceramic workers with radiographic changes resulting from exposure to silica dust, there is an additive effect of inhalation of silica dust and cigarette smoking on clearance rates of 99mTc-DTPA.

Adult↗

Technetium-99m pyridoxylideneglutamate (P.G.) cholescintigraphy.

Technetium-99m P.G. cholescintigraphy was performed in 27 human volunteers and 81 patients referred for hepatobiliary tract disease. The gallbladder, biliary system, and gastrointestinal tract were well visualized in the normal patients and volunteers. The gallbladder was not visualized in 22 patients with histologically proved cholecystitis with cystic duct obstruction. Nine patients with complet extrahepatic obstruction of the common bile duct were correctly diagnosed. Hepatocellular disease and incomplete obstruction, with and without jaundice, were diagnosed with this technique. Oral cholecystography is superior to this method for the detection of cholelithiasis in nonjaundiced patients.

Biliary Tract Diseases↗

Scintigraphic diagnosis of ischemic intestine with technetium-99m sulfur colloid-labeled leukocytes.

Positive scintigrams were obtained in 13 of 15 dogs injected with technetium-99m sulfur colloid-labeled leukocytes following the experimental production of intestinal ischemia. The radioactivity of the ischemic intestines averaged 5.9 times that found in normal control segments of intestine from the same animal. Labeled leukocytes may be used as a rapid noninvasive technique for the early identification of ischemic intestine.

Animals↗

Thallium-201 imaging artifacts not detected by technetium-99m or cobalt-57 quality-control testing.

Early stages of hydration in a sodium iodide crystal may cause artifactual "hot" spots on thallium-201 heart images. This phenomenon was observed when a mobile gamma camera was used even though the daily quality-control flood-field views revealed no apparent abnormalities. Nevertheless, hot spots were visible on thallium-201 and xenon-133 flood-field images. With asymmetric photopeak positioning using a technetium-99m source, hot spots were noted in addition to phototube nonuniformities. Subsequently, the camera head was disassembled, the crystal was inspected visually, and the crystal seal was found to be broken. Hydration of the crystal was confirmed by the camera manufacturer. Quality-control procedures should test for hydration-induced artifacts on a regular basis.

Animals↗

Artifacts in iodine-131 renal images due to coincidence summing of technetium-99m photons.

Technetium-99m gamma camera images of kidneys produced with an iodine-131 energy window showed "ghosts" over and between the kidneys and between the kidneys and the bladder. The cause was coincidence summing at 281 keV due to a high 99mTc counting rate. In older model cameras careful peaking with a proper energy window reduces this effect; more recently developed cameras with pileup rejection circuits do not have this problem.

Humans↗

Work in progress. Gastrointestinal ulcerations: detection using a technetium-99m-labeled ulcer-avid agent.

Technetium-99m-labeled sucralfate, an ulcer-avid material, was shown in preliminary animal and human studies to be stable in vivo with good sensitivity. Eight experimentally produced discrete gastric ulcers in three rabbits were visualized using this material. Of seven human studies, four studies were true-positive and three were true-negative. It is suggested that Tc-99m-labeled sucralfate may prove to have significant clinical advantages for the evaluation of gastrointestinal ulcer disease and other diseases that are associated with loss of mucosal integrity. The method for labeling sucralfate with Tc-99m was developed by the authors.

Aluminum↗

Hyperparathyroidism in high-risk surgical patients: evaluation with double-phase technetium-99m sestamibi imaging.

PURPOSE: To evaluate the accuracy of technetium-99m sestamibi as a single agent in the detection and localization of hyperfunctioning parathyroid tissue in patients who underwent prior neck exploration or who otherwise are high surgical risks. MATERIALS AND METHODS: Thirty-nine patients with hyperparathyroidism underwent 40 double-phase Tc-99m sestamibi studies. Histopathologic correlation was obtained for all studies. RESULTS: Thirty patients had solitary adenomas, and nine had hyperplastic glands. One developed recurrent hypercalcemia after five-gland resection and underwent repeat imaging and operation. Double-phase sestamibi imaging prospectively enabled localization of 46 (77%) of 60 abnormal glands. Twenty-eight (93%) of 30 adenomas were correctly localized, whereas 18 (60%) of 30 hyperplastic glands were localized. The overall specificity of the study was 98% with one false-positive study. Gland weight and vascularity were statistically significant predictors of uptake of sestamibi. CONCLUSION: Double-phase Tc-99m sestamibi imaging is a promising technique for localization of parathyroid adenomas in high-risk surgical patients. Localization of multiple hyperplastic glands remains a challenge.

Adenoma↗

Combined labeled leukocyte and technetium 99m sulfur colloid bone marrow imaging for diagnosing musculoskeletal infection.

The use of labeled leukocyte (white blood cell [WBC]) studies in the diagnosis of osteomyelitis can be problematic. A combined study consisting of WBC imaging and complementary bone marrow imaging performed with technetium 99m (99mTc) sulfur colloid is approximately 90% accurate and is especially useful for diagnosing osteomyelitis in situations involving altered marrow distribution. There are limitations and pitfalls associated with a combined study. If there is no labeled WBC activity in the region of interest, marrow imaging is not useful. The sulfur colloid image becomes photopenic within about 1 week after the onset of infection, so that the study should be interpreted cautiously in the acute setting. Labeled WBC accumulation in lymph nodes can also confound image interpretation, although nodal activity can usually be recognized because it is typically round, discrete, multifocal, linear in distribution, and often bilateral. Furthermore, 99mTc-sulfur colloid that is improperly prepared or is more than about 2 hours old degrades image quality, potentially causing erroneous conclusions. Nevertheless, WBC-marrow imaging is a very accurate technique for diagnosing osteomyelitis. Knowledge of the criteria for image interpretation and of the aforementioned limitations and pitfalls, combined with careful attention to imaging technique, will maximize the value of this study.

Humans↗

Does technetium-99m diethylenetriaminepentaacetate clearance predict the clinical course of idiopathic pulmonary fibrosis?

Clearance of inhaled technetium-99m diethylenetriaminepentaacetate (99mTc-DTPA) is a potential indicator of disease activity and progression in idiopathic pulmonary fibrosis (IPF). The objective of the present study was to evaluate the prognostic value of 99mTc-DTPA scans in IPF. A total of 22 patients (18 males), aged 33 to 80 years with IPF were followed for six to 20 months (mean 13 months). At diagnosis, high resolution computed tomography (HRCT) scans showed a honeycomb pattern with bibasilar reticular opacities in all cases. At T0 (diagnosis) and T1 (follow-up), each patient had pulmonary function tests (forced vital capacity, diffusing capacity of the lung for carbon monoxide and partial arterial O2 pressure), extension of fibrosis evaluated by HRCT visual score and 99mTc-DTPA lung clearance. Results at T0 and T1 were compared, taking into account the whole population and patients with relatively fast and slow 99mTc-DTPA wash-out. 99mTc-DTPA clearance did not show any significant correlation with functional tests or HRCT score. These findings indicate that clearance of inhaled 99mTc-DTPA is not of value in following the progress of IPF.

Administration, Inhalation↗