Nuclear magnetic resonance imaging of liver hemangiomas

Nine patients with cavernous hemangioma of the liver were examined by nuclear magnetic resonance imaging (MRI) with a 0.5 T superconductive magnet. Spin-echo technique was used with varying time to echo (TE) and repetition times (TR). Results were compared with 99mTc red blood cell (RBC) scintigraphy, computed tomography (CT), echography, and arteriography. Four illustrated cases are reported. It was possible to establish a pattern for MRI characteristics of cavernous hemangiomas; rounded or smooth lobulated shape, marked increase in T1 and T2 values as compared with normal liver values. It is concluded that, although more experience is necessary to compare the specificity with that of ultrasound and CT, MRI proved to be very sensitive for the diagnosis of liver hemangioma, especially in the case of small ones which may be missed by 99mTc-labeled RBC scintigraphy.     

Pathology results in [18F]fluorodeoxyglucose positron emission tomography of the thyroid gland

The aim of this retrospective study was to evaluate pathologically increased uptake of [18F]fluorodeoxyglucose (18F-FDG) in positron emission tomography (PET) results of the thyroid gland. Results of 18F-FDG PET and [99mTc]pertechnetate scintigraphy of the thyroid gland are shown, compared to each other and discussed. In a retrospective study 16 patients underwent whole-body 18F-FDG PET and [99mTc]pertechnetate scintigraphy of the thyroid gland within 3 weeks. In addition, an examination of the thyroid gland by using ultrasound and laboratory tests was carried out. The 18F-FDG PET studies were carried out on a dedicated whole-ring PET scanner. Eight patients had a pathological FDG uptake in the thyroid and a cold nodule in [99mTc]pertechnetate scintigraphy of the thyroid gland (in 7/8 cases histology showed malignancy). Five patients had an inhomogeneous FDG uptake in the thyroid gland and were suspected of thyroiditis in 18F-FDG PET (in 3/5 cases thyroiditis was confirmed). Three patients had an especially low FDG uptake compared to normal physiological FDG uptake (no malignancy). Results from studies using 18F-FDG represent a growing body of evidence showing the differentiation between malignant and benign disease: we saw many pathological results in the thyroid gland. High uptake of 18F-FDG in the thyroid gland suggests possible malignancy. Thyroiditis can only be suspected based upon the results of 18F-FDG PET. We conclude that 18F-FDG PET has a potential clinical impact for detecting possible malignant lesions of the thyroid gland, but further studies, in which a higher number of patients are evaluated, are necessary.     

Active inflammatory bowel disease: head-to-head comparison between 99mTc-hexamethylpropylene amine oxime white blood cells and 99mTc(V)-dimercaptosuccinic acid scintigraphy

PURPOSE: Evaluation and comparison between pentavalent 99mTc dimercaptosuccinic acid (99mTc(V)-DMSA) and 99mTc-hexamethylpropylene amine oxime white blood cell (99mTc-HMPAO WBC) scintigraphy in the detection and assessment of disease activity in patients with active inflammatory bowel disease (IBD). MATERIALS AND METHODS: 99mTc(V)-DMSA scintigraphy was performed in 23 patients with active IBD and true positive 99mTc-HMPAO WBC scintigraphy. Images were considered positive when an area of increased uptake was observed. To assess severity of IBD, semi-quantitative analysis was included with reference to the uptake in the iliac crest. Comparison with endoscopic, radiological and clinical data was performed. RESULTS: The diagnostic accuracy of 99mTc-HMPAO WBC and 99mTc(V)-DMSA was 91% and 84%, respectively. A significant correlation between the findings of both radioisotopic methods and scintigraphy score was demonstrated. Endoscopic findings were significantly correlated with scintigraphic results. Kappa statistics showed a moderate to good agreement between the two scintigraphic methods. Two patients (8.8%) had negative findings with 99mTc(V)-DMSA scintigraphy (false negative results). CONCLUSION: 99mTc(V)-DMSA compared to 99mTc-HMPAO WBC could provide a simple, non-invasive alternative method for the assessment of disease activity, although it is slightly inferior to 99mTc-HMPAO WBC scintigraphy especially in the evaluation of disease localization in IBD patients.     

Detection of orchitis and sacroiliitis due to brucellosis by 99mTc polyclonal human immunoglobulin scintigraphy

Here, we report 1 case of Brucella orchitis detected by 99mTc human immunoglobulin scintigraphy and confirmed by testicular ultrasound. A 29-year-old farmer was admitted to our hospital with fever, fatigue, arthralgia, and painful scrotal swelling that had appeared 12 days before admission. Clinically, right sacroiliitis was recorded through the Fabere test Unilateral sacroiliitis and orchitis were detected by 99mTc human immunoglobulin scintigraphy. Hypoechoic left testicular lesions and swelling of the concurrent epididymis were seen on a testicular ultrasound examination. Wright agglutination test and blood specimen culture for Brucella species were positive.     

The clinical utility of nuclear medicine imaging for the detection of occult gastrointestinal haemorrhage

Acute gastrointestinal bleeding is often intermittent and the bleeding source may be difficult to locate, resulting in delay of potentially life-saving treatment. The aim of this study was to determine the clinical utility of 99mTc labelled red blood cell imaging and [99mTc]pertechnetate (Meckel's scan) imaging in a series of 137 patients admitted over a 5 year period to hospital for management of acute gastrointestinal bleeding. Of the 137 patients, 70 had positive 99mTc red blood cell studies. Eleven of 24 patients who had imaging performed beyond 3 h had positive scans that would otherwise have been missed. Only 47 patients had a definite final diagnosis at the time of hospital discharge, of which six were negative on 99mTc red blood cell imaging. The correct site of bleeding was localized in seven of 21 patients with foregut bleeding, and 15 of 20 patients with colonic bleeding. Endoscopy yielded a diagnosis in 13 of the 47 patients (28%). Eleven patients had Meckel's scans but all were negative. Angiography was diagnostic in one of 17 patients studied. 99mTc red blood cell imaging is a useful test in the management of acute gastrointestinal bleeding. Imaging beyond 3 h may further improve the bleeding detection rate. This test, however, may be an unreliable means of localization of bleeding, particularly in the foregut.     

Dual isotope scintigraphy in stroke patients

Summary Platelet scintigraphy is a useful technique to detect atherosclerotic lesions of the neck vessels in stroke patients. The habitual one isotope technique causes false positive and false negative results due to circulating platelet-bound activity. To eliminate these confusing results we performed a dual isotope technique on 20 stroke patients. The new method consists of simultaneous injections of 111-Indium labelled blood platelets and 99mTc labelled red cells, and achieves a calculation of the ratio 111-In/ 99mTc. Thus the subtraction of the red cell blood flow image can render a pure thrombus formation visible. The habitual visually evaluated one isotope scintigraphy showed positive scans in 11 out of 20 patients, whereas under dual isotope scintigraphy 3 patients showed no 111-Indium excess after subtraction of the red cell image; they can thus be qualified as false positive. In the case of another patient with a visually negative image a thrombus formation could be observed after the subtraction procedure. It seems, that the dual isotope technique in platelet scintigraphy is a valuable refinement on the way to verifiable results.Presented in parts at the 3rd International Austrian Atherosclerosis Conference, 6 April 1983, Vienna, Austria     

^99mTc（V）—DMSA骨显像诊断骨转移瘤的临床价值

目的：评价99mTc（V）－DMSA显像在骨转移瘤诊断中的意义。材料和方法：对91例疑骨转移瘤患者行99mTc（V）DMSA全身显像，并与99mTc-MDP全身骨显像及其它检查对比。结果：74例证实存在骨转移瘤者，99mTc．MDP骨显像均显示异常放射性浓聚，99mTc（V）-DMSA显像72例显示了与99mTc-MDP显像某些相同部位的放射性浓聚，2例99mTc（V）DMSA显像阴性。17例骨良性病变，99mTc－MDP骨显像显示轻度异常放射性浓聚，而99mTc（V）-DMSA显像却未见异常的放射性浓聚。结论：99mTc（V）－DMSA诊断骨转移瘤的特异性比99mTc-MDP骨显像高，在骨良恶性肿瘤鉴别诊断中具有重要的临床价值。     

Technetium-99m-labelled red blood cell imaging in the diagnosis of hepatic haemangiomas: the role of SPECT/CT with a hybrid camera

Delayed liver single-photon emission computed tomography (SPECT) after ^99mTc red blood cell (RBC) labelling is helpful in detecting hepatic haemangiomas; however, diagnosis can be difficult when lesions are situated adjacent to structures like the inferior vena cava, the heart or hepatic vessels, where blood activity persists. The aims of this study were to evaluate the usefulness of RBC SPECT and transmission computed tomography (RBC SPECT/CT) performed simultaneously with a hybrid imaging system for correct characterisation of hepatic lesions in patients with suspected haemangioma, and to assess the additional value of fused images compared with SPECT alone. Twelve patients with 24 liver lesions were studied. The acquisitions of both anatomical (CT) and functional (SPECT) data were performed during a single session. SPECT images were first interpreted alone and then re-evaluated after adding the transmission anatomical maps. Image fusion was successful in all patients, with perfect correspondence between SPECT and CT data, allowing the precise anatomical localisation of sites of increased blood pool activity. SPECT/CT had a significant impact on results in four patients (33.3%) with four lesions defined as indeterminate on SPECT images, accurately characterising the hot spot foci located near vascular structures. In conclusion, RBC SPECT/CT imaging using this hybrid SPECT/CT system is feasible and useful in the identification or exclusion of suspected hepatic haemangiomas located near regions with high vascular activity.     

Cardiac blood-pool scintigraphy using technetium-99m DTPA-HSA: comparison with in vivo technetium-99m RBC labeling

We performed cardiac blood-pool scintigraphy using technetium-99m diethylenetriaminepentaacetic acid human serum albumin [( 99mTc] DTPA-HSA), a newly developed blood-pool agent, in 31 patients with various heart diseases and evaluated its clinical usefulness in comparison with the conventional in vivo 99mTc red blood cell (RBC) labeling. Excellent cardiac blood-pool images were obtained by [99mTc]DTPA-HSA method. Biodistribution studies showed higher accumulation of [99mTc]DTPA-HSA than that of 99mTc RBC in the lungs and liver, but similar count ratios of the cardiovascular blood pool to whole body between the two methods. In ECG-gated end-diastolic images, no quantitatively significant difference was observed in left ventricular target-to-background ratios between these two methods. Left ventricular ejection fraction (LVEF) calculated by [99mTc]DTPA-HSA MUGA method was correlated well with that by contrast LVEF (r = 0.91). No side effects were observed in any patient. In conclusion, cardiac blood-pool scintigraphy using [99mTc] DTPA-HSA is readily performed by single i.v. injection and useful for the assessment of cardiac function.     

Simultaneous 99mTc double labelling of the hepatic reticuloendothelial system and of the red blood cells: a simplified method for the detection of liver hemangiomas

Sonographic images of liver hemangioma are not specific. Causal detection imposes further investigations (angiography, CT, NMR) which are not always practicable. 99mTc-red blood cells study after 99mTc colloid liver scintigraphy has been already proposed. Ten patients with hepatic hemangiomas were evaluated by simplified, simultaneous in vivo double labelling of the reticuloendothelial system and red blood cells by means of successive i.v. injections of SnCl2, 99mTc colloid albumin and 99mTc-pertechnetate. Focal colloid defects filled with the labelled RBC were revealed in 9/10 liver hemangiomas. Angioscintigraphy showed decreased perfusion and RBC scintigraphy an increased blood volume in the focal colloid defects due to the hemangiomas.     

Tracers for aerosol ventilation scintigraphy: Tc-99m versus In-113m

113mIn has been proposed as a suitable tracer for aerosol ventilation scintigraphy in combination with 99mTc pulmonary perfusion scintigraphy. The high energy (393 keV) of 113mIn allows it to be detected in the presence of 99mTc, but degrades the spatial resolution which can be achieved. We have compared the resolution obtained with 99mTc and 113mIn in phantom experiments and in aerosol ventilation scans in 14 patients with airways disease. The resolution at the distances from the collimator encountered in lung scintigraphy was 10-20 mm for 99mTc and 15-40 mm for 113mIn. Aerosol ventilation images were abnormal in all patients. The 99mTc images showed peripheral defects and frequently central hot spots reflecting increased local aerosol deposition. In the 113mIn images, the lower resolution had a smoothing effect, the central hot spots were less striking, and the distribution of activity appeared more uniform, some detail was lost in the periphery. It is suggested that 113mIn is useful for ventilation scintigraphy in the diagnosis of pulmonary embolism, but that 99mTc is the tracer of choice if aerosol ventilation scintigraphy is used to study airways disease.     

In vitro labeling of human polymorphonuclear leukocytes with 99mTc

Preliminary experience with 99mTc labeling of isolated polymorphonuclear leukocytes is reported. Leukocytes efficiently purified from 100 ml peripheral blood were labeled in vitro with 99mTc after pretreatment with small amounts of a stannous agent to reduce pertechnetate. A labeling yield of 1.3 mCi equivalent to 12.5% of the added dose of 99mTc and a cell binding efficiency of more than 90% was achieved under sterile conditions. Viability assays showed no influence of the labeling procedure on cell function. The technique may prove a valuable alternative for assessment of local leukocyte accumulation by scintigraphy.     

Imaging techniques for evaluation of postoperative orthopedic infections.

Labeled leukocyte scintigraphy is the preferred imaging technique for the evaluation of suspected postoperative orthopedic infections. Labeled leukocyte localization returns to a normal pattern faster than MRI after bone trauma, surgical procedures, and treatment of osteomyelitis. 99mTc HMPAO labeled leukocyte scintigraphy is useful, particularly in children, because less peripheral blood volume is required for labeling. However, delayed 16-20 hour imaging is usually needed to detect low-grade osteomyelitis, and 111In WBC usually provides better images in adults. Combined 111In WBC/99mTc sulfur colloid marrow images improve the specificity for detection of osteomyelitis in regions containing active bone marrow. Simultaneous 111In leukocyte/99mTc bone SPECT imaging is usually necessary in regions such as the skull, spine, and hips, where there is overlapping bone, and soft tissues.     

Use of 99mTc (V) DMSA scintigraphy in the detection and localization of intestinal inflammation: comparison of findings and colonoscopy and biopsy

PURPOSE: To evaluate the potential use of technetium 99m (99mTc) (V) dimercaptosuccinic acid (DMSA) scintigraphy in the detection and localization of intestinal inflammation. MATERIALS AND METHODS: In a prospective study, 62 patients who were suspected of having intestinal inflammation and 30 control subjects were enrolled. All patients underwent 99mTc (V) DMSA scintigraphy and colonoscopy with biopsy within 1 week. 99mTc (V) DMSA scintigrams were interpreted blindly with respect to clinical information, and radiotracer uptake in the bowel segments was graded. The findings were then compared with the results of the colonoscopy and colonoscopic biopsy. RESULTS: In the detection of intestinal inflammation, findings at 99mTc (V) DMSA scintigraphy were as follows: true-positive in 55, false-positive in two, true-negative in 32, and false-negative in three. Overall sensitivity was 95%; overall specificity, 94%; and overall accuracy, 95%. CONCLUSION: Our results show that 99mTc (V) DMSA scintigraphy is a useful noninvasive diagnostic test for the detection and localization of intestinal inflammation.     

Acute osteomyelitis: advantage of white cell scans in early detection

Acute osteomyelitis was induced in 18 rabbits after direct injection of a solution of Staphylococcus aureus culture into a proximal tibial metaphysis. Serial plain radiographs and radionuclide studies with indium-111 oxide labeled while blood cells and technetium-99m methylene diphosphonate were performed over the next 4 weeks. Visual and quantitative analysis by measuring the isotope activity of 111In and 99mTc over the infected tibias as compared with the opposite bones revealed that the white blood cell scans were positive in 15 (83%) of the 18 rabbits during the first week after injection of the microorganism. During the same period, the 99mTc bone scans were positive in only 22% of the animals (p less than 0.005). In the animals that survived, both white blood cell and bone scans were positive during the second week, and thereafter, the bone scans revealed consistently higher activity than was observed with white blood cell scans. Computed tomography performed in six rabbits revealed an increased attenuation coefficient of the medullary cavities in the infected bones of four animals during the first week and of one more during the second week. Plain radiographs became positive after the 12th day. Results indicate that in patients with suspected acute osteomyelitis, white blood cell scans and probably computed tomography can detect the disease earlier than 99mTc bone scans and plain radiographs.     

Induction of unstable and stable chromosomal aberrations by 99mTc: in-vitro and in-vivo studies

BACKGROUND: Biological dosimetry, which determines the dose of acquired radiation by measuring radiation-induced variation of biological parameters, can help assess radiation damage in an individual. Evaluation of radiation exposure requires setting up reference curves for each type of radiation. AIM: To evaluate the potential induction of chromosome aberrations by a clinical diagnostic dose of 99mTc. METHODS: Dicentrics, rings, excess fragments, complete reciprocal translocations and incomplete reciprocal translocations were scored in peripheral blood lymphocytes from patients exposed to a 99mTc bone scintigraphy. A specific relationship between the radiation dose delivered by 99mTc and the frequency of stable and unstable chromosomal aberrations was established in vitro to estimate whole-body dose. Chromosome analysis using fluorescence plus Giemsa and fluorescence in-situ hybridization was undertaken on six patients before and after a 99mTc bone scintigraphy. Dicentrics, rings, excess fragments, and translocations were scored in blood lymphocytes after in vitro 99mTc external irradiation in order to construct dose calibration curves. RESULTS: Analysis of the in-vitro data shows that the number of both unstable and stable aberrations has a quadratic linear relationship to the dose. Our in-vivo irradiation studies showed that activities of 99mTc-hexamethylene diphosphonate (99mTc-HDP) used for bone investigations do not induce any additional unstable chromosome aberrations and translocations. The frequencies obtained did not differ significantly from background values. CONCLUSIONS: 99mTc can produce unstable and stable chromosomal aberrations in vitro. 99mTc-HDP administration does not induce supplementary chromosomal aberrations. The dose-response curves will allow a more accurate evaluation of the risk related to in-vivo administration of 99mTc labelled radiopharmaceuticals, and they can be used to assess the safe upper limit of injected activity in humans.     

Evaluation of active bleeding into hematomas by technetium-99m red blood cell scintigraphy before angiography

PURPOSE: To evaluate the utility of technetium-99m red blood cell (Tc-99m RBC) scintigraphy in the diagnosis of active hemorrhage into large intra-abdominal hematomas before arteriography. METHODS: This retrospective case series describes four patients (1 man and 3 women) with large abdominal wall and retroperitoneal hematomas confirmed by computed tomography who underwent Tc-99m RBC scintigraphy before angiography. Arterial transcatheter embolization was performed if active hemorrhage was found. RESULTS: Three of the patients had positive findings on Tc-99m RBC scans, which showed spreading of the labeled erythrocytes into the hematoma space. Positive scintigraphy was diagnostic for active hemorrhage and helped localize the bleeding sites. Angiography confirmed the diagnosis in all patients with positive scintigraphy and ruled out active bleeding in the patient with a negative Tc-99m-labeled RBC scan. CONCLUSION: Tc-99m RBC scintigraphy appears to be sensitive and accurate in detecting active hemorrhage into intra-abdominal hematomas.     

Atypical appearance of an hepatic hemangioma with technetium-99m red blood cell scintigraphy

Three-phase 99mTc red blood cell scintigraphy is an established technique for distinguishing hemangiomas from other focal liver lesions. The most widely recognized feature is the perfusion to blood-pool "mismatch" characterized by decreased or normal arterial perfusion, with lesion activity which progressively increases over 1-2 hr. Although increased arterial vascularity of hemangiomas has been described, such cases either involved small portions of the lesion only or occurred in lesions not conclusively proven to be hemangiomas. We report a case of an angiography proven hemangioma with increased arterial vascularity involving a significant portion of the lesion as well as intense early blood-pool activity similar to that seen on delayed imaging. This case emphasizes the diverse appearance of hepatic hemangiomas using 99mTc blood cell scintigraphy.     

Myocardial scintigraphy with technetium 99m methoxyisobutylisonitrile. A comparison with coronary arteriography in patients with suspected ischemic cardiopathy]

Technetium-99m methoxy-isobutyl-isonitrile (MIBI) myocardial scintigraphy has been proposed as an alternative to Thallium 201 myocardial imaging in the evaluation of patients with coronary artery diseases. We studied 39 patients (37 men, mean age 56 +/- 9 years) with suspected coronary artery disease. All patients underwent 99mTc MIBI myocardial scintigraphy after stress and at rest. Coronary arteriography, performed within 1 month, showed significant (greater than or equal to 50%) stenosis of at least 1 epicardial coronary artery in 36 subjects. 99mTc MIBI myocardial scintigraphy exhibited 94% sensitivity (34/36 patients) and 100% specificity (3/3 subjects with normal coronary arteries). Sensitivity for individual vessel stenosis was 81% (96% for the left anterior descending artery, 65% for the circumflex artery and 79% for the right artery). Our data show that 99mTc MIBI myocardial scintigraphy is capable of evaluating patients with coronary artery diseases.     

Active inflammatory bowel disease: evaluation with 99mTc (V) DMSA scintigraphy

PURPOSE: To evaluate the use of pentavalent (V) technetium 99m (99mTc) dimercaptosuccinic acid (DMSA) scintigraphy for the assessment of disease activity in patients with inflammatory bowel disease (IBD). MATERIALS AND METHODS: 99mTc (V) DMSA scintigraphy was performed in 76 patients. There were 36 patients with active IBD (11 with ulcerative colitis, 25 with Crohn disease), 28 patients with inactive disease (eight with ulcerative colitis, 20 with Crohn disease), and 12 patients with miscellaneous bowel disease. Sensitivity and specificity of 99mTc (V) DMSA scintigraphy in the diagnosis of IBD were calculated. In the group with active IBD, the disease activity and laboratory indices, as well as the endoscopic and histologic activity, were compared with the scanning activity index. Correlation coefficients between them were calculated with the Spearman rank test. RESULTS: 99mTc (V) DMSA scintigraphy had a 92% (33 of 36) sensitivity and an 86% (24 of 28) specificity in the detection of active IBD. A significant correlation between disease activity indices and scintigraphy score was demonstrated. Endoscopic and histologic activity was significantly correlated (P =.005 and.02, respectively, overall disease activity) with the scanning activity score. Of the group of patients with miscellaneous bowel disease, three with ischemic colitis had negative findings at scintigraphy. CONCLUSION: 99mTc (V) DMSA scintigraphy provides a noninvasive, practical, and accurate assessment of IBD activity.