Long-term maintenance of weight loss: do people who lose weight through various weight loss methods use different behaviors to maintain their weight?

Obtaining high-quality radiographs of the proximal aspect of equine limbs is difficult because of the large muscles in these regions. The use of scintigraphy may provide further information. Abnormal bone scan findings of the ischial tuberosity or the third trochanter were found in 29 adult horses with obscure hind limb lameness between 1986 and 1996 at the Large Animal Clinic of the University of Bern. Each had abnormal radiopharmaceutical uptake but not all had radiographic changes. Radiopharmaceutical uptake ratios between the ischial tuberosity and the greater trochanter were calculated. The uptake ratio in a control group of 11 clinically sound horses was lower than in 11 lame horses with subjectively enhanced radiopharmaceutical uptake.     

Digital perfusion, evaluated scintigraphically, and hoof wall growth in horses with chronic laminitis treated with egg bar-heart bar shoeing and coronary grooving

Nuclear scintigraphy was used to assess digital perfusion before and after treatment in 10 horses with clinical and radiographic evidence of chronic laminitis. Horses were evaluated for lameness, degree of distal phalanx rotation, and heel-toe hoof wall growth ratio, and randomly divided into two treatment groups. Group 1 horses received only egg bar-heart bar shoeing; Group 2 underwent egg bar-heart bar shoeing and coronary grooving. Horses were re-evaluated for digital perfusion, lameness, degree of distal phalanx rotation, and hoof wall growth at 6 week intervals over the 18 week follow-up period. Prior to treatment, relative scintigraphic activity at the dorsal laminar area was decreased and relative scintigraphic activity at the toe and adjacent solar area was increased. Egg bar-heart bar shoeing was associated with significantly increased dorsal laminar scintigraphic activity and significantly decreased solar scintigraphic activity over the 18 week period. Coronary grooving, in combination with egg bar-heart bar shoeing, resulted in a significantly lower heel-toe hoof wall growth ratio but did not enhance digital perfusion. Seven of 10 (70%) horses were responsive to treatment, defined as an improvement in lameness by at least one grade. Horses that were refractory to treatment had significantly lower dorsal laminar scintigraphic activity and higher palmar coronary scintigraphic activity prior to treatment than horses that responded to treatment. Our results are the first to demonstrate that egg bar-heart bar shoeing is associated with improved dorsal laminar perfusion, and support the use of this technique. In addition, we found that pre-treatment nuclear scintigraphy was predictive of clinical outcome in horses with chronic laminitis treated with corrective shoeing.     

Spasskyellina mandi n. sp. (Proteocephalidea:Monticelliidae), parasite of Pimelodus ornatus Kner, 1857 (Pisces:Pimelodidae) of the Paraná River, Paraná, Brazil

Indium-111 pentetreotide scintigraphy was performed in two patients for the localization of recurrent medullary thyroid carcinoma treated by surgery and external radiotherapy 1 and 10 years earlier. A marked uptake of the radiopharmaceutical was demonstrated in the lung areas that had been irradiated. These cases strongly suggest that this uptake is related to pulmonary fibrosis, a well-known complication of radiotherapy, even long after the irradiation. Therefore, attention must be paid to the avoidance of false-positive interpretation of somatostatin receptor scintigraphy in patients previously treated by radiotherapy.     

Technetium-99m-tetrofosmin uptake in sarcoidosis stage I

The uptake of 99mTc-tetrofosmin in enlarged lymph nodes, of the lung hilus, in the case of sarcoidosis Stage I (histopathologically confirmed by mediastinoscopic biopsy) is demonstrated. On a routine chest radiograph of a 78-yr-old woman, hilar lymphadenopathy was first detected. In the following mammography, disseminated micro calcifications were found in the left breast and a 99mTc-tetrofosmin study was performed for detection of breast cancer. Scintigraphy using 99mTc-tetrofosmin showed clear uptake in the hilar lymph nodes, but not in the left breast. The 99mTc-tetrofosmin uptake in the hilar lymph nodes was due to sarcoidosis confirmed by histology. Therefore, 99mTc-tetrofosmin scintigraphy may be useful in patients with suspected sarcoidosis, especially in Stage I.     

Limited clinical diagnostic specificity of technetium-99m stannous pyrophosphate myocardial imaging in acute myocardial infarction

To test the sensitivity and specificity of technetium-99m stannous pyrophosphate myocardial imaging in the diagnosis of acute myocardial infarction, myocardial scintigrams were performed in 115 patients. Positive scintigrams were found in all 48 patients with acute myocardial infarction; uptake was localized in 29 patients with transmural infarction and diffuse in 2 patients with transmural infarction and in the remaining 17 patients with subendocardial myocardial infarction. Positive scintigrams were also found in 31 of 67 patients without clinical evidence of acute myocardial infarction. Diffusely positive scintigrams were found in 3 of 3 patients with unstable angina pectoris, 7 of 30 patients with stable angina pectoris, 4 of 13 patients who had undergone aortocoronary bypass surgery, 4 of 4 patients with congestive cardiomyopathy and 1 patient studied 1 day after direct current cardioversion. Localized uptake of 99mTc-pyrophosphate was found in 9 of 10 patients with left ventricular aneurysm and in 3 of 13 patients after aortocoronary bypass surgery. All four patients with atypical chest pain and two patients with pericarditis had normal scintigrams. Our data confirm the previously reported sensitivity of 99mTc-pyrophosphate imaging in detection of acute myocardial infarction but indicate that positive scintigrams are not specific for this entity.     

Gross, histological and histomorphometric features of the navicular bone and related structures in the horse

Forelimb navicular bones and associated soft tissues were collected from 3 groups of horses and subjected to pathological examinations. The groups consisted of 38 horses with clinical navicular disease (ND) and 2 control groups, with no history of forelimb lameness, consisting of 25 age-matched mature horses (A-MC) and 9 immature horses (IC). Histological and histomorphometric studies were performed on tissue samples from 10 ND, 10 A-MC and 5 IC horses. Gross changes seen only in ND horses included: full thickness defects in the palmar surface fibrocartilage, palmar cortex erosion, medullary lysis, flexor digitorum profundus tendon (FDPT) surface fibrillation, FDPT core lesions and adhesions between the FDPT and navicular bone. Palmar surface partial thickness fibrocartilage loss and distal border fragmentation were seen with a significantly greater incidence in ND than in A-MC and not observed in IC. Remodelling of the proximal border, FDPT surface colouration, palmar surface fibrocartilage colouration and proximal border entheseous bone were identified in ND and A-MC but not in IC. Mid-ridge synovial fossae and horizontal depressions in the palmar surface were identified in all groups. Histologically palmar fibrocartilage thinning and loss were associated with reduced palmar fibrocartilage cell density and chondrocyte cluster formation. Palmar fibrocartilage fibrillation, palmar cortical bone defects, fibromyxoid stromal change in the medulla, medullary pseudocyst formation and entheseous new bone formation were all seen in ND. The adjacent FDPT showed fibrillation, tag formation and degeneration of the dorsal surface. Necrotic foci were also present within the body of the tendon. Although not always present, medullary bone pseudocysts, separate mineralised foci and most changes on the dorsal surface of the FDPT were specific to ND. Bone histomorphometric parameters were compared among groups. Cross-sectional area reduced from the sagittal ridge to the medial and lateral margins of each navicular bone. IC navicular bones had a smaller subchondral area, subchondral bone volume and a greater osteoid volume than in the AC, indicating that these differences were age-related. In ND the medullary area was decreased but the trabecular bone volume increased. The palmar subchondral area was increased but contained bone with an increased porosity and osteoid volume. Changes occurred from the medial to the lateral margins of the bone in horses with ND indicating remodelling of the bony elements throughout the bone in ND. The histological and histomorphometric changes in the navicular bone and palmar fibrocartilage were considered similar of those found in articular hyaline cartilage and subchondral bone in osteoarthritis.     

Whole-body and pinhole bone scintigraphic manifestations of Reiter''s syndrome: distribution patterns and early and characteristic signs

The characteristic whole-body and pinhole scintigraphic manifestations of osteo-enthesopathy and arthropathy in Reiter's syndrome (RS) are described, with an emphasis on early diagnosis. We analysed 59 sets of whole-body and pinhole bone scintigrams of 59 patients with RS. The population comprised 47 men and 12 women with an age range from 15 to 53 years (mean=29.4). Bone scintigraphy was carried out 2-2.5 h after intravenous injection of technetium-99m hydroxydiphosphonate using a single-head gamma camera (Siemens Orbiter Model 6601) with a low-energy high-resolution and a 4-mm pinhole collimator for whole-body and pinhole scintigraphy, respectively. In total 262 lesions of osteo-enthesopathy and arthritis were detected on 59 whole-body scintigrams, an incidence of 4.4 lesions per patient. As anticipated, the lesional distribution was asymmetrical: 68% were in the lower limb skeleton and 32% in the axial and upper limb skeleton. Pinhole bone scintigraphy, applied selectively to one region of interest in each case, enabled us to accurately diagnose arthritis and osteo-enthesopathy. It was noteworthy that osteo-enthesopathy, alone or in combination with arthritis, occurred in 78.9%, and had a strong predilection for the foot bones, especially the calcaneus (25. 6%). Pinhole scintigraphy detected enthesopathy in the absence of radiographic alteration in 14.1% of cases and portrayed characteristic signs of RS in 6.9%. Whole-body bone scintigraphy augmented with pinhole scintigraphy was found to be useful in order to panoramically display the systemic involvement pattern, to assess the characteristic bone and articular alterations and to detect early signs of RS.     

Observation of live, attenuated hepatitis A vaccines in humans

In a patient with metastatic Hurthle cell carcinoma of the thyroid, a subgroup of follicular carcinoma, scintigraphy with pentavalent 99mTc-labeled dimercaptosuccinic acid (V)DMSA showed a significant uptake of the radiopharmaceutical in all tumor sites. We suggest that the accumulation of 99mTc-(V)DMSA within metastases of Hurthle cell thyroid tumor may have a useful role in the staging of these patients, especially when radioiodine fails to concentrate.     

The utility of a somatostatin-type receptor binding peptide radiopharmaceutical (P829) in the evaluation of solitary pulmonary nodules

OBJECTIVE: Many neoplasms including small cell cancers more densely express somatostatin-type receptors or more avidly bind somatostatin than granulomatous and other nonmalignant processes. While non-small cell neoplasms of the lung have not yet been shown to demonstrate this receptor expression, previous studies have documented non-small cell lung cancer detection with somatostatin analog scintigraphy. This phenomenon can be conceivably exploited utilizing technetium Tc-99m P829 (P829), a unique low molecular weight somatostatin-type receptor binding polypeptide radiopharmaceutical. The objective of this study was to determine the ability of P829 scintigraphy to noninvasively differentiate malignant and nonmalignant solitary pulmonary nodules (SPNs). METHODS: The radiopharmaceutical technetium 99mTc-P829 was utilized for scintigraphy including single photon emission computed tomography. Thirty individuals with indeterminate SPNs of > or = 1 cm and significant risk factors for primary lung cancer were identified and underwent P829 scintigraphy. Tissue diagnosis was then established by transthoracic needle biopsy specimens. RESULTS: Fourteen subjects demonstrated abnormal P829 scans in the region of the radiographic abnormality. Twelve of this group had biopsy specimens revealing neoplasia. Two subjects with necrotizing granuloma on biopsy specimen had abnormal P829 scans in the region of the nodule. Sixteen subjects had no abnormal P829 tracer uptake in the region of the nodule. Fourteen subjects had benign diagnoses on biopsy specimens. One member of this group with a non-diagnostic biopsy specimen refused thoracotomy and remains radiographically stable at 24 months of follow-up. One subject with a squamous cell carcinoma demonstrated no P829 activity in the region of the nodule. The specificity of P829 scintigraphy based on transthoracic needle biopsy specimen was 88%. The sensitivity was 93%. P829 scintigraphy correctly identified or excluded malignancy in 27 of 30 subjects. CONCLUSIONS: P829 scintigraphy reliably identified or excluded malignancy in radiographically indeterminate solitary pulmonary nodules. The sensitivity and specificity compared favorably with the reported results of F-18 fluorodeoxyglucose positron emission tomographic imaging.     

The application of radionuclide infarct scintigraphy to diagnose perioperative myocardial infarction following revascularization

To evaluate the application of radionuclide infarct scintigraphy to diagnose myocardial infarction after revascularization, we obtained postoperative technetium 99m pyrophosphate myocardial scintigrams, serial electrocardiograms and CPK-MB isoenzymes in ten control and 51 revascularized patients. All control patients had negative electrocardiograms and scintigrams, but eight had positive isoenzymes. Eight revascularized patients had positive electrocardiograms, images and enzymes and two had positive scintigrams and enzymes with negative electrocardiograms. Thirty-four patients with negative electorcardiograms and scintigrams had positive isoenzymes; in only seven patients were all tests negative. Our data suggest radionuclide infarct scintigraphy is a useful adjunct to the electrocardiogram in diagnosing perioperative infarction. The frequent presence of CPK-MB in postoperative patients without other evidence of infarction suggests that further studies are required to identify all factors responsible for its release.     

Comparison of technetium 99m nanocolloid and indium 111 leucocytes in the diagnosis of orthopaedic infections

It has been suggested that technetium 99m nanocolloid is as effective an inflammatory radiopharmaceutical as indium 111 leucocytes. This study compares the efficacy of 99Tcm nanocolloid and 111In leucocytes in the detection of orthopaedic infection in 19 patients with a high clinical suspicion of infection. The two scintigrams were performed within 24 h of each other. A scintigram was considered positive where there was an increase in tracer uptake at the site of interest. Concordance rate of 73% was achieved. The numbers of false positives with 111In leucocytes and 99Tcm nanocolloid were three and six respectively. The single false negative in both was of a patient with tuberculous spondylodiscitis. Sensitivity was 75% in both. Specificities were 79% and 60% for 111In leucocytes and 99Tcm nanocolloid respectively. Positive Predictive Value was only 33% with 99Tcm nanocolloid and 50% with 111In leucocytes. 99Tcm nanocolloid also proved less reliable in accurately detecting infected prostheses. We conclude that 99Tcm nanocolloid cannot replace 111In leucocytes in the diagnosis of orthopaedic infections.     

Accessory ossification centres associated with osteochondral fragments in the extremities of horses

Fifty-six tarsocrural joints and 94 metatarsophalangeal joints were examined, at necropsy, from horses aged < or = 2 years. Osteochondral fragments at the cranial aspect of the intermediate ridge of the distal part of the tibia were seen in six horses, and at the proximoplantar aspect of the proximal phalanx in seven horses. Defects in the proximoplantar aspect of the proximal phalanx without osteochondral fragments were seen in a further two horses. Inflammatory and degenerative changes were not observed in any of the joints examined. From the incidence and natural course of these fragments, and from the radiological and microscopical findings, accessory ossification centres would seem the most probable cause of the osteochondral fragments at the cranial aspect of the intermediate ridge of the distal part of the tibia and at the proximoplantar aspect of the proximal phalanx.     

Thyroid scintigram. Sensitivity with sodium pertechnetate Tc 99m and gamma camera with pinhole collimator

To evaluate the reliability of thyroid scintigraphy in the diagnosis of nodular growth, scintigrams of patients who later underwent thyroidectomy were reviewed and correlated with pathologic findings. The scintigrams were all obtained with a 5-mm single-hole collimator-equipped gamma-scintillation camera after intravenous injection of 5 millicuries of sodium pertechnetate Tc 99m. In the group of 92 patients, six of whom had two histologically different lesions, 149 nodules were identified pathologically. There were 26 nodules 2 to 5 mm in diameter, of which 22 were benign and four were malignant. None of the 22 benign nodules were delineated scintigraphically. Superior image quality and resolution, low radiation dose, technical simplicity, and speed make 99mTc pinhole-camera scintigraphy the best procedure available for routine thyroid imaging.     

Thyroid scintigraphy in patients with thyroid tumors using 99mTc-hexakis 2-methoxy isobutyl isonitrile

Early and delayed thyroid scintigraphy with 99mTc-hexakis 2-methoxy isobutyl isonitrile (99mTc-MIBI) was performed in 18 patients with thyroid tumor, including 8 with papillary carcinoma, 1 each with follicular carcinoma, anaplastic carcinoma, and malignant lymphoma, and 7 with thyroid adenoma. Scintigrams obtained were compared with those taken with other radionuclides. In all 11 patients with malignant tumors, increased 99mTc-MIBI uptake was noted in the tumors on early images, although anaplastic carcinoma and malignant lymphoma had mild uptake. On delayed images, 99mTc-MIBI washout was noted in 45.4% (5/11). In one patient with extensive cervical lymph node metastasis, 99mTc-MIBI concentration was evident in the metastatic foci. In the 4 where, the thyroid adenoma consisted mainly of cystic degeneration, a focal defect was noted, but two of the three patients whose thyroid adenoma consisted mainly of a solid component had an intense tracer uptake in the tumors on early and delayed images. In conclusion, there were increased 99mTc-MIBI accumulations in all of the 14 solid thyroid tumors. The quality of 99mTc-MIBI scintigraphic images of thyroid tumors was equal or slightly superior to that taken with 201Tl scintigraphy. 99mTc-MIBI thyroid scintigraphy may be useful in detecting a solid thyroid tumor and its metastasis, although it cannot be used to differentiate between benign and malignant tumors.     

Age-related change of technetium-99m-HMDP distribution in the skeleton

To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolism. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers. METHODS: The whole-body skeletal uptake (WBSU) and tracer distribution pattern were studied in men and women by bone scintigraphy using 99mTc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers. RESULTS: WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites. CONCLUSION: These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone metabolism.     

Radioisotopic study of the adrenal glands using 131I-19-iodocholesterol

Scintigraphy of the adrenal gland with 131I-19-iodocholesterol has recently been added to radiological techniques in adrenal imaging and has been used successfully to demonstrate anatomical and functional disorders of the adrenals in a variety of clinical situations. A review of the authors' experience stresses the diagnostic value of this method. Radiological findings and results of scintillation imaging are complementary: their comparison improves and clarifes indications for scintigraphy. Hyperadrenal cortical diseases always gave satisfactory scintigrams, the most interesting results being obtained in adrenal cortical hyperplasia and unilateral hyperfunctioning adenomas. In these cases the evaluation of the response to stimulation or suppression tests was very useful. On the other hand scintigraphy was less valuable in demonstrating malignant and non malignant tumours.     

Value of color-coded Doppler sonography in the differential diagnosis of nodular thyroid gland changes

AIM: The incidence of functional autonomous adenomas, detected in every second nodular goiter by scintigraphic methods is very high in an area of iodine deficiency. The color-coded Doppler sonography (CCDS) as a diagnostic tool in differentiating thyroid nodules is discussed controversially. METHODS: In this prospective study we investigated the value of CCDS in 200 patients with nodular thyroid alterations compared with 99m-Technetium (Tc) scintigraphy. RESULTS: Focal maximas of Tc-uptake were detected in 22.5% of all patients, and 44.5% of the thyroid nodules showed increased vascularity. There was no correlation between nodular vascularity and thyroid 99m-Tc uptake (TcTU). In contrast to this we could demonstrate a significant relation between vascularity and the diameter of the nodule (p < 0.0001). The results are discussed in the context of method specific limitations of ultrasound examinations. CONCLUSION: Our results confirm that CCDS has no great importance in the differentiation of thyroid nodules. Scintigraphy remains the diagnostic method of choice to assess the topographic thyroid function.     

From eradication to resistance: five continuing concerns about pediculosis

Myocardial scintigraphy was performed three times in a 55-year-old woman with left bundle branch block (LBBB). A significant LAD stenosis had been excluded by coronary angiography. The first scintigraphy was performed with Tc-99m sestamibi after submaximal bicycle exercise and revealed a septal perfusion deficit. This deficit could not be reproduced in the following examinations after pharmacological stress testing with dipyridamole using both Tl-201 and Tc-99m sestamibi. Perfusion at rest assessed with Tl-201 was normal in all studies. It is concluded that pharmacological stress testing with dipyridamole is to be preferred in patients with LBBB. With respect to the accuracy of myocardial perfusion imaging the choice of the radiopharmaceutical plays a less important role.     

Noninvasive evaluation of regional myocardial perfusion in 112 patients using a mobile scintillation camera and intravenous nitrogen-13 labeled ammonia

The short half-life positron emitter 13N, as labeled ammonia (13NH4+), was evaluated as a myocardial imaging agent. Regional myocardial uptake of 13NH4 correlated with the distribution of labeled microspheres in experimental myocardial infarction. Using intravenous 13NH4+, myocardial scintigraphy was performed in 85 cardiac patients and 27 normal subjects. Ninety-five scintigrams were suitable for analysis. Eighteen of 24 normal subjects had homogeneous myocardial images; six had inhomogeneous images attributable to early technical problems. Perfusion defects were observed in the scintigrams of 82% (57/65) of patients with coronary artery disease, being most common in patients with myocardial infarction (27/28). Six sequential studies showed changes in perfusion consistent with the clinical course of each patient. Scintigraphic abnormalities were also observed in 4/6 patients with valvular heart disease. 13NH4+ myocardial scintigraphy is a valid and sensitive method of assessing regional myocardial perfusion and is especially useful for sequential imaging at short intervals.     

Management of specific medical conditions in the perioperative period

BACKGROUND: Reversal of ischemia after myocardial infarction by revascularization is worthwhile only if viability exists in a sufficiently large portion of the left ventricle. METHODS AND RESULTS: To determine myocardial hypoperfusion reversibility and its influence on segmental and global function, we studied 50 patients after myocardial infarction. Three technetium 99m-tetrofosmin scintigraphies were performed: 1 at rest, 1 after 0.6 mg sublingual nitroglycerin (NTG), and 1 after injection at peak stress. First-pass multigated radionuclide angiography was obtained at rest and after NTG. Each patient also underwent a stress redistribution-reinjection thallium-201 scintigraphy. During stress 99mTc-tetrofosmin, 104 segments had normal uptake, 51 showed moderately reduced uptake, and 186 had severely reduced uptake. Of these 186 segments, 33 (18%) improved at rest, and 41 (22%) improved only after NTG. Fifty-nine (79%) of these segments with improved uptake were also found to have reversible defects on 201TI imaging. In the 26 patients with ventricular dysfunction, a 73% agreement was found between the functional and 99mTc-tetrofosmin uptake post-NTG improvement, whereas a 69% agreement was found with thallium reinjection. No significant differences were seen between 99mTc-tetrofosmin and 201T1 imaging. CONCLUSION: Nitroglycerin administration during 99mTc-tetrofosmin scintigraphy improves the detection of myocardium with reversible hypoperfusion in patients with a previous myocardial infarction.