Radiation diagnosis of interstitial lung diseases

The authors analyzed the results of complex radiation study of 1192 patients with various interstitial lung diseases (ILD). An algorithm of differential diagnosis of diffuse and disseminated lesions of the lung was derived by using the findings. The X-ray morphological principle underlies the algorithm. The level of structural lesions of the lung and tissue reactions and the presence of granuloma shadows are the governing criteria for evaluating the gross structure in the differential diagnostic complex. Great emphasis is laid on the significance of computed tomography (CT), high performance CT in particular, which is becoming the priority radiation diagnostic technique in pulmonology. Morphofunctional studies, 99mTc AMA and 67Ga citrate pulmonary scintigraphy in particular, specify the magnitude of changes in the microcirculatory bed and the activity of intrathoracic lymph nodes.     

Gallium-67 for the Diagnosis and Localization of Subphrenic Abscesses

Four septic patients with suspected subphrenic abscess were evaluated with gallium-67 citrate and technetium-99m labeled radiopharmaceuticals. Gallium-67 scintigraphs proved instrumental in correctly diagnosing and localizing one left and three right subphrenic abscesses. Gallium-67 scintigraphy can be a useful noninvasive technique for evaluating patients with suspected subphrenic abscess.     

Radiation diagnosis of Langerhans cell histiocytosis (LCH) of lung

The authors studied the pattern of X-ray changes detectable in the lungs of 41 patients with LCH. The results of classical X-ray study were supplemented by the data of computed tomography, ultrasonography, and 99mTc and 67Ga citrate radioisotopic studies. The diagnostic values of these techniques were compared. X-ray syndromes of changes in the lung in LCH were found to be interstitial, interstitial and granulomatous, tumorous (focal). The authors emphasize the multisystematic character of a lesion, the phasic nature and progression of the disease into fibrosis.     

Gallium-67 scintigraphy and non-small-cell bronchogenic carcinoma: a quantitative in-vivo predictive assay?

Gallium-67 scintigraphy has been of limited use in detecting lung cancers and micrometastases. To study its potential for determining the aggressiveness of a cancer, we reviewed the charts of 44 patients with non-small-cell bronchogenic carcinoma who had not been receiving treatment when 67Ga scintigraphy was performed. The mean length of survival for the 18 patients with low or little uptake of the tracer, corrected for tumour size, was 19.7 months, and for the 26 with high uptake 9.4 months (p less than 0.01). Such in-vivo predictive assays may be a rational goal for tumour scintigraphy.     

Determinación de la certeza diagnóstica de la gammagrafía tiroidea con tecnecio 99 sestamibi en pacientes con nódulo tiroideo y resultado histopatológico definitivo

Background99mTc sestamibi scanning and aspiration biopsy can predict the histopathological result of a thyroid nodule fairly accurately.ObjectiveTo determine the accuracy of 99mTc sestamibi scanning in detecting malignancy in patients with thyroid nodule confirmed by definitive histopathological report after thyroidectomy.Material and methodsA total of 69 patients with a solitary thyroid nodule were studied. In all patients, fine needle aspiration, total thyroidectomy for suspected thyroid cancer, and histological analysis of the surgical specimen were performed. There were 54 patients with a positive 99mTc sestamibi scan; of these, malignancy was confirmed by histological analysis in 25 and excluded in 29. There were 15 patients with a negative 99mTc sestamibi scan; of these, three had a final diagnosis of cancer and 12 were confirmed as cancer-free.ResultsThe diagnostic accuracy of 99mTc sestamibi scanning in detecting malignancy in thyroid nodules was determined through a statistical analysis. 99mTc sestamibi scan for thyroid cancer had a sensitivity of 89.28% and a specificity of 29.25%. The positive predictive value was 46.29% and the negative predictive value was 80%.ConclusionsWe believe that 99mTc sestamibi scan should be routinely used in all patients with a thyroid nodule and an indeterminate result on fine needle aspiration. This procedure is most useful in excluding malignancy in patients with a negative 99mTc sestamibi scan.     

Apport de la scintigraphie au 99mTc-dépréotide pour le diagnostic de lésions osseuses secondaires dans le cancer bronchopulmonaire non à petites cellules stade III–IV

ObjectiveIn non-small cell lung cancer (NSCLC), metastatic bone involvement is usually assessed using conventional ^99mTc-HMDP bone scintigraphy, which has a high sensitivity but a poor specificity. The purpose of this study was to assess the usefulness of the ^99mTc-D scintigraphy for the detection of malignant bone metastases in patients with NSCLC stage III or IV and to compare these results with ^99mTc-HMDP bone scan findings.MethodsNineteen patients (13 M and 6 F, mean age 59 years) with proven NSCLC, suspected to have stage III or IV were enrolled prospectively. All patients underwent whole body ^99mTc-HMDP and ^99mTc-D scintigraphy to detect bone metastases within a mean interval of 14 days. Each focal uptake of ^99mTc-D or ^99mTc-HMDP was considered benign or malignant, leading to positive or negative diagnosis for bone involvement. The final diagnosis of bone metastases was established by a lung specialist, on the basis of additional imaging modalities and of 12 months follow-up.ResultsTwelve bone lesions were identified by ^99mTc-D scintigraphy, 10 were classified as bone metastases and two were classified as inflammatory bone lesions. Four patients were metastatic. Fifty eight bone lesions were detected by ^99mTc-HMDP scintigraphy, 26 of whom were considered malignant, eight patients were thus considered metastatic. Thereby, the two nuclear medicine modalities were concordant for 13 patients, that is 68% of cases and were discordant for six patients, representing 32% of cases. Diagnostic sensitivity, specificity and accuracy of depreotide scintigraphy and ^99mTc-HMDP bone scintigraphy were 75% for both, 93.3 and 73.3%, and 89.5 and 73.3% respectively.ConclusionOur data suggest that depreotide scintigraphy with the same sensitivity, a better accuracy and specificity than those of ^99mTc-HMDP bone scan can detect metastatic bone lesions in patients with NSCLC suspected to have stage III or IV disease.     

Technetium-99m monoclonal antibody fragment (FAb) scintigraphy in the evaluation of small cell lung cancer: a preliminary report

Small cell lung cancer (SCC) has the most rapid growth rate of the four cell types and metastasizes early. Present imaging modalities for staging include chest x-ray, CT, MRI and bone scans. In this preliminary study, we assessed the clinical role of ^99mTc-monoclonal antibody (MOAB) scintigraphy in five patients with histologically proven SCC. Each patient was infused with 20–30 mCi of ^99mTc labeled Fab fragment of MOAB (NR-LU-10, NeoRx, Seattle, Wash.). Total body simultaneous anterior and posterior images were obtained 14–16 h post injection. SPECT images of the chest were obtained through a 360 ° rotation of the gamma camera and recorded on a 62 × 64 × 16 matrix. Images (1.2cm thick) were generated in transaxial, sagittal and coronal views.Fourteen of fifteen chest lesions detected by CT were confirmed by ^99mTc MOAB scintigraphy. Scintigraphy detected one additional chest lesion not seen by CT. Scintigraphy failed to detect a brain lesion (2 cm), a chest lesion, and two adrenal lesions, all of which were seen by CT. In one patient with multiple (more than 10) lesions in the liver, both scintigraphy and CT detected all lesions. Three spine lesions seen on ^99mTc MDP scan and positive for metastasis on MRI concentrated ^99mTc MOAB, but two rib lesions seen on ^99mTc MDP bone scan did not concentrate ^99mTc MOAB. It is concluded from these preliminary results that the potential usefulness of ^99mTc MOAB scintigraphy as a complementary imaging modality in the staging of small cell lung cancer should be investigated further.     

Gallium-67 Scintigraphy and Intraabdominal Sepsis: Clinical Experience in 140 Patients with Suspected Intraabdominal Abscess

In 140 patients with suspected intraabdominal abscess, studies were made using gallium-67 citrate and technetium-99m labeled radiopharmaceuticals. Gallium-67 scintigrams correctly localized 52 of 56 intraabdominal abscesses confirmed at surgical operation or necropsy. In an additional 20 patients in whom findings on scintigrams were abnormal, there were clinically established infections. Sixty-one patients in whom findings on scintigrams were normal were conservatively managed and discharged from the hospital; none proved to have an abscess. Four false-negative and three false-positive studies were recorded. Gallium-67 scintigraphy is a useful noninvasive diagnostic adjunct that should be employed early in the evaluation of patients with suspected intraabdominal sepsis.     

The role of scintigraphy with the use of 99mTc-HYNIC-TOC in the diagnosis of medullary thyroid carcinoma

INTRODUCTION: Recently a new somatostatin analogue labelled with (99m)Tc ((99m)Tc-HYNIC-TOC) has been synthetized. Aim of this study was to evaluate the utility of (99m)Tc-HYNIC-TOC in the radionuclide imaging in patients with medullary thyroid carcinoma (MTC). MATERIAL AND METHODS: 30 patients with MTC aged 22-83 years in different stages of the disease were investigated. In 6 patients (group 1) scintigraphy was performed before surgery directly after diagnosis of MTC. Four patients (group 2) were qualified to the study in the phase of remission after surgical treatment that had been confirmed by low concentrations of calcitonin. Twenty patients (group 3) were investigated due to stagnation or recurrence confirmed by persistent hypercalcitoninemia. The scintigraphy using (99m)Tc-HYNIC-TOC (Tektrotyd, POLATOM) was performed 2 and 4 hours post injection of 20 mCi (740 MBq) of the tracer. Other imaging techniques were also employed and analysed in individual cases (US, CT, (99m)Tc(V)-DMSA, (131)I-MIBG, (99m)Tc-MDP, (111)In-octreotide and FDG-PET). RESULTS: Images obtained 2 and 4 hours p.i. were similar. In group 1, uptake of the tracer was found in the primary tumour of MTC in all patients. In group 2, a false positive result was found in 1 of 6 patients. In the remaining 5 of 6 cases no pathological foci were visualised. In group 3, uptake in the thyroid bed was found in 3 of 20 cases and in the lymph nodes in 14 of 20 patients. In 3 of 20 cases uptake in the bone metastases was found. Globally, sensitivity of the scintigraphy using (99m)Tc-HYNIC-TOC was 86.4%, specificity - 75.0%, and accuracy - 84.6%. CONCLUSION: The scintigraphy using (99m)Tc-HYNIC-TOC showed high utility in the diagnosis of MTC. Confirmation of the presence of somatostatin receptors with this method may be used for treatment planning: surgery or radionuclide therapy.     

Place des explorations isotopiques dans les otites externes nécrosantes

BackgroundThe necrotizing otitis externa (NOE) is potentially lethal which mainly occurs on the most among the elderly and diabetic. The aim of our study was to evaluate the contribution of isotopic explorations in diagnosis, staging and monitoring of the NOE.MethodsOur retrospective study was about 50 patients with a strong suspicion of NOE who benefited a bone and/or gallium scintigraphy.ResultsOur population was composed of 38 men and 12 women with mean age of 68 years. All patients were diabetic. The most common complaint was otalgia (98% of cases). The sensitivity of computed tomography (CT) which was performed in 84% of cases was 66.6% of cases. Bone scintigraphy (BS) was performed in all patients showing increased uptake in the temporal region in 90% of cases. An extension to surrounding structures was objectified in 26% of cases. Follow-up Ga 67 SPECT was performed in 56% of cases, demonstrated increased uptake at the temporal region in 43% of cases. The statistical study showed that only the presence of an extended tympanic lysis on CT was statistically significant to the positivity of BS (P = 0.036). No statistically significant correlation was found between all other CT abnormalities, clinical and biological signs and the positivity of bone scintigraphy.ConclusionIsotopic explorations were a great contribution in the management of the NOE. At the initial phase, the BS allowed to confirm very early an existence of osteomyelitis of the skull base. During the follow-up, the gallium-67 scan allowed the following of the evolution of infectious process.     

Open-label efficacy and safety trial of 42 days of 566C80 for Pneumocystis carinii pneumonia in AIDS patients.

Pneumocystis carinii pneumonia continues to be a cause of morbidity and mortality in AIDS patients. Current therapies have a high rate of toxicity and failure. Compound 566C80 is a 1-4,hydroxynaphthoquinone with potent antiprotozoal activity which shows good efficacy and safety in 21-day treatment trials of P. carinii pneumonia (PCP) in AIDS patients. Because there is a generally high recurrence rate after treatment of PCP and there may be a possible advantage in decreasing the P. carinii burden in the lung with extended anti-Pneumocystis therapy, we performed an open label-trial of the safety and efficacy of 42-day therapy with 566C80 for PCP in AIDS patients. Ten patients were enrolled and one was lost to follow-up. Eight of the remaining nine patients successfully completed 42 days of therapy with minimal toxicity. This trial suggests that 566C80 for 42 days can be an effective, safe, and well-tolerated oral therapy for PCP in AIDS patients.     

Rapid serodiagnosis of human mycobacteriosis by ELISA using cord factor (trehalose-6,6'-dimycolate) purified from Mycobacterium tuberculosis as antigen

IgG antibodies against purified cord factor (trehalose-6,6'-dimycolate, TDM) in sera of 99 patients infected with mycobacteria (42 patients with tuberculosis excreting tubercle bacilli in the sputum, 11 patients with non-tuberculous mycobacteriosis excreting acid-fast bacilli in the sputum, and 46 patients without bacilli in the sputum but diagnosed as having pulmonary tuberculosis by chest X-ray films and physical examination), five patients with lung cancer, and 100 healthy controls which included subjects positive and negative for the tuberculin test were tested by the ELISA with TDM purified from Mycobacterium tuberculosis H37Rv as the antigen. Of the 99 cases of mycobacteriosis, 83 patients (83.8%) had positive results (48 samples from 53 patients, or 90.5%, with bacilli in the sputum, and 35 samples from 46 patients (76%) with tuberculosis diagnosed clinically). The sera of the five patients with lung cancer and the 100 controls all gave negative results. Thus, the sensitivity and specificity were 83.8% and 100%, respectively. ELISA with TDM as the antigen is simple, reproducible, and useful for the rapid serodiagnosis of general mycobacterial infections including tuberculosis, because it does not involve the cultivation of bacteria.     

Diagnostic de l’embolie pulmonaire chez la femme enceinte : apport de la scintigraphie. Étude rétrospective à propos de 116 cas

IntroductionPulmonary embolism during pregnancy is a leading cause of maternal mortality. The aim of our study was to evaluate pregnant women with suspected pulmonary embolism prevalence of lesions on the lung perfusion as well as the relationship between the parenchymal lesions and various clinical factors and biological risk.MethodsThis is a retrospective study of 116 pregnant patients referred for suspected pulmonary embolism. The median age was 30 years, ranging from 15 to 47 years and the median gestational term was 31 weeks with a range of 12 to 40 weeks. Suspicion of pulmonary embolism was established with the presence of clinical signs (dyspnea, chest pain and palpitations). No patient had received a chest radiograph. The patients underwent planar perfusion scintigraphy with injected activity of 40 to 50 MBq of macroaggregates of human albumin (MAA) labeled with 99mTc. The scintigraphic results were classified according to the PIOPED criteria, depending on the likelihood of EP. The scans with low or intermediate probability were included in the same group, that of indeterminate results.ResultsThe scan was positive (with high probability) in 16 patients (13.8%), normal in 78 patients (67.2%) and classified as inconclusive in 22 patients (18.9%). In 16 patients with a positive scan, the lesions were interested the left lung in 10 cases (62.5%), the right lung in 1 case (6.25%) and were bilateral in 5 cases (31.25%).ConclusionsIn cases of suspected pulmonary embolism in a pregnant woman, the choice of imaging technique depends on both its diagnostic value and also its adverse effects. Lung scintigraphy is the examination to be carried out first in pregnant women with a chest radiograph. In others, it is that angiography should be performed as first line.     

Skeletal Scintigraphy: The Use of Technetium 99M-Labeled Complexes in the Detection of Early Osseous Involvement by Metastatic Tumors

Skeletal scintigraphy using Technetium-99m (^99mTc) complexes was carried out in a series of 332 cancer patients. The results of scintigraphy were compared with the results of roentgenography and with the diagnostic usefulness of serum alkaline and acid phosphatase levels and the presence or absence of bone pain. In 25 percent of cases, lesions were first identified with scintigraphs. When metastastic lesions were present on both scintigraphs and roentgenograms, the number was greater on scintigraphs in 72 percent of cases. Six false negative studies were recorded (1 percent). Sixty percent of patients with early metastasis—that is, those with abnormal scintigraphs and negative roentgenograms—were asymptomatic. Serum alkaline and acid phosphatase levels were normal in 40 percent and 42 percent respectively of those with early skeletal involvement. Skeletal scintigraphy with ^99mTc complexes is superior to other commonly employed techniques used to assess bone metastasis.     

Infection de prothèse vasculaire : TEP-FDG vs scintigraphie aux leucocytes marqués (planaires et TEMP/TDM)

Vascular prosthesis infection is an uncommon but life-threatening complication. Its diagnosis is difficult to establish especially due to the low specificity of computed tomography (CT). The aim of this preliminary study was to compare the diagnostic value of positron emission tomography with¹⁸FDG (¹⁸FDG-PET) and ^99mTc-HMPAO-labeled leukocytes scintigraphy in this indication. ¹⁸FDG-PET/CT and ^99mTc-HMPAO-labeled leukocytes scintigraphy (planar at 6th and 24th hours after injection + SPECT/CT at the 6th hour) were prospectively performed in 11 patients (total of 22 vascular prosthesis with 14 clinical suspicions of infection). Both scans were retrospectively and blindly assessed by two independent nuclear medicine physicians. Interpretation was based on visual analysis. The gold standard was bacteriology findings or clinical follow-up greater than 6 months. Eight prostheses were considered as infected. PET found eight true-positive and one false-positive. Scintigraphy found eight true-positive and no false-positive. A focal or heterogeneous FDG-uptake higher or equal than hepatic uptake was considered as positive in PET. A focal prosthetic activity, stable or increased at the 24th hour was considered as positive in labeled leukocyte scintigraphy. SPECT/CT gave accurate anatomic localization and differentiated clearly infections of soft tissues from those of prostheses. ¹⁸FDG-PET could be performed in first-line in suspicion of vascular prosthesis infection. In litigious cases, a^99mTc-HMPAO-labeled leukocytes scintigraphy in association with SPECT/CT could bring additional arguments for infection diagnosis.     

Evaluation of axillary lymph nodes from the results of radioisotopic study

The purpose of the investigation was to study the pattern of 99mTc (MIBI) technitrile uptake in the metastatically involved lymph nodes in breast cancer, by applying the plain scintigraphic technique. The scintigraphic study of the breast and regional metastatic areas by means of the radionuclide 99mTc (MIBI) technitrile was made on a Millennium GE tomographic gamma chamber. The radiotracer 550 (MBq) dissolved in 10-20 ml of saline solution was intravenously injected into the arm cubital vein contralaterally to the lesion. Following 20 minutes of injection of the agent, plain scintigraphy was carried out in three standard projections: frontal and two oblique ones. The scintigraphy was performed using a high-resolution collimator recording a 128 x 128 matrix image. The detector was maximally approximated to the organ being examined. A plain scintigraphic scan was recorded on each side for 10 minutes. By the degree of axillary lymph nodal involvement, the patients were divided into 3 groups in accordance with the international TNM classification: N0 (n = 55), N1 (n = 13), N2 (n = 4). Among 72 patients, axillary lymph nodes could be detected in 6, in 2 of them changes were not diagnosed by X-ray and ultrasound studies. The final pathomorphological study of intraoperative materials revealed axillary lymph nodal metastatic involvement in 17 patients. A micrometastasis in one lymph node was found in 1 patient. None of the radionuclide studies showed tumor spread in 5 cases. The sensitivity, specificity, and precision of the technique were 35.3, 100, and 84.7%, respectively. Thus, a combination of the high cost of the procedure, its radiation load on a patient, and its low sensitivity make the use of plain scintigraphy of axillary regions inexpedient in the complex of studies of the extent of breast cancer in the present development of technology.     

Does autoantibody-negative Graves' disease exist? A second evaluation of the clinical diagnosis.

Advanced technical methods are essential for accurate diagnosis of Graves' or Basedow's disease (GD). Inadequate methods may lead to a false diagnostic conclusion. We have analyzed the clinical features and methodology aspects of cases diagnosed as GD with negative findings for TSH receptor autoantibodies. The initial diagnosis was based on clinical findings (patient record, hypermetabolic state, goiter palpation) and laboratory testing (fT4 and TSH). From a total of 255 newly registered patients with GD, fifty-one (20%) were negative in a conventional porcine TBII assay. All fifty-one patients were retested with 131I or 99mTc uptake tests, thyroid scintigraphy, and a second-generation TBII assay. Results disclosed twenty-one cases (8.3%) with diagnosis other than GD: ten cases of autonomous hyperthyroidism (Plummer's disease), seven cases of painless thyroiditis and four cases of euthyroid endocrine ophthalmopathy. All twenty-one patients remained negative in the second-generation TBII assay. Measurement by second-generation TBII assay was performed on the remaining thirty patients initially found negative for TBII. As a result of this reevaluation, only 234 of the original 255 patients had GD. Of those, 231 (204 according to porcine plus 27 according to human TRAb assay) had detectable TBII (98.7%). This investigation stresses the problem of correct diagnosis and the methodological limitations in the assessment of laboratory parameter validity in GD. Based on this work, TSH receptor autoantibody-negative GD is extremely rare.     

Radioisotopic Bone Scintigraphy with the Gamma Camera in the Investigation of Prostatic Cancer

Experience with x-rays, strontium-87m scintigraphy, and technetium-99m polyphosphate scintigraphy in the identification of bone metastases in 201 patients with prostatic cancer is reviewed. About 40% of the patients had demonstrable metastases in bone at the time of first presentation.Comparative studies of 247 x-ray and ^87mSr surveys indicated that x-rays failed to detect metastases in 10% of cases where they were identified by ^87mSr but that the isotopic survey similarly failed to detect radiologically evident deposits in 7% of cases.Similar studies comparing ^99mTc polyphosphate surveys with x-ray scans showed that x-rays missed isotopically detected metastases in 12% of cases, but in only one survey out of 67 did the isotope miss radiologically evident deposits. In a series of 32 patients investigated by both isotopic techniques ^99mTc polyphosphate did not fail to detect any metastases and identified deposits in one patient in whom they were missed by ^87mSr scintigraphy. About 15% of both x-ray and ^87mSr surveys gave equivocal results, but only 3% (2 out of 67) of ^99mTc polyphosphate surveys were equivocal.We concluded that ^99mTc polyphosphate bone scintigraphy with the gamma camera was the most reliable of the techniques used for the identification of bone metastases in patients with carcinoma of the prostate. The results of scintigraphy with ^87mSr suggested that serial surveys may provide early evidence of hormone resistance in prostatic cancer.     

Biological consequences of irradiation by low doses of technetium 99m: ultrastructural studies, p53 protein expression and cytogenetic effects.

Few studies concerning the potential genetic effects of diagnostic radionuclides used in nuclear medicine have been reported. The aim of this study was to evaluate the biological and cytogenetic consequences of two technetium 99m-labelled radiopharmaceuticals. Ultrastructural modifications of pulmonary cells were first investigated after injection of 99mTc labelled microspheres in the rat. On the same irradiated cells, nuclear expression of p53 protein was assessed using immunohistochemistry. Despite very high previously calculated doses delivered to pulmonary cells, no morpholological cell damage and no significant increase of nuclear expression of the p53 were noted. There was no correlation between the calculated dose and the ultrastructural biological damage. Secondly, a specific in vitro curve, activity/number of unstable chromosomal aberrations, corresponding to physical characteristics of 99mTc, was established to verify the potentiality of 99mTc to induce such aberrations. In vivo, cytogenetic effects were assessed on blood samples of 5 patients with various arthrosic and periarthrosic diseases obtained after bone scintigraphy. Aberration frequencies of both in vitro and in vivo irradiated lymphocytes were determined using the classical Fluorescence Plus Giemsa technique. No cytogenetic effects appeared with the routinely 99mTc injected activities as predicted by the in vitro curve.     

Role of Imaging Tests for Preoperative Location of Pathologic Parathyroid Tissue in Patients with Primary Hyperparathyroidism

Objective: Primary hyperparathyroidism (PHPT) can be cured by parathyroidectomy, and the preoperative location of enlarged pathologic parathyroid glands is determined by imaging studies, especially cervical ultrasonography and scintigraphy scanning. The aim of this retrospective study was to evaluate the use of preoperative cervical ultrasonography and/or parathyroid scintigraphy in locating pathologic parathyroid tissue in a group of patients with PHPT followed in the same endocrine center.Methods: We examined the records of 61 patients who had undergone parathyroidectomy for PHPT following ^99mTc-sestamibi scintigraphy scan and/or cervical ultrasonography. Scintigraphic and ultrasonographic findings were compared to histopathologic results of the surgical specimens.Results: Ultrasonography detected enlarged parathyroid glands in 87% (48/55) of patients with PHPT and ^99mTc-sestamibi scintigraphy in 79% (37/47) of the cases. Ultrasonography was able to correctly predict the surgical findings in 75% (41/55) of patients and scintigraphy in 72% (34/47). Of 7 patients who had negative ultrasonography, scintigraphy correctly predicted the surgical results in 2 (29%). Of 10 patients who had negative scintigraphy, ultrasonography correctly predicted the surgical results in 4 (40%). When we analyzed only patients with solitary eutopic parathyroid adenomas, the predictive positive values of ultrasonography and scintigraphy were 90% and 86%, respectively.Conclusion: Cervical ultrasonography had a higher likelihood of a correct positive test and a greater predictive positive value for solitary adenoma compared to ^99mTc-sestamibi and should be used as the first diagnostic tool for preoperative localization of affected parathyroid glands in PHPT.Abbreviations:Ca = calciumIEDE = Instituto Estadual de Diabetes e Endocrinologia Luiz CapriglionePHPT = primary hyperparathyroidismPTH = parathyroid hormone