Integrated fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT compared to standard contrast-enhanced CT for characterization and staging of pulmonary tumors eligible for surgical resection.

BACKGROUND: Accurate staging is necessary to determine the appropriate therapy in patients with lung cancer. Few studies have compared integrated fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT in the characterization and staging of pulmonary tumors considered eligible for surgical resection. PURPOSE: To compare 18F-FDG PET/CT with standard contrast-enhanced CT for the diagnosis and staging of lung neoplasms eligible for surgical resection. MATERIAL AND METHODS: Seventy-six consecutive patients (56 male, 20 female; mean age+/-SD, 63.4+/-20 years) with 84 pulmonary tumors suspected for malignancy and considered eligible for surgical resection were prospectively enrolled. Seventy-three malignant (65 non-small-cell lung carcinomas, one small-cell lung cancer, two carcinoids, and five metastases) and 11 benign lung tumors (three hamartomas, two sarcoidosis, one amyloidosis, one Wegener granulomatosis, one tuberculosis, and three areas of scarring) were finally diagnosed by histology. Tumor staging was based on the revised American Joint Committee on Cancer. RESULTS: In lesion characterization, the sensitivity and specificity of 18F-FDG PET/CT versus contrast-enhanced CT were 90% vs. 83% and 18% vs. 63% (P<0.05, McNemar test), respectively. In nodal staging, the sensitivity and specificity of 18F-FDG PET/CT versus contrast-enhanced CT were 78% vs. 46% and 80% vs. 93% (P<0.05), respectively. CONCLUSION: In patients with lung neoplasms considered eligible for surgical resection, (18)F-FDG PET/CT versus contrast-enhanced CT revealed higher sensitivity in nodal staging, but lower specificity both in lesion characterization and nodal staging.

MR angiography versus intra-arterial digital subtraction angiography of the lower extremities: activity-based cost analysis.

PURPOSE: The aim of this study was to analyse the costs pertaining to the radiology department of magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA) in the evaluation of arterial disease of the lower limbs. MATERIALS AND METHODS: The differential cost of the two procedures, i.e. the sum of equipment costs (amortisation and service contract), variable costs (supplies and related services) and personnel costs (radiologist, radiographer and nurse) was determined. The common cost (auxiliary personnel and indirect internal costs) was also calculated. Finally, the full cost of the two procedures was obtained (sum of differential and common costs). RESULTS: The differential cost of MRA was 186.14 euro (equipment costs: 50.80 euro, variable costs: 75.04 euro, personnel costs: 60.30 euro) while the differential cost of intra-arterial DSA was 238.18 euro (equipment costs: 57.60 euro, variable costs: 90.13 euro, staff costs: 90.45 euro). The estimated common cost was 5.62 euro. Therefore, the full cost of MRA was 191.76 euro and the full cost of intra-arterial DSA was 243.80 euro (27.1% higher). DISCUSSION AND CONCLUSIONS: Intra-arterial DSA costs more than MRA, mainly because of the higher costs of supplies used during the procedure and higher personnel costs (as a result of the longer duration of intra-arterial DSA). It should be noted that our evaluation considers costs pertaining to the radiology department only. It is evident that an economic analysis considering hospital costs as well would result in much higher costs for DSA if post-procedure hospitalisation is required. Our results cannot be simply exported to other radiology departments since they refer to the technology and organisation adopted in our department. However, our cost analysis model can be easily applied to other environments. MRA provides good diagnostic accuracy in the evaluation of arteries of the lower extremities, and its biological cost is far lower than that of intra-arterial DSA (MRA is noninvasive, it does not use ionising radiation, and the contrast medium is safe). Its lower cost is another argument in favour of the use of MRA instead of intra-arterial DSA in the evaluation of lower-extremity arterial disease.

[Current role of color Doppler ultrasound in acute renal failure]. / Stato attuale dell'eco color-Doppler nell-insufficienza renale acuta.

Acute Renal Failure (ARF) is characterized by a rapid decline of the glomerular filtration rate, due to hypotension (prerenal ARF), obstruction of the urinary tract (post-renal ARF) or renal parenchymal disease (renal ARF). The differential diagnosis among different causes of ARF is based on anamnesis, clinical symptoms and laboratory data. Usually ultrasound (US) is the only imaging examination performed in these patients, because it is safe and readily available. In patients with ARF gray scale US is usually performed to rule out obstruction since it is highly sensitive to recognize hydronephrosis. Patients with renal ARF have no specific changes in renal morphology. The size of the kidneys is usually normal or increased, with smooth margins. Detection of small kidneys suggests underlying chronic renal pathology and worse prognosis. Echogenicity and parenchymal thickness are usually normal, but in some cases there are hyperechogenic kidneys, increased parenchymal thickness and increased cortico-medullary differentiation. Evaluation of renal vasculature with pulsed Doppler US is useful in the differential diagnosis between prerenal ARF and acute tubular necrosis (ATN), and in the diagnosis of renal obstruction. Latest generation US apparatus allow color Doppler and power Doppler evaluation of renal vasculature up to the interlobular vessels. A significant, but non specific, reduction in renal perfusion is usually appreciable in the patients with ARF. There are renal pathologic conditions presenting with ARF in which color Doppler US provides more specific morphologic and functional information. In particular, color Doppler US often provides direct or indirect signs which can lead to the right diagnosis in old patients with chronic renal insufficiency complicated with ARF, in patients with acute pyelonephritis, hepatic disease, vasculitis, thrombotic microangiopathies, and in patients with acute thrombosis of the renal artery and vein. Contrast enhanced US is another useful diagnostic tool in patients with ARF which has been recently introduced in clinical practice. Microbubble administration may reduce technical failure in the evaluation of the renal artery. Moreover, perfusion defects due to stenosis or thrombosis of the renal segmentary vessels are better recognized. New diagnostic possibilities of enhanced US include evaluation of both cortical and medullar vessels, and functional evaluation of renal perfusion. Measuring the transit time of the microbubbles is useful for the diagnosis of renal artery stenosis and, in transplanted kidneys, for differential diagnosis between ATN and acute rejection.

Intravenous lidocaine in the treatment of hiccup.

The word "hiccup" refers to an involuntary, spasmodic contraction of the diaphragm that is followed by the abrupt closure of the glottis to produce the characteristic sound. Among the many documented causes of this occurrence are those due to neurogenic dysfunction. In the past few decades, lidocaine has been shown to be effective in treating a variety of disorders thought to involve neuropathic mechanisms, including seizures, chronic pain, and arrhythmias. We describe a postsurgical patient in whom two successive intravenous infusions of lidocaine, 1.5 mg/kg followed the next day by 0.75 mg/kg, terminated his hiccup twice, whereas multiple other treatments failed to alleviate the problem. Various causes of this phenomenon are discussed, as well as a possible mechanism for the successful treatment.

Technetium-99m-MIBI scintimammography in palpable and nonpalpable breast lesions.

UNLABELLED: The aim of this study was to determine the diagnostic accuracy of 99mTc-MIBI scintimammography in patients with palpable and nonpalpable breast cancer. METHODS: One hundred and forty patients with a clinically palpable breast mass and/or suspicious mammographic finding had prone scintimammography after the intravenous injection of 740 MBq 99Tc-MIBI within 5 days before open biopsy or surgery. All patients had mammography within 2 mo before the scintimammography. The mammography was read as probably benign, probably malignant or indeterminate. The scintimammography was read as positive or negative for breast cancer. The scintigraphic studies were correlated with mammographic findings and with histopathology. RESULTS: Histopathological studies showed that the mean tumor size for 61 palpable tumors was 2.57 cm with a range of 1-6 cm, and for 24 nonpalpable tumors the mean size was 1.34 cm with a range of 0.5-3 cm. Mammography had an overall sensitivity of 91.58% and a specificity of 42.87%; the sensitivity was 90.16% and 95.45% and specificity was 57.14% and 32.14% for palpable and nonpalpable tumors, respectively. Eight cases were considered indeterminate. Scintimammography was true-positive for 71 breast cancers, true-negative for 47, false-positive for 8 and false-negative for 14. The overall sensitivity was 83.5% and the specificity 85.4%. In the patients with palpable masses, sensitivity was 95.1% and specificity 75%; in those with nonpalpable lesions, sensitivity was only 54.2% and specificity, 93.5%. Among 18 cases of palpable abnormalities with probably benign mammography, six had true-positive scintimammography. Of eight patients with indeterminate mammography, one was true-positive on scintimammography. CONCLUSION: Scintimammography is an accurate and clinically useful tool for evaluating patients with palpable breast abnormalities when mammography is negative and in the cases of indeterminate mammography. A significant improvement in lesion detectability is necessary in nonpalpable breast abnormalities.

Predictive value of dobutamine radionuclide ventriculography in detection of functional improvement after acute anterior wall infarction and thrombolytic therapy.

BACKGROUND: Prolonged postischemic ventricular dysfunction (stunned myocardium) may prevent the assessment of myocardial salvage early after thrombolysis. Dobutamine in conjunction with radionuclide ventriculography has been proposed for the early assessment of myocardial viability and prediction of functional recovery. HYPOTHESIS: This study was designed to investigate the effects of low-dose dobutamine infusion on early global and regional function of reperfused myocardium after acute anterior wall myocardial infarction (MI). In particular, our purpose was to examine whether this response can predict late recovery of left ventricular function and correlate with the reperfused status (patency of infarct-related artery). METHODS: In all, 29 consecutive patients with first uncomplicated anterior wall MI, and who had received thrombolytic therapy, underwent radionuclide ventriculography at rest and 2 min after each dose increment of dobutamine infusion (5-15 micrograms/kg/min) on the third day after the infarction, at discharge, and at 3 months' follow-up. Global and regional ejection fraction were calculated at each stage. Four patients with complications were dropped from the study. A significant response to dobutamine was defined as an increase of at least > or = 7% in global or regional ejection fraction at the infarct zones. RESULTS: Of the 25 patients, 18 (72%) fulfilled these criteria. Of these, 10 patients (56%) had a significant improvement in global or regional ejection fraction at discharge and 13 patients (72%) at 3-month follow-up. The overall sensitivity of the dobutamine test in predicting left ventricular improvement was 100% at discharge and 93% at 3-month follow-up. However, the positive and negative predictive values were 56 and 100% at discharge and 72 and 86%, respectively, at 3-month follow-up. CONCLUSION: Low-dose dobutamine radionuclide ventriculography is a safe and useful test for assessing myocardial viability and may predict late functional improvement in patients with anterior wall MI.

Screening for thyroid abnormalities among immigrants to Israel from the former USSR.

The exposure of some former Soviet citizens to radiation following the 1986 Chernobyl disaster has raised the question of the need to enroll these individuals in screening programs for thyroid abnormalities upon their immigration to Israel. Since screening programs have many drawbacks, and screening for thyroid disease has never been shown to decrease mortality or to improve survival, we are of the opinion that the establishment of thyroid screening programs will do more harm than good. The timely diagnosis of the very small excess in benign and malignant thyroid disease to be anticipated among the immigrants can be achieved in the community by the primary care physician armed with specific knowledge of the risks and the initial diagnostic approaches to suspected thyroid disease as well as information on the availability of specialist backup.

Carcinoma of the thyroid in children--a review.

Thyroid cancer is the third most common solid tumor in children and adolescents. A review was made of the data on 540 such patients reported from nine large centers renowned for their experience with thyroid cancer. In respect to the pathogenesis the only factor conclusively known to promote development of thyroid cancer in the pediatric age group is irradiation, as documented by the Chernobyl experience. The evidence indicates that thyroid carcinoma in the pediatric age group is a biologically independent and more aggressive entity than in adults; paradoxically the prognosis is good. In the great majority of cases the only presenting sign was a neck mass. In a high percentage (60-80%) there were also palpable lymph nodes. The findings regarding lung metastases were not clear-cut: in most series they were present in about 10%, with a high of 28% in one group and a low of 5% in another group. Papillary carcinoma or the follicular variant of papillary carcinoma were the dominant histologic types, pure follicular carcinoma being found much less frequently than among adults with thyroid cancer. Despite the relatively advanced stage of the disease upon diagnosis, only 13 patients died of the disease, 12 to 33 years postoperatively. Recurrence rates ranged between 10% to 35%, with involvement of the lateral neck, thyroidal bed or distant sites 3 to 33 years after treatment; most failures responded to further surgery or radioactive iodine. There is almost general agreement that surgical intervention should consist of total or near total thyroidectomy despite the high rates of recurrent laryngeal nerve paralysis and hypocalcemia. In regard to neck metastases less than radical surgery has proved during the years to be sufficiently effective. Radioactive iodine, used by all at some stage of management for treatment purposes, should be used prophylactically only after due consideration in view of possible teratogenicity.

Cancer of the thyroid in children and adolescents.

Thyroid cancer is a rare but intriguing malignancy when it occurs in childhood and adolescence. In this retrospective study 58 young patients with thyroid cancer treated at the Rabin Medical Centre are presented. We found that thyroid carcinoma in children presented in a more advanced stage than in adults, and the incidence of regional metastases at the time of presentation is higher. Nevertheless, the biological behaviour of the tumour is more benign. We believe that near-total thyroidectomy is the treatment of choice in this age group for disease limited to the gland, and total thyroidectomy with perithyroidal neck dissection should be performed in patients with nodal disease. For follow-up, we recommend physical examination with measurement of thyroglobulin and TSH levels, ultrasound examination of the neck and chest radiography.

Treatment decisions in thyroid surgery based upon ultrasonography.

Between 1991 and 1994, 600 thyroidectomies were performed at the Beilinson Medical Center in Israel, 120 of which were due to malignancies. Routine preoperative and follow-up ultrasound examinations were performed in 100 cases. A prospective study comparing preoperative ultrasonic and operative findings revealed that ultrasound offered significant preoperative information that could alter operative decisions. Ultrasound also proved to be a valuable tool in follow-up. Based on ultrasound findings, patients were salvaged at an early stage of recurrent disease.

Well-differentiated thyroid carcinoma.

PURPOSE: This study presents our experience with 728 patients treated in our department for well-differentiated thyroid carcinoma between 1954-1994. MATERIALS AND METHODS: The retrospective evaluation of the prognostic implications of the clinical and pathological findings was performed. Age, sex, histological variants, tumor size, and locoregional and distant spread were evaluated as risk factors in relation to the prognosis. RESULTS: During follow-up, which ranged from 1 to 31 years, 125 locoregional and/or distant metastases developed (17.2% of the patients), 87 of which occurred in the first 10 years after initial therapy. Thirty-two patients with papillary cancer and 20 with follicular cancer died of causes related to malignancy of the thyroid. CONCLUSION: The experience gained in our department has led us to adopt an aggressive approach in the treatment of patients with well-differentiated carcinoma of the thyroid gland.

HLA-DR expression and lymphocytic infiltration in metastatic and non-metastatic papillary carcinoma of the thyroid.

Thyrocyte HLA-DR expression in association with lymphocytic infiltration has been demonstrated in autoimmune diseases of the thyroid. HLA-DR expression has been noted both in association with lymphocytic infiltration and in its absence. However, no prognostic significance was attributed to these findings. The purpose of this study on papillary carcinoma of the thyroid was to examine how tumour behaviour relates independently to HLA-DR expression and lymphocytic infiltration. Fifty patients with papillary carcinoma with known metastatic status were examined for HLA-DR expression utilizing the immunoperoxidase conjugated indirect method. The patients were divided into three groups: no metastases (n = 16), regional lymph node metastases only (n = 25), and distant haematogenous metastases (n = 9). Overall HLA-DR expression was noted in 6, 36 and 55% of the respective groups. Tumour HLA-DR expression without lymphocytic infiltration was noted in 0, 4 and 33% of the respective groups. Tumour HLA-DR expression with lymphocytic infiltration occurred in 6, 32 and 22% of the respective groups. From these findings we conclude that HLA-DR expression with lymphocytic infiltration occurs more frequently than HLA-DR expression in the absence of infiltration. The concurrence of HLA-DR expression and lymphocytic infiltration is most commonly associated with regional lymph node metastasis. HLA-DR expression in the absence of lymphocytic infiltration occurs in tumours with distant haematogenous metastases and is an uncommon feature of tumours that have not metastasized or have metastasized only to lymph nodes. Tumour HLA-DR expression in the absence of lymphocytic infiltration may indicate the potential for more aggressive behaviour.

Papillary carcinoma of the thyroid.

Between 1954 and 1993 503 patients with papillary carcinoma of the thyroid were treated at the Department of Otolaryngology-Head and Neck Surgery of the Beilinson Medical Center. Two thirds of these patients were women. The median follow-up period was 10.3 years. In more than 30% of cases the tumor was discovered because of the presence of an enlarged lymph node and/or invasion to adjacent structures. Total or near-total thyroidectomy was performed in 381 patients. The 48 patients in whom it was necessary to perform a reoperation had a significantly higher complication rate. Multicentricity was found in 65% of those cases in which both thyroid lobes were available for histologic examination. Nineteen patients were found to have a "tail" cell variant, 223 had a pure papillary variant, and 261 a follicular variant. The mortality rate was 6.2% 15 years after initial therapy. A number of factors-age, size of tumor, presence of distant metastases, "tall" cell variant, and type of surgery-were found to be significant predictors of survival. After almost 40 years of experience in treating more than 500 cases of papillary cancer, we have come to the conclusion that the surgical approach should be aggressive.

Effect of dipyridamole on myocardial perfusion and function using technetium-99m MIBI.

Myocardial perfusion imaging with dipyridamole is an accepted method for diagnosing coronary artery disease. However, the simultaneous effect of dipyridamole on perfusion and function in the detection of coronary artery disease has not been studied extensively. The aim of this study was to investigate this effect using technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) imaging. Twenty-eight patients with proven coronary artery disease participated in a 2-day protocol (rest and then 0.56 mg/kg dipyridamole i.v.) using Tc-MIBI for first-pass radionuclide ventriculography followed by SPECT imaging. Fifteen patients (54%) demonstrated a decrease in left ventricular ejection fraction from rest to dipyridamole and/or wall motion abnormality, while 21 patients (75%) showed abnormal perfusion by dipyridamole MIBI SPECT imaging. Concordance between perfusion and function was 65%. Correlation for one-, two- and three-vessel disease (coronary angiography) to perfusion versus function were: 54% vs. 38%, 80% vs. 60% and 80% vs. 80%, respectively. Left ventricular dysfunction using dipyridamole was noted in patients with multivessel disease, and with multi-reversible perfusion filling defects. We conclude that dipyridamole in combination with Tc-MIBI for assessment of perfusion and function serves as a valuable tool to identify patients with multivessel disease and a high amount of myocardium at risk.

High incidence of occult thyroid disease among general medical ward patients.

The objective of this study was to prospectively determine the efficacy of the results of routine testing of thyroid functions in patients admitted to a general medical ward. Blood for thyroid function tests was drawn on admission as part of the laboratory screening panel from 270 consecutive patients. Fifty-one were excluded due to recognition of thyroid-related problems by the clinical staff. 138 patients (63%) had normal free thyroxin (FT4) levels, one patient had hyperthyroidism, 15 patients (6.8%) had laboratory primary hypothyroidism and 65 patients (29.6%) had equivocal results (FT4 < 0.9 ng/dL and TSH < 5.0 mmu/L). In eight out of 31 patients in the latter group, the thyroid releasing hormone (TRH) test revealed primary or secondary hypothyroidism. A total of 55 patients (25.1%) expired within one year. The mortality rate was significantly higher among the low FT4 patients (p < 0.01), and was independent of age and sex. We conclude that inclusion of FT4 in a laboratory screening panel will reveal a large patient population with abnormal results. However, establishing the diagnosis requires additional tests. Therefore, screening for occult hypothyroidism among a select population, not the acutely sick, populations may be more efficient.

Dipyridamole first-pass radionuclide ventriculography: prediction of future cardiac events.

Dipyridamole thallium myocardial perfusion imaging is a useful alternative to stress testing in the diagnostic and prognostic assessment of patients with coronary artery disease. The diagnostic use of dipyridamole radionuclide ventriculography is much more controversial, but no long-term prognostic studies have been reported. Imaging results of 159 consecutive patients who were referred for dipyridamole first-pass radionuclide ventriculography were correlated with subsequent cardiac events over a mean follow-up period of 11 months. An abnormal response to dipyridamole infusion (any reduction in wall motion or absolute decrease in global left ventricular ejection fraction of > or = 5 ejection fraction units) was associated with an increased incidence of nonfatal myocardial infarction (4.5% vs 0%, p < 0.05) and cardiac-related death (9% vs 1%, p < 0.001). The sensitivity, specificity, and negative predictive value of dipyridamole first-pass radionuclide ventriculography in predicting future cardiac events were 86%, 71%, and 98%, respectively, with a relative risk of 15 (confidence interval 12.06 to 18.1). In conclusion, dipyridamole first-pass radionuclide ventriculography demonstrated significant prognostic value in a large unselected patient population. This technique may provide a widely applicable and useful alternative to dipyridamole thallium perfusion imaging in the assessment of cardiac risk in patients with coronary artery disease.

Follicular carcinoma of the thyroid.

BACKGROUND: Follicular carcinomas of the thyroid are less common than papillary carcinomas of the thyroid, and the available data on prognostic factors are relatively scant. A retrospective study covering four decades was undertaken to evaluate clinical and pathologic findings with regard to their effect on prognosis. METHODS: In 195 cases of follicular carcinoma treated from 1954 to 1991 age, sex, histologic type (minimally invasive vs. widely invasive), tumor size, and local, regional, and distant spread as well as the contribution of treatment to survival were evaluated in relation to prognosis. RESULTS: Age was a significant prognostic factor: there was 100% survival of patients younger than 20 years of age at diagnosis and only one death in the 20-39 year age group. Sex was not a significant prognostic factor, although there was a tendency to a better prognosis in females. Tumor size was significant, more than 6 cm having a poor prognosis. Blood vessel invasion influenced prognosis for the first 10 years. The presence of distant metastases was significant regarding survival. Lymph node involvement had a negative effect on the outcome. CONCLUSIONS: The factors of age, tumor size, invasion of blood vessels, and distant metastases are significant predictors of survival for patients with follicular carcinoma, whereas sex is not; regional spread needs to be evaluated further.

Growth hormone releasing activity by intranasal administration of a synthetic hexapeptide (hexarelin).

OBJECTIVE: Hexarelin is a new synthetic growth hormone releasing peptide. We have tested the efficacy of intranasal (i.n.) administration of hexarelin to stimulate plasma GH and have compared this to the intravenous (i.v.) administration of the peptide. PATIENTS: Ten children with familial short stature (FSS) aged 5.5-15.5 years and two known GH deficient patients aged 24 and 28 years without GH treatment. METHODS: All 12 subjects were submitted to i.v. (1 microgram/kg) and i.n. (20 micrograms/kg) hexarelin tests with a one-week interval between tests. Blood samples for GH, TSH, fT4 and T3 were obtained at 0, 15, 30, 60, 90 and 120 minutes. The hormone determinations were made by standard radio-immunoassays (RIA). RESULTS: Both the i.n. and i.v. administration of hexarelin induced a large GH response, the mean (+/- SD) being 72.2 +/- 35.5 mU/l for the i.n. test and 79.6 +/- 53.0 mU/l for the i.v. test. The peak GH in the i.v. test occurred at 15-30 minutes and in the i.n. test between 30 and 60 minutes. The GH deficient patients showed no GH response in either test. Plasma TSH decreased in the FSS children from a mean (+/- SD) of 1.0 +/- 0.26 to 0.64 +/- 0.2 mU/l (P < 0.005) during the i.n. test and from 1.0 +/- 0.3 to 0.7 +/- 0.3 mU/l (P < 0.05) during the i.v. test. In the isolated GH deficient patient, plasma TSH decreased from 1.06 +/- 0.38 mU/l to 0.86 +/- 0.17 during the i.v. test and from 1.60 +/- 0.01 to 1.11 +/- 0.06 mU/l during the i.n. test. There were no significant changes in plasma fT4 or T3 in any of the tests. CONCLUSIONS: The synthetic hexapeptide hexarelin is a potent pituitary GH stimulator when administered intranasally. The GH response was similar to that observed after intravenous hexarelin. Simultaneously, there was a significant decrease in plasma TSH but the concentrations remained in the normal range. These findings appear to be of theoretical and practical relevance to the investigation and management of short children.