Calculating regional tissue volume for hyperthermic isolated limb perfusion: Four methods compared.

INTRODUCTION: Hyperthermic isolated limb perfusion (HILP) can be performed as an alternative to amputation for soft tissue sarcomas and melanomas of the extremities. Melphalan and tumor necrosis factor-alpha are used at a dosage that depends on the volume of the limb. Regional tissue volume is traditionally measured for the purposes of HILP using water displacement volumetry (WDV). Although this technique is considered the gold standard, it is time-consuming and complicated to implement, especially in obese and elderly patients. AIM: The aim of the present study was to compare the different methods described in the literature for calculating regional tissue volume in the HILP setting, and to validate an open source software. METHODS: We reviewed the charts of 22 patients (11 males and 11 females) who had non-disseminated melanoma with in-transit metastases or sarcoma of the lower limb. We calculated the volume of the limb using four different methods: WDV, tape measurements and segmentation of computed tomography images using Osirix and Oncentra Masterplan softwares. RESULTS AND CONCLUSION: The overall comparison provided a concordance correlation coefficient (CCC) of 0.92 for the calculations of whole limb volume. In particular, when Osirix was compared with Oncentra (validated for volume measures and used in radiotherapy), the concordance was near-perfect for the calculation of the whole limb volume (CCC = 0.99). With methods based on CT the user can choose a reliable plane for segmentation purposes. CT-based methods also provides the opportunity to separate the whole limb volume into defined tissue volumes (cortical bone, fat and water).

Assessing response using 99mTc-MIBI early after interstitial chemotherapy with carmustine-loaded polymers in glioblastoma multiforme: preliminary results.

Introduction. Early signs of response after applying wafers of carmustine-loaded polymers (gliadel) are difficult to assess with imaging because of time-related imaging changes. (99m)Tc-sestamibi (MIBI) brain single-photon emission tomography (SPET) has reportedly been used to reveal areas of cellularity distinguishing recurrent neoplasm from radionecrosis. Our aim was to explore the role of MIBI SPET in assessing response soon after gliadel application in glioblastoma multiforme (GBM). Methods. We retrospectively reviewed the charts on 28 consecutive patients with a radiological diagnosis of GBM who underwent MIBI SPET/CT before surgery (with intracavitary gliadel placement in 17 patients), soon after surgery, and at 4 months. The area of uptake was selected using a volume of interest that was then mirrored contralaterally to obtain a semiquantitative ratio. Results. After adjusting for ratio at the baseline, the effect of treatment (gliadel versus non-gliadel) was not statistically significant. Soon after surgery, however, 100% of patients treated with gliadel had a decreased ratio, as opposed to 62.5% of patients in the non-gliadel group (P = 0.0316). The difference between ratios of patients with radical versus partial resection reached statistical significance by a small margin (P = 0.0528). Conclusions. These data seem to suggest that the MIBI ratio could be a valuable tool for monitoring the effect of gliadel early after surgery.

Imaging studies in hypercalcemia.

Hypercalcemia is a relatively common clinical problem, mainly (>90%) related to primary hyperparathyroidism (HPT) and malignancies. The anatomical and functional imaging techniques available for locating enlarged parathyroid glands include ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine imaging techniques. The most commonly employed are US and parathyroid scintigraphy, while CT, MRI, positron emission tomography (PET)/CT, and selective venous sampling are generally used in patients with persistent or recurrent HPT, or when findings of non-invasive studies are negative or conflicting. The reported accuracy is 57-93%, 54-93%, and up to 95% for US, (99m)Tc-sestamibi scintigraphy, and the two modalities combined, respectively. A multimodality approach (x-ray, whole-body scintigraphy, CT, MRI, and PET) is usually recommended for whole body assessment in cases of cancer-induced hypercalcemia (CIH). Imaging studies should evaluate each organ (i.e. breast, kidney, prostate, parathyroid) potentially involved in the pathogenesis of hypercalcemia in patients with CIH. In cases of skeletal metastases, when findings on plain x-ray or bone scans are uncertain, any unexplained region of abnormal uptake should be examined by MRI and/or ¹8F-fluoro-2- deoxyglucose (FDG)-PET/CT, which has proved more accurate than classical bone scintigraphy, especially for dealing with hematologic malignancies. A number of radionuclide tracers, other than ¹8F-FDG, are available for use in selected cases to locate specific tumors (i.e. 68Ga for neuroendocrine tumors). This is a review of recently published information on the imaging techniques currently available for patients with hypercalcemia.

Molecular biology and nuclear medicine in pediatric hydronephrosis.

Pediatric hydronephrosis may correspond to very different clinical situations, ranging from fully benign reversible dilatation to severe obstructive nephropathy. The genetic research is difficult, mainly because the condition is probably polygenic and the embryology of the urinary system is very complex and depends on a multifaceted interaction of genetic and environmental factors. Molecular biology has gained new insights in the complicated urinary system and in the mechanisms of obstructive nephropathy. Some mediators (tumor growth factor, tumor necrosis factor, renin angiotensin system, etc.) could be considered molecular markers of obstruction and it has been proposed to introduce them in clinical decision making, in order to make an accurate selection of patients needing surgical correction. Scintigraphy has been a standard procedure in the management of pediatric hydronephrosis for decades and has been used in many clinical studies designed to evaluate the role of selected molecular markers in clinical settings. The relationships between scintigraphic parameters and molecular mediators seems promising, in particular for the evaluation of the Reanin Angiotensin System, which plays many roles in the natural history of pediatric hydronephrosis. Angiotensin up-regulation is a turning point in many pediatric hydronephrosis and can be unveiled by captopril scintigraphy, which allows a timely diagnosis of obstruction, before irreversible parenchymal injury and loss of renal function.

Accuracy of ultrasonography and 99mTc-sestamibi scintimammography for assessing axillary lymph node status in breast cancer patients. A prospective study.

AIMS: The aim of this study was to evaluate the sensitivity, specificity and accuracy of axillary ultrasonography (US) and (99m)Tc-sestamibi scintimammography (SSM) in patients with breast cancer (BC) undergoing curative surgery. METHODS: A series of 77 consecutive women (median age 54 years, range 36-70) with primary BC underwent both US and SSM from 2 to 15 (median 4) days prior to curative surgery. The results of imaging studies were compared against the final pathology. Breast-conserving surgery with axillary node (AN) dissection was performed in 49 (63.6%) patients, and modified radical mastectomy in 28 (36.4%) patients, according to the tumour staging. RESULTS: Final pathology showed 5 pT1bN0, 1 pT1bN1, 28 pT1cN0, 19 pT1cN1, 7 pT2N0, and 17 pT2N1 BC. Overall, 719 AN were removed of which 106 (14.7%) were metastatized nodes (median 3, range 1-5 per patient). The sensitivity, specificity and accuracy were 67.6%, 80.0%, and 74.0% for US, 78.4%, 85.0%, and 81.8% for SSM, and 91.9%, 92.5%, and 92.2% for US and SSM together, respectively. There was a significant difference (p<0.05) in the number of metastatized AN between patients with metastases correctly detected and undetected by both US (3.1+/-1.3 vs. 2.0+/-0.7) and SSM (3.2+/-1.3 vs. 1.7+/-0.7). CONCLUSIONS: Although the results of each diagnostic tests are strictly dependent on the number of the metastatized AN, the combination of axillary US and SSM is a sensitive low-cost procedure that should be suggested in all patients with BC, when a preoperative evaluation of the AN status is required.

A meta-iodobenzylguanidine scintigraphic scoring system increases accuracy in the diagnostic management of pheochromocytoma.

As observed by other authors, normal adrenal medullary tissue frequently gives an apparently positive meta-iodobenzylguanidine (MIBG) scan in cases studied using 123I-MIBG and less frequently 131I-MIBG. The aim of this study was to assess the usefulness of a scoring system, based on different uptakes of the radiopharmaceutical, to improve the accuracy of 123I-MIBG scintigraphy in patients with either adrenal or extra-adrenal pheochromocytomas. Charts from 67 consecutive patients (29 males and 38 females, median age 48 years, range 14-80 years) with suspected pheochromocytoma (either sporadic or familial: multiple endocrine neoplasia (MEN) 2a, MEN2b, Von Hippel-Lindau, neurofibromatosis type 1) who underwent 123I-MIBG scintigraphy (scans acquired 4-24 h after injection) from 1991 to 2004, were independently reviewed by two experienced nuclear medicine physicians using liver uptake as a reference (scores: 1, uptake absent or less than the liver; 2, equal to the liver; 3, moderately more intense than the liver; 4, markedly more intense than the liver). Interfering medications were discontinued for the appropriate time before MIBG injection. Histological data were obtained for all patients who underwent adrenalectomy. Scintigraphies were classified as positive using the following criteria: extra-adrenal focal uptake, adrenal enlargement together with non-homogeneous uptake and adrenal uptake more intense than the liver (score 3-4). After surgical resection, as confirmed by histological findings and long-term follow-up (range 1-14 years, average 9.25 years), 43 patients were considered true positives using the proposed scoring system, 20 were true negatives, four were false negatives and none was false positive. In conclusion, the proposed scoring system demonstrated high specificity (100%), sensitivity (91.5%) and accuracy (94%) in the management of pheochromocytoma. Positive predictive value and negative predictive value were 100% and 83.3% respectively. Normal adrenal tissue uptake was correctly discriminated from pheochromocytomas in 18 out of 20 patients, with adrenal uptake equal to the liver (grade 2), using the proposed cut-off level.

Relationship between prognostic factors of breast cancer and 99mTc-sestamibi uptake in patients who underwent scintimammography: Multivariate analysis of causes of false-negative results.

The complementary role of sestamibi scintimammography (SSM) in patients with breast cancer (BC) is well established. The aim of this study was to establish whether a relationship exists between sestamibi uptake, evaluated as a tumour-to-background ratio (TBR), and the main prognostic factors of BC. SSM with the measurement of TBR was performed preoperatively in 102 women (median age 57 years, range 32-81 years) who underwent curative surgery for primary BC. Final pathology showed 4 (3.9%) with pT1a, 17 (16.7%) with pT1b, 44 (43.1%) with pT1c and 37 (36.3%) with pT2 breast carcinomas. The overall sensitivity of SSM was 80.4%. An ANOVA showed significant (P<0.01) differences between the TBR of patients with G1 vs. G3 tumours, and between the TBR of those with G2 vs. G3 breast carcinomas. Moreover, there was a difference (P=0.021) between the TBR of patients (n=12, 11.8%) with CEA serum levels >10 ng/ml (2.031+/-0.420), and those with normal (n=90, 88.2%) CEA values (1.713+/-0.446), whilst no difference (P=NS) was found between patients (n=27, 26.5%) with CA 15-3 >30 U/ml (1.893+/-0.401) and those with normal (n=75, 73.5%) CA 15-3 values (1.699+/-0.462). There was a mild inverse correlation between TBR and both the oestrogen (R=0.25, P=0.011) and the progesterone receptor (R=0.23, P=0.02) rate. The logistic regression analysis showed that only size and CA 15-3 serum levels represent true independent parameters, but the function was able to predict only 11 out of 21 (52.4%) patients with false-negative SSM. TBR is independent of age and mainly correlates with the size of the tumour. There are no reliable preoperative prognostic factors that are really useful for improving SSM sensitivity in patients with small breast carcinomas.

Technetium-99m sestamibi scintigraphy and helical CT together in patients with primary hyperparathyroidism: a prospective clinical study.

44 consecutive patients with confirmed primary hyperparathyroidism (HPT) undergoing surgery were prospectively enrolled in the study. There were 13 (29.5%) men and 31 (70.5%) women with an overall median age of 59 years (range 23-78 years). Prior to successful parathyroidectomy both (99)Tc(m)-sestamibi/(99)Tc(m)-pertechnetate subtraction scintigraphy (SS) and helical CT were performed, and the results of imaging studies were compared against intraoperative findings. Final histopathology showed 40 (90.9%) solitary parathyroid (PT) adenomata (median size 18 mm, range 8-40 mm), that were in an ectopic location in 13 (32.5%) patients. Moreover, 3 (6.8%) patients had multiglandular disease (one patient with two PT adenomata, two patients with PT hyperplasia), while one (2.3%) patient had a PT carcinoma. The sensitivity and positive predictive value were 86.0% and 97.4% for SS, 88.1% and 94.9% for CT, and 100% and 97.4% for the combination of SS and CT, respectively. Calcium and parathyroid hormone (PTH) serum levels, and the mean size of the removed PT glands of patients with false negative results were lower than that of those with true positive results, but the difference was not significant. Among patients with solitary PT tumours (N=41) the sensitivity was 88.1% and 90.3% for SS and CT-scan, respectively. In conclusion, our study confirms the usefulness of SS, which should be the initial test for patients undergoing parathyroidectomy. However, the strategy of performing two tests in each patient with primary HPT could be of limited utility when the initial SS is positive.

Hyperfunctioning parathyroid tumours in patients with thyroid nodules. Sensitivity and positive predictive value of high-resolution ultrasonography and 99mTc-sestamibi scintigraphy.

A series of 112 consecutive patients with primary hyperparathyroidism who underwent both high-resolution neck ultrasonography (US) and 99mTc-sestamibi/99mTc-pertechnetate subtraction scintigraphy (SS) prior to successful parathyroidectomy was reviewed. There were 29 (25.9%) men and 83 (74.1%) women, with a median age of 58 years (range 13-78 years). Patients were divided into two groups, according to the preoperative US findings: group A (87 patients, 77.7%) without thyroid diseases, and group B (25 patients, 22.3%) with either multinodular goitre or a solitary nontoxic thyroid nodule. In group B patients partial or total thyroidectomy was also performed, according to the intraoperative findings and frozen-section examination results. Final histopathology showed 99 (88.4%) solitary parathyroid (PT) adenomas and 3 (2.7%) PT carcinomas, while 10 (8.9%) patients had a multiglandular disease. The sensitivity and positive predictive value (PPV) were (group A vs group B) 79.8% vs 70.8% (P=0.25) and 95.7% vs 94.4% (P=0.58) for US, and 83.3% vs 87.0% (P=0.47) and 95.9% vs 90.9% (P=0.32) for SS respectively. Better but similar (P=not significant) results were obtained in patients with solitary PT tumours: 81.5% vs 77.8% (US) and 85.0 vs 94.1% (SS) sensitivity; 97.1% vs 93.3% (US) and 95.8% vs 88.9% (SS) PPV. Overall, the combination of US and SS was 92.9% sensitive (group A=93.1%, group B=92.0%; P=0.55), and the PPV reached 100% in each group. In conclusion, in patients with primary hyperparathyroidism the results of both US and SS are independent of coexistent thyroid disease, especially in patients with solitary PT tumours.

[Changes in esophageal peristalsis in diverse clinical forms and antibody specificity in scleroderma: a scintigraphic study in 100 cases]. / Alterazioni della peristalsi esofagea nelle diverse forme cliniche e specificita' anticorpali della sclerodermia: studio scintigrafico in 100 pazienti.

OBJECTIVE: To define the prevalence and severity of esophageal involvement in systemic sclerosis (SSc) and its relationship with the different clinical forms and ANA specificities of the disease. METHODS: A hundred consecutive patients with SSc, 48 with cutaneous limited, 26 with intermediate and 26 with diffuse form of disease, 49 with anti-centromere and 37 with anti-Scl70 ANA pattern, were submitted to scintigraphy using a semisolid orally ingested bolus to detect esophageal hypomotility. RESULTS: An impairment of esophageal function has been observed in 68% of SSc patients. Esophageal dysmotility was significantly more frequent and severe in patients with cutaneous diffuse and intermediate forms of SSc and with anti-Scl70 ANA pattern. CONCLUSIONS: Esophageal involvement is very common in SSc. The scintigraphy confirms to be a useful and non invasive diagnostic method; moreover it permits to quantify the severity of the esophageal dysmotility by analyzing both global and segmental function.

Non-invasive adrenal imaging in primary aldosteronism. Sensitivity and positive predictive value of radiocholesterol scintigraphy, CT scan and MRI.

The aim of this study was to evaluate the sensitivity and positive predictive value (PPV) of dexamethasone-suppression norcholesterol scintigraphy (NCS), computed tomography (CT) scanning and magnetic resonance imaging (MRI) in patients with primary aldosteronism (PA) who had undergone unilateral adrenalectomy. A series of 49 patients with confirmed PA was reviewed. There were 18 (36.7%) men and 31 (63.3%) women, with a median age of 47 years (range, 23-66 years). NCS was performed in all patients, and 46 (93.9%) and 31 (63.2%) underwent CT scan and MRI, respectively. Final pathology showed an aldosterone-producing adenoma in 45 (91.8%) patients, unilateral nodular cortical hyperplasia (NCH) in two (4.1%) and unilateral microscopic cortical hyperplasia (MCH) in two (4.1%). No aldosterone-producing carcinoma or bilateral adenomas were found. The greatest diameter of the removed adrenal tumour was in the range 8-40 mm (median, 14 mm). The PPV of adrenal imaging was 97.6% for NCS, 85.0% for CT scan (P=0.04) and 83.3% for MRI (P=0.03), and the sensitivity was 85.4%, 85.0% and 74.1%, respectively (P=NS). The age and the main biochemical parameters did not differ significantly (P=NS) between patients with true positive and false negative results of the imaging procedures. NCS accurately depicted all patients with NCH and MCH, whilst CT scan and MRI failed to diagnose such unilateral adrenal gland hyperfunction in two and three patients, respectively. The overall sensitivity of combined NCS and CT scan was 100%. In conclusion, in patients with PA, both NCS and CT scan are necessary to confirm the exclusive unilateral adrenal hyperfunction and, subsequently, to establish the appropriate treatment.

Noninvasive parathyroid imaging in primary hyperparathyroidism.

Several studies suggested that preoperative localization of abnormal parathyroid (PT) glands may be useful in reducing operative time facilitating parathyroidectomy, especially in patients with ectopic PT glands. At present, noninvasive techniques used to evaluate patients with primary HPT include (1) 99mTc-sestamibi scintigraphy, (2) high-resolution neck ultrasonography, (3) CT scanning, and (4) magnetic resonance imaging (MRI). The sensitivity and positive predictive value of each technique range from 70% to 90%, and a combination of two of more tests may significantly improve the results. In the minimally-invasive era both radioguided and video-assisted parathyroidectomy require an accurate preoperative localization of the abnormal PT glands, and PT imaging should be obtained before surgery in all patients with primary hyperparathyroidism, with the aim of reducing operative time and hospital stay.

Positive predictive value of 99mTc sestamibi scintimammography in patients with non-palpable, mammographically detected, suspicious, breast lesions.

The purpose of this study was to analyse whether the use of Tc sestamibi scintimammography improves the positive predictive value of X-ray mammography. A series of 73 women (median age 51 years, range 35-79 years) with non-palpable, mammographically suspicious, breast lesions was reviewed. There were 41 (56.2%) pre-menopausal, and 32 (43.8%) post-menopausal women. All patients underwent sestamibi scintimammography prior to open breast biopsy. Definitive histology showed breast cancer (pT1a=1 (1.9%), pT1b=47 (90.4%), pT1c=4 (7.7%)) in 52 (71.2%) patients, and benign breast lesions in 21 (28.8%). Patients with cancer were significantly older (P <0.01), while the greatest dimension (size) of the excised lesion did not differ (8.47+/-1.51 vs 8.30+/-1.53 mm; P =0.66) between the two groups. Overall, the positive predictive values of mammography and sestamibi scintimammography were 71.2% and 95.7%, respectively (P =0.004). Patients with false positive mammography were significantly younger than those in whom cancer was diagnosed correctly (45.35+/-7.56 vs 53.96+/-10.60 years; P =0.001), while age did not affect the sensitivity of sestamibi scintimammography, which reached 100% in patients with breast lesions > or =8 mm in size. In this subgroup the positive predictive value of mammography, sestamibi scintimammography, and mammography+sestamibi scintimammography together were 63.4%, 95.1% (P =0.001), and 97.6%, respectively, and the majority of the patients with benign lesions (13 of 15 (86.7%)) could have avoided biopsy. It is concluded that the use of Tc sestamibi scintimammography in conjunction with mammography may potentially reduce unnecessary surgical procedures, and should be performed in all patients with mammographically suspicious breast lesions of 8 mm or greater in size.

Usefulness of CT scan, MRI and radiocholesterol scintigraphy for adrenal imaging in Cushing's syndrome.

The aim of this study was to evaluate the sensitivity and accuracy of computed tomography (CT) scanning, 75Se-selenomethyl-norcholesterol scintigraphy (SNS) and magnetic resonance imaging (MRI) in patients with Cushing's syndrome (CS) undergoing adrenalectomy. A series of 67 patients with CS due to benign adrenal disease was reviewed. There were 11 (16.4%) men and 56 (83.6%) women, with an overall median age of 44 years (range 19-69 years). Prior to surgery all patients underwent both CT and SNS, and 58 (86.6%) underwent adrenal MRI. Thirty-five (52.2%) of the patients (group A) had histologically confirmed unilateral adrenal involvement (33 patients with a solitary adrenocortical adenoma, and two with unilateral nodular cortical hyperplasia), while 32 (47.8%) of the patients (group B) had CS caused by bilateral adrenal involvement, including two patients with multinodular adrenal hyperplasia. The sensitivity, specificity and accuracy of adrenal imaging in group A were 97.1%, 100% and 98.5% for SNS, 94.3%, 68.7% (P<0.05, chi2 test) and 82.1% for CT scan, and 92.3%, 60.0% (P<0.05) and 64.3% (P<0.05) for MRI, respectively. In group B the sensitivity, specificity and accuracy were 100%, 97.2% and 98.5% for SNS, 64.5% (P<0.05), 97.2% and 82.1% for CT scan, and 60.0% (P<0.05), 92.3% and 35.7% (P<0.05) for MRI, respectively. In conclusion, SNS represents the most sensitive and specific adrenal imaging study and should be used in all patients with confirmed biochemical diagnosis of CS undergoing adrenalectomy. The sensitivity and specificity of CT scan and MRI are similar, but the latter shows a lower accuracy, especially in patients with bilateral adrenal involvement.

Accuracy of technetium-99m sestamibi scintimammography and X-ray mammography in premenopausal women with suspected breast cancer.

The aim of this study was to evaluate the usefulness of technetium-99m sestamibi scintimammography (SSM) and combined use of SSM and X-ray mammography (MG) in premenopausal patients with small (< or =2 cm) suspicious breast lesions. Eighty-seven premenopausal women (median age 47 years, range 32-52) with breast lesions ranging from 4 to 20 mm in greatest diameter (median 12 mm) and detected by MG, underwent SSM prior to open breast biopsy. A planar camera and single-photon emission tomography (SPET) technique were used in 23 (26.4%) and 64 (73.6%) patients, respectively. At histological examination, 72 (82.8%) breast cancers (pT1a=3, pT1b=27, pT1c=42) and 15 (17.2%) benign masses were found. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MG and SSM were 80.6% vs 80.6%, 60.0% vs 93.3% (P<0.05), 90.6% vs 98.3%, 39.1% vs 50.0% and 77.0% vs 82.8%, respectively. MG + SSM together had a sensitivity of 94.4% (P<0.05 vs SSM alone) and an accuracy of 82.8% for the detection of breast cancer. Tumours undetected by both MG and SSM were significantly (P<0.05) smaller than those correctly diagnosed. Patients with false-negative MG were younger (P<0.05) than those with tumours correctly detected, while SSM sensitivity was independent (P=NS) of age. In conclusion, in premenopausal patients with small breast lesions, the sensitivity of SSM and MG is similar (P=NS), whereas the specificity of SSM is significantly higher (P<0.05) than that of MG. Furthermore, the combination of MG and SSM offers significantly improved sensitivity and accuracy in comparison with the individual techniques, suggesting a complementary role of SSM in the detection of breast cancer in younger patients.

Scintigraphic patterns of adrenocortical carcinoma: morpho-functional correlates.

OBJECTIVE: Adrenocortical scintigraphy has demonstrated clinical utility in the morpho-functional characterization of adrenal tumors. The aim of this study was to identify possible relationships between the scintigraphic pattern and endocrine and/or morphological data in a series of adrenocortical carcinomas. DESIGN AND METHODS: Twenty-one patients with adrenocortical carcinoma (11 nonfunctioning and 10 hormone-secreting) were investigated with 75Se-methyl-nor-cholesterol scintigraphy. Clinical, hormonal, radiological, and pathological data were analyzed. RESULTS: The adrenal mass showed no radiocholesterol uptake in 18 cases (11 nonfunctioning and 7 functioning lesions). Contralateral normal adrenal gland was visualized in all patients with nonfunctioning tumors, whereas classic bilateral nonvisualization was observed in the 7 cases with hyperfunctioning masses. Three patients with cortisol-producing carcinomas showed radiotracer uptake by the mass, without visualization of the contralateral gland. At histology, the tumors were shown to be undifferentiated adrenocortical carcinomas; they had an aggressive clinical behavior. CONCLUSIONS: Radiocholesterol scintigraphy has an important role in diagnosing adrenocortical carcinomas, which typically are not visualized. However, 30% of hypersecreting adrenocortical carcinomas show an atypical increased tracer uptake, not predictive of the biochemical and histological features of the tumor.

Sestamibi scintimammography in pT1 breast cancer: alternative or complementary to X-ray mammography?

The aim of this study was to compare the results obtained using X-ray mammography (MG) and 99mTc-sestamibi scintimammography (SSM) in patients with breast lesions < or = 2 cm. One hundred and thirty-four women (median age 52 years, range 32-78), who had already been selected for open breast biopsy, underwent both MG and SSM prior to surgery. Final pathology showed 27 (20.1%) benign breast lesions and 107 (79.9%) breast cancers (pT1a=5 [4.7%], pT1b=50 [46.7%], pT1c=52 [48.6%]). The sensitivity, positive predictive value, negative predictive value and accuracy were 81.3%, 97.6%, 55.6% and 83.6% for SSM and 83.2%, 89.9%, 48.6% and 79.1% for MG, respectively. The results were similar (p=NS), but patients with breast cancer (BC) undetected by MG were significantly (p<0.05) younger than those in which the tumor was correctly diagnosed, while the age did not affect SSM sensitivity. SSM was more (p<0.05) specific than MG in BC detection both in the overall group of patients (92.6% vs 63.0%) and in those with < or = 10 mm breast lesions (94.7% vs 63.2%). In conclusion, in patients with suspected BC sized < or = 2 cm, SSM may help in surgical planning because of its high specificity, and should be considered complementary to MG, especially in younger women.

Volterra series modelling and compensation of non-linear distortions caused by susceptibility difference artefacts related to the presence of ferromagnetic implants in magnetic resonance imaging.

Magnetic resonance imaging is popular in medical settings due to its unique technical characteristics. However, its full potential has been limited by imaging artefacts caused by various phenomena. Previously, a methodology was proposed to characterize and reduce artefacts caused specifically by magnetic susceptibility differences. In the present work, the Volterra series approach is suggested as an alternative method for describing non-linear distortions induced by susceptibility artefacts. A second-order Volterra series is utilized for characterizing the image non-linearities using a block-by-block processing approach. Subsequently, a corresponding second-order inverse Volterra series is applied to compensate for the quantified distortions. In addition, a technique for automatic demarcation of recoverable and non-recoverable regions in magnetic resonance images is proposed to ameliorate the developed methodology. Experimental results indicate that this approach offers improved accuracy and flexibility in reducing non-linear distortions caused by magnetic susceptibility artefacts.

Angiotensin converting enzyme inhibition worsens the excretory phase of diuretic renography for obstructive hydronephrosis.

PURPOSE: A growing body of evidence identifies the renin-angiotensin system as a key factor in the onset and progression of renal damage in chronic partial obstruction, which often represents a complex diagnostic challenge. A prospective study was undertaken to evaluate the role of captopril mercaptoacetyltriglycine-3 (MAG-3) renography as an early diagnostic test of obstruction. We report the results in a subgroup of children who underwent surgical correction for pyeloureteral obstruction. MATERIALS AND METHODS: Pyeloplasty was performed in 12 patients, including 10 males, 2 to 72 months old (median age 7) with unilateral hydronephrosis, including normal renal function and blood pressure. Basal and captopril enhanced diuretic renography with 99mtechnetium MAG-3 was performed within 24 hours using the same hydration and diuretic stimulus (0.75 mg./kg. furosemide), and 0.75 mg./kg. captopril was administered orally 60 to 90 minutes before scintigraphy. RESULTS: No adverse effects or modifications of the blood pressure were observed after captopril administration. The diuretic response was deeply worsened by angiotensin converting enzyme inhibition in each hydronephrotic kidney even when the basal study was only slightly abnormal (15-minute washout basal -27 +/- 16%, after captopril -9 +/- 13, p <0.005). After surgical correction the diuretic washout during angiotensin inhibition appeared normal in all patients (15-minute washout -56 +/- 14%). Separate renal function and parenchymal transit of MAG-3 were not modified by angiotensin converting enzyme inhibition, preoperatively or postoperatively. CONCLUSIONS: Our data confirm the influence of angiotensin on the kidney excretory system in human hydronephrosis and suggest a role for captopril enhanced diuretic renography in the early diagnosis of pyeloureteral obstruction. Further work is needed to evaluate angiotensin converting enzyme inhibition as a protective agent in obstructive nephropathy.

Usefulness of 99m-Tc-sestamibi scintimammography in suspected breast cancer and in axillary lymph node metastases detection.

AIMS: To evaluate the usefulness of 99m-Tc-sestamibi scintimammography (SSM) in the detection of T1-2, N0-1, M0 breast cancer (BC) and axillary node (AN) metastases. PATIENTS AND METHODS: A series of 239 women (median age 55 years) who had already been selected for breast biopsy underwent both mammography (MG) and SSM before surgery. The final diagnosis confirmed in 207 (86.6%) patients, and benign breast lesions in 32 (13.4%). RESULTS: Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MG and SSM in BC detection were 88.9% vs 87.9%, 62.5% vs 93.8% (P<0.01), 93.9% vs 98.9%, 46.5% vs 54.5%, and 85.4% vs 88.7%, respectively. Age did not affect (P=NS) SSM sensitivity, and in premenopausal patients (n=80 (33.5%)) its specificity was 100%. Overall sensitivity and specificity of SSM for assessing AN involvement were 82.3% and 94.1%, respectively. In patients with <3 AN metastases (n=33 (53.2%)) SSM sensitivity was 69.7%, and only one out of six patients with a single AN metastasis had a positive scan. CONCLUSIONS: In patients with suspicious MG undergoing biopsy, SSM should be considered before surgery because of its high specificity, especially in younger patients. At present, its usefulness in detection of AN metastases is still modest and does not allow a correct pre-operative staging of patients with BC.