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S Maurea

Publications and source records attributed to S Maurea.

At least 19 recordsLinked to original sources

Diagnostic accuracy of chemical-shift MR imaging to differentiate between adrenal adenomas and non adenoma adrenal lesions.

PURPOSE: The objective of this study was to evaluate the diagnostic accuracy of chemical-shift (CS) magnetic resonance (MR) imaging in the differential diagnosis of adenoma and nonadenoma adrenal masses. MATERIALS AND METHODS: We enrolled 36 patients (9 men, 27 women, mean age 51.3+14.4 years) with unilateral (n=31) or bilateral (n=5) adrenal masses incidentally discovered during imaging examinations [ultrasound (US), computed tomography (CT)] performed for other indications. A total of 41 adrenal lesions were evaluated (mean diameter 3.0+2.2 cm). Histology (n=19), biopsy (n=3) or clinical-imaging follow-up (n=19) demonstrated 29 adenomas, five pheochromocytomas, three cysts and four carcinomas. MR imaging was performed using the following breath-hold sequences: T1-fast field echo (FFE) [repetition time (TR)/echo time (TE)=236/4.6 ms], T2-turbo spin echo-single shot (TSE-SSh) (TR/TE=831/80 ms), T1-DUAL-FFE (TR=236, double TE=4.6/2.3 ms in phase and out of phase) and T1-FFE after gadolinium-DTPA (Gd). Axial and coronal imaging planes were used, with a slice thickness of 3-5 mm. MR images were qualitatively assessed for signal intensity of the adrenal mass relative to the liver on T1, T2, CS and T1-Gd scans; diagnostic criteria for adenomas were isointensity or hypointensity on both T1 and T2 scans, out-of-phase CS signal loss and mild transient enhancement after Gd. RESULTS: Analysis of T1-T2 signal intensity showed diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 80%, 72%, 100%, 100% and 60%, respectively. In contrast, analysis of CS and T1-Gd signal intensity showed diagnostic accuracy, sensitivity, specificity, PPV and NPV for both sequences of 93%, 90% (p<0.05 vs. T1-T2 analysis), 100%, 100% and 80% (p<0.05 vs. T1-T2 analysis), respectively. CONCLUSIONS: CS MR imaging significantly improves characterization of adrenal masses compared with conventional T1-T2-weighted images, providing accuracy similar to that of the T1 sequence after Gd. Therefore, the CS sequence is strongly recommended for MR study of adrenal masses, and its use might obviate the need for Gd administration.

Adrenal Cortex Neoplasms↗

Imaging characterization of non-hypersecreting adrenal masses. Comparison between MR and radionuclide techniques.

AIM: In patients with non-hypersecreting adrenal masses, tumor characterization is clinically relevant to establish the appropriate treatment planning. The aim of this study was to comparatively characterize such adrenal lesions using MR and radionuclide techniques. METHODS: Thirty patients with non-hypersecreting unilateral adrenal tumors underwent both MR and adrenal scintigraphy. MR was performed using SE T1- (pre- and post-gadolinium DTPA) and T2-weighted images as well as in- and out-phase chemical-shift imaging (CSI). MR qualitative and quantitative (signal intensity ratios) evaluation was performed. Radionuclide studies consisted of iodine-131 nor-cholesterol (n=20), iodine-131 MIBG (n=15) and fluorine-18 FDG PET (n=11) scans. Histology (n=16), biopsy (n=3) or clinical-imaging follow-up (n=11) demomstrated 13 adenomas, 3 cysts, 2 myelolipomas, 4 pheochromocytomas (pheos), 4 carcinomas, 1 sarcoma and 3 metastases. Comparative imaging analysis was focused on adenomas, pheos and malignant tumors. RESULTS: Qualitative MR evaluation showed: signal T2-hyperintensity in 46% of adenomas and in 100% of pheos and malignant tumors, no gadolinium enhancement in 92% of adenomas and definite signal intensity loss on CSI in 100% of such tumor lesions, gadolinium enhancement in 100% of pheos and in 63% of malignancies and no absolute change of signal intensity on CSI in 100% of both pheos and malignancies. Quantitative MR analysis demonstrated: significantly higher signal T2-hyperintensity of pheos compared to adenomas and malignancies as well as significantly higher enhancement after gadolinium in pheos compared to adenomas and malignancies (p<0.03). Radionuclide studies showed significantly increased nor-cholesterol uptake only in adenomas (n=13), significant MIBG accumulation only in pheos (n=4) and FDG activity only in malignant adrenal lesions (n=8). CONCLUSION: MR techniques may provide some presumptive criteria to characterize non-hypersecreting adrenal masses, such as no gadolinium enhancement and definite signal intensity loss on CSI in adenomas or quantitatively measured T2-hyperintensity and gadolinium enhancement in pheos. On the other hand, radionuclide modalities offer more specific findings in this setting since nor-cholesterol and MIBG scans are respectively able to reveal benign tumors such as adenoma and pheochromocytoma, while FDG imaging allows identification of malignant adrenal lesions. Adrenal scintigraphy is recommended in those patients, when MR images are uncertain or inconclusive.

19-Iodocholesterol↗

FGD-PET in the follow-up of recurrent colorectal cancer.

OBJECTIVE: The current methods of detection of recurrent colorectal cancer after surgical treatment are inaccurate using conventional imaging. This study set out to detect early recurrence by means of PET in patients treated surgically for colorectal cancer by curative resection. METHODS: Thirty-one disease-free patients were recruited and underwent FDG-PET. The results were verified by clinical, surgical and radiological follow up and/or biopsy to evaluate the accuracy for detecting recurrence. RESULTS: PET detected 6 sites of increased activity in 5 patients. Three of these underwent surgery. One was false positive with no evident tumour and two underwent an hepatic resection with removal of a homental metastasis. The sensitivity was 100% and specificity 83.3%. Clinical management was altered in two cases (6.4%). CONCLUSIONS: This study demonstrates that PET is more accurate than conventional imaging for the evaluation of recurrence in colorectal cancer patients. FDG-PET should be considered in the follow-up of patients after treatment for colorectal cancer in addition to other imaging methods.

Adult↗

Diagnostic accuracy of radionuclide imaging using 131I nor-cholesterol or meta-iodobenzylguanidine in patients with hypersecreting or non-hypersecreting adrenal tumours.

The aim of this retrospective study was to evaluate the diagnostic accuracy of nor-cholesterol and meta-iodobenzylguanidine radionuclide imaging in two separate groups of patients with adrenal tumours to characterize lesions as adenoma or pheochromocytoma. We studied 75 patients (22 male and 53 female, mean age 47 +/- 15 years) with hypersecreting (n = 32) or non-hypersecreting (n = 43) unilateral adrenal tumours detected by computerized tomography or magnetic resonance scans. 131I nor-cholesterol adrenal scintigraphy was performed in 41 patients. Meta-[131I]iodobenzylguanidine (131I-MIBG) imaging was acquired in the other 34 patients. Pathology examinations (n = 58) or computerized tomography follow-up studies (n = 17) were obtained. Adrenal lesions were represented by 44 adenomas, four cysts, one myelolipoma, one pseudotumour, one ganglioneuroma, 16 pheochromocytomas, three carcinomas, four metastases and one sarcoma. Radionuclide studies were qualitatively evaluated and the corresponding results were classified as true positive, true negative, false positive and false negative. Diagnostic sensitivity, specificity and accuracy as well as positive and negative predictive values were calculated. The diagnostic values of nor-cholesterol scintigraphy in identifying adrenal adenomas were sensitivity 100%, specificity 71%, accuracy 95%, positive predictive value 94% and negative predictive value 100%; of note, two false positive cases were observed represented by a pheochromocytoma and a myelolipoma. The diagnostic values of MIBG scintigraphy in recognizing pheochromocytoma were sensitivity 100%, specificity 95%, accuracy 97%, positive predictive value 94% and negative predictive value 100%; only one false positive case occurred consisting of a carcinoma. It is concluded that, in the large majority of cases, adrenal scintigraphy using nor-cholesterol or MIBG is able to characterize specific lesions such as adenoma and pheochromocytoma, respectively. These findings show relevant clinical impact, particularly in patients with non-hypersecreting adrenal lasions. Radiotracer selection depends on clinical patient history and department availability; since benign adenomas are the most common cause of non-hypersecreting tumours, nor-cholesterol should be the first choice followed by MIBG if nor-cholesterol shows normal images. However, rare as well as unusual findings may be observed; nor-cholesterol uptake may occasionally be also found in non-adenoma tumours such as myelolipoma and pheochromocytoma. Similarly, MIBG accumulation may occur not only in lesions arising from medullary chromaffin tissue, but also rarely in cortical adrenal carcinoma.

19-Iodocholesterol↗

The diagnostic role of radionuclide imaging in evaluation of patients with nonhypersecreting adrenal masses.

UNLABELLED: The aim of this study was to evaluate the role of radionuclide imaging in the characterization of nonhypersecreting adrenal masses. METHODS: A total of 54 patients (19 men, 35 women; mean age, 50 +/- 16 y) with nonhypersecreting unilateral adrenal tumors that had been originally detected on CT or MRI underwent adrenal scintigraphy using different radiotracers. None of the patients showed specific symptoms of adrenal hypersecretion. Screening tests for excess cortical and medullary products showed normal adrenal hormone levels. Radionuclide studies (n = 73) included (131)I-norcholesterol (n = 24), (131)I-metaiodobenzylguanidine (MIBG) (n = 23), and (18)F-FDG PET (n = 26) scans. RESULTS: Histology after surgery (n = 31) or adrenal biopsy (n = 23) was obtained. Adrenal lesions were represented by 19 adenomas, 4 cysts, 1 myelolipoma, 1 neurinoma, 2 ganglioneuromas, 5 pheochromocytomas, 4 pseudotumors, 6 carcinomas, 2 sarcomas, and 10 metastases (size range, 1.5- to 5-cm diameter; mean, 4.9 +/- 3.1 cm). For norcholesterol imaging, diagnostic sensitivity, specificity, and accuracy were 100%, 71%, and 92%, respectively; the positive predictive value (PPV) of the norcholesterol scan to characterize an adrenal mass as an adenoma was 89%, whereas the corresponding negative predictive value (NPV) to rule out this type of tumor was 100%. For MIBG imaging, diagnostic sensitivity, specificity, and accuracy were 100%, 94%, and 96%, respectively; the PPV of the MIBG scan to characterize an adrenal mass as a medullary chromaffin tissue tumor was 83%, whereas the corresponding NPV to rule out this type of tumor was 100%. For FDG PET, diagnostic sensitivity, specificity, and accuracy were 100%, 100%, and 100%, respectively; the PPV of FDG PET to characterize an adrenal mass as a malignant tumor was 100%, whereas the corresponding NPV to rule it out was 100%. Furthermore, in 7 patients with malignant adrenal tumors, FDG whole-body scanning revealed extra-adrenal tumor sites (n = 29), allowing an accurate diagnosis of the disease's stage using a single-imaging technique. CONCLUSION: In patients with nonhypersecreting adrenal masses, radionuclide adrenal imaging, using specific radiopharmaceuticals such as norcholesterol, MIBG, and FDG, may provide significant functional information for tissue characterization. Norcholesterol and MIBG scans are able to detect benign tumors such as adenoma and pheochromocytoma, respectively. Conversely, FDG PET allows for recognition of malignant adrenal lesions. Therefore, adrenal scintigraphy is recommended for tumor diagnosis and, hence, for appropriate treatment planning, particularly when CT or MRI findings are inconclusive for lesion characterization.

19-Iodocholesterol↗

Imaging of adrenal tumors using FDG PET: comparison of benign and malignant lesions.

OBJECTIVE: The aim of this study was to differentiate benign from malignant adrenal tumors using positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with unilateral adrenal masses originally detected by CT or MR imaging. CONCLUSION: PET imaging with FDG can metabolically characterize adrenal masses. Abnormally increased FDG uptake in adrenal malignancies allows one to differentiate these abnormalities from benign lesions. Whole-body PET can also reveal extraadrenal tumor sites in patients with malignant tumors, using a single imaging technique for accurate disease staging.

Adolescent↗

Tc-99m sestamibi imaging in the diagnostic assessment of patients with lymphomas: comparison with clinical and radiological evaluation.

Tc-99m MIBI imaging has been used in nuclear oncology, but its role in detecting lymphomas has not been widely investigated. In this study, 31 patients with lymphomas (20 non-Hodgkin's and 11 Hodgkin's) underwent Tc-99m MIBI whole-body imaging. A total of 74 tumor lesions were detected in 25 patients, while the remaining 6 patients were disease-free. The diagnostic accuracy of MIBI imaging for lesion detection was 85%. A total of 11 unknown tumor lesions in 3 patients were discovered on MIBI scans. Tumor size was significantly (p = 0.01) higher in lesions with increased MIBI uptake (3.5 +/- 2.0 cm) compared with those with no uptake (1.8 +/- 1.0 cm). No false positive MIBI findings were observed. The accuracy of MIBI scintigraphy in patients with Hodgkin's disease was lower (72%) compared to that of patients with non-Hodgkin's lymphomas (94%). However, this difference was not related to tumor type, but to lesion size. In fact, tumor size was significantly (p = 0.02) lower in lesions of patients with Hodgkin's disease (2.5 +/- 1.3 cm) compared to those of patients with non-Hodgkin's lymphomas (3.7 +/- 2.2 cm). MIBI imaging may be useful in patients with lymphomas for detecting tumor lesions and, hence, may be considered an alternative to gallium scanning, providing better imaging quality. However, the intense Sestamibi activity in the lower chest and abdomen as well as tumor size may limit the diagnostic sensitivity of this radionuclide technique in patients with lymphomas.

Abdominal Neoplasms↗

[Magnetic resonance in the study of suprarenal neoplasms. Qualitative and quantitative analysis of signal intensity].

INTRODUCTION: Magnetic Resonance Imaging (MRI) has been proposed as the diagnostic technique of choice to characterize adrenal tumors. However, the results of the current studies are controversial. MATERIAL AND METHODS: Forty-nine patients with unilateral adrenal masses were submitted to MRI for lesion characterization on the basis of MR signal intensity. Cytology and/or histology demonstrated 14 pheochromocytomas (pheos), 11 adenomas, 3 cysts, 2 myelolipomas, 4 carcinomas, 3 metastases and 1 fibrosarcoma; a clinical diagnosis of adenoma was made in the remaining 11 patients. MR studies were performed using spin-echo (SE) sequences with T1 (TR/TE = 600/17 ms) and T2 (TR/TE = 2000/15-90 ms) weighting. T1-weighted images were also acquired after Gadolinium-DTPA (Gd-DTPA) administration. MR studies were integrated with in- and out-of-phase (TR/TE = 100/4-6 ms) chemical-shift (CS) sequences. MR signal intensity (SI) was analyzed qualitatively and quantitatively; MR results were correlated with tumor type and hormone secretion. RESULTS: The qualitative analysis of T2 images showed high signal intensity in the majority (80%) of adrenal lesions (14 pheos, 12 adenomas, 3 cysts, 2 myelolipomas and 8 malignancies). The quantitative analysis of post-Gd-DTPA T1 images permitted to distinguish adenomas, cysts and myelolipomas from pheos and malignancies. The qualitative analysis of post-Gd-DTPA T2 and T1 images permitted to distinguish pheos and cysts from adenomas and malignancies (p < .05); however, pheos and cysts as well as adenomas and malignancies were not differentiated. MR SI was similar in secreting and nonsecreting adenomas from both a qualitative and a quantitative viewpoints. CS MRI permitted to distinguish adenomas (decreased signal intensity on out-phase relative to in-phase images) from other benign and malignant lesions (no signal change from out-phase to in-phase images). CONCLUSIONS: The qualitative analysis of MR SI on conventional T1 and T2 images does not permit to differentiate adrenal masses. The qualitative evaluation of T1 images after Gd-DTPA administration, the quantitative analysis and CS sequences are technical options improving lesion characterization.

Adrenal Gland Neoplasms↗

[The heterogeneity of myocardial sympathetic innervation in normal subjects: an assessment by iodine-123 metaiodobenzylguanidine scintigraphy].

123I-radiolabeled metaiodobenzylguanidine (123I-MIBG) cardiac imaging has been used to evaluate the distribution of sympathetic nervous system (SNS) in the heart. Different heart diseases have shown impaired cardiac SNS distribution as reflected by MIBG activity. The aim of this study was to assess the cardiac distribution of SNS in normal subjects, using MIBG imaging. Ten normal subjects (1 male and 9 females, mean age 46 +/- 9 years) with no cardiac abnormalities underwent myocardial 123I-MIBG scintigraphy, Tc-99m methoxyisobutylisonitrile (MIBI) cardiac perfusion imaging and equilibrium radionuclide angiography (RNA). Regional myocardial MIBG and MIBI activities were quantitatively evaluated using a region of interest analysis. For this purpose, the left ventricle was divided into 6 myocardial regions as anterior, apical, inferior, septum, lateral and posterolateral. In particular, myocardial MIBG and MIBI activities were measured as myocardium to mediastinum ratio. Regional left ventricular function was assessed by RNA. Myocardial MIBG uptake was homogeneous in anterior (2.2 +/- 0.5), inferior (2.5 +/- 0.7), septal (2.4 +/- 0.4), lateral (2.3 +/- 0.4), and posterolateral (2.3 +/- 0.4) regions. Conversely, MIBG uptake was significantly lower in the apical region (1.9 +/- 0.3) compared to all other left ventricular segments (p < 0.05). Regional myocardial perfusion, as measured by MIBI uptake, was homogeneous in all regions. No regional left ventricular wall motion abnormalities were observed by RNA. In conclusion, our data suggest that a decreased MIBG uptake may be observed in the left ventricular apical region of normal subjects reflecting reduced sympathetic innervation of the apex. This finding is not related to myocardial perfusion or wall motion abnormalities. The knowledge of cardiac sympathetic innervation in normal subjects may be helpful to assess SNS abnormalities in heart disease.

3-Iodobenzylguanidine↗

Tc-99m MIBI scintigraphy in patients with lung cancer. Comparison with CT and fluorine-18 FDG PET imaging.

Tc-99m MIBI imaging has been used to evaluate patients with different neoplastic disorders, but its role in nuclear oncology has not been definitely established. In this study, we compared the results of Tc-99m MIBI (planar and SPECT imaging) with those of F-18 FDG PET radionuclide studies in 19 patients who had proven lung cancer. One patient was studied in follow-up. All patients underwent chest CT scans. MIBI and FDG images were qualitatively and quantitatively analyzed using region of interest analysis. Quantitative evaluation of MIBI and FDG activities in lung-tumor lesions was performed calculating tumor/nontumor ratios. On CT, 18 lung tumors were detected, while one patient was disease free. For lung lesions, the diagnostic sensitivity of planar MIBI imaging was 83%, while those of MIBI SPECT and FDG PET were both 100%. The quantitative analysis of lung-tumor MIBI and FDG activities showed that FDG uptake was significantly (P < 0.001) higher compared with MIBI uptake (5.5 +/- 3.1 vs 2.1 +/- 0.6); concordant MIBI and FDG images were found in 4 lesions in terms of central activity defect showing central necrotic tumor tissue. For lymph node abnormalities, planar MIBI scan only detected 3 lesions in 3 patients, whereas MIBI SPECT identified 9 lesions in 5 patients. FDG PET showed 13 lymph node abnormalities in 5 patients. This study shows similar results of Tc-99m MIBI SPECT and F-18 FDG PET in the diagnostic evaluation of patients with lung tumors. However, FDG lung tumor uptake was significantly higher compared with MIBI accumulation, suggesting a high glucose tumor metabolism. Thus, MIBI SPECT imaging may be useful to evaluate such patients and may be considered an alternative when PET is not available.

Adenocarcinoma↗

Rest-redistribution thallium-201 and rest technetium-99m-sestamibi SPECT in patients with stable coronary artery disease and ventricular dysfunction.

UNLABELLED: Resting sestamibi uptake was compared with 201Tl rest-redistribution uptake in 48 patients with ischemic heart disease and regional ventricular asynergies. METHODS: In 48 patients, rest/4-hr redistribution 201Tl and resting sestamibi tomography were closely performed on separate days. Segmental tracer uptake was quantified. Wall motion in corresponding segments was also assessed by two-dimensional echocardiography in 17 patients. RESULTS: Quantitative analysis indicates that the uptake of the two tracers was comparable in normal segments as well as in segments with fixed 201Tl defects. In contrast, in segments with reversible 201Tl defects, sestamibi uptake was significantly lower than redistribution 201Tl uptake. CONCLUSION: In patients with chronic ischemic heart disease and regional asynergies, quantified sestamibi activity parallels 201Tl redistribution activity in normal segments and in those with fixed 201Tl defects. In segments showing reversible 201Tl defects, whether or not dysfunctioning, sestamibi uptake is significantly lower than 201Tl redistribution.

Aged↗

[Evaluation of left ventricular function in patients with mammary carcinoma after treatment with epidoxorubicin using a high-dose, short-term protocol].

Anthracyclines are effective chemotherapeutic agents against various malignancies but their therapeutic value is limited by well-known dose-related cardiotoxicity, mainly induced by oxygen free radicals. Left ventricular diastolic and systolic functional abnormalities precede the clinical evidence of cardiotoxicity. The aim of this study was to evaluate the possible cardiotoxicity of epidoxorubicin administered as "high-dose short-term" protocol. Twenty patients (mean age 50.4 +/- 7.9 years) without cardiac disease, affected by advanced breast cancer were studied. All patients were treated with epidoxorubicin as neoadjuvant chemotherapy according to the new protocol "high-dose short-term" (cumulative dose 475.8 +/- 35.6 mg/m2, range 450-600 mg/m2, in 4-6 weeks). The effectiveness of cancer chemotherapy was monitored by clinical evaluation and mammography performed before and after treatment. All patients underwent color Doppler echocardiography and resting radionuclide angiocardiography in baseline condition and 30 +/- 10 days after the last cycle of chemotherapy. All patients showed a significant reduction of tumor lesion after chemotherapy. Left ventricular systolic and diastolic function parameters obtained by echocardiography (fractional shortening 33.1 +/- 4.5% vs 32.4 +/- 4.8%; ejection fraction 63.6 +/- 6.2% vs 62.9 +/- 5.7%; E/A ratio 1.73 +/- 0.64 vs 1.82 +/- 0.67; E wave deceleration time 204 +/- 24.6 ms vs 208.5 +/- 31.7 ms;isovolumetric relaxation time 79 +/- 15.7 ms vs 80 +/- 17.8 ms) and radionuclide angiocardiography (ejection fraction 62.4 +/- 7% vs 61.8 +/- 5.9; peak ejection rate 2.87 +/- 0.44 VTD/s vs 2.74 +/- 0.46 VTD/s; peak filling rate 2.72 +/- 0.54 VTD/s vs 2.6 +/- 0.58 VTD/s) did not show significant changes after treatment. In conclusion, our results suggest that epidoxorubicin administration using the "high-dose short-term" protocol in patients with breast cancer does not induce early significant abnormalities of left ventricular systolic and diastolic function.

Antibiotics, Antineoplastic↗

Technetium-99m tetrofosmin imaging in thyroid diseases: comparison with Tc-99m-pertechnetate, thallium-201 and Tc-99m-methoxyisobutylisonitrile scans.

Technetium-99m tetrofosmin is a lipophilic phosphine used for myocardial perfusion imaging. Biodistribution studies have shown significant thyroid uptake of tetrofosmin and preliminary reports have suggested that tetrofosmin imaging may be of value in patients with thyroid cancer. In this study, tetrofosmin whole-body scintigraphy was performed in 35 patients with evidence of thyroid diseases. All patients underwent laboratory evaluation of thyroid function as well as 99mTc pertechnetate scan, thallium-201 (n=16) 99mTc-methoxyisobutylisonitrile (MIBI) (n=19) whole-body studies. Thyroid images were semi-quantitatively analysed by a 4-point score: 0=no significant uptake; 1=uptake increased as compared to background activity, but inferior to normal thyroid tissue; 2=uptake equal to normal thyroid tissue; 3=uptake superior to normal thyroid tissue. Pathology examinations were obtained. A total of 41 thyroid nodules were detected, of which 15 were goitre nodules, 13 adenomas and 13 malignant lesions. In goitre nodules, concordant results of tetrofosmin and pertechnetate uptake (score 1 or 0) were observed in the majority of lesions (87%). In function adenomas (n=10), both tetrofosmin uptake and pertechnetate uptake were score 3. In non-function adenomas (n=3), tetrofosmin uptake was score 3, while pertechnetate uptake was score 0. In six malignant lesions, tetrofosmin uptake was score 3, while pertechnetate uptake was score 0; in the other seven lesions, where a prevalence of goitre abnormalities was observed, results of tetrofosmin and pertechnetate uptake were similar (score 0 or 1). In seven (70%) of the ten patients with malignant nodules, whole-body tetrofosmin images showed increased abnormal uptake in a total of 28 extra-thyroid tumour sites, as subsequently confirmed by other techniques. When tetrofosmin images were compared to 201Tl and 99mTc-MIBI scans, concordant results were observed in all cases. In conclusion, tetrofosmin imaging may be particularly useful to characterize and stage patients with malignant thyroid nodules; it shows similar results to thallium but provides better image quality. Comparable findings were observed between tetrofosmin and MIBI studies. Thus, tetrofosmin may be an alternative to thallium and MIBI in the aforementioned patients.

Adenoma↗

The role of radiolabeled somatostatin analogs in adrenal imaging.

We investigated the role of radiolabeled somatostatin analogs (SAs) in adrenal imaging. We evaluated 15 patients (6 men and 9 women, mean age 47 +/- 17 years) with imaging-detected adrenal tumors. Patient population was divided into two groups on the basis of the nature of adrenal lesions. Group 1 consisted of patients with benign adrenal lesions (n = 10). Group 2 consisted of patients with malignant adrenal lesions (n = 5). Pathology examinations were obtained in 13 cases: 7 pheochromocytomas, 2 adenomas, 2 cysts, 1 carcinoma, and 1 fibro-histiocytoma. One patient had a proven diagnosis of non-small-cell lung cancer associated with the presence of a right adrenal mass. The last patient had a clinical diagnosis of Werner syndrome associated with the presence of a large left adrenal mass. All patients underwent scientigraphic studies using radiolabeled SAs, of which indium-111 (In-111) pentetreotide was used in 11 cases and technetium-99m (Tc-99m)-labeled peptides (P-587 or P-829) were used in the remaining four cases. No significant labeled SAs uptake was observed in the majority (8 of 10, 80%) of the benign adrenal lesions (Group 1); however, increased uptake was found in two benign pheochromocytomas. Conversely, significant labeled SAs uptake was observed in the majority (4 of 5, 80%) of the malignant adrenal lesions (Group 2); however, the last lesion (carcinoma) did not show abnormal uptake. Results of this study show that the majority of benign adrenal tumors do not concentrate radiolabeled SAs; conversely, the majority of malignant adrenal lesions show significant SAs uptake, suggesting the presence of somatostatin receptors. This finding may allow the use of somatostatin as a treatment agent in malignant adrenal tumors. Thus, the main role of labeled SAs in adrenal imaging consists of lesion characterization rather than tumor detection and localization.

Adrenal Gland Neoplasms↗

[Computerized tomography with single photon emission (SPECT) with technetium-99m MIBI (99mTc-MIBI) in the identification of viable myocardium in patients with chronic ischemic cardiopathy and left ventricular dysfunction].

Resting 99mTc-MIBI cardiac imaging may be poorly accurate in identifying the presence of viable myocardium in patients with chronic coronary artery disease (CAD). In this study, we directly compared the results of resting 99mTc-MIBI SPECT with initial (1 hr) and delayed (5 hrs) images with those of 99mTc-MIBI SPECT after nitroglycerine (NTG) administration in 31 patients with chronic CAD. All patients also underwent rest-redistribution thallium-201 (201Tl) SPECT. In 8 patients, echocardiography was performed before and after coronary revascularization (Rev). Of 682 myocardial segments, 197 showed a marked reduction (< 50% of peak) in MIBI uptake on initial images. MIBI uptake (> or = 10%) was increased in 47 (24%) segments on delayed images (from 43 +/- 8% to 60 +/- 8%, p < 0.001) and in 54 (27%) segments after NTG (from 42 +/- 8% to 60 +/- 8%, p < 0.001). The results of delayed and NTG MIBI images were in agreement in most segments (n = 160, 81%). The results of delayed and NTG MIBI images were in disagreement in the remaining 37 (19%) segments. In particular, 15 segments showed reversible defects on delayed, but not on NTG MIBI images, while 22 on NTG, but not on delayed MIBI images. All the segments with reversible MIBI defects on delayed and/or NTG images were identified as viable on TI-201. In the 8 pts examined before and after Rev. 83% of segments with reversible MIBI defects on delayed images and 87% of those with reversible defects after NTG showed functional recovery after Rev; furthermore, in these patients a significant improvement in global left ventricular function was observed after Rev, as shown by ejection fraction values (from 42 +/- 7% to 47 +/- 7%, p < 0.01). These comparative results show that resting delayed and NTG MIBI imaging provide similar information to identify viable myocardium and to predict functional recovery after coronary Rev in chronic CAD.

Adult↗

Diagnostic imaging in patients with paragangliomas. Computed tomography, magnetic resonance and MIBG scintigraphy comparison.

OBJECTIVE: We compared iodine-131 metaiodobenzylguanidine (MIBG), computed tomography (CT) and magnetic resonance (MR) imaging studies in 40 patients with suspected or proven paragangliomas. PATIENTS: 21 patients were studied during the initial evaluation, while 19 were evaluated after surgery for paragangliomas. Furthermore, in 18 patients with benign (n = 10) or malignant (n = 8) tumors, MIBG uptake, MR signal intensity ratios (SIR) and CT parameters were analyzed. RESULTS: In patients studied during the initial evaluation, CT and MR had a significant (p < 0.05) higher diagnostic sensitivity (100% for both) compared to MIBG (82%); conversely, MIBG showed a higher specificity (100%) compared to CT and MR (50% for both); the accuracy of MIBG (86%), CT and MR (91% for both) were similar. In patients evaluated after surgery, MIBG and MR had slightly better sensitivity (85% for both) compared to CT (77%). MIBG showed again better specificity (100%) than CT and MR (83% for both); the accuracy of MIBG, MR and CT were respectively 90%, 84% and 79%. While no significant differences were observed in MR SIR and CT findings between benign and malignant tumors, MIBG uptake was significantly higher in malignant compared to benign lesions (p < 0.03). CONCLUSIONS: Our results suggest that CT and MR are particularly useful in the initial evaluation of patients with suspected paragangliomas. MIBG should be recommended during the post-surgical follow-up of such patients since recurrent, malignant or extra-adrenal disease frequently occur. Finally, while MR SIR and CT features are not able to distinguish malignant paragangliomas from benign tumors, MIBG uptake is higher in malignant lesions compared to benign tumors providing a diagnostic criterion to differentiate these lesions.

3-Iodobenzylguanidine↗