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Biomedical subjects

M Ierardi

Publications and source records attributed to M Ierardi.

At least 19 recordsLinked to original sources

Reliability of visual and quantitative hepatobiliary scintigraphy in the follow-up of patients who have undergone cholecystectomy and transduodenal sphincteroplasty.

A noninvasive scintigraphic technique to assess the efficacy of a surgical procedure (e.g., cholecystectomy and transduodenal sphincteroplasty) depends on the development of reliable and accurate qualitative or quantitative diagnostic criteria that allow early recognition of the occurrence and site of complications. For this purpose, the authors divided biliary flow into a four-step progression process and analyzed transit times from the peripheral vein to the gallbladder, common bile duct, and duodenum and the transit time from the common bile duct to the duodenum. These quantitative parameters were assessed in nine healthy volunteers and 31 asymptomatic patients who had previous cholecystectomy to validate their reliability. The results indicate that the four-step Tc-99m HIDA progression analysis provides a reliable, noninvasive evaluation of biliary flow, so that it can be applied to patients who have had cholecystectomy.

Adult↗

Immunoscintigraphy of venous thrombi: clinical effectiveness of a new antifibrin D-dimer monoclonal antibody.

Safety and thrombus imaging capabilities of the 99mTc-labeled form of a new F(ab')2 monoclonal antibody (MoAb) against fragment D dimers from cross-linked human fibrin, previously shown to be effective labeled to 131I in detecting venous thrombi in the rabbit, were investigated. Sixteen patients (seven men, mean age: 60+/-7 years) with deep (n = three) and superficial (n = 13) venous thromboses of the lower limbs documented at echo-Doppler study underwent, 24 hours before saphenous vein stripping, a scintigraphic study after IV injection of the 99mTc-MoAb (1,129+/-275 MBq/mL), acquiring dynamic images, as well as early and delayed static images of lower limbs. Tracer activity was compared in normal and pathologic areas. At the operation, vessel wall including the thrombotic lesion was isolated, weighed, and counted. Blood radioactivity and MoAb concentration were also measured. No adverse reaction was observed after MoAb administration. Thrombus site appeared as a focal area (hot spot) of asymmetrically increased tracer uptake, already detectable at early images in all patients. All thrombi detected at echo-Doppler study (n=25) were confirmed at scintigraphic study, which showed four additional hot spots subsequently confirmed to represent thrombi at operation. Average percent ratio between pathologic and normal regions was 1.51+/-1.34 (p < 0.05) at time-activity curves, 2.27+/-1.1 (p < 0.05) at early static images, and 2.15+/-1.2 (p < 0.05) at delayed images, respectively. Thrombus-to-blood uptake ratio was 4.3+/-0.9 (p < 0.01). The F(ab')2 MoAb proved to be safe, and low levels of antimouse antibodies were detected in response, although further studies are needed to assess tolerance and effectiveness in case of a second administration in the same patient. The 99mTc-labeled MoAb was very effective in identifying venous thromboses both at deep and superficial localizations, although its sensitivity and specificity need be evaluated in a more numerous group, including also patients with different and clinically more relevant localizations, such as caval thromboses. However, the possibility of obtaining high-quality images within 4 hours of MoAb administration is clinically relevant, and carries also therapeutic implications, especially in pulmonary thromboembolism.

Antibodies, Monoclonal↗

99mTc SESTAMIBI scintigraphic evaluation of skeletal muscle disease in patients with systemic sclerosis: diagnostic reliability and comparison with cardiac function and perfusion.

The diagnosis of skeletal muscle involvement in patients with systemic sclerosis (SSc) is usually based on clinical, laboratory, electromyographic, and bioptic evidence of muscle disorder, whereas SSc cardiac disease is well established by nuclear medicine techniques (radionuclide ventriculography and myocardial scintigraphy). Previous reports have retrospectively hypothesized a possible relationship between cardiac and muscle involvement in scleroderma patients. In order to improve overall diagnostic accuracy in the qualitative/quantitative assessment of skeletal muscle involvement in these patients and to compare these results with those obtained at the cardiac level, diethylenetriaminepentaacetic acid (DTPA)-99mTc radionuclide ventriculography and 99mTc SESTAMIBI myocardial and muscular scintigraphic examinations were performed in 10 SSc patients and in five healthy subjects. Muscular radioactivity, as assessed at thigh and calf levels by means of a segmental score, was significantly decreased in SSc patients in comparison with healthy subjects (global score value 15.6+/-2.2 vs 22.7+/-1.6, p<0.001), as well as right ventricular ejection fraction (RVEF, 34.3%+/-5.3 vs 53.6%+/-4.2, p<0.001) and myocardial segmental perfusion (global score value, 19.6+/-2 vs 25.9+/-1.1, p<0.01). The results show a high frequency of skeletal muscle involvement in patients with SSc. Moreover, scleroderma patients with muscle disorders, as evidenced by scintigraphy, show a comparable occurrence of cardiac involvement, even in the absence of clinical signs of cardiac dysfunction.

Cardiomyopathies↗

99mTc MIBI prone scintimammography in patients with suspicious breast cancer: relationship with mammography and tumor size.

99mTc MIBI prone scintimammography (PSM) is reported to be a specific examination in order to assess the nature of breast lesions. Fifty-three patients whose mammography was stratified according to the breast imaging reporting and data system (BI-RADS), the five category classification of mammography approved by the American college of radiology, were studied with prone scintimammography, with the aim of assessing the accuracy of this exam and its usefulness in clinical practice. Thirty-five out of forty-one patients with BI-RADS category V (high probability of cancer) showed cancer at histology. Thirty-one of them had positive PSM. Three out of the six patients with mammo-graphic features of category IV indicated malignancy. PSM was positive in all of them and negative in the three benign lesions. One of the five patients with category III mammography showed cancer and positive PSM. The PSM was negative in 12/13 patients with benign patology (specificity 92.3%). When the cancers were stratified for T-category significant differences were found between the sensitivity for tumors larger or smaller than 1 cm. The sensitivity was 50% for the cancers smaller than 1 cm and 96.9% for those larger than 1 cm. PSM is a very specific method to determine the nature of breast lesions. Its sensitivity is also high but has to be improved when tumors smaller than 1 cm have to be detected. From a clinical point of view PSM can at the moment be considered as an accurate method for the study of borderline lesions of IV and also of III BI-RADS category. In this case a positive PSM indicates an impact in clinical decision making.

Breast Diseases↗

99mTc-HMPAO granulocyte scintigraphy in the early detection of postoperative asymptomatic recurrence in Crohn's disease.

The usefulness of 99mTc-HMPAO scintigraphy in the early detection of postoperative recurrence of Crohn's disease was evaluated in 17 patients undergoing ileocecal resection and prospectively followed up for one year. Scintigraphy was performed 6 and 12 months after surgery and recurrence assessed by colonoscopy within two weeks. As controls, four patients with ileocecal resection for cecal carcinoma were studied. To perform scintigraphy, autologous granulocytes were labeled with 99mTc-HMPAO, injected, and tau-camera images acquired after 30 min and 3 hr. Six months after surgery, 4/8 Crohn's disease patients showed endoscopic recurrence, and 30-min scintigraphy was positive only in these four patients (four true positives, four true negatives). At 12 months, endoscopic recurrence was detected in 10/14 Crohn's disease patients, and 30-min scintigraphy was positive in 9/14 patients (eight true positives, three true negatives, two false negatives, one false positive). Scintigraphy at 3 hr showed a lower specificity in detecting CD recurrence both at 6 and 12 months. The endoscopic and 30-min scintigraphic score were significantly correlated both at 6 and 12 months (P = 0.007; P = 0.04). Scintigraphy was negative in 4/4 controls at 30 min (four true negatives) and positive in 1/4 (one false positive) at 3 hr. We conclude that 99mTc-HMPAO scintigraphy at 30 min is a sensitive technique for the early detection of Crohn's disease recurrence in patients under regular follow-up after surgery.

Adult↗

Scintigraphic imaging of hepatic epithelioid hemangioendothelioma.

The epithelioid hemangioendothelioma of the liver has been recently characterized as a rare tumor with distinctive pathological features affecting young adults. Our report describes a case of histologically confirmed primary epithelioid hemangioendothelioma of the liver, diagnosed by clinical examination as well as radiological (CT/MR) and scintigraphic imaging (labelled red cells/ phytate-SPECT). This case highlights the usefulness of nuclear medicine techniques during the diagnostic of this rare tumor. Further it stresses the possibility of employing an easy and noninvasive method to adequately follow-up those patients who cannot be considered as disease-free even after orthotopic liver transplantation because of the recurrence of the disease in the transplanted liver.

Diagnostic Imaging↗

99mTc anti-D-dimer MoAb detects venous thrombi in man.

Authors' work is based on the ability of a 99mTc labelled antibody (MoAb) against D-Dimer (D-D) to visualize thrombi in man. D-Dimer is a specific epitope created during the cross-linking process of fibrin strains. Five normal volunteers and 5 patients with leg varices were given 10 mCi of 99mTc anti-D-Dimer MoAb (research approved by our Ethical Committee). Each patient gave his informed consent. Scintigraphic images were taken at 5, 60, 180 min. No adverse reaction was observed. Two patients underwent saphenous stripping 3 hrs after injection, in the other 4 patients scintigraphic images were acquired at 6 and 8 hrs. Twelve hot spots were visualized. Of these, 5 were localized during operation with a pencil-like probe and exsected. Specific activity of exsected thrombi, saphenal walls and blood samples was measured. Thrombus to vein wall ratio of 2.2 +/- 0.6 and a thrombus to blood of 3.1 +/- 0.8 was measured. In non operated patients the best scintigraphic images were obtained between 60 and 180 min. 99mTc anti-D-Dimer MoAb is a promising agent for localization of thrombi.

Antibodies, Monoclonal↗

Inhaled nitric oxide in patients with severe heart failure: changes in lung perfusion and ventilation detected using scintigraphy.

Inhaled nitric oxide (NO) is a selective pulmonary vasodilator in patients with end-stage cardiac failure. Preoperative high pulmonary vascular resistance could modify early and late results after heart transplantation generally due to right-ventricular failure. Aim of this study was to assess pulmonary vascular resistance variability following inhalation of NO by using a scintigraphic method. Our preliminary results suggest that inhaled NO in patients with end-stage heart failure redistributes blood away from apical regions and towards more basal and posterior segments, probably dilating blood vessels in ventilated but nonperfused zones. NO may represent a simple and reliable method to evaluate dynamic response of pulmonary vasculature.

Administration, Inhalation↗

Preliminary evaluation of the usefulness of Tc-99m (V) DMSA in pancreatic neuroendocrine tumors.

The authors describe the possible application of Tc-99m (V) DMSA scintigraphy in pancreatic neuroendocrine tumors. In consideration of the common embryonic origin of these tumors and other neoplastic diseases (medullary thyroid carcinoma, pheocromocytoma, neuroblastoma) that have been well studied with radionuclide imaging, five cases of pancreatic neuroendocrine tumors (two insulinomas, one vipoma, and two unclassified neuroendocrine tumors) were successfully visualized with Tc-99m (V) DMSA scintigraphy, thus giving an overall "imaging confirmation" of the histologic and/or cytologic results in terms of primary and metastatic localization. The authors point out the importance of their results, obtained in a simple and repeatable manner, and suggest a real comparison in this setting between this approach and octreotide scintigraphy.

Female↗

Muscular uptake of Tc-99m MIBI and TI-201 in Duchenne muscular dystrophy.

Lack of dystrophin, a protein localized to the inner surface of the sarcolemma of the muscle fiber, is the cause of Duchenne type muscular dystrophy. Plasma membrane damage of the muscular fiber occurs, followed by Ca++ influx into the fibers. There is severe mitochondrial damage in dystrophic but still viable fibers. Five children aged 5-7 years were studied with MRI, TI-201, and Tc-99m sestamibi scintigraphy of the thighs. These three methods showed that the sartorius is the least damaged muscle in Duchenne type muscular dystrophy. MRI showed mild damage of adductors and quadriceps; TI-201 scintigraphy showed a marked reduction of radioactivity in the same muscles; Tc-99m sestamibi uptake occurred only in the sartorius muscle; the quadriceps was not imaged and adductors showed a faint image. A decrease of water in muscular fibers as well as fatty fibrous substitution, occurs after death of the fibers, whereas plasma membrane and mitochondrial damage reduced the uptake of tracers when the fiber is still viable. The interesting mismatch between sestamibi and TI-201 can be explained by considering that the cellular mechanism of uptake and retention of Tc-99m sestamibi involves both plasma membrane and mitochondria, whereas the uptake of TI-201 is only affected by plasma membrane damage.

Child↗

99m Tc MIBI prone scintimammography in breast Paget's disease: a case report.

A 99m Tc MIBI prone scintimammography (PSM) was performed in a case of underlying Paget's disease of the breast. 99m Tc MIBI PSM showed a diffuse scintigraphic image like a spread of uptake from the deeply located zones of the breast toward epidermis. In vivo, 99m Tc MIBI PSM represents the spread of neoplastic Paget's cells probably attracted by chemotactic factors released by keratinocytes. This spread in Paget's disease is correlated to neu oncogene overexpression which increases the metastatic activity as a consequence of motility enhancement and growth stimulation effect. These scintigraphic images suggest that 99m Tc MIBI PSM could be relevant in management of Paget's disease of the breast.

Biomarkers, Tumor↗

[Clinical use of echo-dipyridamole test in hypertensive subjects with suspected ischemic heart disease].

The aim of this study was to assess the diagnostic capacity of the dipyridamole-echocardiography test (DET) and dipyridamole myocardial scintigraphy (DMS) for coronary artery disease in mild to moderate hypertensive subjects with chest pain. A comparison was performed with exercise stress test (EST) and stress myocardial scintigraphy (SMS) in 20 subjects. Seven patients also underwent coronary angiography. To compare test results, Mc Nemar test was employed. Our results showed a statistically significant difference between DET and EST and a good agreement, in terms of dichotomy response, between DET and SMS. Any difference was further found between SMS and DMS. In conclusion, in hypertensive subjects, DET appears to provide a useful clinical noninvasive tool for coronary artery disease diagnosis and evaluation.

Adult↗

99mTc MIBI scintimammography with a high resolution single tube gamma camera: preliminary study.

99mTc MIBI scintimammography is a sensitive and specific diagnostic technique for breast cancer detection when cancers more than 1 cm sized are considered. However the sensitivity falls in the case of submillimetric lesions. We developed a new Small Field of View, High Resolution Detector, able to image the breast in similar conditions of x-ray mammography: it allows the performance of Single Photon Emission Mammography (SPEM) studies. Seven patients with suspicion of malignant lesions were comparatively submitted to a Prone Scintimammography (PSM) by Anger camera and to a cranio-caudal view SPEM. The final diagnosis was reached by histopathology. Four malignant lesions were identified by SPEM but not by PSM, which that failed to image two submillimetric cancers. Both the cameras gave normal findings for benign lesions, confirming the high sensitivity of this technique. The results allow us to consider the SPEM camera as promising to improve scintimammographic sensitivity, even when small-sized tumors are examined.

Breast Diseases↗

A three center study on the diagnostic accuracy of 99mTc-MIBI scintimammography.

In order to assess specificity and sensitivity of the prone scintimammography (PSM) in a large series with 99m-Tc MIBI, we performed a three-center study; 420 patients were studied; after mammography all the patients were submitted to PSM and biopsy and/or operation. PSM was considered positive if hot spot within the breast was observed. In palpable masses sensitivity was 0.98 and specificity 0.89, non palpable masses showed a sensitivity of 0.62 and a specificity of 0.91. When the cancers were stratified for T category the sensitivity was 0.28 in T1a 0.26 in the group of T1a carcinomas, 0.56 in T1b 0.95 in T1c and 0.97 T2 tumors. Physical factors such as attenuation. Compton scattering from chest, as well as biological factors have a role in breast tumor imaging. In the tumors smaller than 1 cm biological factors are probably involved too.

Adult↗

99mTc-MIBI prone scintimammography in patients with high and intermediate risk mammography.

Mammographic lesions can be classified into categories of high (HR), intermediate (IR) and low risk of breast cancer. We have performed 99mTc MIBI scintimammography on 85 patients with high or intermediate risk lesions in order to verify its ability to diagnose cancer before biopsy. The scintimammography was performed in prone lateral view; all the patients were submitted to excisional biopsy. HR lesions showed 86% of cancers and scintigraphic accuracy of 0.81. The accuracy of scintimammography was 0.97 in lesions larger than 1 cm. IR lesions showed 47% of cancer with scintigraphic accuracy of 0.95. The scintigraphic sensitivity was 0.97 lesions larger than and 0.50 in lesion smaller than 1 cm, whereas the specificity was always about 90%. Our results suggest that scintimammography can substantially decrease the need of biopsy for breast cancer diagnosis.

Adult↗

Single tube gamma camera for scintimammography.

The development of large area Position Sensitive Photo Multiplier Tubes (PSPMT) by Hamamatsu is opening new imaging possibilities in Nuclear Medicine. In particular the realization of the 8" PSPMT prototype represents the first important technological advantage since the discovery of the Anger Camera. PSPMT virtually integrates in one hundreds PMT allowing the creation of dedicated detectors. A Single Tube Gamma Camera based on a 5" PSPMT dedicated to scintimammography is presented and discussed in this work. To optimize gamma camera response two different scintillating arrays were tested: YAP:Ce and CsI (Tl). Their overall size cover all photocathode active area, and crystal pixel size was 2 mm x 2 mm. The detection efficiency was comparable to that of Anger Camera. The best result was obtained by CsI (Tl) scintillating: an intrinsic spatial resolution of 1.6 mm FWHM and a relative energy resolution of 17% FWHM. New image possibilities in scintimammography are offered by Single Tube Gamma Camera operating in the same radiological projection of RX mammography.

Breast Neoplasms↗