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Biomedical subjects

F Scopinaro

Publications and source records attributed to F Scopinaro.

At least 19 recordsLinked to original sources

111In-pentetreotide scintigraphy in the detection of insulinomas: importance of SPECT imaging.

UNLABELLED: The aim of this study was to determine whether the systematic use of SPECT can increase the reported low sensitivity of somatostatin receptor scintigraphy (SRS) in detecting insulinomas. METHODS: Fourteen patients were evaluated. After 111In-pentetreotide injection (approximately 250 MBq intravenously), abdominal SPECT images were obtained at 4 h and multiple planar images were obtained at 4 and 24 h. MRI and CT were performed within 1 mo of SRS. Sixteen tumors were histologically verified after surgery in 14 patients. RESULTS: SPECT revealed 14 lesions in 12 patients (sensitivity, 87.5%), both planar SRS and MRI revealed 7 tumors in 7 patients (sensitivity, 43.8%), and CT revealed only 5 lesions in 4 patients (sensitivity, 31.3%). Moreover, in 4 patients SPECT was the only examination with positive findings. CONCLUSION: SPECT at 4 h is mandatory for preoperative detection of insulinomas using SRS because the images are more sensitive than planar images and are superior to images from other conventional methods.

Female

Technetium-99m sestamibi single-photon emission tomography detects subclinical myocardial perfusion abnormalities in patients with systemic lupus erythematosus.

In patients with systemic lupus erythematosus, involvement of the cardiovascular system is the third leading cause of death. However, although autopsy studies have demonstrated a high incidence of abnormalities in both the myocardium and coronary vessels, clinical manifestations have been reported in only a small percentage of cases. The aim of this study was to evaluate myocardial perfusion in asymptomatic lupus patients using technetium-99m sestamibi single-photon emission tomography (SPET). Twenty-eight patients without overt cardiac involvement and risk factors were studied with 99mTc-sestamibi SPET at rest and after dipyridamole infusion. Perfusion abnormalities were detected in 18 cases: six had persistent defects, three had reversible defects, seven had both persistent and reversible defects, and two showed rest defects which normalized on dipyridamole images ("reverse redistribution pattern"). Coronary angiography was performed in eight patients with positive 99mTc-sestamibi SPET, and showed normal epicardial vessels in all the cases. These results indicate that 99mTc-sestamibi SPET reveals a high prevalence (18 out of 28 patients in this study, i.e. 64%) of myocardial perfusion abnormalities in asymptomatic lupus patients, probably due to the primary immunological damage of this autoimmune disease. In conclusion, rest/dipyridamole 99mTc-sestamibi SPET can be a useful non-invasive method to identify subclinical myocardial involvement in systemic lupus erythematosus, and patients potentially at risk of later cardiac events.

Adult

High-resolution scintimammography improves the accuracy of technetium-99m methoxyisobutylisonitrile scintimammography: use of a new dedicated gamma camera.

The main disadvantage of technetium-99m methoxyisobutylisonitrile (MIBI) prone scintimammography is its limited sensitivity for T1a and T1b cancers with a size of less than 1 cm. We have developed a high-resolution scintimammographic technique using a gamma camera based on a new concept, namely a position-sensitive photo-multiplier tube. The field of view of this camera, previously known as the SPEM (single photon emission mammography) camera, was 10 cm diameter. Scintimammographic images were acquired in the axial view; each breast was compressed to a thickness of 3-6 cm, modal class 4 cm. When the compressed breast was larger than the field of view, more than one study was performed in order to image the entire gland. Fifty-three patients were studied with high-resolution-scintimammography (HRSM) and Anger camera prone scintimammography (ACPSM). HRSM was performed 70 min after i.v. administration of 740 Mbq of (99m)Tc-MIBI; ACPSM images were acquired 10 and 60 min following the injection. Early 10-min ACPSM images were only evaluated for routine diagnostic purposes, while comparison was carried out between the 60-min ACPSM and 70-min HRSM images. At fine-needle aspiration (FNA) and/or open biopsy, 31 patients showed cancer: 15 T1c, 11 T1b and 5 T1a. In T1a-T1b cancers, the sensitivity of scintimammography was 50% with ACPSM and 81.2% with HRSM (P<0.01). Specificity was 86% with both techniques. HRSM is a promising new technique that improves the sensitivity of (99m)Tc-MIBI scintimammography in tumours sized less than 1 cm without apparently reducing its specificity. We are now working on a larger field-of-view camera.

Aged

Immunoscintigraphy of atherosclerotic uncomplicated lesions in vivo with a monoclonal antibody against D-dimers of insoluble fibrin.

To test the effectiveness of a new F(ab')2 monoclonal antibody against human fragment D-dimer of cross-linked fibrin in the detection of uncomplicated atherosclerotic lesions of the carotid vessel previously documented at echo-color-Doppler and selective arteriographic study, 8 patients underwent a scintigraphic study including dynamic and early and delayed (3 h later) static imaging of the neck after injection of a bolus of 99mTc-labeled monoclonal antibody, and were subsequently operated. Vessel specimens and blood samples were drawn at operation and counted. No adverse reaction occurred after administration of the monoclonal antibody. The atherosclerotic lesion appeared as a focal area of asymmetrical tracer uptake, already visible at early images in four patients, and at delayed images in five. The average tracer uptake ratio between pathological and normal vessels was 1.40+0.24 (P < 0.05) at time-activity curves derived from dynamic images, 2.17+/-0.97 (P < 0.05) at early static images and 2.05+/-0.98 (P < 0.05) at delayed static images, respectively. Mean vessel to blood uptake rate of specimens obtained at operation was 2.22+/-0.59 (P < 0.001). The study shows that the 99mTc-labeled antibody was found to be safe and capable of detecting atherosclerotic plaques in humans.

Aged

Recovery of contractility of viable myocardium during inotropic stimulation is not dependent on an increase of myocardial blood flow in the absence of collateral filling.

OBJECTIVES: The purpose of this study was to determine whether contractile recovery induced by dobutamine in dysfunctioning viable myocardium supplied by nearly occluded vessels is related to an increase in blood flow in the absence of collaterals. BACKGROUND: Dobutamine is used to improve contractility in ventricular dysfunction during acute myocardial infarction. However, it is unclear whether a significant increase in regional blood flow may be involved in dobutamine effect. METHODS: Twenty patients with 5- to 10-day old anterior infarction and > or =90% left anterior descending coronary artery stenosis underwent 99mTc-Sestamibi tomography (to assess myocardial perfusion) at rest and during low dose (5 to 10 microg/kg/min) dobutamine echocardiography. Rest echocardiography and scintigraphy were repeated >1 month after revascularization. Nine patients had collaterals to the infarcted territory (group A), and 11 did not (group B). RESULTS: Baseline wall motion score was similar in both groups (score 15.9+/-1.3 vs. 17.4+/-2.0, p = NS), whereas significant changes at dobutamine and postrevascularization studies were detected (F[2,30] = 409.79, p < 0.0001). Wall motion score improved significantly (p < 0.001) in group A both at dobutamine (-5.3+/-2.2) and at postrevascularization study (-5.5+/-1.9), as well as in group B (-3.9+/-2.8 and -4.5+/-2.4, respectively). Baseline 99mTc-Sestamibi uptake was similar in both groups (62.9+/-9.7% vs. 60.3+/-10.4%, p = NS), whereas at dobutamine and postrevascularization studies a significant change (F[2,30] = 65.17, p < 0.0001) and interaction between the two groups (F[2,30] = 33.14, p < 0.0001) were present. Tracer uptake increased significantly in group A both at dobutamine (+ 10.9+/-7.9%, p < 0.001) and at postrevascularization study (12.1+/-8.7%, p < 0.001). Conversely, group B patients showed no change in tracer uptake after dobutamine test (-0.4+/-5.8, p = NS), but only after revascularization (+8.8+/-7.2%, p < 0.001). CONCLUSIONS: The increase in contractility induced by low dose dobutamine infusion in dysfunctional viable myocardium supplied by nearly occluded vessels occurs even in the absence of a significant increase in blood flow.

Adult

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

Lupus carditis: evaluation with technetium-99m MIBI myocardial SPECT and heart rate variability.

The objective of this paper was to investigate the incidence of myocardial perfusion defects in patients with systemic lupus erythematosus (SLE) associated with dysautonomic alterations. Twenty patients without any sign or symptoms of heart disease, selected from a larger population of patients with SLE, underwent technetium-99m sestamibi (Tc-99m MIBI) single photon emission computed tomography (SPECT), at rest and after dipyridamole infusion; they also underwent heart rate variability (HRV) examination by a 24 hour ambulatory electrocardiography, analyzing in the time domain the standard deviation of the R-R intervals average (SDNN) and the percentage of R-R adjacent intervals differing from each other more than 50 msec (pNN50); in the frequency domain the low (LF) and high frequencies (HF) were analyzed. Twenty healthy volunteers served as control group for heart rate variability. At MIBI-SPECT examination, the scan was found abnormal in 15 patients and normal in five: three patients demonstrated reversible defects in the anteroseptal region, four had irreversible defects in a region (two in the anteroseptal region and two in the lateral region), two had rest defects in two different regions (lateral and inferior, lateral and anteroseptal) that improved during dipyridamole scan, and six had both reversible and irreversible defects: four in a single segment (three anteroseptal and one lateral, and two in two different regions, particularly anteroseptal and lateral, lateral and inferior). All 20 patients showed significantly lower HRV parameters in comparison with the control group, except for pNN50, which indicates decreased physiologic periodic fluctuations of the autonomic nervous system. In six patients who underwent coronary angiography, the epicardial vessels were found completely normal. In view of the high incidence of myocardial hypoperfusion in patients with HRV alterations, the authors hypothesize that autonomic dysfunction may be associated with microvascular disease or metabolic alteration. They also believe that MIBI scintigraphy is a suitable technique in detecting myocardial damage in SLE patients free of clinical manifestation.

Adolescent

Single photon emission computed tomography procedure improves accuracy of somatostatin receptor scintigraphy in gastro-entero pancreatic tumours.

In patients with gastro-enteropancreatic neuroendocrine tumours the localization of all the neoplastic lesions and an accurate staging of the diseases have important therapeutic implications. Somatostatin receptor scintigraphy with In-111 pentatreotide has proved to be useful in detecting gastro-enteropancreatic tumours; however, the role of abdominal single photon emission computed tomography has not yet been definitively established. In a series of 52 patients with gastro-enteropancreatic tumours (9 non-functioning islet cell carcinomas, 4 insulinomas, 3 somatostatinomas, 2 VIPomas, 1 glucagonoma and 33 carcinoids) we compared somatostatin receptor scintigraphy with the results of computed tomography and magnetic resonance imaging performed within one month. Four and 24-hour total body planar images and 4-hour abdominal single photon emission computed tomography were acquired after the i.v. injection of approximately 250 MBq of In-111 pentatreotide. Only abdominal localizations were considered: planar scans detected 16 extrahepatic lesions in 13 patients and 54 liver sites in 21 patients; single photon emission computed tomography visualized 31 extrahepatic lesions and 89 liver metastases in 27 and 28 patients, respectively; computed tomography and magnetic resonance imaging detected 11 extrahepatic lesions in 10 patients and 73 liver sites in 21 patients. In-111 pentatreotide single photon emission computed tomography was the only imaging method able to localize tumoural lesions in 13 patients; all these localizations were then histologically verified. The scintigraphic positivity did not depend on the site or on the presence of hormonal hypersecretions. In conclusion, our results indicate that single photon emission computed tomography is more sensitive than planar images and computed tomography/magnetic resonance imaging in detecting abdominal gastro-enteropancreatic tumours and their metastases; it is able to increase both the number of visualized lesions and that of patients with positive findings. Single photon emission computed tomography is particularly useful in patients in whom tumoural lesions have not been already localized; it should be the first imaging modality in patients with gastro-enteropancreatic tumours: its initial use will result in more information and proper management.

Female

Preoperative identification of viable myocardium: effectiveness of nitroglycerine-induced changes in myocardial Sestamibi uptake.

In order to predict tissue viability in infarcted myocardial areas, changes induced by nitroglycerine infusion on Sestamibi myocardial uptake were evaluated in 37 patients with previously confirmed myocardial infarction undergoing coronary artery bypass grafting, and compared with echocardiographic and perfusional changes occurring after the operation. The improvement of Sestamibi uptake after nitroglycerine correctly classified 24/26 (92%) patients showing postoperative improvement of wall motion in the infarcted area, whereas 24/31 (77%) patients with nitroglycerine-induced increase in Sestamibi uptake had improved wall motion after operation. The presence of collateral flow to the infarcted area was associated with a significantly (P < 0.01) higher increase in Sestamibi uptake both during nitroglycerine infusion and postoperatively. An increase in wall motion score after operation was associated with a significantly higher (P < 0.05) increase in Sestamibi uptake score during nitroglycerine infusion. Thus, the results of this study suggest that Sestamibi perfusional myocardial scintigraphy during nitroglycerine infusion is capable of assessing viable but chronically hypoperfused myocardium and predicting postoperative wall motion and perfusional improvement, to yield the best results in patients with evidence of collateral circulation that supplies the infarcted area.

Aged

Role of 99mTc-Sestamibi scintimammography by SPEM camera in the management of breast cancer in the elderly.

The incidence of breast cancer in the elderly is 10 fold higher than in the population younger than 65 years. Moreover, in this segment of the population there are not defined clear practice guidelines regarding patient management. X-ray mammography, the most widely used diagnostic technique, is often inadequate to differentiate benign from malignant lesions. 99mTc Sestamibi scintimammography plays an important role as complement to mammography; in fact it is a very sensitive and specific method for breast cancer detection, when cancers > 1 cm diameter are considered. However, sensitivity values fall to 50-60% in the case of small tumors (T1a and T1b). In this study we present the results of a new Small Field Of View (SFOV) Gamma Camera with very high spatial resolution that allows the first Single Photon Emission Mammography (SPEM). Eighteen patients aged 71 +/- 6 years with mammographically detected breast lesions were submitted to a Prone Scinti Mammography (PSM) by conventional Gamma Camera and to a SPEM on craniocaudal view. A final diagnosis was reached by histopathology. SPEM correctly diagnosed 15 of 16 cancers, while PSM was not able to recognize 5 malignant lesions with subcentimeter size. Both the techniques provided normal findings in the case of benign lesions. The 99mTc Sestamibi scintimammography, particularly when performed by SPEM camera, is a sensitive, specific, and non invasive method to define the nature of radiologically described breast masses and would be very useful as a complement to X-ray mammography in screening programs for breast cancer.

Aged

Functional and ultrastructural evidence of myocardial stunning after acute carbon monoxide poisoning.

OBJECTIVE: To study human myocardial ultrastructural changes after carbon monoxide (CO) poisoning inducing reversible cardiac failure. DESIGN CASE REPORT: clinical, functional and morphologic findings. SETTINGS: Public university-affiliated hospital and electron microscopy laboratory. PATIENT: A 25-yr-old woman with functional evidence of cardiac failure after acute CO poisoning. INTERVENTIONS: Hyperbaric and intensive care treatment over 10 days. Scintigraphic and cardiac angiography with endomyocardial biopsy. MEASUREMENTS AND MAIN RESULTS: Scintigraphy with 99mTc hexakis 2-methoxy-2-isobutyl isonitrile (sestaMIBI) showed an uptake defect in the left anterior descending artery territory. The cardiac angiography demonstrated a slight hypokinesis of the superior two thirds of the anterior wall and of the septal region with completely normal coronary angiograms. Electron microscopy of left ventricular biopsies showed slight ultrastructural changes in the myocytes. In addition, large glycogen deposits were mostly associated with swollen mitochondria. The patient was discharged in good clinical condition on day 10. CONCLUSIONS: Presence of glycogen deposits associated with abnormal mitochondria may be signs of the incapability of myocardial cells in utilizing energy substrata. In the presence of normal myocardial perfusion, our findings are consistent with the presence of a stunned myocardium-like syndrome. Early recognition and treatment of this clinical syndrome allow the prevention of myocardial infarction.

Adult

Noninvasive estimate of bile flux through the gallbladder in humans.

OBJECTIVE: The aim of this study was to assess whether a single noninvasive technique, ultrasonography, is able in vivo: 1) to evaluate the time-related patterns of gallbladder bile storage and emptying, and 2) to quantitate the amount of bile flux through the gallbladder (GB). METHODS: Healthy volunteers were submitted to the simultaneous assessment of gallbladder volume variations by frequent serial ultrasonographic (US) measurements and of hepatic bile flow through the GB by quantitative cholescintigraphy (QC) during continuous i.v. infusion of 99 mTc-HIDA. An ad hoc mathematical analysis of US GB volume measurements was used to estimate the amount of bile flux through the GB. The QC-derived measurements of the flux of hepatic bile through the GB was used to substantiate the US-derived estimates. RESULTS: The curves expressing the time-related GB handling of hepatic bile obtained independently from US and QC measurements were statistically equivalent, and both techniques showed that the patterns and the amount of hepatic bile handled by the gallbladder after meal ingestion is remarkably different during three successive phases. After meals, hepatic bile was mainly 1) stored in the GB in the first phase; 2) emptied from the GB in a second phase; and 3) stored in the GB in the third phase. The ultrasonographic analysis estimated that 1) 23.8+/-12.5 ml (0.44+/-0.11 ml/min), 5.1+/-3.9 ml (0.15+/-0.10 ml/min), and 33.2+/-10.5 ml (0.53+/-0.16 ml/min) of hepatic bile entered into the GB during the three successive postprandial phases, and 2) the entire amount of bile flowing bidirectionally through the cystic duct, during the observation period (132.6+/-23.3 ml) was about five-fold greater than that estimated by the usually employed variables. CONCLUSION: The proposed mathematical analysis of frequent ultrasonographic measurements of the GB volumes enables one to estimate noninvasively the flux of bile through the gallbladder in humans.

Adult

Use of the somatostatin analogue octreotide to localise and manage somatostatin-producing tumours.

BACKGROUND: Somatostatin receptor scintigraphy (SRS) and octreotide therapy have both changed the management of gastroenteropancreatic endocrine tumours, but very few data are available on the use of SRS and octreotide to visualise and treat somatostatinomas. METHOD: The results of SRS and octreotide treatment in three somatostatinoma patients were examined. RESULTS: SRS was able to detect extensive hepatic involvement in patient 1, one hepatic and one pancreatic lesion in patient 2, and one hepatic lesion in patient 3. Octreotide therapy (0.5 mg/day subcutaneously) was effective in decreasing plasma levels of somatostatin in all three patients. Symptoms (diabetes and diarrhoea) were greatly improved in the two patients with "somatostatinoma syndrome". CONCLUSION: The study shows that somatostatinoma, like most other gastroenteropancreatic endocrine tumours, possesses functioning somatostatin receptors.

Aged

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