Cognition and amyloid load in Alzheimer disease imaged with florbetapir F 18(AV-45) positron emission tomography.

OBJECTIVE: To examine the association between regional brain uptake of a novel amyloid positron emission tomography (PET) tracer florbetapir F 18 ([(18)F]-AV-45) and cognitive performance in a pilot study. DESIGN: Cross-sectional comparison of [(18)F]-AV-45 in AD patients versus controls. SETTING: Three specialty memory clinics. PARTICIPANTS: Eleven participants with probable Alzheimer disease (AD) by NINDS/ADRDA criteria and 15 healthy comparison (HC) participants. MEASUREMENTS: Participants underwent PET imaging following a 370 MBq (10 mCi) intravenous administration of [(18)F]-AV-45. Regional/cerebellar standardized uptake value ratios (SUVRs) were calculated. Cognition was assessed using Mini-Mental State Examination, Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Wechsler Logical Memory IA (immediate recall) test (LMIA), and verbal category fluency. RESULTS: Greater [(18)F]-AV-45 SUVR was associated with poorer performance on all cognitive tests. In the HC group, occipital, parietal, precuneus, temporal, and cortical average SUVR was associated with greater ADAS-Cog, and greater anterior cingulate SUVR was associated with lower LMIA. Two HC participants had [(18)F]-AV-45 cortical/cerebellar SUVR greater than 1.5, one of whom had deficits in episodic recall and on follow-up met criteria for amnestic mild cognitive impairment. CONCLUSION: [(18)F]-AV-45 SUVR in several brain regions was associated with worse global cognitive performance particularly in HC, suggesting its potential as a marker of preclinical AD.

Acute thromboscintigraphy with (99m)Tc-apcitide: results of the phase 3 multicenter clinical trial comparing 99mTc-apcitide scintigraphy with contrast venography for imaging acute DVT. Multicenter Trial Investigators.

UNLABELLED: (99m)Tc-apcitide (formerly known as (99m)Tc-P280) is a radiolabeled peptide that binds with high affinity and specificity to the glycoprotein IIb/IIIa receptors expressed on the activated platelets that are involved in acute thrombosis. The purpose of the phase 3 multicenter clinical trials was to compare (99m)Tc-apcitide scintigraphy with contrast venography for imaging acute deep venous thrombosis (DVT). METHODS: A total of 280 patients were enrolled in 2 clinical trials conducted in North America and Europe. Patients were to be within 10 d of onset of signs and symptoms of acute DVT or within 10 d of surgery associated with a high risk of DVT. (99m)Tc-apcitide scintigraphy and contrast venography were to be performed within 36 h. Planar scintigraphic images were obtained at 10, 60, and 120-180 min after injection. (99m)Tc-apcitide scintigrams and contrast venograms were read with masking and also by the institutional investigators. RESULTS: Of a total of 243 patients who were evaluable, 61.7% were receiving heparin at the time of imaging. Masked reading of (99m)Tc-apcitide scintigraphy, compared with masked reading of contrast venography, had a sensitivity, specificity, and agreement of 73.4%, 67.5%, and 69.1%, respectively, which met the prospectively defined target efficacy endpoint in both trials. Institutional reading of (99m)Tc-apcitide scintigraphy, compared with institutional reading of contrast venography, had a sensitivity, specificity, and agreement of 75.5%, 72.8%, and 74.0%, respectively. However, the entire trial population included patients with a history of DVT who may have had old, nonacute venous thrombi that could confound the venography results. Therefore, data from patients having no history of DVT or pulmonary embolism and who presented within 3 d of onset of signs and symptoms (n = 63), i.e., patients for whom a venogram would be expected to be positive only if acute DVT were present, also were analyzed as a subset. In these patients, institutional reading of (99m)Tc-apcitide scintigraphy, compared with institutional reading of contrast venography, had a sensitivity, specificity, and agreement of 90.6%, 83.9%, and 87.3%, respectively. CONCLUSION: (99m)Tc-apcitide scintigraphy is a new diagnostic modality that is highly sensitive for imaging acute DVT.

Diagnostic accuracy of 99mTc-sestamibi breast imaging: multicenter trial results.

UNLABELLED: Although mammography is well established as a first-line tool for breast cancer screening and detection, efforts to develop complementary procedures continue. Observation of 99mTc-sestamibi tumor uptake provided the impetus for its evaluation as an adjunctive technique. This trial's objectives were to determine in a multicenter trial the diagnostic accuracy of 99mTc-sestamibi in women with suspected breast cancer and to investigate factors influencing diagnostic accuracy. METHODS: Our multicenter trial enrolled 673 women (387 with nonpalpable abnormalities; 286 with palpable abnormalities) scheduled for excisional biopsy or mastectomy. Blinded and unblinded interpretations of scintigraphic images were compared with core laboratory established histopathologic diagnoses to define the diagnostic accuracy of 99mTc-sestamibi breast imaging. RESULTS: Blinded readers' diagnostic accuracy was 78%-81%. Inter-reader agreement was excellent, ranging from 95% to 100% (kappa = 0.82-0.99). Overall institutional sensitivity and specificity for 99mTc-sestamibi breast imaging were 75.4% and 82.7%, respectively. In this population with a 40.1% disease prevalence, the positive predictive value was 74.5% and the negative predictive value was 83.4%. The negative predictive value was 94% in patients with a 40% or lower mammographic likelihood of breast cancer. Sensitivity was higher for palpable abnormalities; specificity was higher for nonpalpable abnormalities. Sensitivity was decreased for tumors <1 cm in largest dimension but appeared not to be affected by patient's age. CONCLUSION: As an adjunct to current procedures, 99mTc-sestamibi breast imaging may contribute to patient management decisions in selected populations, including women with dense breasts, mammographically indeterminate lesions >1 cm, and palpable abnormalities.

Current imaging modalities for the diagnosis of breast cancer.

Although mammography still remains the gold standard for breast cancer screening and diagnosis, it typically cannot differentiate benign from malignant disease and is less accurate in patients with dense glandular breasts. This article is an overview of imaging modalities that have emerged to augment mammography and improve the accuracy of non-invasive breast cancer diagnosis. Ultrasound is currently used to differentiate breast masses and guide aspirations and biopsies. Magnetic resonance imaging has excellent sensitivity in demonstrating breast cancer but a low specificity. Nuclear medicine studies have recently emerged that detect the increased metabolic rate and vascularity of breast cancers. Other modalities, such as thermography and computed tomography, have a more limited utility for breast cancer diagnosis. Digital mammography is among other emerging technological advancements that will continue to develop and improve the accuracy of breast cancer diagnosis in the future.

Tc-99m sestamibi scintimammography in the mammographically dense breast.

PURPOSE: The mammographically dense breast or the "difficult-to-interpret mammogram" poses significant clinical and diagnostic imaging concerns. From our experience using Tc-99m sestamibi mammography in more than 650 patients, we share our experience in a pictorial manner and include suggested indications and limitations of this exciting new technique. Examples of Tc-99m sestamibi imaging in six patients with mammographically dense breasts are presented. MATERIALS AND METHODS: All patient examinations were ordered clinically for various indications. Comparison radiographic mammography and, when available, confirmatory pathologic analysis were also done. The examples were chosen from our experience with more than 650 patients at two university hospitals and one outpatient imaging center. RESULTS: Of the six examples presented, four had cancer, one had fibrosis after chemotherapy for ductal cell carcinoma, and one had no evidence of cancer. Tc-99m sestamibi imaging showed no increased uptake in the one patient with no tumor and various degrees of uptake in the other five patients. CONCLUSIONS: Six examples from our clinical experience show the usefulness of Tc-99m sestamibi imaging in patients with mammographically dense breasts. The ability to identify a malignancy or its absence supports the continued use of this procedure in these patients.

Paraspinal ultrasonography: lack of accuracy in evaluating patients with cervical or lumbar back pain.

This study evaluates the ability of paraspinal ultrasonography to identify abnormal echogenicity in patients with cervical or lumbar back pain, or both. Paraspinal ultrasonography was performed on 82 subjects, including 23 asymptomatic controls. Echogenicity in the region of nerve roots and facets was assessed. Readings were correlated with location of patients' symptoms, if any. Receiver operating characteristic analysis demonstrated that evaluation of nerve roots by all four readers did not differ significantly from chance (0.07 < P < 0.99). Specificities ranged from 0 to 0.68. Kappa values were 0.06 for cervical and -0.06 for lumbar spine. Ultrasonography was unable to demonstrate abnormal echogenicity adjacent to facets in symptomatic patients. Paraspinal ultrasonography is neither accurate nor reproducible in evaluating patients with cervical and lumbar back pain.

Uterine adnexal torsion: sonographic findings.

Acute torsion of the uterine adnexal structures (ovary and fallopian tube) is a recognized surgical emergency, but rarely has the diagnosis been made preoperatively on the basis of imaging studies. This report describes 16 cases in which the diagnosis was suggested preoperatively on the basis of sonography and subsequently confirmed at surgery. In all of the patients studied, a pelvic or pelvoabdominal mass was present on sonography. These masses had a sonographic texture ranging from cystic to solid, depending on the presence and extent of internal hemorrhage and/or stromal edema. In the majority of patients (13 of 16), adnexal torsion was associated with a preexisting cystic adnexal mass. Eight of these had thin internal septae. The severity of symptoms was variable and did not correlate directly with the sonographic features of the pelvic mass. Consideration of this entity in the proper clinical setting and with the typical sonographic findings will facilitate prospective recognition of adnexal torsion, thereby improving the chances for salvage of the involved adnexal structures.

Sonographic demonstration of fibromuscular hyperplasia of the cervical internal carotid artery.

Ultrasound examination of the carotid artery has recently become an accepted procedure in screening patients with transient ischemic attacks. We report a patient with fibromuscular hyperplasia of the carotid artery diagnosed successfully with digital gray scale contact ultrasonic scanning and confirmed with arteriography.

Cholescintigraphic diagnosis of cholecystocolic fistula.

The diagnosis of a cholecystocolic fistula has often presented a dilemma to the practicing physician. Routine imaging modalities to confirm this diagnosis have not proven extremely successful. The presence of a small fistulous tract from the gallbladder to the colon is often difficult to demonstrate radiographically. However, with the advent of the newer hepatobiliary radioisotopic scanning agents, the ability to visualize the intrahepatic and extrahepatic bile ducts as well as the presence of the intestinal activity of the radiotracers has improved considerably. The authors present a case of cholecystocolic fistula that was adequately demonstrated with a Tc-99m-PIPIDA hepatobiliary scan. This article is the first to report demonstration of this type of fistula with hepatobiliary scanning.

Candidiasis in the obstructed esophagus.

Four cases of esophageal candidiasis complicating functional or mechanical obstruction are described. The causes of the obstruction included achalasia, scleroderma, and postoperative fundoplication. None of the commonly recognized conditions predisposing to esophageal candidiasis was present. The findings on barium study ranged from plaque-like filling defects to extensive nodularity and roughening of the mucosal surface, which must be distinguished from ingested debris. It is suggested that esophageal stasis of any cause can lead to candidiasis.

Sonographic evaluation of iliac artery aneurysms.

Abdominal aortic aneurysms are not uncommon and their ultrasonic characteristics have become well-known. Ultrasonic detection of iliac artery aneurysms however, has not been well documented. Experience with 125 ultrasonic examinations for clinically suspected absoeminal aortic aneurysms is presented herein. Fifty-two abdominal aortic aneurysms were detected. Six unsuspected iliac artery aneurysms were demonstrated using a special oblique projection. Routine use of this oblique projection in patients with suspected abdominal aortic aneurysms is discussed.