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Biomedical subjects

Suzanne L Aquino

Publications and source records attributed to Suzanne L Aquino.

At least 19 recordsLinked to original sources
PubMed2006

Accuracy of transmission CT and FDG-PET in the detection of small pulmonary nodules with integrated PET/CT.

PURPOSE: The purpose of this study was to determine the accuracy of detection of small pulmonary nodules on quiet breathing attenuation correction CT (CTAC) and FDG-PET when performing integrated PET/CT, as compared with a diagnostic inspiratory CT scan acquired in the same imaging session. METHODS: PET/CT scans of 107 patients with a history of carcinoma (54 male and 53 female, mean age 57.3 years) were analyzed. All patients received an integrated PET/CT scan including a CTAC acquired during quiet respiration and a contrast-enhanced CT acquired during inspiration in the same session. Breathing CTAC scans were reviewed by two thoracic radiologists for the presence of pulmonary nodules. FDG-PET scans were reviewed to determine accuracy of nodule detection. Diagnostic CT was used as the gold standard to confirm or refute the presence of nodules. RESULTS: On the CTAC scans 200 nodules were detected, of which 183 were true positive (TP) and 17, false positive. There were 109 false negatives (FN). Overall, 51 (48%) patients had a false interpretation, including 19 in whom CT was interpreted as normal for lung nodules. The average size of the nodules missed was 3.8+/-2 mm (range 2-12 mm). None of the nodules missed on the CTAC scans were detected by PET. In the right lung there were 20 TP, 42 true negative (TN), 11 FP, and 34 FN interpretations with a sensitivity in nodule detection of 37% (CI 24-51%) and a specificity of 79% (CI 66-89%). In the left lungs there were 16 TP, 65 TN, 3 FP, and 23 FN interpretations, with a sensitivity of 41% (CI 26-58%) and a specificity of 96% (CI 88-99%). CONCLUSION: The detection of small pulmonary nodules by breathing CTAC and FDG-PET is relatively poor. Therefore an additional diagnostic thoracic CT scan obtained during suspended inspiration is recommended for thorough evaluation of those patients in whom detection of pulmonary metastases is necessary for management.

Adolescent↗
PubMed2006

Significance of incidental thyroid lesions detected on CT: correlation among CT, sonography, and pathology.

OBJECTIVE: The purpose of our study was to determine the prevalence of malignancy in incidental abnormalities of the thyroid gland detected on CT and to determine the relative accuracy of characterizing these abnormalities on CT as compared with sonography and pathology. MATERIALS AND METHODS: We searched our department's computerized clinical database for all thoracic and cervical CT scans in which a new abnormality was incidentally identified in the thyroid gland from 1998-2001. Two hundred thirty patients with abnormal findings in the gland on CT subsequently underwent thyroid sonography, and 118 of the 230 patients underwent a diagnostic biopsy or resection. CT and sonographic images were directly reviewed to identify imaging features of each thyroid abnormality, including the location, size, appearance, and presence or absence of calcifications. Associations were evaluated using Fisher's exact test of significance and the Student's t test. The overall rate of malignant and potentially malignant lesions among these incidental abnormalities of the thyroid gland was calculated. RESULTS: CT findings matched the sonographic characterization in 122 patients (53.0%), correctly identified the dominant nodule but missed multinodularity in 69 (30.0%) patients, and underestimated the number of nodules in 24 (10.4%) patients. CT overestimated the number of nodules in 5 (2.2%) patients and was false-positive for lesions in 10 patients (4.3%). Ninety-one patients with a single or dominant nodule on CT had pathologic correlation: 7 nodules were malignant, 17 showed malignant potential, and 67 were benign. Of 27 patients with multinodular or enlarged thyroid glands on CT and histopathologic correlation, 2 lesions were malignant and 25 benign. The presence of punctate calcifications on CT significantly correlated to the presence of microcalcifications on sonography (p < 0.02). Benign nodules were significantly smaller (mean, 2.16 +/- 1.01 cm; range, 0.6-4.5 cm) than malignant and potentially malignant nodules (mean, 2.79 +/- 0.99 cm; range, 0.7-4.6 cm) (p = 0.01). Patients 35 years or younger who had a thyroid lesion on CT were more likely to have malignancy (p < 0.01). Overall, among incidentally detected lesions of the thyroid gland, there was at least a 3.9% rate of malignancy (95% CI: 1.8-7.3%) and 7.4% rate of malignant potential (95% CI: 4.4-11.6%). CONCLUSION: There is at least an 11.3% prevalence of malignant or potentially malignant lesions among incidental thyroid abnormalities detected on CT. Patients 35 years or younger who have incidental abnormalities have a significantly greater rate of malignancy. No CT feature reliably distinguishes benign from malignant lesions in the thyroid gland. CT underestimates the number of nodules relative to sonography, which suggests that sonography is a useful adjunctive test after the incidental detection of a thyroid abnormality on CT.

Adult↗
PubMed2006

Optimal CT breathing protocol for combined thoracic PET/CT.

OBJECTIVE: The objective of this study was to determine the optimal breathing protocol for combined PET/CT scans of the thorax. SUBJECTS AND METHODS: Eighty combined PET/CT scans were obtained in 64 patients (30 women, 34 men; mean age, 57 years; range, 19-86 years). The 80 PET/CT scans consisted of five group of patients (16 PET/CT scans per group) who underwent whole-body combined 18F-FDG PET/CT with different CT breathing protocols: expiration, mid suspended breath-hold, quiet breathing, small breath in, and regular breath in. The quality of alignment was analyzed at the diaphragm, aortic arch, heart, thoracic spine, and lung apices using a scale of ratings from 1 (very poor) to 5 (excellent). The Kruskal-Wallis test was used to compare alignment between breathing protocols for each anatomic reference point. RESULTS: Alignment of the PET and CT data sets was excellent with three breathing protocols: expiration, mid suspended breath-hold, and quiet breathing, with no statistical differences. Significant misalignment occurred at the diaphragm (p < 0.0001) and heart (p < 0.0001) with the small breath-in and regular breath-in techniques. CONCLUSION: Excellent image fusion of combined PET/CT data sets in the thorax, especially at the diaphragm and heart, can be achieved with expiration, mid suspended breath-hold, or quiet breathing. Quiet breathing is recommended for optimal patient comfort during acquisition of attenuation-correction CT data sets.

Adult↗
PubMed2005

Imaging of metastatic disease to the thorax.

Tumor imaging is at the forefront of radiology technology and is the focus of most cutting edge research. Radiologic applications for imaging of metastases are applied to initial staging, restaging after neoadjuvant therapy, and follow-up surveillance after therapy for tumor recurrence. CT is the routine imaging choice in staging, restaging, and detection of recurrence. Fluorodeoxyglucose-positron emission tomography has evolved as an imaging modality that further improves staging as well as the detection of recurrent and metastatic disease.

Diagnostic Imaging↗
PubMed2005

State-of-the-Art FDG-PET imaging of lung cancer.

The D-glucose analog 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radionuclide in positron emission tomography (PET) of lung cancer. FDG-PET is a molecular imaging technique that images the preferential accumulation of FDG in malignant tissues with increased metabolism. Although FDG-PET is sensitive in the detection of lung cancer, FDG is not tumor specific and may accumulate in a variety of nonmalignant conditions. Occasional false-negative results may also occur. Whole body FDG-PET is a useful noninvasive technique to stage known or suspected non-small-cell lung cancer. The results allow more efficient use of invasive methods for histopathological staging. The combined use of CT and PET in dual imaging increases the number of patients with correctly staged non-small-cell lung cancer. CT/PET is also useful in the assessment of recurrent or residual disease. Future imaging agents are being developed which may allow more selective accumulation of radiopharmaceutical in malignant tissues.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Small incidental pulmonary nodules: how useful is short-term interval CT follow-up?

PURPOSE: To determine whether short-term (<6 month) follow-up imaging by thoracic CT is necessary to evaluate small (< or =4 mm) noncalcified nodules (NCN) in patients with no history of malignancy or acute lung disease. MATERIALS AND METHODS: We reviewed serial thoracic helical CT scans between 1999-2000 obtained for the evaluation or follow-up imaging of small NCNs. CT scans were performed at 5-mm collimation. Patients were excluded if they had a history of neoplasm, infection, pulmonary fibrosis, or immune deficiency; also excluded if nodule(s) > or =5 mm at intake, or no follow-up scan within 1 year. NCNs were evaluated for number, size, configuration, and change in size over time. Exact 95% Confidence Intervals were used to estimate chances of nodule growth in 3-, 6-, and 12- month intervals. RESULTS: A total of 1826 patients received a CT for NCNs. Four hundred fourteen patients met inclusion criteria (221 women, 193 men; mean age, 65.6 years). Eighty-five patients had a single NCN, 329 had multiple NCNs. One hundred seventy-three patients had additional > or =5 mm nodules. One hundred twenty-seven patients were lost to follow up within the 1-year period. Eight nodules cleared. None of the < or =4 mm NCNs grew on follow-up imaging within 12 months. Three patients developed lung cancer in other nodules > or =5 mm (5-10 mm). These nodules grew on follow up intervals of 3-13 months. One patient had a 19 mm benign hamartoma that grew in 9 months. The calculated chance that a NCN < or =4 mm will grow within 3, 6, and 12 months (95% CI) is < or =0.89%, 1.01%, and 1.28%, respectively. CONCLUSION: The chance of growth in < or =4 mm NCNs in a 3- to 6-month period in patients with no previous history of malignancy or immune disorder is small; therefore, short-term follow-up imaging (<12 month) for nodules < or =4 mm is not necessary.

Adult↗
PubMed2005

Chest CT performed with z-axis modulation: scanning protocol and radiation dose.

Institutional review board approval of the study protocol and waiver of informed consent were obtained. This study was compliant with the Health Insurance Portability and Accountability Act. The purpose of this study was to retrospectively assess the scanning protocol and radiation dose associated with z-axis automatic tube current modulation in multi-detector row CT scanning of the chest. Fifty-three patients (mean age, 54 years; age range, 26-77 years; 25 men, 28 women) underwent 16-detector row chest CT with z-axis modulation and noise indexes of 10.0, 12.5, and 15.0 HU. Two radiologists independently compared images acquired with z-axis modulation and fixed tube current (180-300 mA) techniques for image noise, diagnostic acceptability, and depiction of peripheral bronchovascular markings. Tube current-time product was calculated for each study. There was good interobserver agreement between the two readers (kappa = 0.72). Compared with the fixed tube current technique, z-axis modulation provides acceptable image noise for chest CT, with an 18% and 26% reduction in tube current-time product at 10.0- and 12.5-HU noise indexes, respectively.

Adult↗
PubMed2005

Comparison of alignment of computer-registered data sets: combined PET/CT versus independent PET and CT of the thorax.

PURPOSE: To retrospectively determine whether alignment of registered positron emission tomographic (PET) and computed tomographic (CT) data sets obtained independently varies significantly from alignment of data sets acquired from a combined PET/CT scanner. MATERIALS AND METHODS: The study was approved by the institution's Human Research Committee with a waiver of informed consent and complied with HIPAA. Whole-body combined PET/CT data sets and separate routinely positioned thoracic CT data sets were obtained from 12 patients (six men, six women; mean age, 48.6 years; range, 24-62 years). Separate PET and thoracic CT data sets matched for patient positioning and respiration were acquired on the same day for nine patients (four men, five women; mean age, 71 years; range, 51-90 years). Computer nonlinear registration was performed on PET and CT data sets from combined PET/CT (fusion group 1), PET data sets from combined PET/CT with unmatched thoracic CT (fusion group 2), and data sets from separate PET and CT matched for patient positioning and respiration (fusion group 3). Quality of alignment was assessed by two radiologists in consensus blinded to the source of registered data in each fusion group at the following anatomic locations: diaphragm, aortic arch, heart, thoracic spine, and lung apices. Results were compared by using the Wilcoxon paired signed rank and unpaired rank sum tests. RESULTS: Quality of alignment did not significantly differ between fusion group 1 and fusion group 3. Fusion group 1 provided significantly better alignment in two of five anatomic locations (P = .008 for diaphragm and P = .031 for heart) than fusion group 2. Fusion group 3 provided significantly better alignment in two of five anatomic locations (P = .037 for diaphragm and P = .009 for heart) than fusion group 2. CONCLUSION: Thoracic anatomic alignment does not significantly differ between registered PET and CT data sets acquired on a combined PET/CT scanner or from separate PET and CT scanners obtained on the same day when carefully matched for anatomic positioning and respiration.

Adult↗
PubMed2005

Lipomatous hypertrophy of the interatrial septum: prevalence and features on fusion 18F fluorodeoxyglucose positron emission tomography/CT.

OBJECTIVE: To determine the prevalence of lipomatous hypertrophy of the interatrial septum (LHIS) on CT and its metabolic pattern on 18F fluorodeoxyglucose (FDG)-positron emission tomography (PET). METHOD AND MATERIALS: Eight hundred two CT PET scans were reviewed. Patients were included if the interatrial septum was > or = 1 cm and excluded if there was evidence of malignancy in the adjacent lung, hilum, or mediastinum. CT scans were fused with PET scans, and the mean standardized uptake value (SUV) was calculated over the LHIS, chest wall (CW) fat, and mediastinal blood pool. CT scans were reviewed for presence of excessive fat in the mediastinum, pericardial, peridiaphragmatic, peritoneal, and retroperitoneal regions and for the presence of emphysema. Medical records were reviewed for body mass index (BMI) and history of arrhythmia. RESULTS: Twenty-three of 802 patients (2.8%) had LHIS on CT (9 women and 14 men); average age was 75.6 years (range, 58 to 95 years). Average BMI of 17 patients (+/- SD) was 31 +/- 4.9 (range, 22.1 to 39.9). Mean CT values were as follows: thickening of LHIS, 1.47 +/- 0.35 cm (range, 1.07 to 2.25 cm); LHIS, - 79.6 + 24.5 Hounsfield unit (HU) [range, - 11 to - 121 HU]. LHIS was dumbbell shaped in 18 patients. Mean SUVs were as follows: LHIS, 1.84 +/- 0.10 (range, 0.48 to 3.48); CW fat, 0.36 + 0.37 (range, 0.04 to 1.98); blood pool, 1.74 + 0.51 (range, 0.25 to 2.71). The SUV of LHIS was greater than the SUV of CW wall fat in all patients (p < 0.0001). There was significant correlation between SUV and thickness of the LHIS on CT (p < 0.0001, r = 0.883). Those with dumbbell-shaped LHIS (p < 0.003) and presence of emphysema (p < 0.0377) had greater LHIS mean SUV. CONCLUSION: The SUV of LHIS was greater than the SUV of CW fat in all patients. LHIS with greater thickness or dumbbell shape had greater FDG uptake. These findings on CT and PET are important to recognize in order to avoid false-positive FDG-PET interpretations.

Aged↗
PubMed2005

Lipomatous hypertrophy of the interatrial septum: increased uptake on FDG PET.

OBJECTIVE: The objective of our study was to evaluate FDG uptake in patients with cardiac lipomatous hypertrophy of the interatrial septum (LHIS). CONCLUSION: Increased FDG uptake occurs in LHIS, a benign fatty infiltration of the interatrial septum. Increased uptake in the right heart on FDG PET warrants correlation with additional imaging to assess for LHIS and avoid false interpretation of malignancy.

Aged↗
PubMed2004

The radiologic appearance of intercostal muscle flap.

BACKGROUND: The intercostal muscle flap (ICMF) is commonly used in airway and esophageal surgery to reinforce an anastomosis or site of closure. These flaps undergo heterotopic ossification that may result in stenosis of adjacent airways or the esophagus. We evaluated the computer tomography (CT) scan, technetium-99m-methylene diphosphonate bone scan and positron emission tomography with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG-PET) findings of ICMF and the frequency of airway or esophageal stenosis. METHODS: A retrospective review was made of the radiologic records of 23 patients (9 women, 14 men) who underwent ICMF. The CT scans were obtained a mean of 36 months (range, 1 week to 58 months) after surgery and the size, morphology, and density of the ICMFs were recorded. Correlative bone scan in 13 patients and FDG-PET scans in 11 patients were reviewed. RESULTS: A discontinuous, thin, linear calcified stripe or parallel stripes (mean thickness, 4 mm; mean density, 430 Houndsfield unit [HU]) were present in all patients on CT. The flap contained fat density (mean, -59 HU) in 18 patients and soft tissue density (mean, 41 HU) in 8 patients and measured about 1 cm in thickness. The appearance of ICMF is characteristic when the ossification extends from the posterolateral chest wall to an adjacent bronchial stump. There was no increased uptake on bone scan or FDG-PET scan. None of the patients had airway or esophageal stenosis. CONCLUSIONS: The ICMF manifests on CT as a thin, linear calcified stripe or parallel stripes with central fat or soft tissue density. Airway stenosis due to ICMF is likely quite rare. We did not detect any airway stenosis.

Adult↗
PubMed2004

Fluorodeoxyglucose positron emission tomography and CT after talc pleurodesis.

BACKGROUND: Talc pleurodesis is widely performed for the management of persistent pneumothorax or pleural effusion, particularly malignant effusions. However, there are very few data characterizing fluorodeoxyglucose (FDG)-positron emission tomography (PET) and CT findings after treatment. METHODS: We retrospectively evaluated the FDG-PET and CT studies of nine patients who underwent talc pleurodesis for the treatment of malignant pleural effusions or persistent air leak. RESULTS: FDG-PET studies were performed on average 22 months after talc pleurodesis, and the mean CT follow-up period was 25 months. There was moderate-to-intense plaque-like or focal nodular-increased FDG uptake in the pleura on PET with mean standardized uptake value of 5.4 (SEM, 1.2; range, 2.0 to 16.3). The FDG uptake was either diffuse (two patients) or focal (seven patients), and most commonly occurred in the posterior costophrenic angles (five patients), followed by the apical regions (three patients), anterior costophrenic angle (one patient), and the anterior chest wall (one patient). On CT, high-density areas of pleural thickening or nodularity (mean, 230 Hounsfield units [HU]; SEM, 23 HU; range, 140 to 380 HU) corresponded to regions of increased FDG uptake. These pleural foci had an average thickness of 1.2 cm and measured up to 8.2 cm (mean, 7.1 cm) in length. Rounded pleural nodules were as large as 3.1 cm (mean, 1.5 cm). CONCLUSIONS: Talc pleurodesis produces increased FDG uptake on PET and high-density areas of pleural thickening on CT that remain unchanged on serial imaging. When PET detects increased uptake in the pleural space, correlation with CT is recommended to detect the presence of pleural thickening of increased attenuation that suggests talc deposits rather than tumor.

Adult↗
PubMed2004

Does whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography have an advantage over thoracic positron emission tomography for staging patients with lung cancer?

BACKGROUND: Whole-body (WB) positron emission tomography (PET) with 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG) is more accurate than other imaging studies for detecting lung cancer and extrathoracic metastatic disease. Thoracic PET (from the skull base through the kidneys) may be equally as useful as WB PET (skull base to mid-thigh). With the recent introduction of hybrid CT-PET systems, use of thoracic PET would minimize radiation dose. METHODS: A retrospective review of a series of WB PET scans performed in our department was performed to identify patients evaluated for a solitary pulmonary nodule or newly diagnosed lung cancer who had distant extracranial and extrathoracic metastases detected by PET. All patients with true extrathoracic metastases were documented by ancillary radiologic and clinical data. Patients were staged according to the American Joint Committee on Cancer TNM system based on findings within the confines of a thoracic PET and WB PET. Comparison was made between staging based on thoracic and WB PET to determine if there was a significant difference. RESULTS: Of 1,026 studies, distant extracranial metastases were described in 35 patients with lung cancer. Findings were determined to be false-positive in nine patients. Of the 26 patients with true metastases on WB PET, 25 patients had metastatic lesions within the confines of thoracic PET. Relative to WB PET, the sensitivity of thoracic PET is 96.2% (95% confidence interval, 1 to 99.3%) for detection of distant metastases. Only one patient had an isolated metastasis that was detected only by WB PET. This patient would have been staged IIIB by thoracic PET as opposed to stage IV by WB PET. CONCLUSIONS: Thoracic PET, when compared to WB PET, is 96.2% sensitive for detecting extrathoracic metastases in patients with newly diagnosed non-small cell lung cancer.

Adult↗
PubMed2004

Current concepts in lymph node imaging.

The accurate identification and characterization of lymph nodes by imaging has important therapeutic and prognostic significance in patients with newly diagnosed cancers. The presence of nodal metastases limits the therapeutic options and also generally indicates worse prognosis in patients. Thus, it becomes crucial to have this information before commencing therapy. Current cross-sectional imaging modalities rely on insensitive size and morphologic criteria and, thus, lack the desired accuracy for characterizing lymph nodes. This is mainly because metastases can be present in non-enlarged lymph nodes and not all enlarged nodes are malignant. PET has overcome some of these limitations but is still constrained by current resolution limits for small nodal metastases. This has fueled the development of targeted techniques for nodal imaging and characterization as outlined in this article. In the past few years, studies have shown that these newer imaging techniques can bridge some of the limitations of existing imaging for nodal characterization and thereby provide the much-needed staging information before the initiation of therapy.

Anatomy, Cross-Sectional↗