From Bench-to-Bedside: How Artificial Intelligence is Changing Thyroid Nodule Diagnostics, a Systematic Review.

CONTEXT: Use of artificial intelligence (AI) to predict clinical outcomes in thyroid nodule diagnostics has grown exponentially over the past decade. The greatest challenge is in understanding the best model to apply to one's own patient population, and how to operationalize such a model in practice. EVIDENCE ACQUISITION: A literature search of PubMed and IEEE Xplore was conducted for English-language publications between January 1, 2015 and January 1, 2023, studying diagnostic tests on suspected thyroid nodules that used AI. We excluded articles without prospective or external validation, nonprimary literature, duplicates, focused on nonnodular thyroid conditions, not using AI, and those incidentally using AI in support of an experimental diagnostic outside standard clinical practice. Quality was graded by Oxford level of evidence. EVIDENCE SYNTHESIS: A total of 61 studies were identified; all performed external validation, 16 studies were prospective, and 33 compared a model to physician prediction of ground truth. Statistical validation was reported in 50 papers. A diagnostic pipeline was abstracted, yielding 5 high-level outcomes: (1) nodule localization, (2) ultrasound (US) risk score, (3) molecular status, (4) malignancy, and (5) long-term prognosis. Seven prospective studies validated a single commercial AI; strengths included automating nodule feature assessment from US and assisting the physician in predicting malignancy risk, while weaknesses included automated margin prediction and interobserver variability. CONCLUSION: Models predominantly used US images to predict malignancy. Of 4 Food and Drug Administration-approved products, only S-Detect was extensively validated. Implementing an AI model locally requires data sanitization and revalidation to ensure appropriate clinical performance.

A multitask approach for automated detection and segmentation of thyroid nodules in ultrasound images.

An increase in the incidence and diagnosis of thyroid nodules and thyroid cancer underscores the need for a better approach to nodule detection and risk stratification in ultrasound (US) images that can reduce healthcare costs, patient discomfort, and unnecessary invasive procedures. However, variability in ultrasound technique and interpretation makes the diagnostic process partially subjective. Therefore, an automated approach that detects and segments nodules could improve performance on downstream tasks, such as risk stratification. Ultrasound studies were acquired from 280 patients at UCLA Health, totaling 9888 images, and annotated by collaborating radiologists. Current deep learning architectures for segmentation are typically semi-automated because they are evaluated solely on images known to have nodules and do not assess ability to identify suspicious images. However, the proposed multitask approach both detects suspicious images and segments potential nodules; this allows for a clinically translatable model that aptly parallels the workflow for thyroid nodule assessment. The multitask approach is centered on an anomaly detection (AD) module that can be integrated with any UNet architecture variant to improve image-level nodule detection. Of the evaluated multitask models, a UNet with a ImageNet pretrained encoder and AD achieved the highest F1 score of 0.839 and image-wide Dice similarity coefficient of 0.808 on the hold-out test set. Furthermore, models were evaluated on two external validations datasets to demonstrate generalizability and robustness to data variability. Ultimately, the proposed architecture is an automated multitask method that expands on previous methods by successfully both detecting and segmenting nodules in ultrasound.

A Multitask Approach for Automated Detection and Segmentation of Thyroid Nodules in Ultrasound Images.

An increase in the incidence and diagnosis of thyroid nodules and thyroid cancer underscores the need for a better approach to nodule detection and risk stratification in ultrasound (US) images that can reduce healthcare costs, patient discomfort, and unnecessary invasive procedures. However, variability in ultrasound technique and interpretation makes the diagnostic process partially subjective. Therefore, an automated approach that detects and segments nodules could improve performance on downstream tasks, such as risk stratification.Current deep learning architectures for segmentation are typically semi-automated because they are evaluated solely on images known to have nodules and do not assess ability to identify suspicious images. However, the proposed multitask approach both detects suspicious images and segments potential nodules; this allows for a clinically translatable model that aptly parallels the workflow for thyroid nodule assessment. The multitask approach is centered on an anomaly detection (AD) module that can be integrated with any U-Net architecture variant to improve image-level nodule detection. Ultrasound studies were acquired from 280 patients at UCLA Health, totaling 9,888 images, and annotated by collaborating radiologists. Of the evaluated models, a multi-scale UNet (MSUNet) with AD achieved the highest F1 score of 0.829 and image-wide Dice similarity coefficient of 0.782 on our hold-out test set. Furthermore, models were evaluated on two external validations datasets to demonstrate generalizability and robustness to data variability. Ultimately, the proposed architecture is an automated multitask method that expands on previous methods by successfully both detecting and segmenting nodules in ultrasound.

Contrast-enhanced ultrasound for abdominal image-guided procedures.

INTRODUCTION: Since FDA approval for contrast-enhanced ultrasound (CEUS), clinical applications have increased to include diagnostic imaging of hepatic, renal, and other abdominal lesions. The modality has also demonstrated utility in certain image-guided procedures. Intravascular ultrasound contrast agents use microbubbles to improve visibility of solid tumors. Lesions not well seen on grayscale or Doppler ultrasound may become amenable to CEUS-guided biopsy or ablation. MATERIALS AND METHODS: This pictorial essay provides eleven examples to illustrate the current use of CEUS in a variety of abdominal image-guided procedures. Hepatic, renal, peritoneal, and soft tissue cases are presented. CONCLUSION: CEUS can improve visualization and targeting in abdominal image-guided procedures, without nephrotoxicity or radiation exposure.

Pregnancies complicated by gestational diabetes and fetal growth restriction: an analysis of maternal and fetal body composition using magnetic resonance imaging.

INTRODUCTION: Maternal body composition may influence fetal body composition. OBJECTIVE: The objective of this pilot study was to investigate the relationship between maternal and fetal body composition. METHODS: Three pregnant women cohorts were studied: healthy, gestational diabetes (GDM), and fetal growth restriction (FGR). Maternal body composition (visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT), pancreatic and hepatic proton-density fat fraction (PDFF) and fetal body composition (abdominal SAT and hepatic PDFF) were measured using MRI between 30 to 36 weeks gestation. RESULTS: Compared to healthy and FGR fetuses, GDM fetuses had greater hepatic PDFF (5.2 [4.2, 5.5]% vs. 3.2 [3, 3.3]% vs. 1.9 [1.4, 3.7]%, p = 0.004). Fetal hepatic PDFF was associated with maternal SAT (r = 0.47, p = 0.02), VAT (r = 0.62, p = 0.002), and pancreatic PDFF (r = 0.54, p = 0.008). When controlling for maternal SAT, GDM increased fetal hepatic PDFF by 0.9 ([0.51, 1.3], p = 0.001). CONCLUSION: In this study, maternal SAT, VAT, and GDM status were positively associated with fetal hepatic PDFF.

Patient-level thyroid cancer classification using attention multiple instance learning on fused multi-scale ultrasound image features.

For patients with thyroid nodules, the ability to detect and diagnose a malignant nodule is the key to creating an appropriate treatment plan. However, assessments of ultrasound images do not accurately represent malignancy, and often require a biopsy to confirm the diagnosis. Deep learning techniques can classify thyroid nodules from ultrasound images, but current methods depend on manually annotated nodule segmentations. Furthermore, the heterogeneity in the level of magnification across ultrasound images presents a significant obstacle to existing methods. We developed a multi-scale, attention-based multiple-instance learning model which fuses both global and local features of different ultrasound frames to achieve patient-level malignancy classification. Our model demonstrates improved performance with an AUROC of 0.785 (p<0.05) and AUPRC of 0.539, significantly surpassing the baseline model trained on clinical features with an AUROC of 0.667 and AUPRC of 0.444. Improved classification performance better triages the need for biopsy.

The Effect Modification of Ultrasound Risk Classification on Molecular Testing in Predicting the Risk of Malignancy in Cytologically Indeterminate Thyroid Nodules.

Background: Thyroid nodules with indeterminate cytology are increasingly subjected to molecular testing. We evaluated the diagnostic performances of Afirma Genomic Sequencing Classifier (GSC) and ThyroSeq v3 in thyroid nodules with high versus low/intermediate suspicion ultrasound classification. Methods: In this prospective cohort study, we analyzed all Bethesda III and IV thyroid nodules that underwent fine-needle aspiration biopsies in the University of California Los Angeles Health System from July 2017 to April 2020. All patients underwent molecular testing with Afirma GSC or ThyroSeq v3 as part of an institutional randomized trial (NCT02681328). Nodules were categorized according to the American Thyroid Association (ATA) ultrasound risk classification. The benign call rate and the positive predictive value of molecular testing were compared between ATA high suspicion versus all other categories. Results: A total of 343 patients with 375 indeterminate thyroid nodules were included. The malignancy rate in ATA high suspicion nodules was not significantly increased by a suspicious Afirma GSC result (77.8% for all ATA high suspicion nodules vs. 87.5% for nodules with ATA high suspicion and suspicious Afirma GSC results, positive likelihood ratio [LR] = 2.0, 95% confidence interval [CI 0.5-8.0], p = 1.0) or by a positive ThyroSeq v3 result (80.0% vs. 80.0%, positive LR = 1.0 [CI 1.0-1.0], p = 1.0). The rate of malignancy in ATA low/intermediate suspicion nodules increased from 21.0% to 56.3% with a suspicious Afirma GSC result (positive LR = 4.8 [CI 3.4-6.9], p < 0.0001) and decreased to 3.8% with a benign Afirma GSC result (negative LR = 0.1 [CI 0.07-0.3], p < 0.0001). Similarly, the rate of malignancy in ATA low/intermediate suspicion nodules increased from 24.3% to 66.7% with a positive ThyroSeq v3 result (positive LR = 6.2 [CI 4.0-9.7], p < 0.0001) and decreased to 2.1% with a negative ThyroSeq v3 result (negative LR = 0.07 [CI 0.02-0.3], p < 0.0001). Conclusions: Afirma GSC and ThyroSeq v3 performed well in ruling out malignancy in sonographically low/intermediate suspicion thyroid nodules but has limited diagnostic value in sonographically high suspicion nodules. Molecular testing can prognosticate more aggressive thyroid cancers, which can inform treatment decisions.

Gynecologic tumor board: a radiologist's guide to vulvar and vaginal malignancies.

Primary vulvar and vaginal cancers are rare female genital tract malignancies which are staged using the 2009 International Federation of Gynecology and Obstetrics (FIGO) staging. These cancers account for approximately 2,700 deaths annually in the USA. The most common histologic subtype of both vulvar and vaginal cancers is squamous cell carcinoma, with an increasing role of the human papillomavirus (HPV) in a significant number of these tumors. Lymph node involvement is the hallmark of FIGO stage 3 vulvar cancer while pelvic sidewall involvement is the hallmark of FIGO stage 3 vaginal cancer. Imaging techniques include computed tomography (CT), positron emission tomography (PET)-CT, magnetic resonance imaging (MRI), and PET-MRI. MRI is the imaging modality of choice for preoperative clinical staging of nodal and metastatic involvement while PET-CT is helpful with assessing response to neoadjuvant treatment and for guiding patient management. Determining the pretreatment extent of disease has become more important due to modern tailored operative approaches and use of neoadjuvant chemoradiation therapy to reduce surgical morbidity. Moreover, imaging is used to determine the full extent of disease for radiation planning and for evaluating treatment response. Understanding the relevant anatomy of the vulva and vaginal regions and the associated lymphatic pathways is helpful to recognize the potential routes of spread and to correctly identify the appropriate FIGO stage. The purpose of this article is to review the clinical features, pathology, and current treatment strategies for vulvar and vaginal malignancies and to identify multimodality diagnostic imaging features of these gynecologic cancers, in conjunction with its respective 2009 FIGO staging system guidelines.

Characterization of Uterine Motion in Early Gestation Using MRI-Based Motion Tracking.

Magnetic resonance imaging (MRI) is a promising non-invasive imaging technique that can be safely used to study placental development and function. However, studies of the human placenta performed by MRI are limited by uterine motion and motion in the uterus during MRI remains one of the major limiting factors. Here, we aimed to investigate the characterization of uterine activity during MRI in the second trimester of pregnancy using MRI-based motion tracking. In total, 46 pregnant women were scanned twice (first scan between 14 and 18 weeks and second scan between 19 and 24 weeks), and 20 pregnant subjects underwent a single MRI between 14 and 18 weeks GA, resulting in 112 MRI scans. An MRI-based algorithm was used to track uterine motion in the superior-inferior and left-right directions. Uterine contraction and maternal motion cases were separated by the experts, and unpaired Wilcoxon tests were performed within the groups of gestational age (GA), fetal sex, and placental location in terms of the overall intensity measures of the uterine activity. In total, 22.3% of cases had uterine contraction during MRI, which increased from 18.6% at 14-18 weeks to 26.4% at 19-24 weeks GA. The dominant direction of the uterine contraction and maternal motion was the superior to the inferior direction during early gestation.

Diagnostic Value of Molecular Testing in Sonographically Suspicious Thyroid Nodules.

OBJECTIVE: Molecular testing can refine the diagnosis for the 20% of thyroid fine-needle aspiration biopsies that have indeterminate cytology. We assessed the diagnostic accuracy of molecular testing based on ultrasound risk classification. METHODS: This retrospective cohort study analyzed all thyroid nodules with indeterminate cytology at an academic US medical center (2012-2016). All indeterminate nodules underwent reflexive molecular testing with the Afirma Gene Expression Classifier (GEC). Radiologists performed blinded reviews to categorize each nodule according to the American Thyroid Association (ATA) ultrasound classification and the American College of Radiology Thyroid Imaging, Reporting and Data System. GEC results and diagnostic performance were compared across ultrasound risk categories. RESULTS: Of 297 nodules, histopathology confirmed malignancy in 65 (22%). Nodules by ATA classification were 8% high suspicion, 44% intermediate, and 48% low/very low suspicion. A suspicious GEC result was more likely in ATA high-suspicion nodules (81%) than in nodules of all other ATA categories (57%; P = .04). The positive predictive value (PPV) of GEC remained consistent across ultrasound categories (ATA high suspicion, 64% vs all other ATA categories, 48%; P = .39). The ATA high-suspicion category had higher specificity than a suspicious GEC result (93% vs 51%; P < .01). A suspicious GEC result did not increase specificity for the ATA high-suspicion category. CONCLUSION: The PPV of molecular testing remained consistent across ultrasound risk categories. However, a suspicious GEC result was very likely in ATA high-suspicion nodules and did not improve specificity in this sonographic category.

BRCA and Beyond: Comprehensive Image-rich Review of Hereditary Breast and Gynecologic Cancer Syndromes.

In addition to the well-characterized BRCA1 and BRCA2 hereditary breast and ovarian cancer syndromes, many other syndromes that are associated with genetic mutations predispose individuals to an increased risk of breast and gynecologic malignancies. Many mutated genes encode for tumor-suppressor products and are inherited in an autosomal dominant manner. Mutations markedly increase an individual's lifetime risk of cancers in different organ systems, depending on the associated syndrome. These syndromes include Lynch syndrome, the most common hereditary cause of endometrial cancer, and Peutz-Jeghers syndrome, which increases the risks of breast cancer, ovarian cancer, and cervical adenoma malignum. Li-Fraumeni syndrome and Cowden syndrome increase the risk of breast cancer, and Gorlin syndrome increases the risk of ovarian fibromas. With advances in genetic testing, clinicians' knowledge and awareness of the numerous additional genes associated with breast and ovarian cancers, such as ATM, CHEK2, and PALB2, are rapidly expanding. Radiologists have essential roles in patient management, which include developing optimal screening protocols for these patients and closely monitoring them for the development or recurrence of disease-specific malignancies. Radiologists' roles continue to increase and evolve as more mutations are identified and high-risk imaging screening recommendations expand to identify these patients. Understanding the epidemiologic, genetic, and pathophysiologic features and the cancers associated with these syndromes enables radiologists to appropriately contribute to patient management, ensure accurate and timely diagnosis, and make syndrome-specific imaging recommendations. ©RSNA, 2020.

Human Placenta Blood Flow During Early Gestation With Pseudocontinuous Arterial Spin Labeling MRI.

BACKGROUND: Noninvasive measurement of placental blood flow is the major technical challenge for predicting ischemic placenta (IPD). Pseudocontinuous arterial spin labeling (pCASL) MRI was recently shown to be promising, but the potential value in predicting the subsequence development of IPD is not known. PURPOSE: To derive global and regional placental blood flow parameters from longitudinal measurements of pCASL MRI and to assess the associations between perfusion-related parameters and IPD. STUDY TYPE: Prospective. POPULATION: Eighty-four women completed two pCASL MRI scans (first; 14-18 weeks and second; 19-24 weeks) from prospectively recruited 118 subjects. A total of 69 subjects were included for the analysis, of which 15 subjects developed IPD. FIELD STRENGTH/SEQUENCE: 3T/T2 -weighted half-Fourier single-shot turbo spin-echo (HASTE) and pCASL. ASSESSMENT: Four perfusion-related parameters in the placenta were derived: placenta volume, placental blood flow (PBF), high PBF (hPBF), and relative hPBF. The longitudinal changes of the parameters and their association with IPD were tested after being normalizing to the 16th and 20th weeks of gestation. STATISTICAL TESTS: Comparisons between two gestational ages within subjects were performed using the paired Wilcoxon tests, and comparisons between normal and IPD groups were performed using the unpaired Wilcoxon tests. RESULTS: The difference between the first and second MRI scans was statistically significant for volume (156.6 cm3 vs. 269.7 cm3 , P < 0.001) and PBF (104.9 ml/100g/min vs. 111.3 ml/100g/min, P = 0.02) for normal subjects, indicating an increase in pregnancy with advancing gestation. Of the parameters tested, the difference between the normal and IPD subjects was most pronounced in hPBF (278.1 ml/100g/min vs. 180.7 ml/100g/min, P < 0.001) and relative hPBF (259.1% vs. 183.2%, P < 0.001) at 16 weeks. DATA CONCLUSION: The high perfusion-related image parameters for IPD were significantly decreased from normal pregnancy at 14-18 weeks of gestation. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 1 J. Magn. Reson. Imaging 2020;51:1247-1257.

3D R2* mapping of the placenta during early gestation using free-breathing multiecho stack-of-radial MRI at 3T.

BACKGROUND: Multiecho gradient-echo Cartesian MRI characterizes placental oxygenation by quantifying R2* . Previous research was performed at 1.5T using breath-held 2D imaging during later gestational age (GA). PURPOSE: To evaluate the accuracy and repeatability of a free-breathing (FB) 3D multiecho gradient-echo stack-of-radial technique (radial) for placental R2* mapping at 3T and report placental R2* during early GA. STUDY TYPE: Prospective. POPULATION: Thirty subjects with normal pregnancies and three subjects with ischemic placental disease (IPD) were scanned twice: between 14-18 and 19-23 weeks GA. FIELD STRENGTH: 3T. SEQUENCE: FB radial. ASSESSMENT: Linear correlation (concordance coefficient, ρc ) and Bland-Altman analyses (mean difference, MD) were performed to evaluate radial R2* mapping accuracy compared to Cartesian in a phantom. Radial R2* mapping repeatability was characterized using the coefficient of repeatability (CR) between back-to-back scans. The mean and spatial coefficient of variation (CV) of R2* was determined for all subjects, and separately for anterior and posterior placentas, at each GA range. STATISTICAL TESTS: ρc was tested for significance. Differences in mean R2* and CV were tested using Wilcoxon Signed-Rank and Rank-Sum tests. P < 0.05 was considered significant. Z-scores for the IPD subjects were determined. RESULTS: FB radial demonstrated accurate (ρc ≥0.996; P < 0.001; |MD|<0.2s-1 ) and repeatable (CR<4s-1 ) R2* mapping in a phantom, and repeatable (CR≤4.6s-1 ) R2* mapping in normal subjects. At 3T, placental R2* mean ± standard deviation was 12.9s-1 ± 2.7s-1 for 14-18 and 13.2s-1 ± 1.9s-1 for 19-23 weeks GA. The CV was significantly greater (P = 0.043) at 14-18 (0.63 ± 0.12) than 19-23 (0.58 ± 0.13) weeks GA. At 19-23 weeks, the CV was significantly lower (P < 0.001) for anterior (0.49 ± 0.08) than posterior (0.67 ± 0.11) placentas. One IPD subject had a lower mean R2* than normal subjects at both GA ranges (Z<-2). DATA CONCLUSION: FB radial provides accurate and repeatable 3D R2* mapping for the entire placenta at 3T during early GA. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:291-303.

En bloc shoulder resection with total shoulder prosthetic replacement: indications and imaging findings.

OBJECTIVE: Our purpose was to highlight the importance of radiologic studies in assessing the appropriateness of total scapular resection and total shoulder prosthetic reconstruction and to examine the role of imaging in evaluating for postoperative complications. CONCLUSION: Evolving surgical and reconstructive techniques for treatment of shoulder girdle tumors require radiologists to familiarize themselves with novel imaging findings associated with these procedures. Readers will better understand the indications for limbsparing surgery with total shoulder prosthetic reconstruction, normal postoperative radiologic findings, and common complications.

F-18 FDG PET and PET/CT evaluation of response to chemotherapy in bone and soft tissue sarcomas.

OBJECTIVE: F-18 FDG PET has been used to grade sarcomas and assess response to therapy in advanced disease. Certain chemotherapy agents are thought to induce an inflammatory response in the tumor bed that can make interpretation of post-therapy FDG PET scans difficult. A review of our experience with PET in assessing therapy response in osseous and soft tissue sarcomas (OSTS) is presented. METHODS: This is a retrospective study (January 1999 to December 2004) of 14 patients with histologic diagnosis of OSTS, who had 2 consecutive PET examinations for evaluation of chemotherapy response. The group included 8 men and 6 women, with age range of 18 to 56 years (average, 36 +/- 14). Semiquantitative assessment of FDG uptake was performed by calculating maximum standard uptake value (SUVmax) before and after treatment. The response to therapy was assessed independently by tumor necrosis at post-therapy surgery and according to European Organization for Research and Treatment of Cancer (EORTC) criteria for PET. The follow-up PET examinations were performed at an interval of 28 to 166 days (average, 90 +/- 45). All patients ended the ifosfamide regimen at 7 to 36 (average, 16 +/- 9) days before the follow-up PET scans. Five of them received methotrexate, adriamycin, and/or cisplatin as well. RESULTS: Based on the EORTC criteria alone, 3 patients (21.4%) had progression of disease (increase in SUVmax of 29%-69%; mean, 48% +/- 20%), 5 patients (35.7%) had stable disease, and 6 patients (42.8%) had partial response (decrease in SUVmax of 27%-84%; mean, 62% +/- 23%). Across all patients, the tumor necrosis postchemotherapy ranged from 5% to 100% (mean, 64% +/- 34%). In 8 patients (57.1%) the tumor necrosis correlated with the SUVmax changes. However, for 3 patients, the SUVmax changes indicated partial response despite necrosis of fewer than 90% of the surgical specimens, whereas 3 patients with >90% tumor necrosis had SUVmax changes indicative of stable disease. CONCLUSION: The pathologically determined degree of necrosis postneoadjuvant chemotherapy was concordant with PET-assessed EORTC classification of response in 57.1% of the cases. However, a significant number of patients had discrepancies, which may be in part explained by chemotherapy-induced inflammation. The latter should be considered during post-therapy PET interpretation in OSTS.

Breast MRI and 18F FDG PET/CT in the management of breast cancer.

GOALS: 18F FDG PET/CT is used for diagnosis, staging and establishing the response to therapy in various malignancies, including breast cancer (BC). Dedicated breast MRI (BMRI) is gaining a role in the management of BC patients (pts), demonstrating high sensitivity and specificity for detection of small lesions. We were therefore prompted to review our experience with PET and BMRI in BC. METHODS: This is a retrospective study of 21 women with BC, 30-76 years old, who had BMRI and whole-body FDG PET/CT at our institution from Jun 2002 to May 2005. A total of 6 patients (group A) had BMRI and PET/CT in the preoperative period and 15 patients (group B) had BMRI and PET/CT after surgery. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed. RESULTS: For group A, BMRI identified breast lesions in 4 patients, while PET/CT was able to identify breast lesions in 5 patients. All these were proven to be malignancy on pathology examination. In group B, BMRI detected recurrent breast lesions in 8 patients, with 88.9% sensitivity and 83.3% specificity. In the same patient population, PET/CT was 33.3% sensitive and 91.7% specific. As a whole body examination, PET/CT revealed metastatic disease in 6 patients (100% sensitive and 90% specific). Overall, sensitivities and specificities for breast disease detection were 85.7% and 85.7% for BMRI, and 75% and 92.3% for 18F FDG PET/ CT. CONCLUSIONS: As expected, BMRI is more sensitive than PET/CT in the detection of breast lesions. However, PET/CT as a whole-body examination changed the management of disease by detection of distant lesions in 6 of the 21 patients. Our study suggests that 18F FDG PET/CT and BMRI should be considered as complimentary imaging tools in the pre- and postoperative work-up of patients diagnosed with breast cancer.

Detection of occult medullary thyroid cancer recurrence with 2-deoxy-2-[F-18]fluoro-D-glucose-PET and PET/CT.

PURPOSE: 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-positron emission tomography (PET) has an established role in restaging of various cancers, including papillary and undifferentiated thyroid carcinoma. However, controversies exist regarding its ability to reliably assess recurrent medullary thyroid cancer (MTC). We were therefore prompted to review our experience with FDG-PET for detection of occult MTC. METHODS: This is a retrospective study (Apr 1, 1997-Mar 31, 2004) of 13 patients with histologic diagnosis of MTC, who had PET examinations. The group included six men and seven women, 15-62 years old (average: 48+/-13). The PET scan request was triggered by rising levels of calcitonin and negative anatomical imaging studies. RESULTS: Recurrent/metastatic disease was identified by PET in seven (54%) of the 13 patients. The lesions were located in superior mediastinum (4), cervical lymph nodes (3), thyroid bed (2), lung (1) and liver (1). The calcitonin levels ranged from 52 to 5,090 pg/ml (average: 1,996 pg/ml) in patients with negative PET scans and from 132 to 9,500 pg/ml (average: 3,757 pg/ml) in patients with positive studies. The sensitivity and specificity of FDG-PET for disease detection in this cohort were 85.7% (95% CI: 48.7-97.4) and 83.3% (95% CI: 43.6-96.9), respectively. CONCLUSION: Our findings suggest a significant role for FDG-PET in patients with suspected MTC recurrence, with sensitivity of 85.7% and specificity of 83.3% for disease detection. FDG-PET provides additional information in a significant fraction of cases (54%) and could be used for restaging of patients with MTC and elevated levels of biomarkers (calcitonin). Additional studies are necessary to further evaluate the role of FDG-PET in MTC.

2-Deoxy-2-[18F]fluoro-D-glucose-positron emission tomography and positron emission tomography/computed tomography diagnosis of patients with recurrent papillary thyroid cancer.

OBJECTIVE: 2-Deoxy-2-[F-18]fluoro-D-glucose positron emission tomography (FDG-PET) has an established role in restaging of various cancers, including papillary and undifferentiated thyroid carcinoma, but detection rates are variable in the published literature. We were therefore prompted to review our experience with FDG-PET in detection of recurrent papillary thyroid cancer (PTC). METHODS: This is a retrospective study (April 1, 1995-March 31, 2005) of 21 patients with histologic diagnosis of PTC who had PET examinations. The group included seven men and 14 women, with age range of 26-75 years (average 50 +/- 16). The PET scan request was triggered by rising levels of thyroglobulin (Tg) in the presence of a negative iodine-131 scan. RESULTS: Recurrent/metastatic disease was identified by PET in 16 (76%) of the 21 patients with PTC. The sensitivity and specificity of FDG-PET for disease detection in this cohort were 88.2% [95% confidence interval (CI), 65.7-96.7] and 75% (95% CI, 30.1-95.4), respectively. The Tg levels were 1.0-10.4 ng/ml (average, 4.52 ng/ml) in the patients with negative PET scans and 1.0-38 ng/ml (average, 16.8 ng/ml) in patients with positive scans. The lesions were located in the cervical lymph nodes (8), thyroid bed (4), lungs (4), and mediastinal lymph nodes (2). CONCLUSION: Our study confirms the feasibility of PET in detection of residual/recurrence of PTC, with sensitivity of 88.2% (95% CI, 65.7-96.7) and specificity of 75% (95% CI, 30.1-95.4). Detectable levels of Tg, even in the presence of negative I-131 scan or anatomic imaging, should prompt restaging with FDG-PET.