Social Determinants of Health Framework to Identify and Reduce Barriers to Imaging in Marginalized Communities.

Social determinants of health (SDOH) are conditions influencing individuals' health based on their environment of birth, living, working, and aging. Addressing SDOH is crucial for promoting health equity and reducing health outcome disparities. For conditions such as stroke and cancer screening where imaging is central to diagnosis and management, access to high-quality medical imaging is necessary. This article applies a previously described structural framework characterizing the impact of SDOH on patients who require imaging for their clinical indications. SDOH factors can be broadly categorized into five sectors: economic stability, education access and quality, neighborhood and built environment, social and community context, and health care access and quality. As patients navigate the health care system, they experience barriers at each step, which are significantly influenced by SDOH factors. Marginalized communities are prone to disparities due to the inability to complete the required diagnostic or screening imaging work-up. This article highlights SDOH that disproportionately affect marginalized communities, using stroke and cancer as examples of disease processes where imaging is needed for care. Potential strategies to mitigate these disparities include dedicating resources for clinical care coordinators, transportation, language assistance, and financial hardship subsidies. Last, various national and international health initiatives are tackling SDOH and fostering health equity.

Refining prognosis in patients with hepatocellular carcinoma through incorporation of metabolic imaging biomarkers.

PURPOSE: 18F-fluorodeoxyglucose positron emission tomopraphy/computed tomography (FDGPET/CT) has been proven to be useful for imaging many types of cancer; however, its role is not well defined in hepatocellular carcinoma (HCC). We assessed the prognostic value of metabolic imaging biomarkers as established by baseline pretreatment FDG PET/CT in patients with HCC. METHODS: We retrospectively analyzed the records of patients with HCC who underwent FDG PET/CT before initial treatment from May 2013 through May 2014. Four PET/CT parameters were measured: maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), metabolic tumor volume (MTV), and tumor-to-normal-liver SUV ratio (TNR). Optimal cut-off values for the PET/CT parameters to stratify patients in terms of overall survival (OS) were determined. Multivariate analysis was performed to determine whether the PET/CT parameters could add to the prognostic value of the Cancer of the Liver Italian Program (CLIP) scoring system and the Barcelona-Clinic Liver Cancer (BCLC) staging system. RESULTS: The analysis included 56 patients. Univariate analysis of the association between OS and continuous variables, including the PET/CT parameters SUVmax, TLG, tumor size, total bilirubin level, and alkaline phosphatase level were significant predictors of OS. SUVmax ≥ 11.7, TLG ≥ 1,341, MTV ≥ 230 mL, and TNR ≥ 4.8 were identified as cut-off values. Multivariate analysis revealed that SUVmax ≥ 11.7 and TNR ≥ 4.8 were independent factors predicting a poor prognosis in both the CLIP scoring system and the BCLC staging system, as was TLG in the BCLC staging system. CONCLUSION: Pretreatment FDG PET/CT in patients with HCC can add to the prognostic value of standard clinical measures. Incorporation of imaging biomarkers derived from FDG PET/CT into HCC staging systems should be considered.

Factors affecting (223)Ra therapy: clinical experience after 532 cycles from a single institution.

PURPOSE: The aim of this study was to identify baseline features that predict outcome in (223)Ra therapy. METHODS: We retrospectively reviewed 110 patients with metastatic castration-resistant prostate cancer treated with (223)Ra. End points were overall survival (OS), progression-free survival (PFS), bone event-free survival (BeFS), and bone marrow failure (BMF). The following parameters were evaluated prior to the first (223)Ra cycle: serum levels of hemoglobin (Hb), prostate-specific antigen (PSA), alkaline phosphatase (ALP), Eastern Cooperative Oncology Group (ECOG) status, pain score, use of chemotherapy, and external beam radiation therapy (EBRT). During/after (223)Ra we evaluated: the total number of radium cycles (RaTot), the PSA doubling time (PSADT), and the use of chemotherapy, EBRT, abiraterone, and enzalutamide. RESULTS: A significant reduction of ALP (p < 0.001) and pain score (p = 0.041) occurred throughout the (223) Ra cycles. The risk of progression was associated with declining ECOG status [hazard ratio (HR) = 3.79; p < 0.001] and decrease in PSADT (HR = 8.22; p < 0.001). RaTot, ALP, initial ECOG status, initial pain score, and use of abiraterone were associated with OS (p ≤ 0.008), PFS (p ≤ 0.003), and BeFS (p ≤ 0.020). RaTot, ALP, initial ECOG status, and initial pain score were significantly associated with BMF (p ≤ 0.001) as well as Hb (p < 0.001) and EBRT (p = 0.009). On multivariable analysis, only RaTot and abiraterone remained significantly associated with OS (p < 0.001; p = 0.033, respectively), PFS (p < 0.001; p = 0.041, respectively), and BeFS (p < 0.001; p = 0.019, respectively). Additionally, RaTot (p = 0.027) and EBRT (p = 0.013) remained significantly associated with BMF. CONCLUSION: Concomitant use of abiraterone and (223)Ra seems to have a beneficial effect, while the EBRT may increase the risk of BMF.

Assessment of Sequential PET/MRI in Comparison With PET/CT of Pediatric Lymphoma: A Prospective Study.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of sequential (18)F-FDG PET/MRI (PET/MRI) and (18)F-FDG PET/CT (PET/CT) in a pediatric cohort with lymphoma for lesion detection, lesion classification, and disease staging; quantification of FDG uptake; and radiation dose. SUBJECTS AND METHODS: For this prospective study of 25 pediatric patients with lymphoma, 40 PET/CT and PET/MRI examinations were performed after a single-injection dual-time-point imaging protocol. Lesions detected, lesion classification, Ann Arbor stage, and radiation dose were tabulated for each examination, and statistical evaluations were performed to compare the modalities. Quantification of standardized uptake values (SUVs) was performed for all lesions. All available examinations and clinical history were used as the reference standard. RESULTS: No statistically significant differences between PET/MRI and PET/CT were observed in lesion detection rates, lesion classification, or Ann Arbor staging. Fifty-four regions of focal uptake were observed on PET/MRI compared with 55 on PET/CT. Both modalities accurately classified 82% of the lesions relative to the reference standard. Disease staging based on PET/MRI was correct for 35 of the 40 studies, and disease staging based on PET/CT was correct for 35 of the 40 studies; there was substantial agreement between the modalities for disease staging (κ = 0.684; p < 0.001). PET SUVs were strongly correlated between PET/CT and PET/MRI (ρ > 0.72), although PET/MRI showed systematically lower SUV measurements. PET/MRI offered an average 45% reduction in radiation dose relative to PET/CT. CONCLUSION: In a pediatric cohort with lymphoma, sequential PET/MRI showed lesion detection, lesion classification, and Ann Arbor staging comparable to PET/CT. PET/MRI quantification of FDG uptake strongly correlated with PET/CT, but the SUVs were not interchangeable. PET/MRI significantly reduced radiation exposure and is a promising new alternative in the care of pediatric lymphoma patients.

Fat-Containing Hypermetabolic Masses on FDG PET/CT: A Spectrum of Benign and Malignant Conditions.

OBJECTIVE: This article focuses on identifying the imaging appearances of hypermetabolic fatty masses and masslike lesions on PET/CT and understanding the diagnostic challenges radiologists may face while interpreting findings of these lesions on PET/CT. This article provides an approach to aid in the diagnosis of these lesions and the appropriate management of patients. CONCLUSION: Both malignant and benign fat-containing masses and masslike lesions can show hypermetabolic activity on PET/CT. Although the differential diagnosis is broad, clinical history, anatomic location, and knowledge of anatomic variants and imaging features can help radiologists avoid misinterpretation of benign fatty lesions as malignancy.

Comparison of Standardized Uptake Values in Normal Structures Between PET/CT and PET/MRI in a Tertiary Pediatric Hospital: A Prospective Study.

OBJECTIVE: The purpose of this study was to compare standardized uptake values (SUVs) of normal tissues using MR attenuation-corrected versus CT attenuation-corrected (18)F-FDG PET in a pediatric population. SUBJECTS AND METHODS: Thirty-five patients (21 boys; mean age, 13.3 years) referred for 47 PET/CT scans were recruited to undergo PET/MRI. MR attenuation correction was performed using an automated three-segment model. ROIs were drawn over nine normal structures to estimate SUV(min), SUV(mean), and SUV(max). Pearson rank correlation coefficients were calculated to compare SUVs obtained from MR and CT attenuation correction. In nine patients who underwent multiple PET/MRI studies, coefficients of variance and intraclass correlation coefficients were calculated to evaluate intrapatient SUV(max) variation. RESULTS: Mean (± SD) time to imaging after FDG injection was 108 ± 17 minutes for PET/CT and 61 ± 6 minutes for PET/MRI. PET/MRI SUVs in all tissues were lower than those for PET/CT (mean difference, -28.9% ± 31.1%; p < 0.05). Very high or high correlation between PET/MRI and PET/CT SUV(max) was found in brain (r = 0.72), myocardium (r = 0.95), and bone marrow (r = 0.85) (p < 0.001). Moderate correlation was found in liver (r = 0.54), fat (r = 0.41), mean blood pool (r = 0.40), and psoas muscle (r = 0.38) (p < 0.01). Weak correlation was found in lung (r = 0.12) and iliacus muscle (r = 0.12). Compared with PET/CT, PET/MRI systematically undermeasured SUV. In nine patients who underwent multiple PET/MRI examinations, moderate or strong agreement was found in the SUV(max) of six of nine tissues, similar to the corresponding PET/CT examinations. CONCLUSION: Our study showed overall high correlation for SUV measurements obtained from MR attenuation correction compared with CT attenuation correction, although PET/MRI underestimated SUV compared with PET/CT. SUVs measured from PET/MRI indicated good intrapatient reliability.

Qualitative FDG PET Image Assessment Using Automated Three-Segment MR Attenuation Correction Versus CT Attenuation Correction in a Tertiary Pediatric Hospital: A Prospective Study.

OBJECTIVE: The purpose of this study was to systematically evaluate the diagnostic quality of (18)F-FDG PET images generated using MR attenuation correction (MRAC) compared with those images generated using CT attenuation correction (CTAC) in a pediatric population. SUBJECTS AND METHODS: Forty-two patients (mean age, 12.8 years; percentage who were male, 57%) who were referred for 62 indicated whole-body PET/CT studies were prospectively recruited to undergo PET/MRI examinations during the same clinic visit in which PET/CT was performed. MRAC was performed using an automatic three-segment model. Three nuclear radiologists scored the diagnostic quality of the PET images generated by MRAC and CTAC using a Likert scale (range of scores, 1-5). Images graded with a score of 1-3 were considered clinically unacceptable, whereas images with a score of 4-5 were considered clinically acceptable. A Wilcoxon signed-rank test was used to compare differences in the grading of PET/MRI and PET/CT images. The Fisher exact test was used to evaluate potential differences in clinically acceptable image quality and the presence of artifact. Fleiss kappa statistics were used to examine interobserver agreement. RESULTS: There was no statistically significant difference in the proportion of PET images generated with MRAC and CTAC for which image quality was considered clinically acceptable. A total of 3.9% of PET assessments generated with MRAC were of unacceptable image quality, compared with 2.2% of PET images generated with CTAC. Two of the three radiologists who reviewed the PET images reported the presence of artifacts more often on MRAC-derived images, and they graded the mean quality of these images 0.48 and 0.29 points lower on the 5-point Likert scale than they graded the mean quality of CTAC-derived images (p < 0.0001). Interobserver agreement was fair (κ = 0.39). CONCLUSION: The diagnostic quality of PET images obtained from a pediatric population with the use of an automatic three-segmentation MRAC method was comparable to that of PET images obtained with the use of CTAC.

Impact of initial PET/CT staging in terms of clinical stage, management plan, and prognosis in 592 patients with non-small-cell lung cancer.

PURPOSE: Our objective was to determine the impact of initial (18)F-FDG PET/CT (PET/CT) staging on clinical stage and the management plan and the prognostic value of PET/CT in patients with non-small-cell lung cancer (NSCLC). METHODS: We retrospectively reviewed the records of 592 patients with NSCLC who were referred to The University of Texas MD Anderson Cancer Center during 2002/2011 and had both PET/CT and conventional CT for initial staging. Clinical stages and management plans were compared between PET/CT and CT. The impact of PET/CT on management plans was considered medium/high when PET/CT changed the planned treatment modality or treatment intent. PET/CT and CT stages were compared with all-cause mortality and survival rates. We also assessed potential prognostic factors for progression-free survival (PFS) and overall survival (OS). RESULTS: PET/CT changed the stage in 170 patients (28.7 %; 16.4 % upstaged, 12.3 % downstaged). PET/CT had a medium/high impact on the management plan in 220 patients (37.2 %). PFS and OS were significantly worse in patients with upstaged disease than in patients with no change in stage (median PFS 29.0 vs. 53.8 months, P < 0.001; median OS:64.7 vs. 115.9 months, P = 0.006). PFS and OS were significantly worse in patients with medium/high impact of PET/CT than in patients with no/low impact of PET/CT (median PFS 24.7 vs. 60.6 months, P < 0.001; median OS 64.7 vs. 115.9 months, P < 0.001). In multivariate analysis, a medium/high impact of PET/CT was an independent predictor of worse PFS (hazard ratio, HR, 1.73; 95 % CI 1.30 - 2.29; P = 0.0002) and OS (HR 1.84; 95 % CI 1.26 - 2.69; P = 0.002). CONCLUSION: Initial PET/CT staging not only impacts stage and management plan but also has prognostic value.

Correlation of PUV and SUV in the extremities while using PEM as a high-resolution positron emission scanner.

OBJECTIVE: Owing to its unique configuration of two adjustable plate detectors positron emission mammography, or PEM, could theoretically also function as a high-resolution positron emission scanner for the extremities or neck. PEM quantitates its activity via a "PEM uptake value," or PUV, and although its relationship to the standardized uptake value, or SUV, has been demonstrated in the breasts, to our knowledge there are no studies validating PUV in other sites such as the extremities. MATERIALS AND METHODS: This was a retrospective chart review of two separate protocols of a total of 15 patients. The patients all had hypermetabolic lesions in the extremities or neck on imaging with PET/CT and were sent after their PET/CT to PEM for further imaging. Owing to the sequential nature of these examinations no additional radiotracer was administered. RESULTS: Spearman's rank order correlation was calculated between the PUVmax obtained from PEM images, and the SUVmax for all. Spearman's rank order correlation for all sites was 0.42, which is not significantly different from 0 (p = 0.13). When neck lesions were excluded from the group, there was a strong and statistically significant correlation between PUVmax and SUVmax, with Spearman's rank correlation of 0.73, and significantly different from 0 (p = 0.0068). DISCUSSION: The correlation of PUV and SUV in the extremities indicates the potential use of PEM as a semiquantitative, high-resolution positron emission scanner and warrants further investigation, especially in the realms of disease processes that often present in the extremities, such as melanoma, osteomyelitis, and arthritis, as well as playing a role in the imaging of patients with metallic hardware post-limb salvage surgery.

Generative Artificial Intelligence Biases, Limitations and Risks in Nuclear Medicine: An Argument for Appropriate Use Framework and Recommendations.

Generative artificial intelligence (AI) algorithms for both text-to-text and text-to-image applications have seen rapid and widespread adoption in the general and medical communities. While limitations of generative AI have been widely reported, there remain valuable applications in patient and professional communities. Here, the limitations and biases of both text-to-text and text-to-image generative AI are explored using purported applications in medical imaging as case examples. A direct comparison of the capabilities of four common text-to-image generative AI algorithms is reported and recommendations for the most appropriate use, DALL-E 3, justified. The risks use and biases are outlined, and appropriate use guidelines framed for use of generative AI in nuclear medicine. Generative AI text-to-text and text-to-image generation includes inherent biases, particularly gender and ethnicity, that could misrepresent nuclear medicine. The assimilation of generative AI tools into medical education, image interpretation, patient education, health promotion and marketing in nuclear medicine risks propagating errors and amplification of biases. Mitigation strategies should reside inside appropriate use criteria and minimum standards for quality and professionalism for the application of generative AI in nuclear medicine.

Impact of the COVID-19 Pandemic and Vaccine Availability on Utilization of Breast Imaging in a Multistate Radiology Practice.

Method: Data were obtained from medical health records across 77 Radiology Partners practices in the US. The data provided us with the total monthly mammography, breast ultrasound, and breast MRI procedures from January 2019 to September 2022. An interrupted time-series (ITS) analysis was conducted to evaluate the effect of the COVID-19 pandemic and the COVID-19 vaccination. We chose March 2020 and December 2020 as critical time points in the pandemic and analyzed trends before and after these dates. Results: The starting level (at baseline in January 2019) of the total breast imaging procedure volume was estimated at 114,901.5, and this volume appeared to significantly increase every month prior to March 2020 by 4,864.0 (p < 0.0001, CI = [3,077.1, 6,650.9]). In March 2020, there appeared to be a significant decrease in volume by 104,446.3 (p=0.003, CI = [-172,063.1, -36,829.5]), followed by a significant increase in the monthly trend of service volume (relative to the pre-COVID trend) of 20,660.7 per month (p=0.001, CI = [8,828.5, 32,493.0]). In December 2020, there appeared to be a significant decrease in service volume by 69,791.2 (p=0.012, CI = [-123,602.6, -15,979.7]). Compared to the period from March to November 2020, there was a decrease in the monthly trend of service volumes per month by 24,213.9 (p < 0.0001, CI = [-36,027.6, -12,400.2]). After March 2020, the total service volume increased at the rate of 25,524.7 per month (p < 0.0001, CI = [13,828.2, 37,221.2]). In contrast, the service volumes after December 2020 appeared to grow steadily and slowly at a rate of 1,310.8 per month (p=0.118, CI = [-348.8, 2970.3]). Conclusion: Our study revealed that there has been a recovery and a further increase in breast imaging service volumes compared to prepandemic levels. The increase can be best explained by vaccination rollout, reopening of elective/nonemergency healthcare services, insurance coverage expansion, the decline in the US uninsured rate due to government interventions and policies, and the recovery of jobs with employer-provided medical insurance post-pandemic.

(18)F-FDG PET/CT predicts survival in patients with inflammatory breast cancer undergoing neoadjuvant chemotherapy.

PURPOSE: The objective of this study was to evaluate the role of (18)F-FDG PET/CT in predicting overall survival in inflammatory breast cancer patients undergoing neoadjuvant chemotherapy. METHODS: Included in this retrospective study were 53 patients with inflammatory breast cancer who had at least two PET/CT studies including a baseline study before the start of neoadjuvant chemotherapy. Univariate and multivariate analyses were performed to assess the effects on survival of the following factors: tumor maximum standardized uptake value (SUVmax) at baseline, preoperatively and at follow-up, decrease in tumor SUVmax, histological tumor type, grade, estrogen, progesterone, HER2/neu receptor status, and extent of disease at presentation including axillary nodal and distant metastases. RESULTS: By univariate analysis, survival was significantly associated with decrease in tumor SUVmax and tumor receptor status. Patients with decrease in tumor SUVmax had better survival (P = 0.02). Patients with a triple-negative tumor (P = 0.0006), a Her2/neu-negative tumor (P = 0.038) or an ER-negative tumor (P = 0.039) had worse survival. Multivariate analysis confirmed decrease in tumor SUVmax and triple-negative receptor status as significant predictors of survival. Every 10% decrease in tumor SUVmax from baseline translated to a 15% lower probability of death, and complete resolution of tumor FDG uptake translated to 80% lower probability of death (P = 0.014). Patients with a triple-negative tumor had 4.11 times higher probability of death (P = 0.004). CONCLUSION: Decrease in tumor SUVmax is an independent predictor of survival in patients with inflammatory breast cancer undergoing neoadjuvant chemotherapy. Further investigation with prospective studies is warranted to clarify its role in assessing response and altering therapy.

Radiation Dosimetry, Artificial Intelligence and Digital Twins: Old Dog, New Tricks.

Developments in artificial intelligence, particularly convolutional neural networks and deep learning, have the potential for problem solving that has previously confounded human intelligence. Accurate prediction of radiation dosimetry pre-treatment with scope to adjust dosing for optimal target and non-target tissue doses is consistent with striving for improved the outcomes of precision medicine. The combination of artificial intelligence and production of digital twins could provide an avenue for an individualised therapy doses and enhanced outcomes in theranostics. While there are barriers to overcome, the maturity of individual technologies (i.e. radiation dosimetry, artificial intelligence, theranostics and digital twins) places these approaches within reach.

Fast Dixon whole-body MRI for detecting distant cancer metastasis: a preliminary clinical study.

PURPOSE: To evaluate the feasibility of fast Dixon whole-body (WB) magnetic resonance imaging (MRI) for detecting bone and liver metastasis in clinical patients and to compare its performance with skeletal scintigraphy (SS) for detecting bone metastases using reference imaging with >1 year follow-up as the gold standard. MATERIALS AND METHODS: Twenty-nine patients with bone metastases prospectively underwent WB MRI and SS. WB MRI included coronal T2, axial T1 with and without intravenous gadolinium (including triphasic liver sequences), and axial diffusion-weighted imaging, plus spinal sagittal postcontrast T1-weighted images. The skeleton was divided into 16 segments. Reviewers blinded to other images identified up to five lesions per segment and rated them using a five-point confidence scale for metastatic disease. Sensitivities and specificities were compared using the McNemar test. RESULTS: The sensitivity of WB MRI and SS in detecting bone metastases was 70.8% and 59.6% (P = 0.003), respectively; specificity was 89.1% and 98.7% (P < 0.0001). WB MRI detected all livers with metastases (n = 8). One focal nodular hyperplasia was classified as a metastasis on WB MRI. CONCLUSION: Fast Dixon WB MRI is feasible in clinical patients, highly specific, and more sensitive than SS in detecting bone metastases, and can detect metastases of the liver.

A software tool for stitching two PET/CT body segments into a single whole-body image set.

A whole-body PET/CT scan extending from the vertex of the head to the toes of the patient is not feasible on a number of commercially available PET/CT scanners due to a limitation in the extent of bed travel on these systems. In such cases, the PET scan has to be divided into two parts: one covering the upper body segment, while the other covering the lower body segment. The aim of this paper is to describe and evaluate, using phantom and patient studies, a software tool that was developed to stitch two body segments and output a single whole-body image set, thereby facilitating the interpretation of whole-body PET scans. A mathematical model was first developed to stitch images from two body segments using three landmarks. The model calculates the relative positions of the landmarks on the two segments and then generates a rigid transformation that aligns these landmarks on the two segments. A software tool was written to implement this model while correcting for radioactive decay between the two body segments, and output a single DICOM whole-body image set with all the necessary tags. One phantom, and six patient studies were conducted to evaluate the performance of the software. In these studies, six radio-opaque markers (BBs) were used as landmarks (three on each leg). All studies were acquired in two body segments with BBs placed in the overlap region of the two segments. The PET/CT images of each segment were then stitched using the software tool to create a single DICOM whole-body PET/CT image. Evaluation of the stitching tool was based on visual inspection, consistency of radiotracer uptake in the two segments, and ability to display the resultant DICOM image set on two independent workstations. The software tool successfully stitched the two segments of the phantom image, and generated a single whole-body DICOM PET/CT image set that had the correct alignment and activity concentration throughout the image. The stitched images were viewed by two independent workstations from two different manufacturers, attesting the ability of the software tool to produce a DICOM compliant image set. The study demonstrated that this software tool allows the stitching of two segments of a whole-body PET/CT scan with minimal user interaction, thereby facilitating the interpretation of whole body PET/CT scans from a number of scanners with limited extent of bed travel.

DOTATATE Uptake in an Axillary Lymph Node After COVID-19 Vaccination.

ABSTRACT: A 58-year-old man underwent DOTATATE PET/CT scan for follow-up of pulmonary neuroendocrine tumor after resection and adjuvant chemotherapy. On screening paperwork, the patient indicated having received the Johnson & Johnson/Janssen COVID-19 vaccine (Janssen Biotech, Inc) 1 day previously, administered in the right deltoid muscle. Reactive changes in regional lymph nodes is a known response for all 3 currently Food and Drug Administration-approved COVID-19 vaccines. Recent published data have demonstrated FDG PET-avid axillary lymphadenopathy subsequent to COVID-19 vaccination, and included here is a report of DOTATATE PET-avid axillary lymph node after injection of the Johnson & Johnson COVID-19 vaccine.

An Unusual Case of Breast Implant-Associated Anaplastic Large Cell Lymphoma.

Introduction: Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare disease entity associated with textured breast implants. Though the clinical course is typically indolent, BIA-ALCL can occasionally invade through the capsule into the breast parenchyma with spread to the regional lymph nodes and beyond including chest wall invasive disease. Case: We present the case of a 51-year-old female with a history of bilateral silicone breast implants placed approximately twenty years ago who presented with two months of progressively enlarging right breast mass. Ultrasound-guided biopsy of right breast mass and right axillary lymph node showed CD 30-positive ALK-negative anaplastic large cell lymphoma, and staging work up showed extension of the tumor to chest wall and ribs consistent with advanced disease. She received CHP-BV (cyclophosphamide, doxorubicin, prednisone, and brentuximab vedotin) for six cycles with complete metabolic response. This was followed by extensive surgical extirpation and reconstruction, radiation for residual disease and consolidation with autologous stem cell transplant. She is currently on maintenance brentuximab vedotin with no evidence of active disease post autologous stem cell transplant. Conclusion: Treatment guidelines for advanced chest wall invasive BIA-ALCL are not well defined. Lack of predictive factors warrants mutation analysis and genetic sequencing to identify those at highest risk of progression to chest wall invasive disease. This rare case highlights the need for definitive consensus on the optimal management of chest wall invasive BIA-ALCL.

Investigating the limit of detectability of a positron emission mammography device: a phantom study.

PURPOSE: A new positron emission mammography (PEM) device (PEM Flex Solo II, Naviscan Inc., San Diego, CA) has recently been introduced and its performance characteristics have been documented. However, no systematic assessment of its limit of detectability has been evaluated. The aim of this work is to investigate the limit of detectability of this new PEM system using a novel, customized breast phantom. METHODS: Two sets of F-18 infused gelatin breast phantoms of varying thicknesses (2, 4, 6, and 8 cm) were constructed with and without (blank) small, shell-less contrast objects (2 mm thick disks) of varying diameters (3-14.5 mm) [volumes: 0.15-3.3 cc] and activity concentration to background ratio (ACR) (2.7-58). For the phantom set with contrast objects, the disks were placed centrally inside the phantoms and both phantom sets were imaged for a period of 10 min on the PEM device. In addition, scans for the 2 and 6 cm phantoms were repeated at different times (0, 90, and 150 min) post phantom construction to evaluate the impact of total activity concentration (count density) on lesion detectability. Each object from each phantom scan was then segmented and placed randomly in a corresponding blank phantom image. The resulting individual images were presented blindly to seven physician observers (two nuclear medicine and five breast imaging radiologists) and scored in a binary fashion (1-correctly identified object, 0-incorrect). The sensitivity, specificity, and accuracy of lesion detectability were calculated and plots of sensitivity versus ACR and lesion diameters for different phantom thicknesses and count density were generated. RESULTS: The overall (mean) detection sensitivity across all variables was 0.68 (95% CI: [0.64, 0.72]) with a corresponding specificity of 0.93 [0.87, 0.98], and diagnostic accuracy of 0.72 [0.70, 0.75]. The smallest detectable object varied strongly as a function of ACR, as sensitivity ranged from 0.36 [0.29, 0.44] for the smallest lesion size (3 mm) to 0.80 [0.75, 0.84] for the largest (14.5 mm). CONCLUSIONS: The detectability performance of this PEM system demonstrated its ability to resolve small objects with low activity concentration ratios which may assist in the identification of early stage breast cancer. The results of this investigation can be used to correlate lesion detectability with tumor size, ACR, count rate, and breast thickness.

Pitfalls in Interpretation of PET/CT in the Chest.

Whole body positron emission tomography (PET)/computed tomography (CT) imaging with [18F]-fluoro-2-deoxy-D-glucose (FDG) is widely used in oncologic imaging. In the chest, common PET/CT applications include the evaluation of solitary pulmonary nodules, cancer staging, assessment of response to therapy, and detection of residual or recurrent disease. Knowledge of the technical artifacts and potential pitfalls that radiologists may encounter in the interpretation of PET/CT in the thorax is important to avoid misinterpretation and optimize patient management. This article will review pitfalls in the interpretation of PET/CT in the chest related to technical factors, physiologic uptake, false positive findings, false negative findings, and iatrogenic conditions.