Opportunistic screening for coronary artery calcium deposition using chest radiographs - a multi-objective models with multi-modal data fusion.

Background: To create an opportunistic screening strategy by multitask deep learning methods to stratify prediction for coronary artery calcium (CAC) and associated cardiovascular risk with frontal chest x-rays (CXR) and minimal data from electronic health records (EHR). Methods: In this retrospective study, 2,121 patients with available computed tomography (CT) scans and corresponding CXR images were collected internally (Mayo Enterprise) with calculated CAC scores binned into 3 categories (0, 1-99, and 100+) as ground truths for model training. Results from the internal training were tested on multiple external datasets (domestic (EUH) and foreign (VGHTPE)) with significant racial and ethnic differences and classification performance was compared. Findings: Classification performance between 0, 1-99, and 100+ CAC scores performed moderately on both the internal test and external datasets, reaching average f1-score of 0.66 for Mayo, 0.62 for EUH and 0.61 for VGHTPE. For the clinically relevant binary task of 0 vs 400+ CAC classification, the performance of our model on the internal test and external datasets reached an average AUCROC of 0.84. Interpretation: The fusion model trained on CXR performed better (0.84 average AUROC on internal and external dataset) than existing state-of-the-art models on predicting CAC scores only on internal (0.73 AUROC), with robust performance on external datasets. Thus, our proposed model may be used as a robust, first-pass opportunistic screening method for cardiovascular risk from regular chest radiographs. For community use, trained model and the inference code can be downloaded with an academic open-source license from https://github.com/jeong-jasonji/MTL_CAC_classification . Funding: The study was partially supported by National Institute of Health 1R01HL155410-01A1 award.

Role of lipoprotein(a) concentrations in bioprosthetic aortic valve degeneration.

OBJECTIVES: Lipoprotein(a) (Lp(a)) is associated with an increased incidence of native aortic stenosis, which shares similar pathological mechanisms with bioprosthetic aortic valve (bAV) degeneration. However, evidence regarding the role of Lp(a) concentrations in bAV degeneration is lacking. This study aims to evaluate the association between Lp(a) concentrations and bAV degeneration. METHODS: In this retrospective multicentre study, patients who underwent a bAV replacement between 1 January 2010 and 31 December 2020 and had a Lp(a) measurement were included. Echocardiography follow-up was performed to determine the presence of bioprosthetic valve degeneration, which was defined as an increase >10 mm Hg in mean gradient from baseline with concomitant decrease in effective orifice area and Doppler Velocity Index, or new moderate/severe prosthetic regurgitation. Levels of Lp(a) were compared between patients with and without degeneration and Cox regression analysis was performed to investigate the association between Lp(a) levels and bioprosthetic valve degeneration. RESULTS: In total, 210 cases were included (mean age 74.1±9.4 years, 72.4% males). Median time between baseline and follow-up echocardiography was 4.4 (IQR 3.7) years. Bioprostheses degeneration was observed in 33 (15.7%) patients at follow-up. Median serum levels of Lp(a) were significantly higher in patients affected by degeneration versus non-affected cases: 50.0 (IQR 72.0) vs 15.6 (IQR 48.6) mg/dL, p=0.002. In the regression analysis, high Lp(a) levels (≥30 mg/dL) were associated with degeneration both in a univariable analysis (HR 3.6, 95% CI 1.7 to 7.6, p=0.001) and multivariable analysis adjusted by other risk factors for bioprostheses degeneration (HR 4.4, 95% CI 1.9 to 10.4, p=0.001). CONCLUSIONS: High serum Lp(a) is associated with bAV degeneration. Prospective studies are needed to confirm these findings and to investigate whether lowering Lp(a) levels could slow bioprostheses degradation.

Diagnosis of Primary Scrotal Lymphedema Using 99mTc-Sulfur Colloid Lymphoscintigram: Correlation With MR Lymphangiogram.

ABSTRACT: We report a case of a 19-year-old man who presented with severe scrotal swelling. His medical history was notable for severe global edema at birth. Most areas of swelling had resolved by adolescence with exception of the scrotum and the left lower extremity. 99mTc-filtered sulfur colloid lymphoscintigraphy of the lower extremities demonstrated prominent dermal backflow into the superficial scrotum and thighs, which were confirmed on the SPECT/CT images, and correlated with findings on MR lymphangiogram. Lymphoscintigram and MR lymphangiogram may provide complementary information to aid diagnosis and management of primary scrotal lymphedema.

Identification of Acute Mesenteric Ischemia on 18F-FDG PET/CT.

ABSTRACT: Acute mesenteric ischemia resulting in bowel necrosis is a surgical emergency. First identification of acute mesenteric ischemia with FDG PET/CT is uncommon, because patients with bowel ischemia are usually diagnosed by other imaging methods such as CT. Nevertheless, prompt imager recognition of the PET/CT findings of mesenteric ischemia and necrosis is critical for proper triage of the patient to potentially lifesaving interventions. We present a 39-year-old woman with portal vein thrombosis who was sent for 18F-FDG PET/CT evaluation of a suspected pancreatic head neoplasm but was unexpectedly found to have ischemic and necrotic small bowel secondary to mesenteric venous infarction.

Thumb Metacarpal-Trapezoid Impingement as an Etiology of Pain After Trapeziectomy and Basal Joint Soft Tissue Arthroplasty: A Case Series.

PURPOSE: To report a poorly described etiology for pain after trapeziectomy and soft tissue basal joint arthroplasty, diagnosed with the aid of nuclear imaging. METHODS: Five patients (4 women and 1 man), average age 62 years (range, 59-65 years) presented with pain an average of 7 months (range, 2-11 months) after basal joint arthroplasty. The dominant hand was involved in all cases. Advanced imaging including 25 mCi 99mTc methylene diphosphonate bone scintigraphy and single-photon emission computed tomography (CT) showed intense tracer uptake between the base of the thumb metacarpal and residual trapezoid. Computed tomography scans confirmed abutment between these bones. The symptoms were attributed to this finding, and revision surgery consisting of excision of the trapezoid and arthrodesis of the index and middle finger carpometacarpal joints was performed. RESULTS: Mean follow-up was 40 months (range, 12-60 months). Grip strength improved from a mean of 10.5 to 23 kg, and lateral pinch strength improved from a mean of 3 to 6.75 kg. Radiographic fusion of the index finger metacarpal to capitate was confirmed in 4 of 5 patients; it was indeterminate in one patient who was completely pain-free. Radiographic fusion of long finger carpometacarpal joints was indeterminate in 3 patients. Patient-Rated Wrist Evaluation pain scores improved from 35 to 6, Patient-Rated Wrist Evaluation function scores from 78 to 14, and Quick-Disabilities of the Arm, Shoulder, and Hand scores from 37 to 18. CONCLUSIONS: Impingement between the base of the thumb metacarpal and remaining trapezoid should be considered a potential source of pain after trapeziectomy and soft tissue arthroplasty. Advanced imaging (bone scintigraphy and single-photon emission CT and standard CT) are helpful to confirm the diagnosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Nuclear Medicine and Molecular Imaging in Nodal Staging and Surveillance of Ocular Melanoma: Case Reports and Review of the Literature.

Ocular melanoma (OM) is a rare noncutaneous malignancy and consists of 2 different subtypes based on the anatomic location in the eye: uveal melanoma and conjunctival melanoma. Like cutaneous melanoma, OM benefits from nuclear medicine and molecular imaging in nodal staging and clinical management. Through the illustration of 2 distinctive cases, we aim to demonstrate the complementary roles of standard lymphoscintigraphy, advanced SPECT/CT, 18F-FDG PET/CT, and 18F-FDG PET/MRI in accurate nodal staging and surveillance of OM. We also review the epidemiology, existing staging guidelines, and management of uveal melanoma and conjunctival melanoma.

Advanced Nuclear Medicine and Molecular Imaging in the Diagnosis of Cardiomyopathy.

OBJECTIVE. The purpose of this article is to summarize the protocol, interpretation, and diagnostic performance of nuclear medicine and molecular imaging in imaging two distinctive, underdiagnosed cardiomyopathies: cardiac amyloidosis and cardiac sarcoidosis. CONCLUSION. Emerging new radiotracers and advanced molecular imaging modalities enable us to noninvasively characterize certain types of cardiomyopathies, including cardiac amyloidosis and cardiac sarcoidosis, with great confidence. We expect to improve recognition and promote the application of such advanced techniques in the imaging and management of these potentially lethal cardiomyopathies.

Nodular Fat-Sparing Hepatic Parenchyma as 11C-Choline-Avid Finding on PET/CT.

Focal nodular fat sparing of the liver may show, on PET/CT imaging, prominent tracer uptake over a background of less metabolic features of steatosis. This finding, already reported with F-FDG, may mimic primary or secondary neoplasms of the liver. The authors present an additional case of nodular fat-sparing hepatic parenchyma exhibiting C-choline avidity during PET/CT assessment for biochemical recurrence of prostate cancer.

Molecular Imaging in Diagnosis of Tumor-induced Osteomalacia.

Tumor induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by overproduction of fibroblast growth factor 23 (FGF23) secreted by benign mesenchymal neoplasm. Due to its nonspecific clinical presentation or lack of awareness, the diagnosis of TIO is often significantly delayed resulting in patients' prolonged physical suffering or psychological distress. Successful detection or complete surgical resection of the causative tumor typically leads to rapid resolution of symptoms or reversal of biochemical imbalance. Nuclear medicine and molecular imaging have been playing a promising role as the first-line imaging modalities in the diagnosis and localization of occult FGF23 secreting mesenchymal tumor, especially with the emerging whole-body, head-to-toe Ga68-DOTATATE PET/CT technique. Combined focused diagnostic CT and/or MRI are imperative for accurate delineation of tumor and surgical guidance.

"Migratory" Pattern of Corticosteroid-Related Multifocal Bone Infarction on Bone Scintigraphy.

We present serial bone scintigraphy examinations in a 38-year-old woman who presented with posterior left rib pain in the setting of adrenal insufficiency secondary to pituitary damage as a result of radiation treatment for orbital sarcoma.

99mTc-Sulfur Colloid Bone Marrow Scintigraphy in Diagnosis of Diffuse Pulmonary Extramedullary Hematopoiesis Secondary to Myelofibrosis.

Our objective was to define the role of combined 99mTc-sulfur colloid bone marrow (SC BM) scintigraphy, SPECT or SPECT/CT, and chest CT in diagnosing diffuse pulmonary extramedullary hematopoiesis (PEMH) in patients with myelofibrosis. Methods: We retrospectively reviewed 99mTc-SC BM scintigraphy scans performed at our institution for the diagnosis of diffuse PEMH, as well as accompanying chest CT and SPECT/CT imaging findings. Relevant clinical information, including respiratory manifestations, pulmonary hypertension, and subjective response to whole-lung radiation therapy, was also summarized. Results: Twenty-two myelofibrosis patients with 27 99mTc-SC BM scintigraphy scans were diagnosed with diffuse PEMH. In 21 patients (95%) with accompanying chest CT and SPECT/CT scans, the most common CT findings were ground-glass opacity, interstitial infiltration, and pleural effusion. Of 20 patients (91%) who underwent 2-dimensional echocardiography studies, 12 (55%) were diagnosed with pulmonary hypertension. All 12 patients exhibited the aforementioned nonspecific CT imaging findings, with 8 (66%) of them presenting with respiratory symptoms, including dyspnea, shortness of breath, and cough. In the remaining 8 patients, without pulmonary hypertension, half had similar respiratory symptoms. Fourteen patients (64%) of this cohort received whole-lung radiation therapy, of whom 7 (50%) experienced symptom relief after therapy. Conclusion: Nonspecific respiratory symptoms should raise concern about pulmonary hypertension and diffuse PEMH in patients with advanced-stage myelofibrosis. Combined 99mTc-SC BM scintigraphy and SPECT/CT is a promising noninvasive imaging tool to diagnose this rare clinical entity.Key Words: hematology; respiratory; SPECT/CT; pulmonary hematopoiesis; Tc-99m sulfur colloid scintigraphy; myelofibrosis.

A Prospective Trial of Intensity Modulated Radiation Therapy (IMRT) Incorporating a Simultaneous Integrated Boost for Prostate Cancer: Long-term Outcomes Compared With Standard Image Guided IMRT.

PURPOSE: This report describes the long-term outcomes of a prospective trial of intensity modulated radiation therapy (IMRT), integrating a 111In capromab pendetide (ProstaScint) scan-directed simultaneous integrated boost (SIB) for localized prostate cancer. METHODS AND MATERIALS: Seventy-one patients with T1N0M0 to T4N0M0 prostate cancer were enrolled, and their ProstaScint and pelvic computed tomography scans were coregistered for treatment planning. The entire prostate received 75.6 Gy in 42 fractions with IMRT, whereas regions of increased uptake on ProstaScint scans received 82 Gy as an SIB. Patients with intermediate- and high-risk disease also received 6 months and 12 months of adjuvant hormonal therapy, respectively. RESULTS: The study enrolled 31 low-, 30 intermediate-, and 10 high-risk patients. The median follow-up was 120 months (range, 24-150 months). The 10-year biochemical control rates were 85% for the entire cohort and 84%, 84%, and 90% for patients with low-, intermediate-, and high-risk disease, respectively. The 10-year survival rate of the entire cohort was 69%. Pretreatment prostate-specific antigen level >10 ng/mL and boost volume of >10% of the prostate volume were significantly associated with poorer biochemical control and survival. The outcomes were compared with those of a cohort of 302 patients treated similarly but without the SIB and followed up for a median of 91 months (range, 6-138 months). The 5- and 10-year biochemical control rates were 86% and 61%, respectively, in patients without the SIB compared with 94% and 85%, respectively, in patients in this trial who received the SIB (P=.02). The cohort that received an SIB did not have increased toxicity. CONCLUSIONS: The described IMRT strategy, integrating multiple imaging modalities to administer 75.6 Gy to the entire prostate with a boost dose of 82 Gy, was feasible. The addition of the SIB was associated with greater biochemical control but not toxicity. Modern imaging technology can be used to locally intensify the dose to tumors and spare normal tissues, producing very favorable long-term biochemical disease control.

99mTc-Macroaggregated Albumin SPECT/CT Perfusion Imaging of Omental Extrahepatic Vascularization.

The authors present a case of omental perfusion by an extrahepatic branch of the right hepatic artery depicted during pre-embolization planning with 99mTc-macroaggregated albumin SPECT/CT imaging. This omental scintigraphic finding corresponds to an extrahepatic branch of the right hepatic artery demonstrated by selective angiography and related CT angiography. The authors would like to add the omentum to the previously reported sites of extrahepatic vascularization encountered during the hepatic pre-embolization imaging.

Diuretic Renal Scintigraphy in Patients with Sulfonamide Allergies: Possible Alternative Use of Ethacrynic Acid.

UNLABELLED: Furosemide may trigger life-threatening sulfonamide cross-hypersensitivity reactions, posing a dilemma in patients who need diuretic renal scintigraphy. METHODS: We present our experience using ethacrynic acid as a nonsulfonamide alternative diuretic in 5 patients, with a discussion of the diuretic molecular structure, potential side effects, protocol development, and imaging results. RESULTS: Diuretic renal scintigraphy using ethacrynic acid provided useful information about the obstruction status in all patients, with no adverse clinical impact. CONCLUSION: Ethacrynic acid is a potential alternative to furosemide for patients with severe sulfonamide reactions.

Pilot study: Evaluation of dual-energy computed tomography measurement strategies for positron emission tomography correlation in pancreatic adenocarcinoma.

We sought to determine whether dual-energy computed tomography (DECT) measurements correlate with positron emission tomography (PET) standardized uptake values (SUVs) in pancreatic adenocarcinoma, and to determine the optimal DECT imaging variables and modeling strategy to produce the highest correlation with maximum SUV (SUVmax). We reviewed 25 patients with unresectable pancreatic adenocarcinoma seen at Mayo Clinic, Scottsdale, Arizona, who had PET-computed tomography (PET/CT) and enhanced DECT performed the same week between March 25, 2010 and December 9, 2011. For each examination, DECT measurements were taken using one of three methods: (1) average values of three tumor regions of interest (ROIs) (method 1); (2) one ROI in the area of highest subjective DECT enhancement (method 2); and (3) one ROI in the area corresponding to PET SUVmax (method 3). There were 133 DECT variables using method 1, and 89 using the other methods. Univariate and multivariate analysis regression models were used to identify important correlations between DECT variables and PET SUVmax. Both R2 and adjusted R2 were calculated for the multivariate model to compensate for the increased number of predictors. The average SUVmax was 5 (range, 1.8-12.0). Multivariate analysis of DECT imaging variables outperformed univariate analysis (r = 0.91; R2 = 0.82; adjusted R2 = 0.75 vs. r < 0.58; adjusted R2 < 0.34). Method 3 had the highest correlation with PET SUVmax (R2 = 0.82), followed by method 1 (R2 = 0.79) and method 2 R2 = 0.57). DECT thus has clinical potential as a surrogate for, or as a complement to, PET in patients with pancreatic adenocarcinoma.

Incarcerated inguinal hernia from metastatic pleural mesothelioma: PET/CT imaging.

PET/CT provides a comprehensive staging, post-therapeutic surveillance, and outcome prognosis of malignant pleural mesothelioma based on its hypermetabolic behavior. This ability of PET may allow the monitoring, prediction, and detection of uncommon distant gastrointestinal clinical manifestations of this disease. The authors present a case of PET/CT imaging of pleural mesothelioma disseminating to the abdomen and pelvis, inducing an incarcerated inguinal hernia.