Stephen M. Broski

The Added Value of 18F-FDG PET/CT for Evaluation of Patients with Esthesioneuroblastoma

The purpose of this study was to evaluate the clinical utility of 18F-FDG PET/CT in esthesioneuroblastoma staging and restaging and quantify the additional benefit of PET/CT to conventional imaging. Methods: A retrospective review was performed with institutional review board approval for patients with a diagnosis of esthesioneuroblastoma who underwent PET/CT from 2000 to 2010. PET/CT results were retrospectively reviewed by 2 radiologists who were unaware of the clinical and imaging data. Positive imaging findings were classified into 3 categories: local disease, cervical nodal spread, and distant metastasis. All conventional imaging performed in the 6 mo preceding PET/CT, and the medical records, were reviewed to determine the potential added value. Results: Twenty-eight patients (mean age, 52.3 ± 10 y; range, 23–81 y) were identified who underwent a total of 77 PET/CT examinations. Maximum standardized uptake value (SUVmax) was 8.68 ± 4.75 (range, 3.6–23.3) for the primary tumor and 8.57 ± 6.46 (range, 1.9–27.2) for the metastatic site. There was no clear association between primary tumor SUVmax and tumor grade (P = 0.30). Compared with conventional imaging, PET/CT changed disease stage or altered clinical management in 11 (39%) of 28 esthesioneuroblastoma patients. Of these, 10 (36%) of 28 were upstaged on the basis of their PET/CT studies. Cervical nodal metastases were found in 5 (18%) of 28, local recurrence in 2 (7%) of 28, cervical nodal and distant metastases in 2 (7%) of 28, and distant metastases in 1 (4%) of 28. One patient (4%) was downstaged after negative findings on PET/CT. Conclusion: PET/CT is a useful adjunct to conventional imaging in the initial staging and restaging of esthesioneuroblastoma by detecting nodal and distant metastatic disease not demonstrated by conventional imaging and identifying local recurrence hidden by treatment changes on conventional imaging.

Anatomy of the Adductor Magnus Origin: Implications for Proximal Hamstring Injuries

Background: The adductor magnus (AM) has historically been a potential source of confusion in patients with suspected proximal hamstring avulsion injuries. Purpose: To investigate the anatomic characteristics of the AM, including its osseous origin, anatomic dimensions, and relationship to the proximal hamstring tendons. Study Design: Descriptive laboratory study. Methods: Dissection of the AM origin was performed in 11 (8 cadavers) fresh-frozen hip-to-foot cadaveric hemipelvis specimens. The gross anatomy and architecture of the proximal hamstring and AM tendons were studied. After dissecting the hamstring tendons away from their origin, the dimension, shape, and orientation of the tendon footprints on the ischial tuberosity were determined. Results: The AM was identified in all cadaveric specimens. The mean tendon thickness (anterior to posterior [AP]) was 5.7 ± 2.9 mm. The mean tendon width (medial to lateral [ML]) was 7.1 ± 2.2 mm. The mean tendon length was 13.1 ± 8.7 cm. The mean footprint height (AP dimension) was 12.1 ± 2.9 mm, and mean footprint width (ML dimension) was 17.3 ± 7.1 mm. The mean distance between the AM footprint and the most medial aspect of the conjoint tendon footprint was 8.5 ± 4.2 mm. Tendon measurements demonstrated a considerable degree of both intra- and interspecimen variability. Conclusion: The AM tendon is consistently present just medial to the conjoint tendon at the ischial tuberosity, representing the lateral-most portion of the AM muscle. This study found wide variation in the dimensional characteristics of the AM tendon between specimens. Its shape and location can mimic the appearance of an intact hamstring (conjoint or semimembranosus) tendon intraoperatively or on diagnostic imaging, potentially misleading surgeons and radiologists. Therefore, detailed knowledge of the AM tendon anatomy, footprint anatomy, and its relationship to the hamstring muscle complex is paramount when planning surgical approach and technique. Clinical Relevance: The reported data may aid surgeons in more accurate recognition, diagnosis, and repair of proximal hamstring avulsion injuries.

Accuracy of 18-F FDG PET/CT to detect bone marrow clearance in patients with peripheral T-cell lymphoma – tissue remains the issue

Abstract Staging of peripheral T-cell non-Hodgkin lymphoma (PTCL) is determined by 18-F FDG PET scan and bone marrow biopsy. This study addressed the accuracy of PET at detecting bone marrow (BM) involvement at restaging in patients with known involvement pretreatment. We identified patients with biopsy proven BM PTCL at diagnosis and concomitant BM and PET at the end of therapy. Pre-treatment PET demonstrated 50% (8/16) had a false-negative PET scan of the BM. After induction, repeat biopsy revealed 62.5% (10/16) with BM involvement. Of these 10, two had a positive PET; eight were false negative by PET. Of the six patients with a negative posttherapy BM biopsy, four were PET negative and two false positive. The sensitivity of PET at end of treatment was 20% (2/10) with a specificity of 66.7% (4/6). PET/CT is not an accurate predictor of BM involvement in patients with known PTCL in the marrow.

Applications of PET-MRI in musculoskeletal disease: PET-MRI of MSK Disease

New integrated PET‐MRI systems potentially provide a complete imaging modality for diagnosis and evaluation of musculoskeletal disease. MRI is able to provide excellent high‐resolution morphologic information with multiple contrast mechanisms that has made it the imaging modality of choice in evaluation of many musculoskeletal disorders. PET offers incomparable abilities to provide quantitative information about molecular and physiologic changes that often precede structural and biochemical changes. In combination, hybrid PET‐MRI can enhance imaging of musculoskeletal disorders through early detection of disease as well as improved diagnostic sensitivity and specificity. The purpose of this article is to review emerging applications of PET‐MRI in musculoskeletal disease. Both clinical applications of malignant musculoskeletal disease as well as new opportunities to incorporate the molecular capabilities of nuclear imaging into studies of nononcologic musculoskeletal disease are discussed. Lastly, we discuss some of the technical considerations and challenges of PET‐MRI as they specifically relate to musculoskeletal disease.

Clinical PET/MRI: 2018 Update

OBJECTIVE The purpose of this article is to provide an update on clinical PET/MRI, including current and developing clinical indications and technical developments. CONCLUSION PET/MRI is evolving rapidly, transitioning from a predominant research focus to exciting clinical practice. Key technical obstacles have been overcome, and further technical advances promise to herald significant advancements in image quality. Further optimization of protocols to address challenges posed by this hybrid modality will ensure the long-term success of PET/MRI.

Osteolytic-variant POEMS syndrome: an uncommon presentation of “osteosclerotic” myeloma

Polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, a form of osteosclerotic myeloma, is a multisystem disease related to a monoclonal plasma cell proliferative disorder. Osseous lesions are most commonly sclerotic on radiographs and computed tomography (CT), demonstrate low T1 and T2 signal intensity on magnetic resonance imaging (MRI), and have variable degrees of avidity on positon emission tomography (PET) imaging using 18-fluorodeoxyglucose (18F-FDG). We present three cases of POEMS syndrome manifesting as osteolytic lesions with indolent features, including well-defined thin sclerotic rims, no cortical disruption or periosteal reaction, no associated soft-tissue mass, and a periarticular location, all features that could lead to misinterpretation as benign bone lesions. We also report increased T1 signal and diffuse solid enhancement of these lesions on MRI, features previously unreported. POEMS syndrome should not be discounted as a diagnostic consideration in the setting of osteolytic lesions with non-aggressive imaging characteristics on radiographs or CT, especially in the presence of other supportive clinical features.

Gastrointestinal: Multiparametric hybrid 18‐FDG PET/MRI evaluation of gastric adenocarcinoma

A 40-year-old female patient with upper abdominal discomfort underwent esophagogastroduodenoscopy, which demonstrated an infiltrative submucosal ulcerated mass in the distal gastric body (Fig. 1). Biopsy demonstrated poorly differentiated adenocarcinoma with signet ring cell features. The patient underwent 18-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (PET/MRI) (Fig. 2) using a hybrid PET/MRI system (SIGNA, GE Healthcare, Milwaukee, WI). This device combines a PET scanner with digital silicon photomultipliers capable of time-of-flight image reconstruction and a 3-Tesla MRI in a single gantry. This enables simultaneous acquisition of PET and MR data resulting in excellent temporal and spatial coregistration. Our standard clinical protocol consists of the following: (i) a whole body survey geared towards evaluation of distant metastasis; and (ii) a focused abdominal scan combining diagnostic MRI sequences including diffusionweighted imaging and dynamic 3D post-gadolinium imaging with respiratory-gated PET acquisition. In this patient, staging abdominal PET/MRI (Fig. 2a–c) demonstrated a locally advanced malignant-appearing mass along the greater curvature of the stomach, consistent with patient’s known carcinoma. Two subcentimeter lymph nodes adjacent to the gastric antrum showed features consistent with nodal metastatic disease. There was no distant metastasis on the whole body survey PET/MRI. Restaging PET/MRI (Fig. 2d–f) performed after neoadjuvant chemotherapy demonstrated disease progression by both MRI and PET criteria. However, there was no evidence of distant metastatic disease or new nodal metastasis. The patient underwent subtotal distal gastrectomy, Billroth II end-to-side gastrojejunostomy, and regional lymphadenectomy. Surgical pathology demonstrated invasive poorly differentiated signet-ring cell carcinoma forming a 6.5 × 6.5 × 2.8-cm mass in the distal stomach. There was no histologic evidence of treatment response. Margins were negative but several resected regional lymph nodes were involved by tumor, which confirmed the findings of staging PET/MRI. Multi-parametric evaluation with hybrid PET/MRI represents an exciting advance in oncologic imaging. It enables simultaneous acquisition of complementary anatomic, functional, and metabolic information. It has recently been shown to be clinically feasible in unresectable gastric cancer patients and provide significant predictive factors for treatment response evaluation after chemotherapy. In our patient, PET/MRI served as a one-stop-shop study that enabled accurate staging and post-chemotherapy response evaluation by combining independent yet synergistic information from MRI and PET.

Double Aortic Arch Causing Severe Tracheal Compression

<zdoi;10.1097/ALN.0000000000001439> Anesthesiology, V 126 • No 2 326 February 2017 A double aortic arch results in a vascular ring that may compress the trachea and esophagus.1 Although the incidence of double aortic arch is unknown, they represent less than 1% of all congenital heart disease. Symptoms commonly include stridor, dyspnea, cough, recurrent upper respiratory tract infections, dysphagia, and feeding difficulty.1–3 Although more common in children, adults may present with new symptoms or chronic symptoms misdiagnosed as other diseases, as was the case in a 47-yr-old woman who presented with long-standing dyspnea (presumed for decades to be due to asthma) and dysphagia. Her symptoms had progressed to include new orthopnea with inability to lay supine and worsening dysphagia. Three-dimensional volume-rendered (A) and axial (b) contrast-enhanced computerized tomography demonstrated an incomplete double aortic arch with mirror image branching and an atretic left arch segment, with resulting compression and narrowing of the distal trachea and esophagus. After airway topicalization, severe tracheal compression was noted during awake fiberoptic intubation (C) performed in the sitting position. The 7.5-mm endotracheal tube was advanced past the area of tracheal compression, general anesthesia was induced with sevoflurane, and the patient was positioned supine. operative repair typically consists of division of the lesser or atretic aortic arch via a left thoracotomy, resulting in postoperative symptom resolution.1–3 The potential for tracheal compression resulting in the inability to intubate must be assessed before induction of general anesthesia to ensure safe airway management (fig. left aortic arch [lAA], left common carotid [lCC], left subclavian artery [lSA], right aortic arch [RAA], right common carotid [RCC], right subclavian artery [RSA]).

Voriconazole-induced periostitis: beyond post-transplant patients

Voriconazole-induced periostitis (VIP) is a rare but increasingly encountered entity since Food and Drug Administration (FDA) approval of the second generation antifungal medication in 2002. Literature reports most commonly include transplant recipients on immunosuppressive therapy simultaneously requiring antifungal therapy. Nontransplant patients receiving long-term voriconazole have an equal risk of developing the disease, but may experience a delay in diagnosis due to a lack of familiarity with the process outside of the post-transplant and/or immunosuppressed population. We present a case of VIP in a nontransplant, immunocompetent patient on suppressive antifungal therapy for prior abdominal aortic stent graft fungal infection. Radiologist review of current medications and recognition of periostitis on multiple imaging modalities may hasten the diagnosis and lead to earlier treatment and resolution of symptoms.

Skeletal Metastasis Evaluation: Value and Impact of PET/Computed Tomography on Diagnosis, Management and Prognosis

A number of PET agents are useful for evaluation of skeletal metastatic disease, and have significant advantages over 99mTc-MDP scintigraphy, including superior diagnostic accuracy, higher spatial resolution, and shorter imaging times- often with the ability to depict soft tissue local recurrence and metastasis in the same examination. While these agents have excellent diagnostic utility, they are not 100% specific for skeletal metastasis, and so normal patterns of biodistribution, benign osseous lesions that may demonstrate radiotracer uptake, and the significance of morphologic changes on CT such as osteolysis or osteosclerosis must be kept in mind to ensure accurate interpretation.