Increased Fluorodeoxyglucose Uptake Research Articles

Polymer clip granuloma mimicking lymph node recurrence: a case report

BackgroundForeign body granulomas are postoperative inflammatory reactions to surgical materials within the body. Traditionally, sutures have been the leading cause of foreign body granulomas in the abdomen, commonly referred to as “suture granuloma”. However, the use of polymer clips in modern surgeries has introduced new challenges, and reports of intra-abdominal foreign body granulomas caused by surgical clips are limited. Herein, we present a case of an intra-abdominal foreign body granuloma formed due to polymer clips.Case presentationA 45-year-old woman who underwent laparoscopic resection for sigmoid colon adenocarcinoma subsequently developed a suspected lymph node recurrence during follow-up. Imaging showed an enlarging mass adjacent to the inferior mesenteric artery with increased fluorodeoxyglucose uptake. Laparoscopic surgical resection revealed the formation of a foreign body granuloma in response to the polymer clips.ConclusionsThis case suggests that nonabsorbable polymer clips can induce granulomatous reactions postoperatively, and the appearance of lymph node recurrence may be foreign body granulomas.

Surgical Resection of Benign Nodules in Lung Cancer Screening: Incidence and Features

IntroductionInterventions and surgical procedures are common for nonmalignant lung lesions detected on lung cancer screening (LCS). Inadvertent surgical resection of benign nodules with a clinical suspicion of lung cancer can occur, can be associated with complications, and adds to the cost of screening. The objective of this study is to assess the characteristics of surgically resected benign nodules detected on LCS computed tomography which were presumed to be lung cancers. MethodsThis retrospective study included 4798 patients who underwent LCS between June 2014 and January 2021. The benign lung nodules, surgically resected with a presumed cancer diagnosis, were identified from the LCS registry. Patient demographics, imaging characteristics, and pathologic diagnoses of benign nodules were analyzed. ResultsOf the 4798 patients who underwent LCS, 148 (3.1%) underwent surgical resection of a lung nodule, and of those who had a resection, 19 of 148 (12.8%) had a benign diagnosis (median age = 64 y, range: 56–77 y; F = 12 of 19, 63.2%; M = seven of 19, 36.8%). The median nodule size was 10 mm (range: 6–31 mm). Most nodules were solid (15 of 19, 78.9%), located in the upper lobes (11 of 19; 57.9%), and were peripheral (17 of 19, 89.5%). Most nodules (13 of 17; 76.5%) had interval growth, and four of 17 (23.5%) had increased fluorodeoxyglucose uptake. Of the 19 patients, 17 (89.5%) underwent sublobar resection (16 wedge resection and one segmentectomy), whereas two central nodules (10.5%) had lobectomies. Pathologies identified included focal areas of fibrosis or scarring (n = 8), necrotizing granulomatous inflammation (n = 3), other nonspecific inflammatory focus (n = 3), benign tumors (n = 3), reactive lymphoid hyperplasia (n = 1), and organizing pneumonia (n = 1). ConclusionsSurgical resections of benign nodules that were presumed malignant are infrequent and may be unavoidable given overlapping imaging features of benign and malignant nodules. Knowledge of benign pathologies that can mimic malignancy may help reduce the incidence of unnecessary surgeries.

Cardiac Sarcoidosis treated with non-steroidal immunosuppressive therapy

Abstract Background Non-steroidal immunosuppressive therapy is a potential treatment strategy for cardiac sarcoidosis. However, due to the lack of robust evidence, it is not recommended as an established treatment option in the guideline. Purpose The purpose of the study is to demonstrate the clinical outcome of the patients with cardiac sarcoidosis using non-steroidal immunosuppressive therapy in a retrospective registry entitled ILLUMINATE-CS (ILLUstration of the Management and prognosIs of JapaNese pATiEnts with Cardiac Sarcoidosis). Methods Of an entire cohort of 512 patients, 26 who received immunosuppressive therapy other than steroids were recruited for the analysis. The clinical outcome included all-cause death, fatal ventricular arrhythmic event (FVAE), and worsening heart failure with hospitalization. Results The reasons to use non-steroidal immunosuppressant were increased fluorodeoxyglucose (FDG) accumulation on the heart suggesting worsened inflammation (n = 13), side effects of steroid (n = 7), ventricular tachycardia or frequent ventricular premature contraction (n=4), complete atrioventricular block (n = 2), worsened symptom relating to non-cardiac sarcoidosis including neuro and pulmonary sarcoidosis (n = 2), and the other reason (n = 2), with some overlapping. Used non-steroidal immunosuppressants were comprised of methotrexate (n = 20, 6.9 ± 2.1 mg/week), cyclosporine (n =2, 75 or 100 mg/day), cyclophosphamide (n = 2, 25 or 50 mg/day), and azathioprine (n = 3, 100 mg/day in each). Side effects of non-steroidal immunosuppressant were observed in six cases and included one with methotrexate-related interstitial pneumonia, one with a methotrexate-associated lymphoproliferative disorder, one with septic coxitis with methotrexate, one with methotrexate-induced acute kidney injury, one with methotrexate-induced hepatic dysfunction, and one with azathioprine-induced anemia. After the addition of a non-steroidal immunosuppressant, steroids could be reduced in 14 cases of 26 cases with a median maintenance dose of 5 (interquartile range of 5–17) mg, although no cases stopped steroids. Of 13 cases who started non-steroidal immunosuppressant for the increased FDG uptake, decreased FDG uptake was observed in seven cases at the follow-up scan. Clinical outcome events were observed in 11 cases (42.3%). Detected events included all-cause death in five cases (19.2%), FVAE in four cases (15.4%), and worsening heart failure with hospitalization in five cases (19.2%), with some overlapping. Conclusions Non-steroidal immunosuppressive therapy may be a possible treatment option for patients who are not stabilized using sole steroid therapy or who suffer from the side effects of steroids.

Recurrent petit mal seizures in Erdheim-Chester disease mimicking an intra-axial brain tumor: illustrative case.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterized histologically by foamy histiocytes and Touton giant cells in a background of fibrosis. Bone pain with long bone osteosclerosis is highly specific for ECD. Central nervous system involvement is rare, although dural, hypothalamic, cerebellar, brainstem, and sellar region involvement has been described. A 59-year-old man with a history of ureteral obstruction, medically managed petit mal seizures, and a left temporal lesion followed with serial magnetic resonance imaging (MRI) presented with worsening seizure control. Repeat MRI identified bilateral amygdala region lesions. Gradual growth of the left temporal lesion over 1 year with increasing seizure frequency prompted resection. A non-Langerhans cell histiocytosis with a BRAF V600E mutation was identified on pathology. Imaging findings demonstrated retroperitoneal fibrosis and long bone osteosclerosis with increased fluorodeoxyglucose uptake that, together with the neuropathologic findings, were diagnostic of ECD. This case of biopsy-proven ECD is unique in that the singular symptom was seizures well controlled with medical management in the presence of similarly located bilateral anterior mesial temporal lobe lesions. Although ECD is rare intracranially, its variable imaging presentation, including the potential to mimic seizure-associated medial temporal lobe tumors, emphasizes the need for a wide differential diagnosis.

Multimodality imaging of myocardial tuberculosis presenting as right ventricular cardiomyopathy: A case report.

An 18-year male with no significant past medical history presented with features of right-sided heart failure. Haematological investigations revealed raised erythrocyte sedimentation rate (23 mm/h). Transthoracic echocardiography (TTE) demonstrated biventricular systolic dysfunction with thickened free wall of right ventricle (RV). Whole-body fluorodeoxyglucose (FDG)-positron emission tomography (PET) computed tomography (FDG-PET-CT) showed intensely increased FDG uptake in the thickened RV wall and an FDG avid lesion in the left medial temporal lobe. Cardiac magnetic resonance imaging (CMR) characterized thickening and suggested an infiltrative disease (isointense on TI, hyperintense on myocardial oedema sensitive sequence with transmural enhancement on late gadolinium sequence). Magnetic resonance imaging (MRI) brain showed a thick rim enhancing ring lesion in the body of hippocampus. Endomyocardial biopsy revealed moderately dense lymphomononuclear inflammation with the formation of granulomas. Since tuberculosis is endemic in our country and considering all laboratory, imaging and biopsy findings a working diagnosis of tuberculosis was considered, and standard anti-tubercular treatment was started. There was an improvement in clinical status and follow-up imaging (TTE, CMR, brain MRI and FDG-PET-CT) showed improvement in biventricular function with regression in myocardial thickening and resolution of brain lesion, confirming the diagnosis of tuberculosis.

A rare case of giant hepatic angiomyolipoma with subcapsular rupture.

Hepatic angiomyolipoma (HAML) is a rare mesenchymal neoplasm that predominantly affects middle-aged women. In this study, we present a case of a 49-year-old woman with a giant HAML accompanied by spontaneous subcapsular rupture. The patient initially experienced nausea and abdominal distention, followed by an enlargement of the upper abdominal circumference. Laboratory examination revealed decreased serum hemoglobin, while tumor biomarkers were within normal ranges. Imaging studies, such as abdominal ultrasound and contrast-enhanced computed tomography (CT), demonstrated a large upper abdominal mass with heterogeneous density and hypervascularity. The tumor appeared to have invaded the left liver, raising concerns about possible malignancy. Subsequent positron-emission tomography/CT confirmed increased fluorodeoxyglucose uptake in the mass. Laparoscopic exploration revealed a protruding, well-encapsulated tumor from the left liver, exhibiting subcapsular hemorrhage. Surgical resection of the tumor and the left liver was performed, leading to a successful outcome.

Tumor-induced Osteomalacia Secondary to Phosphaturic Mesenchymal Tumor.

HomeRadiology: Imaging CancerVol. 5, No. 2 PreviousNext Images in CancerFree AccessTumor-induced Osteomalacia Secondary to Phosphaturic Mesenchymal TumorAmit Agarwal , Girish Bathla, Vivek GuptaAmit Agarwal , Girish Bathla, Vivek GuptaAuthor AffiliationsFrom the Departments of Radiology (A.A.) and Neuroradiology (V.G.), Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224; and Department of Radiology, Mayo Clinic, Rochester, Minn (G.B.).Address correspondence to A.A. (email: [email protected]).Amit Agarwal Girish BathlaVivek GuptaPublished Online:Mar 10 2023https://doi.org/10.1148/rycan.220170MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Tumor-induced osteomalacia (TIO), or oncogenic osteomalacia, is an uncommon paraneoplastic syndrome characterized by urinary phosphate wasting due to an increased production of fibroblast growth factor 23 (FGF23), secondary to an underlying phosphaturic mesenchymal tumor (PMT). Patients usually present with bone pain and pathologic fractures caused by hypophosphatemic hyperphosphaturic osteomalacia (Fig 1), characterized by high serum FGF23 levels (Fig 2) and low serum calcitriol levels. Given the rarity of this entity and nonspecific clinical and imaging features, these tumors are challenging to diagnose and can go undetected for many years (1). Tumors can be found in any osseous or soft-tissue location, however, and are typically observed in the extremities, most commonly the femur, of middle-aged adults. TIO is also associated with other mesenchymal tumors, including solitary fibrous tumors and giant cell tumors, primarily due to FGF23 secretion. A combination of nuclear scans using somatostatin analogs, such as gallium-68 tetraazacyclododecane tetraacetic acid octreotate (68Ga-DOTATATE) and indium-111 (111In)-pentetreotide (OctreoScan), provides the highest sensitivity for detecting tumors, which are usually small in size and not evident at clinical examination. These lesions appear to be moderately fluorodeoxyglucose avid, potentially aiding in diagnosis, but have wide variability in uptake and limited specificity. CT and MRI are noncontributory for initial location but are usually needed later to evaluate anatomic extent. Surgical resection of PMTs is typically curative, resulting in complete resolution of the syndrome (2,3). While few cases of PMT have been reported, it is important to consider this diagnosis in all patients with hypophosphatemic osteomalacia.Figure 1: (A) Methylene diphosphonate bone scan in a 65-year-old female patient with bone pain reveals multiple foci of increased uptake (arrowheads) over bilateral femur and sternum, along with prominent costochondral beadings (rosary), suggesting metabolic bone disease (osteomalacia). Serologic workup revealed a high serum fibroblast growth factor 23 (FGF23) level of 1155 reference unit (RU)/mL (reference range, ≤180 RU/mL) with low serum phosphate level and elevated alkaline phosphatase level. (B) Coronal noncontrast CT image of the lumbar spine reveals a lytic lesion in the right transverse process of L3 (arrow) with (C) increased fluorodeoxyglucose uptake (standardized uptake value, 9.8) (arrow) on the axial PET/CT image.Figure 1:Download as PowerPointOpen in Image Viewer Figure 2: Histopathologic features of phosphaturic mesenchymal tumors, with predominantly spindled cells on hematoxylin-eosin (H&E) stains and strong expression of fibroblast growth factor 23 (FGF-23) mRNA on in situ hybridization (ISH).Figure 2:Download as PowerPointOpen in Image Viewer Disclosures of conflicts of interest: A.A. Consulted for and expert testimony for Authnetic4D in 2020; institutional CME fund (attending meetings/travel); stocks in Gilead Pharma. G.B. Grant from Foundation of Sarcoidosis Research, unrelated to current work. V.G. No relevant relationships.Keywords: Osteomalacia, Phosphaturic, Spine, Tumor MicroenvironmentAuthors declared no funding for this work.

Potential Clinical Utility of FDG-PET in Non-malignant Pulmonary Disorders: A Pilot Study

Fluorodeoxyglucose (FDG) positron emission tomography (PET) is emerging as an important non- invasive investigation in benign pulmonary conditions too. The aim of this study was to investigate its utility in the diagnosis and monitoring of various benign pulmonary diseases. In this prospective observational hospital-based study 50 consecutive patients (26 males) with benign lung diseases underwent computed tomography of chest followed by FDG-PET at baseline and after treatment where appropriate. The findings of FDG scan are reported in the context of clinical, histopathological, physiological and radiological findings. All patients showed increased FDG uptake in the lung corresponding to CT findings. Of the 9 patients with sarcoidosis stage 1 (n=1), stage 2 (n=3) and stage 3 (n=5), additional uptake in the myocardium and thyroid was noted in two patients which resulted in a change in the modality of treatment. Repeat FDG scan post-treatment showed decreased uptake in all patients which was consistent with clinico-radiologic, microbiological or spirometry findings. Increased uptake was seen in one patient with pulmonary tuberculosis (TB) and in one patient with TB mediastinal lymphadenopathy at the end of intensive phase discordant with clinical and microbiological response. Of nine cases of idiopathic interstitial pneumonias (IIPs), additional intense FDG uptake was found in two cases which corresponded to the areas of honeycombing. FDG-PET scan can be used as an important adjunct non-invasive investigation in diagnosing and monitoring of various benign lung conditions. It also helps in assessing whole body disease burden which may change therapeutic decisions.

Multicentric Castleman disease with trismus.

A 58-year-old man visited our hospital with trismus and anorexia in the past 1 month (Fig. 1A, B). Multicentric Castleman disease was suspected due to cervical and axillary lymphadenopathy on CT, a high inflammatory response and IL-6 level elevation. Lymph node biopsy revealed mantle zone development, interfollicular expansion, extensive plasma cell infiltration and cluster of differentiation 3-positive (CD3+) T cell accumulation, leading to the diagnosis of plasmacytic Castleman disease. CT findings could not explain the cause of trismus (Fig. 1C). PET-CT revealed increased fluorodeoxyglucose uptake in the right temporomandibular joint, implicating temporomandibular joint arthritis as the cause of trismus (Fig. 1D, arrow). Trismus rapidly improved after prednisolone and IL-6 inhibitor administration. Similar to RA, Castleman disease is a lymphoproliferative disease with IL-6–related systemic inflammation. Temporomandibular joint arthritis is an articular symptom of RA, but arthritis in Castleman disease has rarely been reported. Activation of CD3+ cells by IL-6 is a potential mechanism of arthritis [1]. CD3+ T cells were clearly observed in the lymph nodes in our patient, which indicates arthritis. We report a case of trismus associated with temporomandibular arthritis, which we consider to be highly representative of the pathophysiology of Castleman disease.

Follicular Lymphoma Treated with First-Line Immunochemotherapy: A Review of PET/CT in Patients Who Did Not Achieve a Complete Metabolic Response in the GALLIUM Study.

Complete metabolic response (CMR) on PET/CT was the sole independent predictor of overall survival in the PET substudy of the phase III GALLIUM trial (NCT01332968) in first-line treatment of high-tumor-burden follicular lymphoma. The aim of this analysis was to further investigate the outcome of patients not achieving CMR. Methods: Two international experts rereviewed PET/CT scans from patients failing to achieve CMR assessed by the Independent Review Committee masked otherwise to committee results. Metabolic response category and Deauville score were assigned. Progression-free survival (PFS) was investigator-assessed with contrast-enhanced CT. Kaplan-Meier methodology was used to estimate landmark PFS and time to next treatment from end of induction by Deauville score. Patients who experienced CT-based progressive disease at the end of induction were excluded. Results: Fifty-four patients were reviewed. Six had CMR, 37 had a partial metabolic response, 2 had no metabolic response, and 9 had progressive metabolic disease. Patients were reassigned to CMR because 18F-FDG uptake was considered inflammatory (n = 2), was considered incidental neoplasia (n = 2), or was visually close to liver uptake but quantitatively lower (n = 2). There was a trend for shorter PFS and time to next treatment for patients with a Deauville score of 5 than a score of 4. High-grade mesenteric uptake at the end of induction was common, occurring in 20 patients with non-CMR, 14 of whom achieved CMR at all other sites. Only 3 of 14 (21%) patients with mesenteric uptake as the only site of disease experienced progression or death within 24 mo, whereas 4 of 6 patients (67%) with mesenteric and additional sites of 18F-FDG-avid disease experienced progression or death within 24 mo. All patients with early progression had measurable disease on contrast-enhanced CT at 18F-FDG-avid sites at the end of induction. Conclusion: After induction immunochemotherapy, CMR was assigned after reassessment in some patients, in whom increased 18F-FDG uptake was considered due to inflammation or incidental neoplasia rather than to lymphoma. Quantitative assessment to confirm the visual impression of residual uptake in lesions is suggested. Isolated mesenteric 18F-FDG uptake is likely a common false-positive finding at the end of induction and does not warrant changes in clinical management or disease surveillance unless there is measurable disease on contrast-enhanced CT or clinical suspicion of active disease.

Discrepancies between F-18-FDG PET/CT findings and conventional imaging in Langerhans cell histiocytosis.

Accurate risk stratification of Langerhans cell histiocytosis (LCH) is essential as management can range from conservative in single system, low risk for central nervous system (CNS) involvement lesions to intensive chemotherapy for multisystem or high-risk disease. Additionally, being able to differentiate metabolically active from inactive lesions is essential for both prognostic reasons and to avoid potentially unnecessary treatment. A retrospective review was performed on all patients with histopathology-confirmed LCH at Cincinnati Children's Hospital Medical Center (CCHMC) between 2009 and 2019. One hundred seven positron emission tomography (PET)/computerized tomography (CT) images were included in the review. A discrepancy between PET/CT and conventional imaging occurred on 53 occasions. On 13 occasions, increased uptake was observed on PET in an area with no identifiable lesion on conventional imaging. On 40 occasions, lesions were found on conventional imaging where no increased uptake was observed on PET. On eight skeletal surveys, three other radiographs, four diagnostic CTs, five localization CTs, and one bone scan, no lesion was identified in an area with increased fluorodeoxyglucose (FDG) uptake. This occurred exclusively in bone. On nine skeletal surveys, one other radiograph, four diagnostic CTs, six localization CTs, 19 magnetic resonance imaging (MRI) scans, and one bone scan, a lesion was identified in a location without increased FDG uptake. This occurred in bone, CNS, and lungs. F-18-FDG PET/CT is vital in the evaluation of LCH lesions given its ability to detect LCH lesions not detectable on conventional imaging modalities, as well as its ability to distinguish metabolically active from inactive disease. MRI and diagnostic CT are still useful adjunctive tests for identification of CNS and lung lesions.

Clinical Significance of Increased FDG Uptake in the Waldeyer Ring and the Nasopharynx Region Identified by PET-CT in Postchemotherapy Follow-up in Patients With Lymphoma: When Should We Perform Biopsy?

PurposeTo identify whether fluorodeoxyglucose (FDG) uptake in the Waldeyer ring (WR)/nasopharyngeal (NP) region by positron emission tomography–computed tomography (PET-CT) was physiologic or pathologic in the follow-up of lymphoma patients receiving postchemotherapy treatment. Patients and MethodsWe retrospectively examined FDG uptake in the WR/NP region in 534 patients with lymphoma as assessed by PET-CT used for both diagnosis and follow-up. ResultsForty-nine patients had FDG uptake in the WR/NP region by PET-CT performed after completion of a chemotherapy regimen. Biopsy was performed for 11 of these patients in whom the uptake was considered to be pathologic, and results indicated the presence of reactive follicular hyperplasia. It was considered to be physiologic in 38 patients. PET-CT was repeated after 1 year, and no significant difference was identified between the standardized maximum uptake values (SUVmax; P = .107). The initial diagnosis of 20 patients was made via biopsy performed in the WR/NP region. The SUVmax for the FDG uptake in these patients, asymmetry, SUVmax of the coexisting lymphadenopathies in the neck, and FDG uptake with a counterpart finding by CT were significantly higher than other groups (P = .047, .001, and .005). ConclusionWhen deciding whether to resample after treatment completion, it should be taken into account that, in addition to the SUVmax of the lesion, asymmetry, and the SUVmax of the coexisting lymphadenopathy in the neck, a crucial criterion is whether the FDG uptake has a counterpart finding by CT.

Mechanisms underlying the predictive power of high skeletal muscle uptake of FDG in amyotrophic lateral sclerosis

BackgroundWe recently reported that enhanced [18F]-fluorodeoxyglucose (FDG) uptake in skeletal muscles predicts disease aggressiveness in patients with amyotrophic lateral sclerosis (ALS). The present experimental study aimed to assess whether this predictive potential reflects the link between FDG uptake and redox stress that has been previously reported in different tissues and disease models.MethodsThe study included 15 SOD1G93A mice (as experimental ALS model) and 15 wildtype mice (around 120 days old). Mice were submitted to micro-PET imaging. Enzymatic pathways and response to oxidative stress were evaluated in harvested quadriceps and hearts by biochemical, immunohistochemical, and immunofluorescence analysis. Colocalization between the endoplasmic reticulum (ER) and the fluorescent FDG analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) was performed in fresh skeletal muscle sections. Finally, mitochondrial ultrastructure and bioenergetics were evaluated in harvested quadriceps and hearts.ResultsFDG retention was significantly higher in hindlimb skeletal muscles of symptomatic SOD1G93A mice with respect to control ones. This difference was not explained by any acceleration in glucose degradation through glycolysis or cytosolic pentose phosphate pathway (PPP). Similarly, it was independent of inflammatory infiltration. Rather, the high FDG retention in SOD1G93A skeletal muscle was associated with an accelerated generation of reactive oxygen species. This redox stress selectively involved the ER and the local PPP triggered by hexose-6P-dehydrogenase. ER involvement was confirmed by the colocalization of the 2-NBDG with a vital ER tracker. The oxidative damage in transgenic skeletal muscle was associated with a severe impairment in the crosstalk between ER and mitochondria combined with alterations in mitochondrial ultrastructure and fusion/fission balance. The expected respiratory damage was confirmed by a deceleration in ATP synthesis and oxygen consumption rate. These same abnormalities were represented to a markedly lower degree in the myocardium, as a sample of non-voluntary striated muscle.ConclusionSkeletal muscle of SOD1G93A mice reproduces the increased FDG uptake observed in ALS patients. This finding reflects the selective activation of the ER-PPP in response to significant redox stress associated with alterations of mitochondrial ultrastructure, networking, and connection with the ER itself. This scenario is less severe in cardiomyocytes suggesting a relevant role for either communication with synaptic plaque or contraction dynamics.

18F-Fluorodeoxyglucose positron emission tomography may not visualize radiation pneumonitis

BackgroundRadiation pneumonitis is a common and potentially fatal complication of radiotherapy (RT). Some patients with radiation pneumonitis show increases in uptake of fluorodeoxyglucose (FDG) on positron emission tomography (PET), but others do not. The exact relationship between radiation pneumonitis and 18F-FDG PET findings remains controversial.MethodsWe used an animal model of radiation pneumonitis involving both radiation and simulated bacterial infection in Wistar rats. Treatment groups (10 rats/group) were as follows: control, RT-only, lipopolysaccharide (LPS)-only, and RT+LPS. All rats had micro-PET scans at 7 weeks after RT (or sham). Histologic, immunohistochemical, and biochemical analyses were performed to evaluate potential mechanisms.ResultsIrradiated rats had developed radiation pneumonitis at 7 weeks after RT based on pathology and CT scans. Maximum and mean standardized uptake values (SUVmax and SUVmean) at that time were significantly increased in the LPS group (P < 0.001 for both) and the RT+LPS group (P < 0.001 for both) relative to control, but were not different in the RT-only group (P = 0.156 SUVmax and P = 0.304 SUVmean). The combination of RT and LPS increased the expression of the aerobic glycolysis enzyme PKM2 (P < 0.001) and the glucose transporter GLUT1 (P = 0.004) in lung tissues. LPS alone increased the expression of PKM2 (P = 0.018), but RT alone did not affect PKM2 (P = 0.270) or GLUT1 (P = 0.989).ConclusionsAseptic radiation pneumonitis could not be accurately assessed by 18F-FDG PET, but was visualized after simulated bacterial infection via LPS. The underlying mechanism of the model of bacterial infection causing increased FDG uptake may be the Warburg effect.

Positron emission tomography visualized stimulation of the vestibular organ is localized in Heschl's gyrus.

The existence of a human primary vestibular cortex is still debated. Current knowledge mainly derives from functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) acquisitions during artificial vestibular stimulation. This may be problematic as artificial vestibular stimulation entails coactivation of other sensory receptors. The use of fMRI is challenging as the strong magnetic field and loud noise during MRI may both stimulate the vestibular organ. This study aimed to characterize the cortical activity during natural stimulation of the human vestibular organ. Two fluorodeoxyglucose (FDG)‐PET scans were obtained after natural vestibular stimulation in a self‐propelled chair. Two types of stimuli were applied: (a) rotation (horizontal semicircular canal) and (b) linear sideways movement (utriculus). A comparable baseline FDG‐PET scan was obtained after sitting motion‐less in the chair. In both stimulation paradigms, significantly increased FDG uptake was measured bilaterally in the medial part of Heschl's gyrus, with some overlap into the posterior insula. This is the first neuroimaging study to visualize cortical processing of natural vestibular stimuli. FDG uptake was demonstrated in the medial‐most part of Heschl's gyrus, normally associated with the primary auditory cortex. This anatomical localization seems plausible, considering that the labyrinth contains both the vestibular organ and the cochlea.

Sarcoidosis-Associated Hypercalcemia and Calciphylaxis in a Patient on Dialysis with Left Ventricular Assist Device - A Tale of Caution

Introduction Sarcoidosis is a systemic disease that is difficult to diagnose in the absence of biopsy-proven non-caseating granulomas. We report a rare case of sarcoidosis-associated hypercalcemia and calciphylaxis in a patient on hemodialysis (HD) with left ventricular assist device (LVAD). Case A 53-year-old man with non-ischemic cardiomyopathy, poorly controlled diabetes, and chronic kidney disease (CKD) presented with decompensated heart failure and ventricular tachycardia. Positron emission tomography-computed tomography (PET-CT) of the heart suggested myocardial inflammation and sarcoidosis. He developed cardiogenic shock despite steroids and received an LVAD. Apical core biopsy showed normal myocardium. His CKD progressed to end-stage renal disease (ESRD) requiring HD six months later. He developed bilateral lower extremity pain thought to be diabetic neuropathy. He had hypercalcemia with normal parathyroid and thyroid hormones, but high angiotensin-converting enzyme level. Whole body PET-CT showed increased fluorodeoxyglucose (FDG) uptake in the spleen, liver, and small lung nodules. Biopsy of supraclavicular node with increased FDG uptake was negative for granulomas or malignancy. Serum protein electrophoresis did not yield monoclonal protein, and bone marrow biopsy showed no lymphoma. Bilateral calves and glans penis developed painful plaques with sharp borders and thick eschar (Figure A). Punch biopsy showed vascular calcifications in subcutaneous tissue, consistent with calciphylaxis (Figure B-D). Sodium thiosulfate was started with resultant shrinkage of lesions. Hypercalcemia resolved with prednisone and hydroxychloroquine. Unfortunately, the patient developed sepsis from the skin lesions and suffered a hemorrhagic stroke. His family decided to withdraw care. Discussion In this case, the diagnosis of sarcoidosis was made based on indirect evidence, and supported by resolution of hypercalcemia with prednisone. Hypercalcemia in sarcoidosis stems from calcitriol overproduction by monocytes, leading to increased intestinal calcium absorption. High calcium and phosphate levels, often found in patients with ESRD, have been implicated in the pathogenesis of calciphylaxis. For his LVAD, the patient was on warfarin, a known risk factor for calciphylaxis. Previous studies reported

CAROTID PLAQUE INFLAMMATION IS ASSOCIATED WITH INFLAMMATORY ACTIVITY OF VISCERAL ADIPOSE TISSUE

Objective:Visceral adipose tissue is thought to confer increased cardiovascular risk through leukocyte infiltration and increased adipose macrophage activity. Previous positron emission tomography (PET) studies using fluorodeoxyglucose (FDG) demonstrated that increased FDG uptake could reflect the s

An Unusual Transformation of a Nonseminomatous Germ Cell Tumor to Adenocarcinoma

Transformation of germ cell tumor to an alternate malignancy is rare; and it is believed to be secondary to teratomatous elements of the initial tumor surviving chemotherapy and subsequently proliferating. Here, we describe a patient with transformation of a nonseminomatous germ cell tumor to adenocarcinoma. A 55-year-old male with history of nonseminomatous germ cell tumor of the left testicle, previously resected, followed by four cycles of BEP chemotherapy, on active surveillance, presented nearly 20 years later with nausea and rising alpha-fetoprotein levels. Computed tomography (CT) abdomen revealed bulky retrocrural lymphadenopathy with increased fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan. Biopsy revealed metastatic adenocarcinoma, staining strongly positive for SALL4 and CDX2, with focal rare positivity for CK20 in the tumor cells, consistent with germ cell origin. FOLFOX therapy was therefore initiated. This is one of few documented cases showing transformation of nonseminomatous germ cell tumor to adenocarcinoma, for which surgical resection is favored as primary therapy. However, aggressive adjuvant chemotherapy may be considered and should be directed towards the most aggressive found histology. J Med Cases. 2019;10(5):123-125 doi: https://doi.org/10.14740/jmc3301

Clinical Utility of Pretreatment and 3-Month 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Standardized Uptake Value in Predicting and Assessing Recurrence in T3-T4 Laryngeal Carcinoma Treated With Definitive Radiation.

The aim of this study was to investigate the utility of pretreatment and 3-month 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) standardized uptake value (SUV) in predicting and assessing recurrence in T3-T4 laryngeal carcinoma treated with definitive radiation therapy (RT). Patients with newly diagnosed T3-T4 laryngeal squamous cell carcinoma treated with definitive RT from 2004 to 2014 were reviewed. Patients who underwent pretreatment or 3-month PET/CT 2 to 4 months after treatment were included. Those with prior systemic, surgical, or RT treatment were excluded. The primary objective was to assess whether pretreatment or posttreatment maximum SUV of the primary site (pSUV) of disease was associated with local recurrence-free survival. Overall survival was a secondary end point. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to assess the accuracy of 3-month PET/CT at the larynx primary. Twenty-eight patients were eligible for analysis. Median follow-up time was 34.7 months (range, 5.3-138.7 months), and median age was 57 years. Most patients had supraglottic (71.4%), T3 (89.3%), N2 (50.0%) disease, received chemotherapy (96.4%), and had histories of tobacco use (96.4%). On univariate analysis, 3-month posttreatment pSUV was associated with local recurrence-free survival ( P < .01), while pretreatment pSUV was not ( P = .41). No other associations were found with local recurrence-free survival. Neither pretreatment nor 3-month pSUV was significantly associated with overall survival. The calculated sensitivity, specificity, positive predictive value, and negative predictive value of 3-month PET/CT at the primary site were 33%, 85%, 40%, and 81%, respectively. High initial fluorodeoxyglucose uptake in T3-T4 laryngeal primaries did not show an association with the risk for postradiation local relapse or overall survival, while increased fluorodeoxyglucose uptake at 3 months was associated with increased local recurrence. At 3 months, the relatively low sensitivity and positive predictive value may limit the utility of PET/CT in the assessment of persistent advanced laryngeal cancer after definitive radiation.

Effect of cocoa on the brain and gut in healthy subjects: a randomised controlled trial.

Dark chocolate is claimed to have effects on gastrointestinal function and to improve well-being. This randomised controlled study tested the hypothesis that cocoa slows gastric emptying and intestinal transit. Functional brain imaging identified central effects of cocoa on cortical activity. Healthy volunteers (HV) ingested 100 g dark (72 % cocoa) or white (0 % cocoa) chocolate for 5 d, in randomised order. Participants recorded abdominal symptoms and stool consistency by the Bristol Stool Score (BSS). Gastric emptying (GE) and intestinal and colonic transit time were assessed by scintigraphy and marker studies, respectively. Combined positron emission tomography-computed tomography (PET-CT) imaging assessed regional brain activity. A total of sixteen HV (seven females and nine males) completed the studies (mean age 34 (21-58) years, BMI 22·8 (18·5-26·0) kg/m2). Dark chocolate had no effect on upper gastrointestinal function (GE half-time 82 (75-120) v. 83 (60-120) min; P=0·937); however, stool consistency was increased (BSS 3 (3-5) v. 4 (4-6); P=0·011) and there was a trend to slower colonic transit (17 (13-26) v. 21 (15-47) h; P=0·075). PET-CT imaging showed increased [18F]fluorodeoxyglucose (FDG) in the visual cortex, with increased FDG uptake also in somatosensory, motor and pre-frontal cortices (P&lt;0·001). In conclusion, dark chocolate with a high cocoa content has effects on colonic and cerebral function in HV. Future research will assess its effects in patients with functional gastrointestinal diseases with disturbed bowel function and psychological complaints.