Asymmetric diffuse thyroid uptake on 18F-FDG PET/CT in patient with subacute thyroiditis: Case report and literature review.

A 48-year-old man with an intermittent fever of 39.0oC for more than three weeks underwent computed tomography (CT) and blood testing, which revealed no clues. Antibiotics wereadministered, but his condition did not improve. Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) showed right-lobe-dominant diffuse thyroid uptake. On technetium-99m (99mTc) pertechnetate scintigraphy, the thyroid gland could not be visualized, and he was diagnosed with subacute thyroiditis (SAT). When asymmetric 18F-FDG diffuse thyroid uptake on PET/CT is observed in a patient with a fever of unknown origin (FUO), SAT may need to be considered.

High 18F-FDG Uptake in a Papillary Craniopharyngioma of the Third Ventricle.

ABSTRACT: Craniopharyngioma is a benign tumor classified as grade 1 by the World Health Organization Classification of Tumors of the Central Nervous System. We present a rare case of a high-18F-FDG-avidity papillary craniopharyngioma of the third ventricle. A 65-year-old man underwent CT and MRI examinations for gait disturbance, lower-limb weakness, and urinary incontinence, and an oval solid tumor that extended from the suprasellar region to the third ventricle was identified. 18F-FDG PET/CT showed high accumulation (SUVmax, 22.3) in the tumor. A transventricular endoscopic tumor biopsy led to the diagnosis of papillary craniopharyngioma.

The usefulness of the total metabolic tumor volume for predicting the postoperative recurrence of thoracic esophageal squamous cell carcinoma.

BACKGROUND: Induction or adjuvant therapies are not always beneficial for thoracic esophageal squamous cell carcinoma (ESCC) patients, and it is thus important to identify patients at high risk for postoperative ESCC recurrence. We investigated the usefulness of the total metabolic tumor volume (TMTV) for predicting the postoperative recurrence of thoracic ESCC. METHODS: We retrospectively analyzed the cases of 163 thoracic ESCC patients (135 men, 28 women; median age of 66 [range 34-82] years) treated at our hospital in 2007-2012. The TMTV was calculated from the fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in the primary lesion and lymph node metastases. The optimal cut-off values for relapse and non-relapse were obtained by the time-dependent receiver operating curve analyses. Relapse-free survival (RFS) was evaluated by the Kaplan-Meier method, and between-subgroup differences in survival were analyzed by log-rank test. The prognostic significance of metabolic parameters and clinicopathological variables was assessed by a Cox proportional hazard regression analysis. The difference in the failure patterns after surgical resection was evaluated using the χ2-test. RESULTS: The optimal cut-off value of TMTV for discriminating relapse from non-relapse was 3.82. The patients with a TMTV ≥3.82 showed significantly worse prognoses than those with low values (p < 0.001). The TMTV was significantly related to RFS (model 1 for preoperative risk factors: TMTV: hazard ratio [HR] =2.574, p = 0.004; model 2 for preoperative and postoperative risk factors: HR = 1.989, p = 0.044). The combination of the TMTV and cN0-1 or pN0-1 stage significantly stratified the patients into low-and high-risk recurrence groups (TMTV cN0-1, p < 0.001; TMTV pN0-1, p = 0.004). The rates of hematogenous and regional lymph node metastasis were significantly higher in the patients with TMTV ≥3.82 than those with low values (hematogenous metastasis, p < 0.001, regional lymph node metastasis, p = 0.011). CONCLUSIONS: The TMTV was a more significantly independent prognostic factor for RFS than any other PET parameter in patients with resectable thoracic ESCC. The TMTV may be useful for the identifying thoracic ESCC patients at high risk for postoperative recurrence and for deciding the patient management.

Comparison between gradient and spin-echo (GRASE) and compressed sensing sequences for single breath-hold three-dimensional magnetic resonance cholangiopancreatography in patients with T1 hyperintense bile.

PURPOSE: To compare image quality and the detectability of gallstones in patients with T1 hyperintense bile between single breath-hold three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) with gradient and spin-echo (GRASE) and with compressed sensing (CS). METHODS: We retrospectively evaluated patients who underwent MRCP using GRASE and CS and had hyperintense bile on T1-weighted fat-suppressed images. The relative duct-to-periductal contrast ratios (RCs) of each bile duct segment were calculated. Pancreaticobiliary duct visibility, motion artifacts, background suppression, and overall image quality were scored on a 5-point scale. The Wilcoxon signed-rank test was used to analyze differences in qualitative and quantitative results. Diagnostic performance in detecting common bile duct (CBD) and gallbladder stones was assessed using receiver operating characteristic (ROC) curves. RESULTS: In total, 96 patients were included in the study. RCs of all bile duct segments in GRASE MRCP were significantly lower than those in CS MRCP (p < 0.001). All biliary duct visibility and overall image quality had significantly higher scores in GRASE MRCP than in CS MRCP (p < 0.001-0.003). Area under ROC curves of GRASE MRCP and CS MRCP were 1.00 and 0.88 for CBD stone (p = 0.14) and 0.93 and 0.82 for gallbladder stone (p = 0.08), respectively. CONCLUSIONS: GRASE MRCP provides better image quality than CS MRCP in patients with hyperintense bile on T1-weighted images. The detectability of biliary stones was also higher in GRASE MRCP than in CS MRCP, although not significantly.

Utility of contrast-enhanced harmonic endoscopic ultrasonography for predicting the prognosis of pancreatic neuroendocrine neoplasms.

BACKGROUND AND AIMS: Pancreatic neuroendocrine neoplasms (PanNENs), including Grade 1 (G1) or G2 tumors, can have a poor prognosis. This study investigated the value of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for predicting the prognosis of PanNENs. METHODS: This single-center, retrospective study included 47 consecutive patients who underwent CH-EUS and were diagnosed with PanNEN by surgical resection or EUS-guided fine needle aspiration between December 2011 and February 2016. Patients were divided into aggressive and non-aggressive groups according to the degree of clinical malignancy. CH-EUS was assessed regarding its capacity for diagnosing aggressive PanNEN, the correspondence between contrast patterns and pathological features, and its ability to predict the prognosis of PanNEN. RESULTS: There were 19 cases of aggressive PanNEN and 28 cases of non-aggressive PanNEN. The aggressive group included three G1, four G2, three G3 tumors, three mixed neuroendocrine non-neuroendocrine neoplasms, and six neuroendocrine carcinomas. CH-EUS was superior to contrast-enhanced computed tomography for the diagnosis of aggressive PanNEN (P < 0.001): hypo-enhancement on CH-EUS was an indicator of aggressive PanNEN, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 94.7%, 100%, 100%, 96.6%, and 97.9%, respectively. Among G1/G2 PanNENs, cases with hypo-enhancement on CH-EUS had a poorer prognosis than those with hyper/iso-enhancement (P = 0.0009). Assessment of 36 resected specimens showed that hypo-enhancement on CH-EUS was associated with smaller and fewer vessels and greater degree of fibrosis. CONCLUSION: Contrast-enhanced harmonic endoscopic ultrasonography may be useful for predicting the prognosis of PanNENs.

Magnetic Resonance Imaging of Recurrent Adult Granulosa Cell Tumor of the Ovary: A Retrospective Analysis of 11 Cases.

OBJECTIVE: The aim of the study was to characterize magnetic resonance imaging findings in patients with recurrent ovarian adult granulosa cell tumors (AGCTs). METHODS: Clinical and magnetic resonance imaging manifestations of recurrent AGCTs were evaluated in 11 patients. RESULTS: Initial recurrences of AGCT were diagnosed between 13 months and 30 years (mean, 11.3 years). Recurrent tumors were located in the pelvic peritoneum, the abdominal peritoneum, the retroperitoneum, and bone. The number of recurrent tumors varied from 1 to 5. Tumors varied in morphology and all margins were well circumscribed. The internal structures noted were as follows: multilocular cystic and solid and cystic. Furthermore, internal hemorrhage and sponge-like multicystic components were identified. CONCLUSIONS: Ovarian AGCTs recurred in the pelvic peritoneum, abdominal peritoneum, and the retroperitoneal lymph nodes. Large recurrent AGCTs were commonly well circumscribed, round or lobulated, and multilocular cystic or solid and cystic. Moreover, they frequently included internal hemorrhage and sponge-like multicystic components.

Efficiency of a computer-aided diagnosis (CAD) system with deep learning in detection of pulmonary nodules on 1-mm-thick images of computed tomography.

PURPOSE: To evaluate the performance of a deep learning-based computer-aided diagnosis (CAD) system at detecting pulmonary nodules on CT by comparing radiologists' readings with and without CAD. MATERIALS AND METHODS: A total of 120 chest CT images were randomly selected from patients with suspected lung cancer. The gold standard of nodules ≥ 3 mm was established by a panel of three expert radiologists. Two less experienced radiologists read the images without and afterward with CAD system. Their reading times were recorded. RESULTS: The radiologists' sensitivity increased from 20.9% to 38.0% with the introduction of CAD. The positive predictive value (PPV) decreased from 70.5% to 61.8%, and the F1-score increased from 32.2% to 47.0%. The sensitivity significantly increased from 13.7% to 32.4% for small nodules (3-6 mm) and from 33.3% to 47.6% for medium nodules (6-10 mm). CAD alone showed a sensitivity of 70.3%, a PPV of 57.9%, and an F1-score of 63.5%. Reading time decreased by 11.3% with the use of CAD. CONCLUSION: CAD improved the less experienced radiologists' sensitivity in detecting pulmonary nodules of all sizes, especially including a significant improvement in the detection of clinically important-sized medium nodules (6-10 mm) as well as small nodules (3-6 mm) and reduced their reading time.

Coronary artery to aortic luminal attenuation ratio in coronary CT angiography for the diagnosis of haemodynamically significant coronary artery stenosis.

OBJECTIVE: This study aimed to assess and compare the diagnostic performance of the coronary artery to aortic luminal attenuation ratio (CAR), transluminal attenuation gradient (TAG), and corrected coronary opacification (CCO) difference on coronary CT angiography (cCTA) for detecting haemodynamically significant coronary artery stenosis. METHODS: 33 patients who underwent cCTA, gated SPECT myocardial perfusion imaging (MPI), and invasive coronary angiography within 3 months were included in this retrospective study. The degree of coronary stenosis on cCTA was visually assessed in all patients. Additionally, CAR, TAG, and CCO difference were analyzed and calculated in all patients. Haemodynamically significant coronary stenosis was defined as a vessel with ≥50% luminal stenosis on invasive coronary angiography and an associated abnormal perfusion defect on MPI in the same territory. Diagnostic performance was assessed on a per-vessel basis by the area under the receiver operating characteristic (ROC) curve (AUC). RESULTS: Among 99 vessels, 12 were excluded and the remaining 87 were analyzed. 17 (19.5%) vessels were determined as haemodynamically significant coronary artery stenosis. On ROC analysis, the AUC was 0.71 for cCTA, 0.80 for CAR, 0.61 for TAG, 0.74 for CCO, 0.87 for combined CAR and cCTA, 0.77 for combined TAG and cCTA, and 0.75 for combined CCO and cCTA. The AUC for combined CAR and cCTA was significantly greater compared with cCTA alone (p < 0.01). CONCLUSION: Non-invasive CAR derived from 64-detector row CT was feasible and might be helpful for the detection of haemodynamically significant coronary artery stenosis. Still, further investigations such as intra- and inter-reader correlation, evaluation of larger numbers in different settings, and time efficiency are required for applying CAR in various situations. ADVANCES IN KNOWLEDGE: CAR could be used as novel noninvasive technique to detect haemodynamically significant coronary artery stenosis.

Intravertebral pneumatocysts of the cervical spine.

INTRODUCTION: The aim of this study was to investigate the prevalence of intravertebral pneumatocyst (IVP) of the cervical spine by age group, compared with that of intradiscal vacuum (IDV). METHODS: We investigated 500 consecutive patients who underwent cervical computed tomography (CT) from May 2012 to May 2013 for various indications. CT datasets were assessed for the presence of IVPs and IDVs with stratification by age. RESULTS: IVPs of the cervical spine were detected in 8 % (7 of 86 subjects) of patients in their forties or below, 30 % (23 of 75) in their fifties, 49 % (67 of 136) in their sixties, 55 % (76 of 137) in their seventies, and 60 % (40 of 66) in their eighties or over. IDVs of the cervical spine were detected in 6, 25, 48, 54, and 57 %, respectively. Coexistence of both phenomena was identified in 4, 17, 33, 40, and 43 %, respectively. CONCLUSION: IVPs of the cervical spine are a common incidental finding, increasing in prevalence with age and more common than IDV in all age groups.