Thin-slice Two-dimensional T2-weighted Imaging with Deep Learning-based Reconstruction: Improved Lesion Detection in the Brain of Patients with Multiple Sclerosis.

PURPOSE: Brain MRI with high spatial resolution allows for a more detailed delineation of multiple sclerosis (MS) lesions. The recently developed deep learning-based reconstruction (DLR) technique enables image denoising with sharp edges and reduced artifacts, which improves the image quality of thin-slice 2D MRI. We, therefore, assessed the diagnostic value of 1 mm-slice-thickness 2D T2-weighted imaging (T2WI) with DLR (1 mm T2WI with DLR) compared with conventional MRI for identifying MS lesions. METHODS: Conventional MRI (5 mm T2WI, 2D and 3D fluid-attenuated inversion recovery) and 1 mm T2WI with DLR (imaging time: 7 minutes) were performed in 42 MS patients. For lesion detection, two neuroradiologists counted the MS lesions in two reading sessions (conventional MRI interpretation with 5 mm T2WI and MRI interpretations with 1 mm T2WI with DLR). The numbers of lesions per region category (cerebral hemisphere, basal ganglia, brain stem, cerebellar hemisphere) were then compared between the two reading sessions. RESULTS: For the detection of MS lesions by 2 neuroradiologists, the total number of detected MS lesions was significantly higher for MRI interpretation with 1 mm T2WI with DLR than for conventional MRI interpretation with 5 mm T2WI (765 lesions vs. 870 lesions at radiologist A, < 0.05). In particular, of the 33 lesions in the brain stem, radiologist A detected 21 (63.6%) additional lesions by 1 mm T2WI with DLR. CONCLUSION: Using the DLR technique, whole-brain 1 mm T2WI can be performed in about 7 minutes, which is feasible for routine clinical practice. MRI with 1 mm T2WI with DLR enabled increased MS lesion detection, particularly in the brain stem.

Association of prediabetes with reduced brain volume in a general elderly Japanese population.

OBJECTIVES: Diabetes frequently results in cognitive impairment, but it is less clear if brain health is adversely affected during the prediabetic stage. Our aim is to identify possible changes in brain volume as measured by magnetic resonance imaging (MRI) in a large elderly population stratified according to level of "dysglycemia." METHODS: This is a cross-sectional study of 2144 participants (median age 69 years, 60.9% female) who underwent 3-T brain MRI. Participants were divided into 4 dysglycemia groups based on HbA1c levels (%): normal glucose metabolism (NGM) (< 5.7%), prediabetes (5.7 to < 6.5%), undiagnosed diabetes (6.5% or higher), and known diabetes (defined by self-report). RESULTS: Of the 2144 participants, 982 had NGM, 845 prediabetes, 61 undiagnosed diabetes, and 256 known diabetes. After adjustment for age, sex, education, body weight, cognitive status, smoking, drinking, and disease history, total gray matter volume was significantly lower among participants with prediabetes (0.41% lower, standardized ß = - 0.0021 [95% CI - 0.0039, - 0.00039], p = 0.016), undiagnosed diabetes (1.4% lower, standardized ß = - 0.0069 [95% CI - 0.012, - 0.002], p = 0.005), and known diabetes (1.1% lower, standardized ß = - 0.0055 [95% CI - 0.0081, - 0.0029], p < 0.001) compared to the NGM group. After adjustment, total white matter volume and hippocampal volume did not differ significantly between the NGM group and either the prediabetes group or the diabetes group. CONCLUSION: Sustained hyperglycemia may have deleterious effects on gray matter integrity even prior to the onset of clinical diabetes. KEY POINTS: • Sustained hyperglycemia has deleterious effects on gray matter integrity even prior to the onset of clinical diabetes.

Quantification of the Intrinsic T1 and T2 of Heschl's Gyri with MR Fingerprinting.

PURPOSE: The human primary auditory cortex is located in the Heschl's gyrus (HG). To assess the intrinsic MR property in the gray matter of the HG (GM-HG) with T1 and T2 values using a commercially available MR fingerprinting (MRF) technique. METHODS: The subjects were 10 healthy volunteers (with 20 HGs; mean age, 31.5 years old; range, 25-53 years old). Coronal T1 and T2 maps were obtained with commercially available MRF using a 3-Tesla MR system. Two radiologists measured the T1 and T2 values of the GM-HG, the GM in the superior temporal gyrus (GM-STG), and the GM in the middle temporal gyrus (GM-MTG) by drawing a ROI on coronal maps. RESULTS: For both radiologists, the mean T1 and T2 values of the GM-HG were significantly lower than those in the GM-STG or GM-MTG (P < 0.01). The interobserver reliability using the intraclass correlation coefficients (ICC) (2,1) showed strong agreement for the measurement of the T1 and T2 values (ICCs =⃥ 0.80 and 0.78 for T1 and T2 values, respectively). CONCLUSION: The T1 and T2 values on MRF for the GM-HG were lower than those for the GM-STG and GM-MTG, likely reflecting a higher myelin content and iron deposition in the GM-HG. Quantitative measurements using the MRF can clarify cortical properties with high reliability, which may indicate that MRF mapping provides new insights into the structure of the human cortical GM.

Improved visualization of the subthalamic nucleus on synthetic MRI with optimized parameters: initial study.

BACKGROUND: Synthetic magnetic resonance imaging (SyMRI) enables to reformat various images by adjusting the MR parameters. PURPOSE: To investigate whether customization of the repetition time (TR), echo time (TE), and inversion time (TI) in SyMRI could improve the visualization of subthalamic nucleus (STN). MATERIAL AND METHODS: We examined five healthy volunteers using both coronal SyMRI and quantitative susceptibility mapping (QSM), seven patients with Parkinson's disease (PD) using coronal SyMRI, and 15 patients with PD using coronal QSM. Two neuroradiologists reformatted SyMRI (optimized SyMRI) by adjusting TR, TE, and TI to achieve maximum tissue contrast between the STN and the adjacent brain parenchyma. The optimized MR parameters in the PD patients varied according to the individual. For regular SyMRI (T2-weighted imaging [T2WI] and STIR), optimized SyMRI, and QSM, qualitative visualization scores of the STN (STN score) were recorded. The contrast-to-noise ratio (CNR) of the STN was also measured. RESULTS: For the STN scores in both groups, the optimized SyMRI were significantly higher than the regular SyMRI (P < 0.05), and there were no significant differences between optimized SyMRI and QSM. For the CNR of differentiation of the STN from the substantia nigra, the optimized SyMRI was higher than the regular SyMRI (volunteer: T2WI P = 0.10 and STIR P = 0.26; PD patient: T2WI P = 0.43 and STIR P = 0.25), but the optimized SyMRI was lower than the QSM (volunteer: P = 0.26; PD patient: P = 0.03). CONCLUSIONS: On SyMRI, optimization of MR parameters (TR, TE, and TI) on an individual basis may be useful to increase the conspicuity of the STN.

Correlation of magnetic resonance images with neuropathology of irreversible metronidazole-induced encephalopathy: an autopsy case report.

BACKGROUND: Neurological symptoms and radiographic abnormalities may remain in a small proportion of patients with metronidazole-induced encephalopathy (MIE). Although experimental animal models of MIE have suggested a Wernicke's encephalopathy-like pathology, little is known about the histopathological features of MIE. Here we report the first autopsy case of irreversible MIE. CASE PRESENTATION: A 72-year-old Japanese woman with pancreatic neuroendocrine tumour and metastatic tumours in the liver developed intraabdominal bleeding from a hepatic abscess. She was administered metronidazole for 79 days (1.5 g/day), which caused dysarthria followed by hand tremor and altered mental status. Brain magnetic resonance imaging at the time of onset revealed hyperintensities in the deep white matter of the bilateral parietal lobes and splenium of the corpus callosum on diffusion-weighted imaging (DWI) with reduced apparent diffusion coefficient (ADC) values. Despite the improvement of dysarthria and hand tremor, her cognition remained affected even after the withdrawal of metronidazole. She died of pancreatic neuroendocrine tumour at the age of 74 years. Histopathological examinations of the brain confirmed a combination of severe demyelination and moderate axonal degeneration, which corresponded to the regions showing abnormal signal intensities on DWI with reduced ADC values. There were no pathological findings suggestive of Wernicke's encephalopathy in the brain. CONCLUSION: We have demonstrated the clinical, radiographic and histopathological aspects of irreversible MIE. Hyperintensities on DWI with reduced ADC values in affected regions may indicate a poor clinical prognosis due to irreversible pathological damage.

Chest radiotherapy after left upper lobectomy may be a risk factor for thrombosis in the pulmonary vein stump.

BACKGROUND: Thrombosis in the pulmonary vein stump (PVS) is not a well-known complication after pulmonary lobectomy, but it has the potential to cause embolism to vital organs. The aim of this study was to evaluate the risk factors for thrombosis in the PVS after pulmonary lobectomy. METHODS: A total of 439 patients who underwent pulmonary lobectomy from 2008 to 2017 were retrospectively reviewed, and 412 patients were further analyzed. The state of the PVS was evaluated by chest contrast-enhanced computed tomography (CECT). Univariate analysis was performed to evaluate the potential risk factors for thrombosis in the PVS. RESULTS: Thrombosis in the PVS was detected in 6 of 412 (1.5%) patients, and 5 of them underwent left upper lobectomy (LUL) (5/100, 5.0%) (P = 0.004). In the analyses of the LUL group, postoperative chest radiotherapy was identified as a risk factor for thrombosis in the PVS (P = 0.024), and postoperative atrial fibrillation showed a tendency to be a risk factor for thrombosis (P = 0.058). CONCLUSIONS: Chest radiotherapy after LUL is a possible risk factor for thrombosis in the PVS. Periodic chest CECT is recommended after postoperative chest radiotherapy for patients after LUL.

Effectiveness of Cytological Diagnosis with Outer Cannula Washing Solution for Computed Tomography-Guided Needle Biopsy.

RATIONALE AND OBJECTIVES: We evaluated the availability of cytological diagnosis with outer cannula washing solution (C-OCWS) as a clinical diagnostic tool for computed tomography (CT)-guided needle biopsy. MATERIALS AND METHODS: We retrospectively assessed 109 consecutive patients (71 males, 38 females; median age 68 years), who underwent CT-guided needle biopsy. In all patients, the specimens sampled by the inner needle were used for histological diagnosis, and those taken from the outer cannula were rinsed with 0.9% saline solution: outer cannula washing solution for cytological diagnosis. The accuracy of C-OCWS in addition to histological diagnosis were compared with that of histological diagnosis alone. We used binary logistic regression analysis to determine the variables associated with diagnostic accuracy for malignancy and lesion characteristics. RESULTS: The C-OCWS method precisely diagnosed 7 (6.4%) malignant lesions (i.e., effective cases) in the 109 patients characterized as "negative for malignancy" via histological diagnosis alone. The accuracy of the combination of C-OCWS and histological diagnoses was significantly higher than that of histological diagnosis alone (0.95 vs. 0.89, respectively; p = 0.023). Multivariate logistic regression analysis showed that increasing only a marginal ratio (failure rate for proper position of biopsy needle within the tumor) was independently associated with a high rate of effective cases (p = 0.003). CONCLUSION: C-OCWS may be helpful for improving the quality of CT-guided needle biopsy, and is a simple method that may not necessarily increase the patients' physical burden.

Characteristics of α2,3-sialyl N-glycosylated PSA as a biomarker for clinically significant prostate cancer in men with elevated PSA level.

BACKGROUND: The presence of glycosylated isoforms of prostate-specific antigen (PSA) in prostate cancer (PC) cells is a potential marker of their aggressiveness. We characterized the origin of α2,3-sialylated prostate-specific antigen (S23PSA) by tissue-based sialylation-related gene expression and studied the performance of S23PSA density (S23PSAD) alone and in combination with multiparametric magnetic resonance imaging (MRI) for the detection of clinically significant prostate cancer in men with elevated PSA. METHODS: Tissue-based quantification of S23PSA and sialyltransferase and sialidase gene expression was evaluated in 71 radical prostatectomy specimens. The diagnostic performance of S23PSAD was studied in 1099 men retrospectively enrolled in a multicenter systematic biopsy (SBx) cohort. We correlated the S23PSAD with Prostate Imaging Reporting and Data System (PI-RADS) scores in 98 men prospectively enrolled in a single-center MRI-targeted biopsy (MRI-TBx) cohort. The primary outcome was the PC-diagnostic performance of the S23PSAD, the secondary outcome was the avoidable biopsy rate of S23PSAD combined with DRE and total PSA (tPSA), and with or without PI-RADS. RESULTS: S23PSA was significantly higher in Gleason pattern 4 and 5 compared with benign prostate tissue. In the retrospective cohort, the performance of S23PSAD for detecting PC was superior to tPSA or PSA density (PSAD) (AUC: 0.7758 vs. 0.6360 and 0.7509, respectively). In the prospective cohort, S23PSAD was superior to tPSA, PSAD, and PI-RADS (AUC: 0.7725 vs. 0.5901, 0.7439 and 0.7305, respectively), and S23PSAD + PI-RADS + DRE + tPSA was superior to DRE + tPSA+PI-RADS with avoidance rate of MRI-TBx (13% vs. 1%) at 30% risk threshold. CONCLUSIONS: The diagnostic performance of S23PSAD was superior to conventional strategies but comparable to mpMRI.

Leptomeningeal and intraventricular myelomatosis manifesting an aggressive form of communicating hydrocephalus.

Leptomeningeal myelomatosis (LMM) is a fatal complication that occurs in < 1% of patients with multiple myeloma. Many patients with LMM present with neurologic symptoms referable to cranial neuropathies, while the manifestation of communicating hydrocephalus has been underrecognized. A Japanese man with Bence Jones protein-κ multiple myeloma developed fever and headache at age 54 years. He then became somnolent and went into a coma. Neuroimaging analyses identified rapidly progressive communicating hydrocephalus due to meningitis. He died 83 days after the onset of headache without any response to treatment at age 55 years. No symptoms or signs associated with cranial nerves were found during the course of illness. Postmortem examination revealed hydrocephalus and diffuse infiltration of myeloma cells into the subarachnoid space of the cerebrum, cerebellum, and brainstem. In addition, the interstitial tissue of the choroid plexuses was filled with myeloma cells. These myeloma cells were positive for CD156 and light chain κ. The Ki-67 labeling index in myeloma cells of the central nervous system (CNS) was 30-40%. Histopathological examination further revealed many myeloma cells on the surface of the lateral, third and fourth ventricles and at the area postrema of the medulla oblongata. Patients with LMM can develop an aggressive form of communicating hydrocephalus. Given that cerebrospinal fluid, produced by epithelial cells in the choroid plexuses of the ventricles, passes into the subarachnoid space through the third and fourth ventricles, myeloma cells may invade the CNS through the choroid plexuses.

Preoperative CT Findings for Predicting Acute Exacerbation of Interstitial Pneumonia After Lung Cancer Surgery: A Multicenter Case-Control Study.

BACKGROUND. Acute exacerbation (AE) is a life-threatening complication of inter-stitial pneumonia (IP). Thoracic surgery may trigger AE. OBJECTIVE. The purpose of this study is to explore the role of preoperative CT findings in predicting postoperative AE in patients with IP and lung cancer. METHODS. This retrospective case-control study included patients from 22 institutions who had IP and underwent thoracic surgery for lung cancer. AE was diagnosed on the basis of symptoms and imaging findings noted within 30 days after surgery and the absence of alternate causes. For each patient with AE, two control patients without AE were identified. After exclusions, the study included 92 patients (78 men and 14 women; 31 with AE [the AE group] and 61 without AE [the no-AE group]; mean age, 72 years). Two radiologists independently reviewed preoperative thin-slice CT examinations for pulmonary findings and resolved differences by consensus. The AE and no-AE groups were compared using the Fisher exact and Mann-Whitney U tests. Multivariable logistic regression was performed. Interreader agreement was assessed by kappa coefficients. RESULTS. A total of 94% of patients in the AE group underwent segmentectomy or other surgery that was more extensive than wedge resection versus 75% in the no-AE group (p = .046). The usual IP pattern was present in 58% of the AE group versus 74% of the no-AE group (p = .16). According to subjective visual scoring, the mean (± SD) ground-glass opacity (GGO) extent was 6.3 ± 5.4 in the AE group versus 3.9 ± 3.8 in the no-AE group (p = .03), and the mean consolidation extent was 0.5 ± 1.2 in the AE group versus 0.1 ± 0.3 in the no-AE group (p = .009). Mean pulmonary trunk diameter was 28 ± 4 mm in the AE group versus 26 ± 3 mm in the no-AE group (p = .02). In a model of CT features only, independent predictors of AE (p < .05) were GGO extent (odds ratio [OR], 2.8), consolidation extent (OR, 9.4), and pulmonary trunk diameter (OR, 4.2); this model achieved an AUC of 0.75, a PPV of 71%, and an NPV of 77% for AE. When CT and clinical variables were combined, undergoing segmentectomy or more extensive surgery also independently predicted AE (OR, 8.2; p = .02). CONCLUSION. The presence of GGO, consolidation, and pulmonary trunk enlargement on preoperative CT predicts AE in patients with IP who are undergoing lung cancer surgery. CLINICAL IMPACT. Patients with IP and lung cancer should be carefully managed when predictive CT features are present. Wedge resection, if possible, may help reduce the risk of AE in these patients. TRIAL REGISTRATION. University Hospital Medical Information Clinical Trial Registry UMIN000029661.

High-signal venous sinuses on MR angiography: discrimination between reversal of venous flow and arteriovenous shunting using arterial spin labeling.

PURPOSE: It is sometimes difficult to differentiate between high signals originating from a reverse flow on magnetic resonance angiography (MRA) and occult arteriovenous shunting. We attempted to determine whether arterial spin labeling (ASL) can be used to discriminate reversal of venous flow from arteriovenous shunting for high-signal venous sinuses on MR angiography. METHODS: Two radiologists evaluated the signals of the venous sinus on MRA and ASL obtained from 364 cases without arteriovenous shunting. In addition, the findings on MRA were compared with those on ASL in an additional 13 patients who had dural arteriovenous fistula (DAVF). RESULTS: In the 364 cases (728 sides) without arteriovenous shunting, a high signal due to reverse flow in the cavernous sinuses (CS) was observed on 99 sides (13.6%) on MRA and none on ASL. Of these cases, a high signal in the sigmoid sinus, transverse sinus, and internal jugular vein was seen on 3, 3, and 8 sides, respectively. All of these venous sinuses showed a high signal from the reverse flow on MRA images. CONCLUSION: ASL is a simple and useful MR imaging sequence for differentiating between reversal of venous flow and CS DAVF. In the sigmoid and transverse sinus, ASL showed false-positives due to the reverse flow from the jugular vein, which may be a limitation of which radiologists should be aware.

Diagnosis and conservative treatment of a rare case of femoral intraosseous arteriovenous malformation in a patient with polyostotic fibrous dysplasia: A case report.

Pure intraosseous arteriovenous malformation (AVM) in a limb bone is extremely rare. Furthermore, there is currently insufficient information on the diagnostic and therapeutic strategies for pure intraosseous AVMs. We herein report a case of pure intraosseous AVM of the proximal femur occurring in a patient with polyostotic fibrous dysplasia. The patient was a 39-year-old woman who presented with pain in the right thigh. Plain radiographs and computed tomography scans revealed a medullary lytic lesion with expansion and thinning of the bone cortex in the right proximal femur, mimicking a primary bone tumor. Magnetic resonance imaging (MRI) examination revealed intramedullary signal voids and feeding arteries arising from the deep femoral artery. A non-surgical approach using embolization and denosumab achieved satisfactory results, which included complete obliteration of the AVM, increased cortical thickness of the right proximal femur, and attenuation of the high-turnover bone metabolism 1 year later. Careful review of MRI images is crucial for distinguishing between bone tumors and intraosseous AVM, which exhibit signal voids and feeding arteries, in order to avoid unnecessary interventions such as bone biopsy or surgery.

Dual energy CT is useful for the prediction of mesenteric and lateral pelvic lymph node metastasis in rectal cancer.

The aim of the present retrospective study was to investigate the predictability of dual-energy computed tomography (DECT) for pararectal lymph node (PRLN) metastasis and lateral pelvic lymph node (LPLN) metastasis in rectal cancer (RC). The present study involved 44 patients with RC who were examined by DECT and then underwent surgery between May 2015 and September 2017. LPLN dissection was performed in 24 patients. The normalized iodine concentration (nIC), the ratio of iodine concentration in the lymph node (LN) to that in the common iliac artery on DECT, of the largest PRLN and LPLN was calculated, and the association between LN metastasis and nIC was analyzed. The median nIC value for PRLNs was significantly lower in PRLN metastasis-positive cases compared with PRLN metastasis-negative cases in the arterial phase [0.18 vs. 0.25; P=0.01; cut-off, 0.24; area under the curve (AUC), 0.733] and portal phase (0.47 vs. 0.61; P=0.03; cut-off, 0.59; AUC, 0.701). A significant difference was not identified between the median maximum short axis diameter of PRLNs in PRLN metastasis-positive and metastasis-negative cases (7.6 vs. 6.4 mm; P=0.33). The nIC for LPLNs was not significantly different between LPLN metastasis-positive and metastasis-negative cases in the arterial phase (0.15 vs. 0.21; P=0.19); but was significantly lower in LPLN metastasis-positive cases compared with LPLN metastasis-negative cases in the portal phase (0.29 vs. 0.56; P=0.04; cut-off, 0.29; AUC, 0.877). The maximum short axis diameter of LPLNs was significantly larger in metastasis-positive cases compared with LPLN metastasis-negative cases (9.1 vs. 4.8 mm; P=0.03; cut-off, 7.0 mm; AUC, 0.912). In conclusion, the nIC was identified to be significantly lower in metastasis-positive cases, which may be useful for the prediction of PRLN and LPLN metastases. A combination of size-based diagnosis and DECT may increase the accuracy of preoperative diagnosis.

Interventional Treatment for Giant Hepatic Hemangioma Accompanied by Arterio-portal Shunt with Ascites.

A 73-year-old woman with massive ascites associated with a giant hepatic mass accompanied by arterio-portal (AP) shunt was admitted to our hospital. Based on contrast-enhanced computed tomography (CT) and angiography findings, hepatic hemangioma with AP shunt and ascites due to portal hypertension was diagnosed. Transcatheter arterial embolization (TAE) by N-butyl-2-cyanoacrylate (NBCA) was performed without complications. The patient's ascites disappeared, and her liver function test results improved after the treatment. The patient has maintained a steady state for two years. This case indicates that TAE with NBCA is a safe and effective treatment for hepatic hemangioma accompanied by AP shunt.

Impact of pretreatment whole-tumor perfusion computed tomography and 18F-fluorodeoxyglucose positron emission tomography/computed tomography measurements on local control of non-small cell lung cancer treated with stereotactic body radiotherapy.

This study aimed to investigate the correlation between the average iodine density (AID) detected by dual-energy computed tomography (DE-CT) and the maximum standardized uptake value (SUVmax) yielded by [18F] fluorodeoxyglucose positron emission tomography (18F-FDG PET) for non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Seventy-four patients with medically inoperable NSCLC who underwent both DE-CT and 18F-FDG PET/CT before SBRT (50‒60 Gy in 5‒6 fractions) were followed up after a median interval of 24.5 months. Kaplan-Meier analysis was used to determine associations between local control (LC) and variables, including AID, SUVmax, tumor size, histology, and prescribed dose. The median AID and SUVmax were 18.64 (range, 1.18-45.31) (100 µg/cm3) and 3.2 (range, 0.7-17.6), respectively. No correlation was observed between AID and SUVmax Two-year LC rates were 96.2% vs 75.0% (P = 0.039) and 72.0% vs 96.2% (P = 0.002) for patients classified according to high vs low AID or SUVmax, respectively. Two-year LC rates for patients with adenocarcinoma vs squamous cell carcinoma vs unknown cancer were 96.4% vs 67.1% vs 92.9% (P = 0.008), respectively. Multivariate analysis identified SUVmax as a significant predictor of LC. The 2-year LC rate was only 48.5% in the subgroup of lower AID and higher SUVmax vs >90% (range, 94.4-100%) in other subgroups (P = 0.000). Despite the short follow-up period, a reduction in AID and subsequent increase in SUVmax correlated significantly with local failure in SBRT-treated NSCLC patients. Further studies involving larger populations and longer follow-up periods are needed to confirm these results.

Hypoxia is important in F­18 FDG accumulation in thecoma­fibroma tumors on F­18 FDG PET/CT scans.

Several studies have noted benign thecoma­fibroma tumors with positive F­18 fluorodeoxyglucose (FDG) accumulation mimicking malignant ovarian tumors following F­18 FDG positron emission tomography (PET). The present study analyzed four cases with false­positive F­18 FDG PET/computed tomography (CT) diagnoses of thecoma­fibroma tumors as malignant tumors due to F­18 FDG accumulation, compared with eight cases of FDG­positive ovarian cancers and two cases of FDG­negative fibromas. Hypoxia inducible factor (HIF)­1α expression was examined in the six thecoma­fibroma tumors using reverse transcription­polymerase chain reaction (RT­PCR). The four F­18 FDG­positive cases exhibited higher cellularity, maximum standard uptake and signal intensity on T2­weighted imaging, and gadolinium (Gd) enhancement using magnetic resonance imaging than the two FDG-negative fibroma cases. In the F­18 FDG­positive thecoma­fibroma group, Ki­67 expression was low and LAT1 expression was not identified, ruling out the diagnosis and potential for malignancy. However, considerable glucose transporter 1, HIF­1α, and vascular endothelial growth factor expression was observed. HIF­1α expression was elevated in all four false­positive cases by RT­PCR. From these results, it was hypothesized that hypoxia due to elevated cellularity may stimulate HIF­1α expression and be associated with F­18 FDG accumulation in F­18­positive thecoma­fibroma tumors.

[Evaluation of the Therapeutic Effect of Using Dual-Energy CT for Rectal Cancer after Neoadjuvant Chemotherapy].

It is difficult to know the effects of preoperative treatment on advanced rectal cancer even if using a variety of diagnostic imaging modalities. We report the efficacy of evaluating the therapeutic effect of using dual-energy CT(DECT)against rectal cancer after neoadjuvant chemotherapy(NAC). The subject sample consisted of1 1 patients who underwent rectal cancer surgery after NAC from September 2015 to January 2016. The pathological effective grade was higher if the after/before ratio ofcontrast enhancement on DECT was small(Grade 1a: 1.4, Grade 1b: 0.8, Grade 2: 0.4, Grade 3: 0.3). Therefore, a successful response rate occurred if blood flow was reduced after NAC. In this study, it was possible to predict the pathological response grade for rectal cancer via contrast enhancement using DECT.

Temporal variations in stump pressure and assessment of images obtained from cone-beam computed tomography during balloon-occluded transarterial chemoembolization.

AIM: Balloon-occluded transcatheter arterial chemoembolization (B-TACE) was used to show the optimized duration of balloon occlusion to start injection of lipiodol in order to maximize lipiodol deposition in the nodule, and to reveal the endpoint of lipiodol injection. METHODS: Of 29 consecutive patients who underwent balloon-occluded TACE between November 2013 and February 2014, we were able to measure stump pressure for 219 nodules in 27 patients. Tumors were counted, measured and could be visually assessed in 20 of these patients at 26 sites. Tumors with multiple feeders were found in eight patients. Arterial blood pressure was measured before, immediately after and 5 min after balloon occlusion prior to intra-arterial injection, as well as before and after balloon deflation after intra-arterial injection. Images were assessed qualitatively by two radiologists as well as quantitatively by calculating the contrast-to-noise ratio. RESULTS: We found no significant difference in pressure between immediately after and 5 min after balloon occlusion. Mean stump pressure before balloon deflation after intra-arterial injection was 70.4 mmHg. We observed a significant increase in qualitative scores after balloon occlusion (P < 0.001), and the mean score in the third-order branch was significantly higher than that in the first-order branch (P = 0.048). CONCLUSION: Our results indicate that intra-arterial injection can be started at any time after balloon occlusion and that 70 mmHg may be considered as a possible indicator of the end-point for arterial injection.

A successful case of transcatheter arterial embolization with n-butyl-2-cyanoacrylate for pancreatic arteriovenous malformation.

A 57-year-old man was referred and admitted to our hospital for treatment of a symptomatic pancreatic mass. Pancreatic arteriovenous malformation (AVM) was diagnosed based on the findings of contrast-enhanced computed tomography (CT) and angiography, and transcatheter arterial embolization (TAE) with N-butyl-2-cyanoacrylate (NBCA) was performed without complications. The patient's symptoms subsequently improved after TAE, and resolution of the pancreatic AVM was detected on contrast-enhanced CT performed six months after the embolization procedure. This case indicates that TAE with NBCA is a safe and effective treatment for pancreatic AVM.