Usefulness of advanced monoenergetic reconstruction technique in dual-energy computed tomography for detecting bladder cancer.

PURPOSE: Detecting bladder cancer (BC) in routine CT images is important but is sometimes difficult when cancer is small. We evaluated the ability of 40-keV advanced monoenergetic images to depict BC. MATERIALS AND METHODS: Fifty-two patients with a median age of 74 years (range 45-92) who were diagnosed as BC with transurethral resection or cystectomy, were included. They were examined with contrast-enhanced dual-energy CT (DE-CT) and advanced virtual monoenergetic images (40 keV) were reconstructed. For evaluating depictability of BC on 40-keV or virtual-120-kVp images, the difference in CT number between the cancer and bladder wall (BC-BW value) were calculated. We also subjectively assessed depictability of BC in virtual-120-kVp and 40-keV images using a 4-grade Likert scale (3: clear, 0: not visualized). RESULTS: In 42 of 52 patients, BC-BW values could be calculated because BC was detected on CT images. The mean BC-BW value at 40 keV was significantly higher than that of virtual 120 kVp [80.5 ± 54 (SD) vs. 11.4 ± 12.5 HU, P < 0.01]. Average scores of subjective evaluations in the virtual-120-kVp and 40-keV images were 1.7 ± 1.2 and 2.1 ± 1.2, respectively (P < 0.001). CONCLUSION: The advanced monoenergetic reconstruction technique reconstructed using DE-CT image is useful to depict BC.

Myelolipoma mimicking osteosarcoma in the distal femur.

INTRODUCTION AND IMPORTANCE: Periosteal reactions indicate malignant bone tumors, including osteosarcoma; establishing an accurate diagnosis is key to determining the most appropriate treatment strategy. We describe a rare case of myelolipoma in the distal femur metaphysis with massive extraskeletal lesions and periosteal reactions. CASE PRESENTATION: A 25-year-old woman was referred to our hospital to treat a gradually expanding mass around her knee that grew to the size of a baby's head. She had a history of hydrocephalus caused by congenital cytomegalovirus infection and was bedridden for life. Radiography showed a prominent osteoblastic rim and osteolytic lesion with a moth-eaten appearance. Osteosarcoma was suspected due to excessive extraskeletal invasion and periosteal reactions. T1- and T2-weighted magnetic resonance images showed a high-signal-intensity homologous lesion. Biopsy specimens contained adipose and hematopoietic tissues. A myelolipoma was diagnosed. Due to her fragility, surgical intervention was suspended. Two years after diagnosis, the tumor size did not change. CLINICAL DISCUSSION: Myelolipomas are benign tumors that typically arise from the adrenal gland and rarely develop in the extremities. This type of tumor typically does not cause any tumor-related symptoms or endocrine disturbances and has been reported as a type of incidentaloma. To effectively manage myelolipoma patients, differential diagnosis of tumors mimicking malignant bone tumors is important. CONCLUSION: We successfully managed a destructive ectopic myelolipoma in the distal femoral metaphysis, with massive extraskeletal lesions and periosteal reactions. Clinicians should appropriately differentiate myelolipoma from tumors mimicking malignant bone tumors.

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.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study.

OBJECTIVES: PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis. METHODS: This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment. RESULTS: Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis. CONCLUSION: Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

Advanced monoenergetic reconstruction technique for dual-energy computed tomography to evaluate endoleaks after endovascular stent-graft placement.

PURPOSE: To evaluate the usefulness of the advanced monoenergetic imaging (AMI) reconstruction technique for dual-energy computed tomography to evaluate endoleaks after endovascular stent-graft placement. MATERIALS AND METHODS: Ninety-five dual-phase (early and delayed phases) enhanced CT examinations were performed for 60 patients who underwent endovascular stent-graft placement. AM images were reconstructed at 40 keV and compared with the standard 120-kVp images (SI). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the aorta and endoleak were measured. Two radiologists subjectively assessed endoleak delineation and contrast enhancement conditions using a 5-point Likert scale (1: poor-5: excellent). RESULTS: Mean SNRs of the aorta were higher by AMI (early; 34.7 ± 10.2 [SD], delay; 11.4 ± 3.2) than by SI (early; 23.1 ± 6.3, delay; 8.6 ± 2.2) (P < 0.001). SNRs of the endoleak were higher by AMI (early; 26.3 ± 7.5, delay; 10.5 ± 3.1) than by SI (early; 18.2 ± 4.7, delay; 8.3 ± 2.1) (P < 0.001). CNRs by AMI (early; 32.9 ± 9.8, delay; 8.9 ± 2.8) were higher than those by SI (early; 19.5 ± 6.0, delay; 4.7 ± 1.6) in both phases (P < 0.001). Endoleak delineation and contrast enhancement conditions by AMI (4.4 ± 1.0 and 4.5 ± 0.6) were higher than those by SI (3.4 ± 1.0 and 3.3 ± 0.8) in the delayed phase (P < 0.001). There was no difference in the early phase. CONCLUSION: AMI may be useful for evaluating endoleaks after endovascular stent-graft placement.

Comparison of Real-Time Virtual Sonography Navigation Versus BioJet Navigation on Magnetic Resonance Imaging-Guided Prostate Needle Biopsy: A Single Institutional Analysis.

Objective: To analyze the effectiveness and complication rate of MRI-guided prostate needle biopsies by using real-time virtual sonography (RVS) vs BioJet navigation. Methods: We retrospectively reviewed 171 patients who underwent an MRI-guided prostate needle biopsy at our institution. Patients whose prostate-specific antigen level was >4.0 ng/mL and who had suspicious prostate cancer (PCa) lesions by multiparametric MRI (mpMRI) underwent 2-core MRI-guided targeted biopsy (TB) and for MRI-guided TB: RVS and BioJet. RVS navigation synchronized mpMRI images with transrectal ultrasound (TRUS) images. BioJet navigation used a software program that merged images from mpMRI and TRUS to produce a composite image. We retrospectively compared the detection rate of PCa and the frequency of severe adverse events (AEs) between these two navigation systems, focusing on patients. In addition, we compared the detection rate of MRI-guided TB cores of two navigation systems regarding anatomical position (transitional zone [TZ] or peripheral zone [PZ]). Results: Data from RVS and BioJet biopsy groups were from 65 and 106 patients, respectively. Of these, RVS-TB included 141 cores (PZ: 49 cores, TZ: 92 cores), and BioJet-TB included 276 cores (PZ: 73 cores, TZ: 203 cores). In detecting PCa, by conducting both systematic biopsy and TB, and AEs in patients, a significant difference was not noted between RVS and BioJet navigation systems. In addition, there was no significant difference in the total detection rate for PCa in TB cores between the two methods. However, in the TZ, BioJet navigation showed a significantly higher detection rate of PCa than RVS navigation (35.0% vs 17.4%, p = 0.0023) by analyzing the cores of MRI-guided TB. Conclusion: When targeting TZ lesions, BioJet navigation had a greater detection rate for PCa compared with that of RVS navigation.

Usefulness of the advanced monoenergetic image reconstruction in dual-energy computed tomography for detecting the perforator vein of lower extremity varix.

BACKGROUND: Identification of the perforator vein is important for treating lower extremity varix. PURPOSE: We evaluated the ability of 40-keV advanced monoenergetic images to depict the perforator vein in patients with lower extremity varix. MATERIAL AND METHODS: Thirty-three patients aged 52-86 years were examined with contrast-enhanced dual-energy computed tomography (CT) and advanced virtual monoenergetic images (40 keV) were reconstructed. For evaluating enhancement of a lower extremity vein and the difference in CT number between the vein and muscle, we set the region of interest on the popliteal vein (PV). We also evaluated the ability of 100-kVp and 40-keV volume-rendering (VR) images to depict the perforator veins. RESULTS: The mean CT numbers of the PV at 100 kVp and 40 keV were 113 ± 16 and 321 ± 63 HU, respectively (P < 0.01). In 40-keV transverse images of 33 patients, 84 of the perforator veins were detected. In those 84 veins, 70 (83%) were depicted and 14 (17%) were not depicted on VR images that were reconstructed from 40-keV transverse images. At 100 kVp, 10 (12%) of the perforator veins could be depicted in VR images because the muscles buried them or the PVs were blurred due to insufficient enhancement. CONCLUSION: The advanced monoenergetic reconstruction technique is useful for evaluating the perforator vein in patients with lower extremity varix.

Evaluation of Thin-slice Coronal Single-shot Turbo Spin-echo Diffusion-weighted Imaging of the Hand: A Comparison with Conventional Echo-planar Diffusion-weighted Imaging.

We prospectively evaluated thin-slice coronal turbo spin-echo (TSE) diffusion-weighted imaging (DWI) covering a larger area with the recently-developed techniques on a 3T MRI scanner, compared with echo-planar imaging (EPI)-DWI in patients undergoing routine hand MRI. Visual score assessment and apparent diffusion coefficient (ADC) measurement were performed for patients with suspected hand tumors. TSE-DWI was superior to EPI-DWI, with less image distortion. The visual score and ADC comparison assessments proved that the image noise of TSE-DWI was acceptable.

Detailed presurgical evaluation of a case of congenital bladder diverticulum.

Congenital bladder diverticulum is rare and is usually observed in male children. An 8-year-old Japanese boy was referred to a hospital with fever and gross hematuria and was treated with a course of antibiotics. Because the dilatation of the ureter was suspected by abdominal ultrasonographic examination, he was referred to our hospital. We diagnosed congenital bladder diverticulum by computed tomographic scan and carried out laparoscopic bladder diverticulectomy and extravesical ureteral reimplantation. Four years later, there was no recurrence of gross hematuria or urinary tract infection.

Multifaceted structural magnetic resonance imaging findings in demented patients with pathologically confirmed TDP-43 proteinopathy.

This short report clarifies the heterogeneity of structural magnetic resonance imaging (MRI) findings in seven demented patients due to pathologically accumulated TAR DNA-binding protein-43 (TDP-43) protein using visual analyses including visual rating scales (i.e., global cortical atrophy and medial temporal atrophy scales). In addition to the well-known frontotemporal lobar atrophy, structural MRI has revealed multifaceted imaging findings including asymmetric atrophy of the frontoparietal lobe and cerebral peduncle, midbrain atrophy, and localized or diffuse white matter T2 hyperintensity. Understanding of these multifaceted neuroimaging findings is important for the precise antemortem diagnosis of TDP-43 proteinopathy.

Visibility of the hilar lymph nodes using advanced virtual monoenergetic low-keV images for preoperative evaluation of lung cancer.

OBJECTIVE: The purpose of our study was to evaluate the visibility of the hilar lymph nodes (LNs) using advanced virtual monoenergetic low-keV images compared with early-phase contrast-enhanced CT. METHODS: Dual energy contrast-enhanced CT was performed for pre-operative evaluation of lung cancer at 20 and 60 s after administration of contrast media in 50 patients (32 males and 18 females; mean age, 69 years). Five kinds of images (A: 20 s/120 kV; B: 60 s/40 keV; C: 60 s/50 keV; D: 60 s/120 kV; E: 60 s/100 kV) were reconstructed. We measured the CT number of the bilateral main pulmonary arteries (PAs), pulmonary veins (PVs) and hilar LNs, and evaluated the differences in CT number (Hounsfield units, HUs) between the PA/PV and LNs (PA-LN and PV-LN contrast). Artifacts from the superior vena cava (SVC) were also evaluated. RESULTS: The mean PA-LN contrast (HU) was 415 in image group A, 299 in B, 180 in C, 80 in D, and 100 in E. The mean PV-LN contrasts in each group were 306, 287, 177, 78, and 99, respectively. Image group B showed the second highest PA-LN contrast following image group A. There was no significant difference in the PV-LN contrast between image groups A and B. The PA-LN and PV-LN contrasts of image groups B and C were significantly higher than those of E. SVC artifacts were lower in the delayed-phase images (Group B-E) than in Group A. CONCLUSION: To evaluate the hilar LNs with a single image series, advanced virtual monoenergetic 40-keV imaging at the delayed 60-s phase seems to be the most valuable. ADVANCES IN KNOWLEDGE: Advanced virtual monoenergetic image is useful for evaluation of both hilar LNs and tumors in the delayed phase without artifact derived from the streak artifact from dense contrast media in the SVC.

Characteristic asymmetric limbic and anterior temporal atrophy in demented patients with pathologically confirmed argyrophilic grain disease.

PURPOSE: The purpose of this study is to clarify the characteristic structural magnetic resonance imaging (MRI) findings in demented patients with pathologically confirmed argyrophilic grain disease (AGD). METHODS: Nine pathologically confirmed AGD patients with cerebral three-dimensional T1-weighted MRI were evaluated in this study. In addition to visual rating scales of atrophic and asymmetric changes in the limbic and temporal lobes, voxel-based morphometry (VBM) was performed to assess group difference between pathologically confirmed AGD and Alzheimer's disease (AD) patients. RESULTS: On visual analyses of AGD patients, the medial temporal, anterior temporal, and posterior temporal atrophy scores were 3.3 ± 0.7, 1.7 ± 0.5, and 1.0 ± 0.7, respectively. Asymmetric scores of the hippocampus and parahippocampal gyrus, amygdala and ambient gyrus, anterior temporal, and posterior temporal lobes were rated as 1.1 ± 0.7, 1.6 ± 0.5, 1.3 ± 0.8, and 0.4 ± 0.7, respectively. In spite of no statistical differences in atrophic scores, AGD patients showed the higher score and proportion of anterior temporal asymmetric score than AD (p = 0.03 and 0.02). Compared with controls, VBM analysis revealed left dominant asymmetric atrophy predominantly in the limbic and anterior temporal lobe in AGD patients. By contrast, there was no significant gray matter reduction between AGD and AD patients. CONCLUSIONS: Asymmetric atrophy relatively localized to the anterior temporal and limbic lobes including the amygdala and ambient gyrus is a characteristic MRI finding of AGD. For the precise antemortem diagnosis, especially to differentiation from AD, it is important to pay attention to this asymmetric change.

Laparoscopic radical surgery produces a good prognosis in an elderly patient with small Wilms' tumor.

INTRODUCTION: Renal nephroblastoma, also known as Wilms' tumor, is the most common malignant renal tumor to affect children. Although rare in adults, nephroblastoma in adults is often found in its advanced stages and has a poorer prognosis than cases occurring in childhood. No report has described the efficacy of laparoscopic surgery in small diameter renal tumors in elderly patients. CASE PRESENTATION: Here, we report a very rare case of 71-year-old woman with asymptomatic small nephroblastoma removed by laparoscopic radical nephrectomy. CONCLUSION: The patient refused additional treatments but shows no sign of recurrence 15 months after surgery. These findings support, therefore, that laparoscopic surgery may be effective for small nephroblastoma in elderly patients refusing other treatment modalities.

Ultrasonographic findings of Diphyllobothrium nihonkaiense: A case report.

A 6-year-old girl was admitted to our hospital due to discharging the strobila of a tapeworm (Diphyllobothrium nihonkaiense) from her anus. Before excreting the tapeworm completely with anthelmintics, ultrasonography was performed. The tapeworm was shown as a slightly high echoic strand-like lesion on ultrasonography in the terminal ileum. In this strand-like lesion, some high echoic spots were detected. This finding was considered as a characteristic of Diphylloborthriasis.

Fibrin sheath of a peripherally inserted central catheter undepicted with gray-scale (real-time B-mode) ultrasonography: A case report.

An 11-year-old male was admitted to our hospital with the acute exacerbation of chronic heart failure. A peripherally inserted central catheter (PICC) was inserted from the left forearm. Ten days after its insertion, the withdrawal of PICC was attempted because of occlusion. However, it was not possible to remove PICC because a fibrin sheath had attached around its tip. A color Doppler and probe compression technique revealed the presence of a fibrin sheath, which could not be detected by gray-scale (real-time B-mode) ultrasonography. This case demonstrated that the color Doppler and probe compression technique is useful for detecting a fibrin sheath.

Useful computed tomography features for differentiating between focal atelectasis and pleural dissemination on preoperative evaluations of thymic epithelial tumors.

PURPOSE: Distinguishing between focal atelectasis (FA) and pleural dissemination (PD) is important for determining the optimal therapeutic strategy for thymic epithelial tumors (TET). This study aimed to identify useful computed tomography (CT) features for distinguishing between these two conditions. MATERIALS AND METHODS: We retrospectively analyzed preoperative CT images of 27 TET, which included 40 PD and 40 FA lesions. Two radiologists independently interpreted the pleural lesions without knowing the final diagnosis. The CT images were evaluated to assess the lesion location, size, and shape, presence of a spinous shadow and ground glass opacities (GGO) near to the lesion, and the shortest distance from the lesion to the nearest peripheral pulmonary artery (PA). RESULTS: FA lesions tended to occur on the dorsal side (90%, P = 0.024); have shorter major and minor axes (P < 0.001), a triangular shape (43%, P = 0.002), a spinous shadow (45%, P = 0.001) and GGO (28%, P = 0.006); and be close to a peripheral PA (P = 0.007). Ninety percent of PD lesions were located in the left thorax, and all of them were ipsilateral to the tumor (both P < 0.001). The 9 examined factors exhibited sensitivity, specificity, positive predictive, and negative predictive values of 85%, 95%, 94%, and 86%, respectively, for diagnosing FA (when ≥3 factors were present), and 90%, 48%, 63%, and 83%, respectively, for diagnosing PD (when ≥4 factors were present). CONCLUSION: The site, size, and shape of a lesion; the presence of a spinous shadow/GGO; and the distance to the nearest PA are useful for distinguishing between PD and FA.

Investigation of an appropriate contrast-enhanced CT protocol for young patients following the Fontan operation.

PURPOSE: Children with congenital heart diseases (CHDs) may need to be followed up with contrast-enhanced CT following the Fontan operation because complications such as the occlusion of conduits may occur. The purpose of the present study was to develop an adequate contrast-enhanced CT protocol for children with CHD following the Fontan operation. MATERIALS AND METHODS: Between July 2012 and July 2017, 29 CT examinations for 26 patients aged 2-11 years (median 5 years) with CHD following the Fontan operation were performed using dual-source CT. A non-ionized contrast medium was injected through the dorsum manus vein. Scanning began 60 or 70 s after the start of the injection. The delayed phase was randomly selected to be 60 s in 14 cases and 70 s in 15 cases. We evaluated the enhancement of conduits following the Fontan operation at delayed phases. RESULTS: The CT numbers of conduits at 60 and 70 s were 185 ± 46 and 185 ± 31 HU, respectively (P = 0.97). CONCLUSION: In contrast-enhanced CT for children after the Fontan operation, both of the delayed phases (60 and 70 s) appeared to be adequate for evaluating intraconduit patency.