Endometriosis, a common but enigmatic disease with many faces: current concept of pathophysiology, and diagnostic strategy.

Endometriosis is a benign, common, but controversial disease due to its enigmatic etiopathogenesis and biological behavior. Recent studies suggest multiple genetic, and environmental factors may affect its onset and development. Genomic analysis revealed the presence of cancer-associated gene mutations, which may reflect the neoplastic aspect of endometriosis. The management has changed dramatically with the development of fertility-preserving, minimally invasive therapies. Diagnostic strategies based on these recent basic and clinical findings are reviewed. With a focus on the presentation of clinical cases, we discuss the imaging manifestations of endometriomas, deep endometriosis, less common site and rare site endometriosis, various complications, endometriosis-associated tumor-like lesions, and malignant transformation, with pathophysiologic conditions.

Combined visual and quantitative assessment of somatostatin receptor scintigraphy for staging and restaging of neuroendocrine tumors.

PURPOSE: Somatostatin receptor scintigraphy (SRS) using 111In-DTPA-DPhe1-octreotide (pentetreotide) has become an integral part of neuroendocrine neoplasm management. The lack of precise quantification is a disadvantage of SRS. This study aimed to adapt the standardized uptake value (SUV) to SRS, establish the SUV range for physiological uptake in the liver, kidney, and spleen, and elucidate the utility of combined visual and quantitative SRS assessment for staging and restaging of neuroendocrine tumors (NETs). MATERIALS AND METHODS: This study included 21 patients with NETs who underwent 111In-pentetreotide SRS. The SUV of physiological and pathological uptake was calculated using bone single-photon emission computed tomography (SPECT) quantitative analysis software (GI-BONE). For visual analysis, the primary and metastatic lesions were scored visually on planar and SPECT images using a five-point scale. We assessed the relationships between the SUVs of the liver, kidney, and spleen in the dual phase, and among quantitative indices, visual score, and pathological lesions classification. RESULTS: Sixty-three NEN lesions were evaluated. The mean ± standard deviation maximum SUVs (SUVmax) were liver: 4 h, 2.6 ± 1.0; 24 h, 2.2 ± 1.0; kidney: 4 h, 8.9 ± 1.8; 24 h, 7.0 ± 2.0; and spleen; 4 h, 11.3 ± 4.5; 24 h, 11.5 ± 7.6. Higher SUVmax was significantly associated with higher visual scores on dual-phase SPECT (4 h, p < 0.001; 24 h, p < 0.001) (4 h: scores 3 and 4, p < 0.05; scores 3 and 5: p < 0.01; scores 4 and 5: p < 0.01; 24 h: scores 3 and 4, p = 0.0748; scores 3 and 5: p < 0.01; scores 4 and 5: p < 0.01). CONCLUSION: We adapted the SUV to SRS and established the range of SUV for physiological uptake in the liver, kidney, and spleen. Combined visual and quantitative assessment is useful for imaging individual lesions in greater detail, and may serve as a new tumor marker of SRS for staging and restaging of NETs.

A novel CT-based radiomics model for predicting response and prognosis of chemoradiotherapy in esophageal squamous cell carcinoma.

No clinically relevant biomarker has been identified for predicting the response of esophageal squamous cell carcinoma (ESCC) to chemoradiotherapy (CRT). Herein, we established a CT-based radiomics model with artificial intelligence (AI) to predict the response and prognosis of CRT in ESCC. A total of 44 ESCC patients (stage I-IV) were enrolled in this study; training (n = 27) and validation (n = 17) cohorts. First, we extracted a total of 476 radiomics features from three-dimensional CT images of cancer lesions in training cohort, selected 110 features associated with the CRT response by ROC analysis (AUC ≥ 0.7) and identified 12 independent features, excluding correlated features by Pearson's correlation analysis (r ≥ 0.7). Based on the 12 features, we constructed 5 prediction models of different machine learning algorithms (Random Forest (RF), Ridge Regression, Naive Bayes, Support Vector Machine, and Artificial Neural Network models). Among those, the RF model showed the highest AUC in the training cohort (0.99 [95%CI 0.86-1.00]) as well as in the validation cohort (0.92 [95%CI 0.71-0.99]) to predict the CRT response. Additionally, Kaplan-Meyer analysis of the validation cohort and all the patient data showed significantly longer progression-free and overall survival in the high-prediction score group compared with the low-prediction score group in the RF model. Univariate and multivariate analyses revealed that the radiomics prediction score and lymph node metastasis were independent prognostic biomarkers for CRT of ESCC. In conclusion, we have developed a CT-based radiomics model using AI, which may have the potential to predict the CRT response as well as the prognosis for ESCC patients with non-invasiveness and cost-effectiveness.

MR Imaging Findings of Uterine Adenomatoid Tumors.

PURPOSE: Adenomatoid tumor is a rare benign genital tract neoplasm of mesothelial origin. Uterine adenomatoid tumors occur in the outer myometrium and may mimic leiomyomas. Because hormonal treatment is not applicable to adenomatoid tumors and laparoscopic enucleation is not easy as myomectomy, it is important to differentiate adenomatoid tumors from leiomyomas for the adequate treatment. The purpose of this study is to evaluate the MRI findings of adenomatoid tumor for the differentiation from leiomyoma. METHODS: MRI findings of surgically proven 10 uterine adenomatoid tumors in 9 women were retrospectively evaluated with correlation to histopathological findings. RESULTS: All 10 tumors appeared as solid myometrial masses and showed heterogeneous signal intensity with admixture of partially ill-defined slight high-intensity areas containing abundant tubular tumor cells and well-defined myoma-like low-intensity areas reflecting smooth muscle hypertrophy on T2WI including 4 lesions with peripheral ring-like high intensity. High-intensity areas on T2WI tended to show high intensity on diffusion-weighted imaging (DWI) with relatively high apparent diffusion coefficient (ADC), suggesting T2 shine-through effect due to abundant tubules. Intra-tumoral hemorrhage revealed on MRI was rare. Early intense contrast-enhanced areas on dynamic contrast-enhanced study were observed dominantly within the high-intensity areas but rarely within the low-intensity areas on T2WI. CONCLUSION: The outer myometrial mass with the admixture of well-defined low- and ill-defined high-intensity areas on T2WI may be suggestive of adenomatoid tumor. Peripheral ring-like high intensity on T2WI and DWI may also be suggestive. Dynamic contrast-enhanced MR study may be helpful for the differentiation from leiomyoma.

A Case of Anti-NXP2 Antibody-positive Juvenile Dermatomyositis with Characteristic Fascial Thickening on Muscle Ultrasound and Improvement with Immunotherapy.

We herein report a 12-year-old boy who presented with a fever, erythematous rash on the cheeks, back pain, and dysphagia. Blood tests revealed increased creatine kinase levels, and muscle ultrasonography (MUS) revealed characteristic fascial thickening in the lumbar paraspinal muscles, where myalgia was prominent. Sarcoplasmic expression of myxovirus-resistant protein A on a muscle biopsy and the presence of anti-nuclear matrix protein 2 (NXP2) antibodies confirmed the diagnosis of dermatomyositis. Prednisolone and intravenous immunoglobulin therapy improved the clinical and laboratory parameters as well as fascial thickening. MUS is useful for evaluating fasciitis associated with anti-NXP2 autoantibodies and monitoring therapeutic efficacy.

Dynamic contrast-enhanced MR imaging of uterine endometrial carcinoma with/without squamous differentiation.

PURPOSE: Endometrial carcinoma with strong enhancement on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is suggestive of high-grade type II endometrial carcinoma. However, low-grade type I endometrial carcinoma may also sometimes show strong enhancement. We hypothesized that squamous differentiation would contribute to the strong enhancement at the early phase on DCE-MRI-like uterine cervical squamous cell carcinoma and compared the DCE-MRI findings of endometrial carcinoma with and without squamous differentiation. METHODS: DCE-MRI of endometrial carcinoma including 41 low-grade type I endometrial carcinomas without squamous differentiation (LG), 39 low-grade type I endometrial carcinomas with squamous differentiation (LGSD), and 20 high-grade type II endometrial carcinomas (HG) was retrospectively evaluated. RESULTS: Significant difference in the time-intensity curves was found between LG and HG and LG and LGSD, whereas no significant difference was seen between HG and LGSD. Curve type 3 (initial signal rise which is steeper than that of the myometrium) was more frequent in HG (60%) and LGSD (77%) than in LG (34%). CONCLUSION: It should be recognized as a pitfall that high-grade type II endometrial carcinoma and low-grade type I endometrial carcinoma with squamous differentiation may show similar early strong enhancement on DCE-MRI.

Nationwide Laboratory Surveillance of Progressive Multifocal Leukoencephalopathy in Japan: Fiscal Years 2011-2020.

Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disease caused by JC virus (JCV), predominantly affecting patients with impaired cellular immunity. PML is a non-reportable disease with a few exceptions, making national surveillance difficult. In Japan, polymerase chain reaction (PCR) testing for JCV in the cerebrospinal fluid (CSF) is performed at the National Institute of Infectious Diseases to support PML diagnosis. To clarify the overall profile of PML in Japan, patient data provided at the time of CSF-JCV testing over 10 years (FY2011-2020) were analyzed. PCR testing for 1537 new suspected PML cases was conducted, and 288 (18.7%) patients tested positive for CSF-JCV. An analysis of the clinical information on all individuals tested revealed characteristics of PML cases, including the geographic distribution, age and sex patterns, and CSF-JCV-positivity rates among the study subjects for each type of underlying condition. During the last five years of the study period, a surveillance system utilizing ultrasensitive PCR testing and widespread clinical attention to PML led to the detection of CSF-JCV in the earlier stages of the disease. The results of this study will provide valuable information not only for PML diagnosis, but also for the treatment of PML-predisposing conditions.

11C-Methionine PET/CT and 18F-FDG PET/CT in the Evaluation of Adult Alveolar Rhabdomyosarcoma.

A 70-year-old man with a tumor in the nasal and paranasal space, was pathologically diagnosed with an alveolar rhabdomyosarcoma, with right cervical lymph node metastasis. Magnetic resonance imaging revealed a primary tumor in the nasal and paranasal sinuses, with associated intracranial infiltration. 11C-methionine positron emission tomography/computed tomography (PET/CT) revealed increased uptake in the primary tumor and right cervical lymph node metastasis. 18F-fluorodeoxyglucose PET/CT also revealed increased uptake in the primary tumor and right cervical lymph node. However, the physiological brain uptake overlapped with the primary tumor uptake. Our case suggests the usefulness of 11C-methionine PET/CT for accurately assessing the extent of alveolar rhabdomyosarcoma, especially in cases with intracranial infiltration or those approximating the brain.

New quantitative indices of cardiac amyloidosis with 99mTc-pyrophosphate scintigraphy.

PURPOSE: Amyloid light chain (AL) and transthyretin (ATTR) are the major subtypes of cardiac amyloidosis (CA). 99mTc-pyrophosphate (PYP) scintigraphy is used to differentiate ATTR from other CA subtypes. We adapted the standardized uptake value (SUV) for 99mTc-PYP and proposed two quantitative indices, amyloid deposition volume (AmyDV) and total amyloid uptake (TAU). This study aimed to evaluate the utility of these quantitative indices in differentiating ATTR from non-ATTRs. MATERIALS AND METHODS: Before the SUV measurement, the Becquerel calibration factor (BCF) of 99mTc was obtained by a phantom experiment. Thirty-two patients who had undergone hybrid SPECT/CT imaging 3 h after injection of 99mTc-PYP (370 MBq) were studied. CT attenuation correction for image reconstruction was applied in all. We calculated SUV, AmyDV, and TAU using a quantitative analysis software program for bone SPECT (GI-BONE) and analyzed AmyDV using two methods: threshold method (set 40%); and constant value method (average SUVmax of ribs). We assessed the diagnostic ability of heart-to-contralateral lung (H/CL) ratio, SUV, AmyDV, and TAU to differentiate ATTR from non-ATTR using receiver operating characteristic (ROC) analysis. RESULTS: Statistically significant differences in all quantitative indices were observed between ATTR and non-ATTR. The area under the curve of each quantitative index for discriminating between ATTR and non-ATTR were as follows: H/CL, 0.997; SUVmax, 0.953; SUVmean (M1), 0.964; SUVmean (M2), 0.969; AmyDV (M1), 0.875; AmyDV (M2), 0.974; and TAU, 0.974. The AmyDV (M2) had higher diagnostic ability than AmyDV (M1). Thus, TAU was calculated as AmyDV (M2) × SUVmean (M2). In the ROC curve, SUV, AmyDV, and TAU had almost the same diagnostic ability as H/CL in distinguishing ATTR from non-ATTRs. CONCLUSIONS: We propose two novel 3D-based quantitative parameters (AmyDV and TAU) that have almost equal ability to discriminate ATTR from non-ATTR.

Imaging features of a myoepithelial carcinoma of the nasal cavity: A case report and literature review.

Myoepithelial carcinoma of the nasal cavity is extremely rare. We report the case of a 66-year-old man with myoepithelial carcinoma of the nasal cavity. Computed tomography (CT) and magnetic resonance imaging revealed a lobulated soft tissue mass with central necrosis and hemorrhage, as well as an invasion of the skull base and left orbit. The patient presented with continuous nasal congestion and heavy head and had no elevated level of squamous cell carcinoma-related antigen. CT, magnetic resonance imaging, or 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT revealed no evidence of a metastatic lesion. 18F-FDG accumulation in the tumor was inhomogeneous and moderate. Histopathological examination of the resected specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was a myoepithelial carcinoma of the left nasal cavity. This case shows that nasal myoepithelial carcinoma might appear as a well-defined lobulated mass with hemorrhagic necrosis and intense contrast enhancement in the solid component. We conjecture that hemorrhagic necrosis and intense enhancement values may be potential markers of nasal myoepithelial carcinoma.

18F-FDG PET/CT Showing Rare Mediastinal Growing Teratoma Syndrome Following Chemotherapy.

Growing teratoma syndrome (GTS) is a condition in which poorly differentiated cells in a mixed-germ cell tumor (GCT) regress after chemotherapy, and the number of well-differentiated components increases. A 60-year-old man had an 8.0 cm mediastinal tumor with strong 18F-fluorodeoxyglucose (FDG) uptake [maximum standardized uptake value (SUVmax): 9.2], which was diagnosed as a GCT. After chemotherapy, serum alpha fetoprotein, beta-human chorionic gonadotropin, and tumor 18F-FDG uptake decreased (SUVmax: 3.9), but the tumor volume increased. The tumor was completely resected, and pathology confirmed the diagnosis of GTS. 18F-FDG positron emission tomography after chemotherapy reflects the proliferation of highly differentiated tumor components with poor 18F-FDG uptake.

Multicystic Biliary Hamartoma With Xanthogranulomatous Inflammation on 18F-FDG PET/CT.

ABSTRACT: A 70-year-old man with a liver tumor was pathologically diagnosed with multicystic biliary hamartoma with xanthogranulomatous inflammation. Plain CT revealed an inhomogeneous low-density liver tumor, measuring 43 × 35 mm. Dynamic contrast-enhanced CT revealed a cyst, measuring approximately 15 mm, with a ring-shaped enhancement, within the tumor. There was delayed enhancement on the outer portion of the tumor. Mild peripheral bile duct dilation was also observed. 18F-FDG PET/CT showed focal high uptake with an SUVmax of 5.2 near the cyst. The findings of this case mimicked that of intrahepatic cholangiocellular carcinoma.

Magnetic resonance imaging characteristics of polypoid endometriosis and review of the literature.

AIM: Polypoid endometriosis is a rare variant of endometriosis and may mimic malignancy. The purpose of this study is to evaluate magnetic resonance (MR) imaging characteristics of polypoid endometriosis for the differential diagnosis with malignancy. METHODS: MR imaging findings of four histologically proven polypoid endometriosis were retrospectively evaluated with the review of the literature. RESULTS: All polypoid endometriosis exhibited high signal intensity on T2-weighted images reflecting abundant dilated endometrial glands. Peritoneal lesions were surrounded by low signal intensity rim represented the "black rim sign" reflecting endometriotic fibrous adhesion. Two cases arising from endometriotic cysts showed transmural extension (peritoneal extension and myometrial infiltration). Endometriotic hemorrhagic foci were demonstrated in four lesions as high signal intensity on T1-weighted images and/or susceptibility-induced signal voids on susceptibility-weighted MR sequence. Diffusion-weighted images showed high signal intensity with relatively high apparent diffusion coefficient (ADC) due to T2 shine-through effect but no diffusion restriction, and dynamic contrast-enhanced (DCE) MR imaging showed gradually increasing contrast-enhancement pattern like benign pathologies. CONCLUSIONS: Polypoid endometriosis may mimic malignancy; however, black rim sign may be a characteristic MR imaging finding for the peritoneal lesions, and no diffusion restriction and gradually increasing contrast-enhancement pattern may reflect its benign nature.

Increased 18F-FDG Uptake in the Axillary Lymph Nodes of the Vaccinated Side Associated with COVID-19 Vaccination.

A 50-year-old female patient underwent (18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) following modified radical mastectomy for cancer of the left breast. Ten days before the PET/CT, the coronavirus disease-2019 (COVID-19) vaccine was injected intramuscularly into the right deltoid muscle. Increased (18F-FDG uptake of maximum standardized uptake value (11.0) was observed in the lymph nodes of the right axilla, which had not been observed in the previous PET/CT. The size of the oval-shaped lymph nodes was up to approximately 11×9 mm; however, it was larger than that observed on the previous PET/CT. We contemplate that the increased (18F-FDG uptake was a reactive change in the lymph nodes associated with the COVID-19 vaccine.

Quantitative parameter mapping of contrast agent concentration and relaxivity and brain tumor extracellular pH.

In clinical magnetic resonance imaging, gadolinium-based contrast agents are commonly used for detecting brain tumors and evaluating the extent of malignancy. We present a new method to evaluate relaxivity (r1) and contrast agent concentration separately in contrast-enhanced lesions using quantitative parameter mapping (QPM). Furthermore, we also aimed to estimate the extracellular pH (pHe) of tumor lesions. We demonstrated that it is possible to evaluate pathophysiological tumor changes due to therapeutic efficacy by measuring r1 in contrast-enhanced lesions. In this study, the primary brain tumor group showed significantly higher r1 values than other brain disease groups (P < 0.001). Moreover, mean pHe value showed a trend for tumor malignancy having a lower pHe value and primary brain tumor having a significantly lower pHe than other brain diseases (P < 0.001). Our results might suggest that QPM can separately quantify r1 and CA concentration in brain tumors and that pHe brain tumor mapping could serve as a tumor biomarker. In conclusion, our method has potential clinical applications for assessing the treatment effects.

The feasibility of reduced field-of-view diffusion-weighted imaging in evaluating bladder invasion of uterine cervical cancer.

OBJECTIVES: Uterine cervical cancer with bladder mucosal invasion is classified as FIGO stage IVA with poor prognosis. MRI can rule out the bladder invasion and skipping cystoscopy may be possible; however, high false-positive rate may be problematic. The purpose of this study is to evaluate the diagnostic performance of reduced field-of-view (FOV) diffusion-weighted imaging (DWI) in evaluating bladder mucosal invasion of cervical cancer. METHODS: 3T MRI including T2WI and reduced FOV DWI in 15 women with histologically proven cervical cancer (two stage IIIB, six stage IVA, seven stage IVB) were retrospectively evaluated compared with cystoscopic findings. RESULTS: Cystoscopy revealed mucosal invasion in 13 of 15 cases. The border between the tumor and the bladder wall was unclear on T2WI and clear on reduced FOV DWI in all 15 cases. The diagnosis of mucosal invasion on reduced FOV DWI had a sensitivity of 100%, specificity of 50%, accuracy of 93%, PPV of 93%, and NPV of 100%. CONCLUSIONS: Addition of reduced FOV DWI may improve the staging accuracy of MRI for cervical cancer in assessing the bladder mucosal invasion. ADVANCES IN KNOWLEDGE: Reduced FOV DWI may improve the staging accuracy of cervical cancer in assessing bladder mucosal invasion with high NPV and PPV, which may be helpful for avoiding unnecessary cystoscopy.

Combined Small-Angle Neutron Scattering/Small-Angle X-ray Scattering Analysis for the Characterization of Silver Nanoparticles Prepared via Photoreduction in Water-in-Oil Microemulsions.

In this study, we used small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) to investigate the formation process of silver (Ag) nanoparticles (NPs) in water-in-oil (w/o) reverse microemulsions comprising sodium bis(2-ethylhexyl) sulfosuccinate (AOT), water, and organic solvents (such as benzene, octane, and decane) by the photoreduction of silver perchlorate (AgClO4). Combining SANS and SAXS, the structural changes in the w/o microemulsions before and after the formation of Ag NPs via photoreduction were quantitatively evaluated. From the SANS experiments performed using the contrast-variation method, the size of water cores containing Ag NPs and the thickness of the AOT shells were calculated using the core-shell hard-sphere model. The size of the Ag NPs and their aggregates was calculated via SAXS analysis based on the polydisperse sphere model with a Schulz-Zimm distribution. We found that aggregates of three or four primary Ag NPs are formed by, first, the aggregation of water droplets through the entanglement of the tails of the AOT shell, followed by the self-assembly of Ag NPs into their aggregates because of particle-particle attractive interactions.

A reduced physiological 18F-fluorodeoxyglucose uptake in the brain and liver caused by malignant lymphoma being deprived of the tracer.

Purpose : To investigate whether or not the physiological brain and liver FDG uptake are decreased in patients with highly accelerated glycolysis lesions. Methods : We retrospectively analyzed 51 patients with malignant lymphoma. We compared the FDG uptake in the brain and liver of the patients with that in a control group. In 24 patients with a complete response (CR) or partial response (PR) to treatment, we compared the brain and liver uptake before and after treatment. Results : The maximum standardized uptake value (SUVmax) and total glycolytic volume (TGV) of the brain as well as the SUVmax and mean standardized uptake value (SUVmean) of the liver in malignant lymphoma patients were 13.1 ±â€…2.3, 7386.3 ±â€…1918.4, 3.2 ±â€…0.5, and 2.3 ±â€…0.4, respectively ; in the control group, these values were 14.9 ±â€…2.4, 8566.2 ±â€…1659.5, 3.4 ±â€…0.4, and 2.5 ±â€…0.3, respectively. The SUVmax and TGV of the brain and the SUVmean of the liver in malignant lymphoma patients were significantly lower than the control group. The SUVmax and TGV of the brain after treatment were significantly higher than before treatment. Both the SUVmax and SUVmean of liver after treatment were higher than before treatment, but not significant. Conclusion : A decreased physiological brain and liver FDG uptake is caused by highly accelerated lesion glycolysis. J. Med. Invest. 68 : 181-185, February, 2021.