Pictorial Review of Pleural Disease: Multimodality Imaging and Differential Diagnosis.

The pleura is a thin, smooth, soft-tissue structure that lines the pleural cavity and separates the lungs from the chest wall, consisting of the visceral and parietal pleurae and physiologic pleural fluid. There is a broad spectrum of normal variations and abnormalities in the pleura, including pneumothorax, pleural effusion, and pleural thickening. Pneumothorax is associated with pulmonary diseases and is caused by iatrogenic or traumatic factors. Chest radiography and US help detect pneumothorax with various signs, and CT can also help assess the causes. Pleural effusion occurs in a wide spectrum of diseases, such as heart failure, cirrhosis, asbestos-related diseases, infections, chylothorax, and malignancies. Chest US allows detection of a small pleural effusion and evaluation of echogenicity or septa in pleural effusion. Pleural thickening may manifest as unilateral or bilateral and as focal, multifocal, or diffuse. Various diseases can demonstrate pleural thickening, such as asbestos-related diseases, neoplasms, and systemic diseases. CT, MRI, and fluorodeoxyglucose (FDG) PET/CT can help differentiate between benign and malignant lesions. Knowledge of these features can aid radiologists in suggesting diagnoses and recommending further examinations with other imaging modalities. The authors provide a comprehensive review of the clinical and multimodality imaging findings of pleural diseases and their differential diagnoses. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Multimodality Imaging of Primary Hepatic Lymphoma: A Case Report and a Literature Review.

Primary hepatic lymphoma (PHL) is a rare form of non-Hodgkin lymphoma primarily affecting the liver. We present a case of an 84-year-old man diagnosed with PHL, incidentally detected during abdominal ultrasonography. The ultrasonography showed a hypoechoic nodule. When examined by CEUS, the nodule showed hyperenhancement in the arterial phase and hypoenhancement in the portal and late phases. Conversely, CECT demonstrated hypoenhancement through all the phases. The patient declined a tumor biopsy and opted for follow-up care. Ten months later, the lobular mass had increased from 15 mm to 65 mm, presenting as hypoechogenic and demonstrating the "vessel-penetrating sign" on color Doppler imaging. CEUS revealed reticulated enhancement, indicating intratumoral vessels. The mass displayed hypoattenuation on plain CT, hypointensity in T1-weighted images, and hyperintensity in T2-weighted images and exhibited significant restriction in diffusion-weighted images. Both CECT and contrast-enhanced MRI exhibited hypoenhancement. The patient underwent a partial hepatic segmentectomy, and the mass was pathologically diagnosed as a diffuse large B-cell lymphoma. Subsequent postoperative radiological examinations revealed no other lesions, confirming the diagnosis of PHL. Our report highlights specific ultrasonographic signs of PHL observed from an early stage and presents a review of the relevant literature.

Clinical outcomes of sentinel node navigation surgery in patients with preoperatively estimated stage IA endometrial cancer and evaluation of validity for continuing sentinel node navigation surgery based on dispersion of recurrence probability.

BACKGROUND: To evaluate the feasibility of the use and continuation of sentinel lymph node navigation surgery (SNNS) as an alternative to pelvic lymph node dissection (PLND) for patients with preoperatively estimated stage IA endometrial cancer. METHODS: This retrospective study selected the electronic medical records of all patients who had received CT scans and MRI imaging before surgery from April 1, 2009 to March 31, 2021. Sentinel lymph nodes (SLNs) were detected by administrating 99mTc-phytate and/or indocyanine green into the cervix, and the clinical outcomes of the patients who underwent SNNS or PLND were evaluated. Furthermore, in case of nodal recurrence, a new procedure to determine whether the facility should continue with SNNS or not was developed that compares the maximum likelihood hypothesis and an alternative one based on recurrence rates. RESULTS: Among 137 patients, SLN biopsies with ultrastaging were performed on 91 patients. The SLN detection rate was 95.6%. Over a 59-month median observation period, no statistically significant differences were shown in overall survival, disease-specific survival and disease-free survival between the SNNS and PLND groups when introducing the propensity score method (p-values: 0.06, 0.153, and 0.625, respectively). Our procedure demonstrated that, in our department without recurrence up to the 65th attempt, it was possible to continue SNNS if a recurrence occurs at the 66th attempt. CONCLUSION: This study suggests the validity of SNNS as an alternative to PLND. Even in the absence of evidence from randomized controlled trials, we can confirm the validity of continuing SNNS using our procedure.

Leydig cell tumor of the testis with characteristic contrast patterns of tumor and non-tumorous testicular parenchyma on MRI: a case report.

PURPOSE: Testicular Leydig cell tumor (LCT) is a rare subtype of testicular neoplasms that occurs in the interstitial tissue of testes, accounting for 1-3% of total testicular masses removed annually. We report a case of 70-year-old man diagnosed as testicular LCT. This report demonstrates a testicular LCT with intratumoral and non-tumorous testicular parenchymal enhancement in the affected testis, which should be considered characteristic findings of LCT. METHODS: Ultrasonography showed a hypoechoic mass. On magnetic resonance imaging, the tumor showed low signal intensity comparable to the surrounding testicular tissue on T1-weighted images (T1WI) and low signal intensity on T2-weighted images (T2WI). On gadolinium contrast-enhanced T1WI (CE-T1WI), the tumor showed a rapid and marked wash-in and subsequent prolonged washout. The spared, non-tumorous testicular parenchyma showed slow and progressive enhancement in the early phase, which was as strong as or stronger than that of the mass in the delayed phase. The patient underwent right orchiectomy. RESULTS: Pathologically, the tumor was diagnosed as a testicular Leydig cell tumor (LCT). Leydig cell proliferation was observed with well-developed microvessels, atrophy of the seminiferous tubules, and stromal edema in the non-tumorous testicular parenchyma. Leydig cells in the non-tumorous parenchyma were positive for estrogen receptors. CONCLUSION: Since the contrast findings in the non-tumorous testicular parenchymal region on CE-T1WI likely match the histopathological features of LCT, our case suggests that the presence of non-tumorous testicular parenchymal enhancement on imaging might indicate a diagnosis of LCT.

Accuracy of magnetic resonance imaging in predicting dentate line invasion in low rectal cancer.

PURPOSE: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in predicting dentate line invasion in low rectal cancer. MATERIALS AND METHODS: Eighty-one patients with primary rectal cancer were assessed by dynamic contrast-enhanced MRI. The location of the dentate line was assessed on MRI in 27 patients with upper-mid rectal cancer. Two observers independently evaluated the distance between the distal tumor edge and the MRI-defined dentate line in 54 patients with low rectal cancer, and the imaging and histological findings were compared. RESULTS: The MRI-defined dentate line was 24.0 ± 3.8 mm above the anal verge in patients with upper-mid rectal cancer. The dentate line invasion status agreed with the histological findings in 49/54 (91%) patients (κ = 0.72 [95% CI 0.50-0.95]) for observer 1, and in 51/54 (94%) patients (κ = 0.83 [0.65-1.00]) for observer 2 in patients with low rectal cancer. Interobserver agreement was good (κ = 0.83 [0.65-1.00]). The MRI-derived distance between the distal tumor edge and the dentate line had significant correlation with the histological distance (r = 0.86 for reader 1 and 0.75 for observer 2). CONCLUSION: MRI demonstrates high accuracy in predicting dentate line invasion in low rectal cancer.

Uterine adenomatoid tumor associated with lymph node lesions: a case report.

We report a case of uterine adenomatoid tumor (AT) with regional lymph node involvement in a 49-year-old woman. Magnetic resonance imaging revealed an aggregated cystic mass in the posterior uterine wall with partial protrusion of the tumor outside the uterus, and cystic masses of same characteristics in the bilateral obturator and right common iliac lymph nodes. FDG PET/CT revealed no significant FDG uptake in the uterine and lymph node lesions. Taking possible lymph node metastasis into consideration, hysterectomy and lymph node biopsy were performed and it revealed AT of the uterus and the lymph nodes histopathologically.

Development of a framework catalyst for photocatalytic hydrogen evolution.

The controlled self-assembly of a catalyst module composed of a Rh(ii) paddle-wheel dimer bearing 1,8-naphthalimide-based moieties afforded a novel heterogeneous framework catalyst (FC-1). The framework catalyst exhibited long-lived activity for photocatalytic hydrogen production from water and was easily reused without considerable loss of catalytic activity.

Detection of unusual very-long-chain fatty acid and ether lipid derivatives in the fibroblasts and plasma of patients with peroxisomal diseases using liquid chromatography-mass spectrometry.

Metabolic changes occur in patients with peroxisomal diseases owing to impairments in the genes involved in peroxisome function. For diagnostic purposes, saturated very-long-chain fatty acids (VLCFAs) such as C24:0 and C26:0, phytanic acid, pristanic acid, and plasmalogens are often measured as metabolic hallmarks. As the direct pathology of peroxisomal disease is yet to be fully elucidated, we sought to explore the fatty acid species that accumulate in patients with peroxisomal diseases. We developed a method for detecting a range of fatty acids implicated in peroxisomal diseases such as Zellweger syndrome (ZS) and X-linked adrenoleukodystrophy (X-ALD). To this end, we employed an ultra-performance liquid chromatography-mass spectrometry (LC-MS) coupled with negatively charged electrospray ionization. Fatty acids from patients and control subjects were extracted from total lipids by acid-hydrolysis and compared. In accordance with previous results, the amounts of VLCFAs, phytanic acid, and pristanic acid differed between the two groups. We identified extremely long and highly polyunsaturated VLCFAs (ultra-VLC-PUFAs) such as C44:12 in ZS samples. Moreover, three unknown molecules were prominent in control samples but scarcely detectable in ZS samples. LC-MS/MS analysis identified these as 1-alkyl-sn-glycerol 3-phosphates derived from ether lipids containing fatty alcohols such as C16:0, C18:0, or C18:1. Our method provides an approach to observing a wide range of lipid-derived fatty acids and related molecules in order to understand the metabolic changes involved in peroxisomal diseases. This technique can therefore be used in identifying metabolic markers and potential clinical targets for future treatment.

Comparison of visibility of circumscribed masses on Digital Breast Tomosynthesis (DBT) and 2D mammography: are circumscribed masses better visualized and assured of being benign on DBT?

OBJECTIVE: To compare the visibility of circumscribed masses on digital breast tomosynthesis (DBT) images and 2D mammograms and determine the usefulness of DBT for differentiation between benign and malignant circumscribed masses. METHODS: Seventy-one (19 malignant and 52 benign) mammographic well-circumscribed masses were included. Visibility of the masses and halo signs on DBT images were retrospectively compared with 2D mammograms. The effects of mammographic breast density on mass visibility were also evaluated. RESULTS: For DBT, 83% were superior and 17% were equivalent in visibility of the masses to that of 2D, and superiority of DBT was significantly enhanced in the high breast density group compared with the low breast density group (91% vs 68%, respectively, p = 0.016). Three lesions were only detected on DBT. There was no significant difference in the superiority of DBT for lesion visibility between malignant and benign masses. The halo sign was detected in 58% lesions on DBT and in 4% on 2D (p < 0.001). CONCLUSION: Circumscribed masses were better visualized on DBT than on 2D mammograms, particularly in high-density breasts. The halo sign often appeared on DBT and gave a clearer mass margin. However, circumscribed masses on DBT are not assured of being benign. KEY POINTS: • Circumscribed masses were better visualized on breast tomosynthesis than on 2D mammography. • Tomosynthesis visualized circumscribed masses better than 2D for all breast density categories. • Halo signs often appeared on tomosynthesis and contributed to detect circumscribed margins. • Circumscribed masses on tomosynthesis images are not assured of being benign lesions.

MR findings of Lynch syndrome-related uterine endometrial carcinoma: a case report.

A 41-year-old woman presented with atypical genital bleeding. Magnetic resonance imaging demonstrated a polypoid mass from the lower uterine segment to cervical canal, approximately 32 mm in size. Additionally, a thickened sigmoid colon wall showing a markedly high signal intensity on diffusion-weighted imaging was observed. Barium enema and colonoscopy revealed a type I sigmoid colon cancer. Since this patient was relatively young and had multiple relatives with colon cancer, Lynch syndrome was suspected and proved by an immunohistochemical survey. Uterine endometrial carcinoma related to Lynch syndrome tends to occur in the lower uterine segment. Radiologists should be aware of this syndrome so that the correct diagnosis can be suggested in the imaging report.

Porous frameworks constructed by non-covalent linking of substitution-inert metal complexes.

The incorporation of active sites into metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) is an attractive way to functionalise these materials. However, the methodology to organise substitution-inert metal-based secondary building units (SBUs) with active sites into MOFs or PCPs via coordination driven self-assembly is severely limited. In this study, we successfully assembled substitution-inert paddle-wheel Rh(II) dimers to afford three novel porous frameworks, Rh2(ppeb)4(THF)2 (1-THF), Rh2(ppeb)4(3-pentanone)2 (1-PN) and Rh2(ppeb)4(1-adamantylamine)2 (1-AD) (ppeb = 4-[(perfluorophenyl)ethynyl]benzoate), by using non-covalent interactions. Multipoint arene-perfluoroarene (Ar-Ar(F)) interactions, which allow the unidirectional face-to-face interaction mode of aromatic rings, were used to assemble the substitution-inert paddle-wheel Rh(II) dimers. The obtained frameworks were structurally characterisation by single crystal X-ray diffraction, and it is found that all structures exhibited a one-dimensional channel with active axial sites exposed to the pores. The porous properties of the obtained frameworks were also investigated by thermogravimetric analysis, gas adsorption and powder X-ray diffraction measurements. Moreover, the ligand substitution reaction at the active axial sites was examined at the crystalline state and the flexible structural transformation with the change of channel shapes and sizes was observed.

Correlation between the ABC classification and radiological findings for assessing gastric cancer risk.

PURPOSE: To investigate the correlation between ABC risk assessment and radiological findings of gastric mucosa and to propose an improved method for gastric cancer screening. MATERIALS AND METHODS: We evaluated 318 participants with Helicobacter pylori (Hp) antibody titers, serum pepsinogen (PG) and upper GI radiography and then classified them into three groups: A, double-negative; B, Hp-positive, PG-negative; C, PG-positive. Group A was subclassified as: A-1, Hp antibody titer <3.0 U/ml; A-2, Hp antibody titer ≥3.0 U/ml. Results for group A and non-A (B or C) participants and radiological findings of gastric mucosa (fold and area gastricae) were analyzed retrospectively. RESULTS: Radiological findings differed significantly between the 207 A-1 and 98 non-A group. Odds ratios were 17.72 for fold distribution, 10.63 for fold thickness, 6.10 for fold characteristics, and 10.62 for area gastricae. Presence of ≥2 risk factors offered 90.3 % sensitivity, 94.7 % specificity, and 93.3 % accuracy. Nine (69.2 %) of the 13 A-2 group participants and 11 (5.3 %) A-1 group participants had a risk for gastric cancer according to radiological findings. CONCLUSION: A good correlation exists between ABC classifications and radiological findings for gastric cancer risk, but some discrepant cases exist. We recommend both methods as screening for gastric cancer.

Dispersed Ru nanoclusters transformed from a grafted trinuclear Ru complex on SiO2 for selective alcohol oxidation.

Ru nanoclusters (average diameter = 1.3 ± 0.3 nm) were successfully prepared by using a Ru3 cluster Ru3O(CH3COO)6(H2O)3·(CH3COO) grafted on a pyridine-functionalized SiO2 surface. The pyridine moiety dispersed on the SiO2 surface spread the Ru3 cluster, controlling its surface density, and the nanoclusterization of the Ru cluster proceeded on the surface. The structures of the Ru nanoclusters were characterized by means of elemental analysis; thermogravimetric analysis; FT-IR, UV/vis, and solid-state NMR spectroscopy; BET analysis; X-ray photoelectron spectroscopy; X-ray diffraction; transmission electron microscopy; and Ru K-edge X-ray absorption fine structure analysis. It was found that the catalytic activity for the selective oxidation of alcohol to the corresponding aldehyde using O2 highly depended on the dispersion and structures of the Ru particles, and the Ru nanocluster was found to be efficient in the selective oxidation of a variety of alcohols.

Ectopic pregnancy: MRI findings and clinical utility.

PURPOSE: To assess the utility of magnetic resonance imaging (MRI) in patients with clinically suspected ectopic pregnancy (EP). METHODS: We retrospectively reviewed MRIs of 26 consecutive patients who were clinically suspected of having an EP. The diagnostic utility of MRI features of EP was analyzed retrospectively as follows: (1) Direct sign detection of ectopic gestational sac (GS); (2) Indirect signs tubal dilatation with hemosalpinx, adnexal hematoma, and hemorrhagic ascites. The diagnostic accuracy of each sign and their combination was compared to surgical records. The MRI findings of an ectopic GS were reviewed as follows: size, shape, signal intensity, and enhancement pattern. RESULTS: Of 26 patients, 24 had a tubal pregnancy; 22 of these 24 patients (92%) had a direct sign (sensitivity: 91.3%; specificity: 100%; positive predictive value: 100%). The diagnostic accuracy of the direct sign was 92%; this was more accurate than that of any single indirect sign (39%, 54%, and 50%, respectively). However, the diagnostic accuracy of EP increased to 100% when diagnostic criteria required the presence of a direct sign or at least two indirect signs. CONCLUSIONS: MRI is an effective modality for diagnosing EP with a high detection rate of extrauterine GSs. The combination of direct and indirect signs is useful for establishing the correct diagnosis.

Visualization of ovarian tumors using 3T MR imaging: diagnostic effectiveness and difficulties.

PURPOSE: We evaluated the diagnostic effectiveness of magnetic resonance (MR) imaging at 3 tesla to visualize ovarian tumors and problems associated with its use. MATERIALS AND METHODS: From the records of 423 consecutive women who underwent pelvic MR imaging using a 3T system from April 2009 to June 2010, we analyzed 50 continuous cases of ovarian tumors proved by histopathology. We evaluated visualization of these tumors for image quality and artifacts using 5-point scales. For qualitative assessment, we scored overall image quality (1, poor, to 5, excellent), degree of conviction regarding the diagnosis (1, undiagnosable, to 5, diagnosable with high certainty), and 4 representative artifacts (penetrating, chemical shift, motion, and susceptibility artifact) (1, severe, to 5, little degradation). We also retrospectively reviewed the diagnostic features of the ovarian tumors and preoperative diagnostic accuracy. For quantitative assessment, we determined tumor size and ADC value. RESULTS: Overall quality score was scored 4.9±0.5, and conviction regarding diagnosis was 4.9±0.3. Artifacts caused little degradation in most cases: penetrating, 4.8±0.5; chemical shift, 4.3±0.5; motion, 4.6±0.6; and susceptibility, 3.8±0.9. Preoperative diagnostic accuracy was 92% (sensitivity 94.7%, specificity 90.3%). Mean tumor diameter was 88.3±61 mm. The mean ADC value was 1.04±0.3 in malignant tumors and 1.15±0.5 (×10⁻6 mm²/s) in benign tumors. CONCLUSION: The quality of ovarian tumor images obtained with a 3T MR imaging system is adequate for diagnosis, with only slight degradation from penetrating or susceptibility artifacts.

Retained placental tissue: role of MRI findings in diagnosis and clinical assessment.

OBJECTIVE: To assess the role of MRI in diagnosis and predicting clinical outcome in women with retained placental tissue. PATIENTS AND METHODS: Eleven patients with pathologically proven RPT were retrospectively studied. All underwent MRI. The following MRI parameters of RPT were studied: size, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic study, extent of attachment to the uterine myometrium, and myometrial thickness at the attachment site. Clinical reports were reviewed and MRI findings were compared with respect to outcome. RESULTS: RPT diameter varied from 30 to 102 mm. On T2-weighted images, 10 cases showed high intensity, while on T1-weighted images, seven cases showed high intensity. Nine cases were hypervascular. The myometrium was thinner at the attachment side than at the opposite side. All five cases in which RPT was delivered spontaneously showed an attachment area of less than a semicircle, hence broad attachment appears to impede detachment and necessitate additional therapy. After uterine arterial embolization, two patients showed complete infarction of RPT on enhanced MRI. CONCLUSION: MRI is useful for diagnosis and follow-up of RPT. The evaluation of extent of RPT attachment to the myometrium and vascularity on MRI can help the clinical assessment.

Ultrasound follow-up of infantile hypertrophic pyloric stenosis (IHPS) during conservative therapy: ultrasound findings as criteria for diagnosis and cure.

PURPOSE: During conservative therapy of infantile hypertrophic pyloric stenosis (IHPS) with atropine sulfate, there are many patients who do not achieve normal values of pyloric wall thickness and canal length even though they are clinically cured (vomiting has ceased); an objective criterion for cure has not yet been established. The aim of this study was to examine whether the appearance of pyloric wall stratification can be used as a criterion for cure. METHODS: Twenty infants with IHPS who were treated conservatively were enrolled. Two of them ultimately required surgery. Ultrasound examinations were done serially and the pyloric wall thickness and canal length were measured. The echogenicity of the pyloric wall and the presence of wall stratification were noted. RESULTS: On admission, all infants satisfied the ultrasound criteria for IHPS and had a heterogeneous pyloric wall without stratification. With conservative therapy, symptoms disappeared, the pyloric wall thickness and the canal length gradually decreased, the echogenicity gradually became homogeneous and hypoechoic, and wall stratification appeared (in most cases before the pyloric wall thickness and the canal length had normalized). The absence of wall stratification suggests that cellular interstitial changes, such as edema or inflammation, are present in the pyloric wall in the acute stage. CONCLUSION: Pyloric wall stratification was absent during the acute stage, but it appeared after initiation of treatment but before the pyloric wall thickness and the canal length had normalized. The presence of pyloric wall stratification can be used as a criterion for cure; the absence of wall stratification can be added to ultrasound diagnostic criteria for IHPS.

A novel practical synthesis of benzothiazoles via Pd-catalyzed thiol cross-coupling.

A convenient synthesis of substituted benzothiazoles from 2-bromoanilides has been accomplished. The various 2-bromoanilides were reacted with an alkyl thiolate in high yields using a palladium catalyst. The resulting sulfides were easily converted to the corresponding benzothiazoles via the simultaneous generation of thiols and condensation under basic or acidic conditions.

Combined effect of salinomycin and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet.

The aim of this study was to investigate the effects of salinomycin (SL) and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet (25% orchardgrass hay and 75% commercial concentrate). Four adult sheep were fed the diet with or without 20 mg x kg(-1) diet of SL once daily for each 3 wk. The rates of glucose entry and utilization were determined before and during 3 h after feeding using a [ (13)C(6)] glucose dilution approach. Ruminal characteristics and concentrations of blood volatile fatty acids (VFA) and plasma glucose and insulin were also measured. Metabolizable energy intake was unaffected (P = 0.22) with SL. Salinomycin decreased (P = 0.06) the ratio of acetate to propionate in rumen fluid. Salinomycin increased (P = 0.01) both rates of entry and utilization of glucose, but did not affect (P > 0.10) concentrations of blood VFA or plasma glucose or insulin. Feeding caused gradual increases in concentrations of blood acetate (P < 0.01) and propionate (P = 0.01), a transient increase in plasma insulin concentration (P = 0.05), a transient decrease in plasma glucose concentration (P < 0.01), and persistent increases in both rates of glucose entry (P < 0.01) and utilization (P < 0.01). No SL x feeding interaction was observed (P > 0.10) on any measurements. We conclude that SL and feeding would have an additive effect on both rates of glucose entry and utilization without modifications with SL to feeding responses of peripheral concentrations of blood VFA, plasma glucose and insulin.

Practical thiol surrogates and protective groups for arylthiols for Suzuki-Miyaura conditions.

We have developed practical thiol surrogates and arylthiol protective groups for the Suzuki-Miyaura reaction. 2-Ethylhexyl-3-mercaptopropionate and 4-(2'-mercaptoethyl)pyridine were shown to be not only good thiol surrogates but also good protective groups for thiol. We have demonstrated toleration of these protective groups under aqueous Suzuki-Miyaura conditions.