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.

Evaluation of background parenchymal enhancement in breast contrast-enhanced ultrasound with Sonazoid®.

PURPOSE: The objective of this study was to retrospectively evaluate the association between background parenchymal enhancement (BPE) on contrast-enhanced ultrasound (CEUS) with Sonazoid® and patient characteristics. Additionally, background parenchymal tissues with the high-contrast effect were pathologically observed compared to those showing the low-contrast effect. METHODS: A total of 65 patients who underwent breast CEUS with Sonazoid® between January 2010 and November 2013 were enrolled. Regions of interest (ROIs) were put on the tumor and on the background parenchymal tissue. The dB values during the nonenhanced time and at peak contrast enhancement were measured based on the time intensity curve (TIC) drawn by the ROI. The differences in the dB values of pre- and post-enhanced time were obtained separately for ROIs on the tumor and ROIs on the parenchymal tissue. The patient characteristics studied were age, menstrual status, mammographic density, BPE on magnetic resonance imaging (MRI), and pathological diagnoses of breast tumors. RESULTS: There was a weak negative correlation between BPE on CEUS and age. As for the contrast effect of parenchymal tissue, there was a significant difference between the menstruating and menopausal groups. There was no significant difference among the levels of mammographic density, and among the degrees of contrast effect on MRI. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status. The parenchymal tissue with the low-contrast effect showed pathological atrophy. CONCLUSION: The degree of BPE on CEUS appeared related to age, menstruating or menopausal, and atrophy of breast tissue. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status.

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.

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.

MR signal changes on hepatobiliary imaging after oral ingestion of manganese chloride tetrahydrate: preliminary examination.

PURPOSE: To clarify magnetic resonance (MR) signal changes during hepatobiliary imaging after oral ingestion of manganese chloride tetrahydrate (Bothdel Oral Solution 10) (MCT). MATERIALS AND METHODS: Subjects were an MCT phantom, 10 healthy volunteers and 155 consecutive patients. The phantom study evaluated the relationship between MCT concentration and MR signal intensity. The volunteer study qualitatively and quantitatively analyzed the time course of hepatobiliary imaging immediately and 30, 60, 120 and 180 min after oral ingestion of MCT. The clinical study analyzed the incidence and factors affecting signal changes on additional MRCP with MCT as a final scan during routine clinical MRCP. RESULTS: In the phantom study, a significant and excellent positive linear correlation was found between MCT concentration and R2* measurement (r(2) = 0.996, p < 0.01). In the volunteer study, biliary imaging and hepatic R2* values changed significantly after oral ingestion of MCT (p < 0.05). In the clinical study, a signal drop on MRCP with MCT was visually confirmed in 14.8 % of cases. Multivariate logistic regression found no factors significantly affecting signal drop. CONCLUSION: We recommend performing MRCP early after oral ingestion of MCT, because signal changes occur even during routine MRCP.