The value of diffusion-weighted and dynamic contrast-enhanced imaging in the diagnosis of thymic epithelial tumors.

Background: Thymic epithelial tumors (TETs) are clinically the most frequently encountered neoplasm of the prevascular mediastinum in adults. The role of chest magnetic resonance (MR) imaging has been increasingly stressed thanks to its excellent contrast resolution, freedom from ionizing radiation, and capability to provide additional information regarding tumors' cellular structure and vascularity. Methods: This study aimed to establish the relationship between the MR findings and pathological classification of TETs, focusing on diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) imaging. This retrospective cross-sectional study included 44 TET patients who underwent chest MR scanning. The tumors were classified into three groups according to the WHO classification: low-risk thymoma (LRT), high-risk thymoma (HRT), and non-thymoma (NT). Along with morphological characteristics, the apparent diffusion coefficient (ADC) value, time-intensity curve (TIC) pattern, and time to peak enhancement (TTP) of the tumors were recorded and compared between the three groups. Results: A smooth contour and complete or almost complete capsule were suggestive of LRTs. The median ADC value of the 44 tumors was 0.95 × 10-3 mm2/sec. Among the three groups, LRTs had the highest ADC values, while NTs had the lowest. The differences between the ADC values of the three groups were statistically significant (p = 0.006). Using an ADC cutoff of 0.82 × 10-3 mm2/sec to differentiate between LRTs and tumors of the two remaining groups, the area under the curve was 0.775, sensitivity was 100%, specificity was 50%, and accuracy was 65.91%. The washout (type 3) TIC pattern was the most prevalent, accounting for 45.45% of the population; this pattern was also predominantly observed in LRTs (71.43%). Although the median TTP of LRTs was lower than that of HRTs or NTs, no statistically significant differences were found between the TTPs of the three groups (p = 0.170). Conclusions: MR is a good imaging modality to preoperatively assess TETs. Morphological features, ADC value, TIC pattern, and TTP are helpful in preoperatively predicting TET pathology.

Role of diffusion-weighted MRI in differentiation between benign and malignant anterior mediastinal masses.

Diffusion-weighted imaging (DWI) is considered to be a useful biomarker to characterize the cellularity of lesions, yet its application in the thorax to evaluate anterior mediastinal lesions has not been well investigated. The aims of our study were to describe the magnetic resonance (MR) characteristics of anterior mediastinal masses and to assess the role of apparent diffusion coefficient (ADC) value in distinguishing benign from malignant lesions of the anterior mediastinum. We conducted a retrospective cross-sectional study including 55 patients with anterior mediastinal masses who underwent preinterventional MR scanning with the following sequences: T1 VIBE DIXON pre and post-contrast, T2 HASTE, T2 TIRM, DWI-ADC map (b values of 0 and 2000 sec/mm2). The ADC measurements were obtained by two approaches: hot-spot ROI and whole-tumor histogram analysis. The lesions were grouped by three distinct ways: benign versus malignant, group A (benign lesions and type A, AB, B1 thymoma) versus group B (type B2, B3 thymoma and other malignant lesions), lymphoma versus other malignancies. The study was composed of 55 patients, with 5 benign lesions and 50 malignant lesions. The ADCmean, ADCmedian, ADC10, ADC90 in the histogram-based approach and the hot-spot-ROI-based mean ADC of the malignant lesions were significantly lower than those of benign lesions (P values< 0.05). The hot-spot-ROI-based mean ADC had the highest value in differentiation between benign and malignant mediastinal lesions, as well as between group A and group B; the ADC cutoffs (with sensitivity, specificity) to differentiate malignant from benign lesions and group A from group B were 1.17 x 10-3 mm2/sec (80%, 80%) and 0.99 x 10-3 mm2/sec (78.4%, 88.9%), respectively. The ADC values obtained by using the hot-spot-ROI-based and the histogram-based approaches are helpful in differentiating benign and malignant anterior mediastinal masses.

Correlation of Chest X-Ray Scores in SARS-CoV-2 Patients With the Clinical Severity Classification and the Quick COVID-19 Severity Index.

Objectives This study aimed to assess the role of chest X-ray (CXR) scoring methods and their correlations with the clinical severity categories and the Quick COVID-19 Severity Index (qCSI). Methods We conducted a retrospective study of 159 COVID-19 patients who were diagnosed and treated at the University Medical Center between July and September 2021. Chest X-ray findings were evaluated, and severity scores were calculated using the modified CXR (mCXR), Radiographic Assessment of Lung Edema (RALE), and Brixia scoring systems. The three scores were then compared to the clinical severity categories and the qCSI using Spearman's correlation coefficient. Results Overall, 159 patients (63 males and 96 females) (mean age: 58.3 ± 15.7 years) were included. The correlation coefficients between the mCXR score and the Brixia and RALE scores were 0.9438 and 0.9450, respectively. The correlation coefficient between the RALE and Brixia scores was marginally higher, at 0.9625. The correlation coefficients between the qCSI and the Brixia, RALE, and mCXR scores were 0.7298, 0.7408, and 0.7156, respectively. The significant difference in the mean values of the three CXR scores between asymptomatic, mild, moderate, severe, and critical groups was also noted. Conclusions There were strong correlations between the three CXR scores and the clinical severity classification and the qCSI.

Differentiation Between Surgical and Nonsurgical Intussusception: A Diagnostic Model Using Multi-Detector Computed Tomography.

BACKGROUND: The differentiation of surgical from nonsurgical adult intussusception may enable the appropriate selection of management strategies. OBJECTIVE: This study aimed to investigate the diagnostic potential of multidetector computed tomography (MCDT) features to differentiate surgical from nonsurgical adult intussusception and develop a diagnostic model. METHODS: A retrospective study was performed on 96 patients with intussusceptions at the University Medical Center Hospital between January 2014 and January 2020. Two radiologists reviewed all images, and intussusception characteristics were documented. The location of intussusception, length, diameter, interposed fat thickness, lead point, and complications were evaluated. Based on the results, a diagnostic tree model was developed to differentiate between surgical and nonsurgical adult intussusception. RESULTS: A total of 99 intussusceptions in 96 patients (mean age: 53.0 ± 16.5 years), including 35 (35.3%) enteroenteric, 27 (27.3%) enterocolic, and 37 (37.4%) colocolic lesions, were evaluated. Of the enteroenteric intussusceptions, 22 (62.9%) were surgical, including 19 (79.2%) with lead points. Among colon intussusceptions, 63 (98.4%) were surgical, and 100% had lead points. The characteristics used to predict surgical intussusceptions included lead point presence, length ≥ 5.0 cm, diameter ≥ 3.2 cm, interposed fat thickness ≥ 0.5 cm, and complications (p < 0.001). Based on these features, we established a diagnostic tree model that correctly classified 96 (97%) of 99 lesions. CONCLUSION: Our study reinforces the importance of MDCT for the diagnosis and guided management of adult intussusceptions. The characteristics that predicted surgical intussusceptions included lead points, length, diameter, interposed fat thickness, and complications. A systematic approach using this diagnostic tree model could be used to distinguish surgical and nonsurgical adult intussusception.

Endovascular repair for abdominal aortic aneurysm in a kidney transplant recipient.

Surgical treatment of abdominal aortic aneurysm in patients with a transplanted kidney is true a challenge. Conventional open repair of the aneurysm requires aortic cross-clamping. Therefore, it can pose a risk of ischemic injury to the transplanted kidney. Endovascular repair, which limits the duration of interruption of blood flow to the transplanted kidney, is a suitable alternative for repair of abdominal aortic aneurysm, if feasible anatomically. Here, we present a case of a 62-year-old woman who was transferred to our hospital because of abdominal pain and had a history of renal transplant 14 years ago. Computed tomography confirmed a large infrarenal fusiform abdominal aortic aneurysm 6 cm in maximal diameter and another 4 cm fusiform aneurysm in the left common iliac artery. We successfully performed endovascular aneurysm repair combined with femoro-femoral bypass. The postoperative course was uneventful, and the patient was discharged on the 5th postoperative day.

Imaging findings of three cases of large mediastinal mature cystic teratoma.

Mature cystic teratoma (MCT) is a benign, slow-growing tumor and accounts for approximately 75% of mediastinal germ cell tumors. Patients with MCT are often asymptomatic when the tumors are small. Most of the symptoms are frequently related to compression of the mediastinal structures. We herein describe 3 adult cases of MCT. The patients were a 37-year-old man, a 35-year-old woman, and a 54-year-old woman. They were hospitalized with compression-related symptoms, such as chest pain, dyspnea, and cough. Findings from conventional chest radiograph, computed tomography (CT), magnetic resonance imaging were characterized. Conventional chest radiography still plays a major role in the initial evaluation of MCT, while CT remains the preferred modality for initial cross-sectional imaging evaluation of mediastinal lesions. However, thoracic magnetic resonance imaging provides more detailed and often definitive evaluation of mediastinal masses than CT because of its superior tissue characterization.

Radiofrequency Ablation for Benign Thyroid Nodules: 1-Year Follow-Up in 184 Patients.

BACKGROUND: Benign thyroid nodules are common, and must be treated when symptomatic. Non-surgical minimally invasive modalities, including radiofrequency ablation (RFA), have been widely used with good results. The factors related to the efficacy of RFA are still debated. This study was to evaluate the safety, efficacy and related factors of RFA in the treatment of benign thyroid nodules. METHODS: A retrospective single-center study was conducted on 251 benign thyroid nodules in 184 patients treated with RFA. The procedure was performed under ultrasound (US) guidance using the trans-isthmic approach and the moving-shot technique. Clinical and US examinations were performed at 1, 3, 6, 12 months, and then at 6 month intervals. Study outcomes were volume reduction ratio (VRR) and complications. RESULTS: There were 153 women and 31 men included in the study. The mean age was 43.9 years. The median initial largest diameter and volume of nodules were 30 mm and 6.18 ml. The median length of follow-up was 12 months. Two minor complications were found. The mean VRR was 66.8; 74.3; and 81% after 3, 6, and 12 months, respectively. Initial solidity was a factor related to the efficacy: cystic nodules had higher VRR compared to solid ones. CONCLUSIONS: RFA is safe, effective and can be used as a routine treatment for benign thyroid nodules. More prospective multicenter studies with long-term follow-up are required to improve the safety and efficacy of RFA.