Multimodal modeling with low-dose CT and clinical information for diagnostic artificial intelligence on mediastinal tumors: a preliminary study.

BACKGROUND: Diagnosing mediastinal tumours, including incidental lesions, using low-dose CT (LDCT) performed for lung cancer screening, is challenging. It often requires additional invasive and costly tests for proper characterisation and surgical planning. This indicates the need for a more efficient and patient-centred approach, suggesting a gap in the existing diagnostic methods and the potential for artificial intelligence technologies to address this gap. This study aimed to create a multimodal hybrid transformer model using the Vision Transformer that leverages LDCT features and clinical data to improve surgical decision-making for patients with incidentally detected mediastinal tumours. METHODS: This retrospective study analysed patients with mediastinal tumours between 2010 and 2021. Patients eligible for surgery (n=30) were considered 'positive,' whereas those without tumour enlargement (n=32) were considered 'negative.' We developed a hybrid model combining a convolutional neural network with a transformer to integrate imaging and clinical data. The dataset was split in a 5:3:2 ratio for training, validation and testing. The model's efficacy was evaluated using a receiver operating characteristic (ROC) analysis across 25 iterations of random assignments and compared against conventional radiomics models and models excluding clinical data. RESULTS: The multimodal hybrid model demonstrated a mean area under the curve (AUC) of 0.90, significantly outperforming the non-clinical data model (AUC=0.86, p=0.04) and radiomics models (random forest AUC=0.81, p=0.008; logistic regression AUC=0.77, p=0.004). CONCLUSION: Integrating clinical and LDCT data using a hybrid transformer model can improve surgical decision-making for mediastinal tumours, showing superiority over models lacking clinical data integration.

Review of clinical and diagnostic imaging of the thymus: from age-related changes to thymic tumors and everything in between.

The thymus, a primary lymphoid organ of the immune system, undergoes several changes due to a variety of reasons, ranging from aging to pathological conditions. These changes can make distinguishing between benign and neoplastic changes in the thymus challenging, thereby complicating the histopathological diagnoses of thymic tumors. Moreover, most patients with thymic tumors are asymptomatic at the time of diagnosis. Therefore, imaging plays an extremely important role in the evaluation of thymic lesions. In this review, we introduced the imaging characteristics of the thymus, ranging from benign findings, such as normal maturation and benign lesions, to neoplasms.

Intravascular large B-cell lymphoma appearance on dual-energy computed tomography: a case report.

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is the proliferation of neoplastic B lymphocytes in the vascular space. Since conventional computed tomography (CT) shows nonspecific findings, differentiation between IVLBCL and other lung diseases, such as diffuse interstitial lung disease, is difficult. CASE PRESENTATION: A 73-year-old man presented with dyspnea and hypoxemia. Laboratory findings showed an increased lactate dehydrogenase level of 1690 U/L (normal: 130-235 U/L) and soluble interleukin-2 receptor level of 1140 U/mL (normal: 157-474U/mL). Dual-energy CT iodine mapping showed a significant symmetrical decrease in iodine distribution in the upper lungs, suggesting an unusual distribution of pulmonary hypoperfusion. Therefore, IVLBCL was suspected. A random skin biopsy confirmed the diagnosis of IVLBCL. Due to the severity of the disease, lung biopsy was averted. After admission to the hospital, high-dose methotrexate was administered for central nervous system involvement, due to findings of suspected intracranial infiltration on a brain magnetic resonance imaging and elevated cell counts on lumbar puncture. Subsequently, oxygen demand improved, and rituximab along with cyclophosphamide, doxorubicin, vincristine, and prednisone was added to the patient's regime. Eventually, oxygen administration was terminated, the patient's general condition improved, and the patient was discharged after 47 days of hospitalization. CONCLUSIONS: Since the diagnosis of IVLBCL depends on whether it is possible to suspect IVLBCL, the finding of decreased iodine perfusion demonstrated on dual-energy CT is considered important information for diagnosis. An immediate diagnosis of IVLBCL is needed to avoid rapid disease progression and introduce early treatment for a favorable prognosis. In this case, unique pulmonary hypoperfusion demonstrated by dual-energy CT promoted early diagnosis of IVLBCL.

Ex-vivo 1.5T MR Imaging versus CT in Estimating the Size of the Pathologically Invasive Component of Lung Adenocarcinoma Spectrum Lesions.

PURPOSE: The purpose of this study was to investigate whether ex-vivo MRI enables accurate estimation of the invasive component of lung adenocarcinoma. METHODS: We retrospectively reviewed 32 patients with lung adenocarcinoma who underwent lung lobectomy. The specimens underwent MRI at 1.5T. The boundary between the lesion and the normal lung was evaluated on a 5-point scale in each three MRI sequences, and a one-way analysis of variance and post-hoc tests were performed. The invasive component size was measured histopathologically. The maximum diameter of each solid component measured on CT and MR T1-weighted (T1W) images and the maximum size obtained from histopathologic images were compared using the Wilcoxon signed-rank test. Inter-reader agreement was evaluated using intraclass correlation coefficients (ICC). RESULTS: T1W images were determined to be optimal for the delineation of the lesions (P < 0.001). The histopathologic invasive area corresponded to the area where the T1W ex-vivo MR image showed a high signal intensity that was almost equal to the intravascular blood signal. The maximum diameter of the solid component on CT was overestimated compared with the maximum invasive size on histopathology (mean, 153%; P < 0.05), while that on MRI was evaluated mostly accurately without overestimation (mean, 108%; P = 0.48). The interobserver reliability of the measurements using CT and MRI was good (ICC = 0.71 on CT, 0.74 on MRI). CONCLUSION: Ex-vivo MRI was more accurate than conventional CT in delineating the invasive component of lung adenocarcinoma.

Incidental mediastinal masses detected at low-dose CT screening: prevalence and radiological characteristics.

PURPOSE: The primary and secondary aims were to investigate the prevalence of incidental mediastinal masses on low-dose chest CT examinations during health check-ups, and to review the radiological characteristics of prevascular mediastinal masses, respectively. MATERIALS AND METHODS: This retrospective study included 38,861 participants (mean age: 57.1 years; range: 21-99 years; men: 51.3%; never-smokers: 57.4%) who underwent low-dose chest CT examinations between January 2011 and December 2016. All images with incidental mediastinal masses were reviewed, and prevascular mediastinal masses were assessed for qualitative and quantitative imaging characteristics by two radiologists. Univariate and multivariate analyses were performed in clinical and CT features between some combinations of participants. RESULTS: Overall, 653 participants (1.68%, 653 of 38,861) had incidental mediastinal masses; 578 in prevascular mediastinum, including 93 intrathymic cysts and 24 thymic epithelial tumors. Presence of mediastinal mass was not significantly associated with sex (p = 0.089) and smoking history (p = 0.098) but with age (p < 0.001). Significant differences were found between intrathymic cysts and thymic epithelial tumors in terms of shapes (p = 0.049), contours (p = 0.018), and CT values (p = 0.012). CONCLUSION: The prevalence of asymptomatic mediastinal masses on low-dose chest CT was 1.68%. CT values, shapes, and contours may effectively distinguish intrathymic cysts from thymic epithelial tumors.

MR Imaging of Mushroom-like Skin Adnexal Tumors in the Scalp: A Report of Two Cases.

Few studies had been published regarding imaging findings of skin adnexal tumors. We experienced two giant cases of them with a characteristic mushroom-like growth pattern. MRI showed a circumscribed mushroom-like shaped mass extruding from the subcutaneous tissue with microcystic lesions. Although differentiation between benignancy and malignancy may be difficult by radiological examinations, MRI may be helpful to identify its origin and differentiate soft tissue tumors with skin adnexal tumors in having these imaging findings.

Pediatric oncologic emergencies: Clinical and imaging review for pediatricians.

Children with cancer are at increased risk of life-threatening emergencies, either from the cancer itself or related to the cancer treatment. These conditions need to be assessed and treated as early as possible to minimize morbidity and mortality. Cardiothoracic emergencies encompass a variety of pathologies, including pericardial effusion and cardiac tamponade, massive hemoptysis, superior vena cava syndrome, pulmonary embolism, and pneumonia. Abdominal emergencies include bowel obstruction, intussusception, perforation, tumor rupture, intestinal graft-versus-host disease, acute pancreatitis, neutropenic colitis, and obstructive uropathy. Radiology plays a vital role in the diagnosis of these emergencies. We here review the clinical features and imaging in pediatric patients with oncologic emergencies, including a review of recently published studies. Key radiological images are presented to highlight the radiological approach to diagnosis. Pediatricians, pediatric surgeons, and pediatric radiologists need to work together to arrive at the correct diagnosis and to ensure prompt and appropriate treatment strategies.

Value of a Computer-aided Detection System Based on Chest Tomosynthesis Imaging for the Detection of Pulmonary Nodules.

Purpose To assess the value of a computer-aided detection (CAD) system for the detection of pulmonary nodules on chest tomosynthesis images. Materials and Methods Fifty patients with and 50 without pulmonary nodules underwent both chest tomosynthesis and multidetector computed tomography (CT) on the same day. Fifteen observers (five interns and residents, five chest radiologists, and five abdominal radiologists) independently evaluated tomosynthesis images of 100 patients for the presence of pulmonary nodules in a blinded and randomized manner, first without CAD, then with the inclusion of CAD marks. Multidetector CT images served as the reference standard. Free-response receiver operating characteristic analysis was used for the statistical analysis. Results The pooled diagnostic performance of 15 observers was significantly better with CAD than without CAD (figure of merit [FOM], 0.74 vs 0.71, respectively; P = .02). The average true-positive fraction and false-positive rate per all cases with CAD were 0.56 and 0.26, respectively, whereas those without CAD were 0.47 and 0.20, respectively. Subanalysis showed that the diagnostic performance of interns and residents was significantly better with CAD than without CAD (FOM, 0.70 vs 0.62, respectively; P = .001), whereas for chest radiologists and abdominal radiologists, the FOM with CAD values were greater but not significantly: 0.80 versus 0.78 (P = .38) and 0.74 versus 0.73 (P = .65), respectively. Conclusion CAD significantly improved diagnostic performance in the detection of pulmonary nodules on chest tomosynthesis images for interns and residents, but provided minimal benefit for chest radiologists and abdominal radiologists. © RSNA, 2017 Online supplemental material is available for this article.

Human papillomavirus-associated plantar epidermoid cysts: MR and US imaging appearance.

Epidermoid cysts are epithelial cysts that present as slow-growing intradermal or subcutaneous lesions. While recent epidemiological studies have isolated human papillomavirus (HPV) from plantar epidermoid cysts, imaging findings in HPV-associated epidermoid cysts have not been previously reported. We describe imaging findings in two patients with HPV-associated plantar epidermoid cysts. Magnetic resonance (MR) imaging and ultrasonography (US) showed linear arrangement of several adjacent globular cysts. This appearance is hypothesized to result from HPV-associated eccrine duct metaplasia leading to cyst formation and later traumatic rupture leading to formation of multiple adjacent cystic components. It may be useful to suggest assessing the presence of HPV antigen in plantar lesions having these imaging findings.

Imaging of vascular tumors with an emphasis on ISSVA classification.

The International Society for the Study of Vascular Anomalies (ISSVA) classification is becoming the international standard classification system for vascular tumors and vascular malformations. The ISSVA classification strictly distinguishes vascular tumors (neoplastic lesions) from vascular malformations (non-neoplastic lesions) based on whether there is a proliferation of vascular endothelial cells present, and it is an extremely useful classification system for determining therapeutic measures. For vascular tumors, it is clinically significant in terms of discriminating infantile hemangioma and rapidly involuting congenital hemangioma, which are expected to spontaneously regress, from other vascular tumors requiring treatment. Needless to say, clinical courses are important for diagnosis, and it is also important for radiologists to understand imaging findings on vascular tumors because such tumors have unique findings on diagnostic images. In this paper, vascular tumors are classified based on the ISSVA classification, and clinical and imaging findings are reviewed.

Magnetic resonance imaging for extramammary Paget's disease: radiological and pathological correlations.

Extramammary Paget's disease (EMPD) is a rare cutaneous neoplasm that is thought to represent intraepithelial adenocarcinoma developing in an area rich in apocrine glands. Magnetic resonance imaging (MRI) findings for this disease are not well established. We report three cases of pathologically confirmed EMPD in which MRI was performed before surgery. The lesions were widespread in the epidermis and the dermis. Lesions were sharply well enhanced on gadolinium-enhanced T1-weighted imaging and appeared hyperintense on diffusion-weighted imaging in all cases. Areas with enhancement in depth corresponded well with the pathological lesion. In addition, different malignant legions were found on the same images from MRI in two cases, indicating potential associations with other malignancies. We describe the MRI findings and their pathological correlation. MRI could be useful for preoperative evaluation of disease spread and detection of associated malignancies.

Malignant pleural mesothelioma detected by spontaneous pneumothorax.

We report a middle-aged man, without occupational or environmental exposure to asbestos, who presented with spontaneous pneumothorax. Computed tomography showed a 13-mm right apical mass. He underwent tumorectomy and was diagnosed with malignant pleural mesothelioma. A local recurrence with multiple and diffuse pleural involvement later appeared. The patient eventually underwent panpleuropneumonectomy, recovered well, and has been doing well for 18 months.

Phase II study of oral fludarabine in combination with rituximab for relapsed indolent B-cell non-Hodgkin lymphoma.

Oral fludarabine is more convenient than intravenous fludarabine in an outpatient setting. To assess the efficacy and toxicity of oral fludarabine in combination with rituximab in patients with relapsed indolent B-cell non-Hodgkin lymphoma (B-NHL), we conducted a multicenter phase II study. Patients with relapsed indolent B-NHL with two or fewer prior regimens and up to 16 doses of rituximab were eligible. Patients received 375 mg/m(2) rituximab on day 1, and 40 mg/m(2) oral fludarabine once daily on days 1 through 5 every 28 days for up to six cycles. The primary endpoint was the overall response rate. Forty-one patients were enrolled, including 38 (93%) with follicular lymphoma. Thirty-four patients (83%) had received rituximab as prior therapy. Twenty-seven patients (66%) completed the planned six cycles. Dose reduction of oral fludarabine was required in 17 patients (41%). The overall response rate was 76% (31 of 41 patients; 95% confidence interval, 60-88%) with a complete response rate of 68% (28 of 41 patients; 95% confidence interval, 52-82%). Median progression-free survival for the 41 patients was 19.7 months (95% confidence interval, 12.3-26.5 months). Hematological toxicities, including grade 4 neutropenia (68%), were the most frequent toxicities. Non-hematological toxicities were mild, except for one patient who died of Pneumocystis jiroveci pneumonia 4 months after the protocol treatment. In conclusion, oral fludarabine in combination with rituximab is a highly effective and convenient therapy for patients with relapsed indolent B-NHL who have mostly been pretreated with rituximab.

Phase I/II and pharmacokinetic study of cladribine with 2-h infusion in Japanese patients with relapsed indolent B-cell lymphoma mostly pretreated with rituximab.

We conducted a phase I/II study to investigate the toxicity, pharmacokinetics, and efficacy profiles of cladribine with 2-h intravenous infusion for five consecutive days every four weeks in Japanese patients with relapsed indolent B-cell lymphoma. This was a dose-escalation study to confirm the safety of the doses which have been recommended for Caucasian patients (phase I), and to further evaluate the efficacy and safety (phase II). In the phase I portion for nine patients, no dose-limiting toxicities were observed at levels 1 (0.09 mg/kg/day, n = 3) and 2 (0.12 mg/kg/day, n = 6). No appreciable accumulation of plasma cladribine concentration was suggested. We enrolled a total of 20 patients, and an additional 14 patients in the phase II portion at level 2 (0.12 mg/kg/day). Eighteen patients, including 13 with follicular lymphoma, were eligible for efficacy evaluation, and 15 (83%) were pretreated with rituximab. The overall response rate was 50% (9/18; 80% confidence interval, 35-65%), with 11% (2/18) complete response. With a median follow-up of 296 days, the estimated median time to progression for 18 eligible patients was 382 days. The most frequent adverse events were hematologic toxicities, including grade 4 neutropenia. Non-hematologic toxicities were mild. In conclusion, cladribine with 2-h intravenous infusion for five consecutive days every four weeks is effective with acceptable toxicities for Japanese patients with relapsed indolent B-cell lymphoma, including those pretreated with rituximab.

Japanese phase II study of 90Y-ibritumomab tiuxetan in patients with relapsed or refractory indolent B-cell lymphoma.

There is no data about the efficacy and safety of radioimmunotherapy with 90Y-ibritumomab tiuxetan in patients with relapsed or refractory indolent B-cell lymphoma pretreated with rituximab-containing chemotherapy. We focused on this in a Japanese phase II study. Radioimmunotherapy with 90Y-ibritumomab tiuxetan (11.1 and 14.8 MBq) was evaluated in patients with 100-149x10(9) and >150x10(9) platelets/L, respectively. The primary endpoint was the overall response rate. Forty patients were treated with 90Y-ibritumomab tiuxetan (18 with 11.1 MBq/kg and 22 with 14.8 MBq/kg). Thirty-five patients (88%) had been pretreated with rituximab, including 27 (68%) pretreated with rituximab-containing chemotherapy. The overall response rate was 83% (33/40; 95% confidence interval, 67-93%), and the complete response rate was 68% (27/40; 95% confidence interval, 51-81%). The overall response rates in patients pretreated with rituximab-containing chemotherapy and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were 83% (19/23) and 94% (17/18), respectively. The median progression-free survival time of the 40 patients who received 90Y-ibritumomab tiuxetan was 9.6 months. Toxicity was primarily hematological and mostly transient. No grade 4 non-hematological toxicity was observed. In conclusion, radioimmunotherapy with 90Y-ibritumomab tiuxetan is safe and highly effective in patients with relapsed or refractory indolent B-cell lymphoma, including those pretreated with rituximab-containing chemotherapy. (ClinicalTrials.gov number NCT00220285).

Phase II study of oral fludarabine phosphate in relapsed indolent B-Cell non-Hodgkin's lymphoma.

PURPOSE: Although intravenous (IV) fludarabine phosphate is effective against indolent B-cell non-Hodgkin's lymphoma (B-NHL), IV administration for 3 to 5 consecutive days is inconvenient in an outpatient setting. To assess the efficacy and toxicity of oral fludarabine phosphate in patients with indolent B-NHL, we conducted a multicenter phase II study. PATIENTS AND METHODS: Patients with relapsed indolent B-NHL received fludarabine phosphate tablets orally once daily on days 1 through 5 every 28 days for three to six cycles. The efficacy was separately analyzed in a mantle-cell lymphoma (MCL) cohort and indolent B-NHL except for MCL (IL) cohort. The primary end point was the overall response rate (ORR). RESULTS: Fifty-two patients, including 46 in the IL cohort (41 with follicular lymphoma) and six in the MCL cohort, were registered, and all patients were eligible. Forty-one patients (79%) had received rituximab as prior therapy. In the IL cohort, the ORR and complete response rate were 65% (30 of 46 patients; 95% CI, 50% to 79%) and 30% (14 of 46 patients; 95% CI, 18% to 46%), respectively. One of six patients with MCL achieved a partial response. The median times to treatment failure for the 46 patients in the IL cohort and for the six patients in the MCL cohort were 8.6 and 6.1 months, respectively. Hematologic toxicities, including grade 4 neutropenia (37%), were the most frequent toxicities, and nonhematologic toxicities were mild. CONCLUSION: Oral fludarabine phosphate is highly effective in patients with relapsed indolent B-NHL who have mostly been pretreated with rituximab and is more convenient than the IV formulation.

Percutaneous sacroplasty for hemorrhagic metastases from hepatocellular carcinoma.

Percutaneous injection of bone cement is a promising treatment for metastatic tumors. We present a case of hemorrhagic sacral metastases from hepatocellular carcinoma treated successfully by percutaneous sacroplasty with combined injections of bone cement and n-butyl cyanoacrylate resulting in pain relief.