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The aim of this study was to evaluate the findings of CT scans in patients with pathologically confirmed primary colorectal squamous-cell carcinoma (SCC). The clinical presentation and CT findings in eight patients with pathologically confirmed primary colorectal squamous-cell carcinoma were retrospectively reviewed by two gastrointestinal radiologists. Hematochezia was the most common symptom (n = 5). The tumors were located in the rectum (n = 7) and sigmoid colon (n = 1). The tumors showed circumferential wall thickening (n = 4), bulky mass (n = 3), or eccentric wall thickening (n = 1). The mean maximal wall thickness of the involved segment was 29.1 mm ± 13.4 mm. The degree of tumoral enhancement observed via CT was well enhanced (n = 4) or moderately enhanced (n = 4). Necrosis within the tumor was found in five patients. The mean total number of metastatic lymph nodes was 3.1 ± 3.3, and the mean short diameter of the largest metastatic lymph node was 16.6 ± 5.7 mm. Necrosis within the metastatic node was observed in six patients. Invasions to adjacent organs were identified in five patients (62.5%). Distant metastasis was detected in only one patient. In summary, primary SCCs that arise from the colorectum commonly present as marked invasive wall thickening or a bulky mass with heterogeneous well-defined enhancement, internal necrosis, and large metastatic lymphadenopathies.

Rare pancreatic tumors and non-neoplastic tumor-like lesions present a diagnostic challenge due to their uncommon occurrence and overlapping imaging characteristics with more prevalent pancreatic neoplasms. Advances in imaging technologies and diagnostic criteria have contributed to increased detection of these rare entities in clinical practice. This pictorial review focuses on the radiologic–pathologic correlation of rare pancreatic tumors, including colloid carcinoma, acinar cell carcinoma, pancreatoblastoma, primary pancreatic lymphoma, and non-neoplastic tumor-like lesions such as hamartomas and inflammatory pseudotumors. Detailed imaging features, such as signal intensities on MRI and enhancement patterns on CT, are correlated with pathological findings to assist in the differential diagnosis. Familiarity with these characteristics is crucial for radiologists to ensure accurate diagnosis and guide appropriate treatment strategies, as management and prognosis significantly differ from common pancreatic neoplasms.

Electrical stimulation such as transcranial direct current stimulation (tDCS) is widely used to treat neuropsychiatric diseases and neurological disorders. Computational modeling is an important approach to understand the mechanisms underlying tDCS and optimize treatment planning. When applying computational modeling to treatment planning, uncertainties exist due to insufficient conductivity information inside the brain. In this feasibility study, we performed in vivo MR-based conductivity tensor imaging (CTI) experiments on the entire brain to precisely estimate the tissue response to the electrical stimulation. A recent CTI method was applied to obtain low-frequency conductivity tensor images. Subject-specific three-dimensional finite element models (FEMs) of the head were implemented by segmenting anatomical MR images and integrating a conductivity tensor distribution. The electric field and current density of brain tissues following electrical stimulation were calculated using a conductivity tensor-based model and compared to results using an isotropic conductivity model from literature values. The current density by the conductivity tensor was different from the isotropic conductivity model, with an average relative difference |rD| of 52 to 73%, respectively, across two normal volunteers. When applied to two tDCS electrode montages of C3-FP2 and F4-F3, the current density showed a focused distribution with high signal intensity which is consistent with the current flowing from the anode to the cathode electrodes through the white matter. The gray matter tended to carry larger amounts of current densities regardless of directional information. We suggest this CTI-based subject-specific model can provide detailed information on tissue responses for personalized tDCS treatment planning.

We present the first documented case of a fistula between the treated zone and the appendix after RFA in a patient with HCC. Contrast-enhanced CT and MRI revealed a subcapsular hepatic nodule with image findings of HCC located adjacent to the ascending colon and cecum. An ultrasound-guided core needle biopsy was subsequently performed to distinguish between hepatic metastasis and HCC. Post-RFA imaging identified a low-attenuating ablated area adjacent to an air-filled appendix. The patient later experienced complications, including increased liver enzymes and an abscess at the ablation site. Imaging revealed a fistulous tract between the RFA zone and the appendix. Over the following months, the patient underwent conservative treatment involving intravenous antibiotics and repeated percutaneous drainage, exhibiting eventual symptom relief and an absence of the fistulous tract upon subsequent imaging. This case highlights the rare complications that can arise during RFA due to peculiar anatomical variations, such as a subhepatic appendix, resulting from midgut malrotation and previous surgery. It is imperative for operators to be cognizant of potential anatomical variations when considering RFA treatment, ensuring comprehensive pre-procedural imaging and post-procedure monitoring. This case also emphasizes the potential viability of nonoperative management in complex scenarios in which surgical interventions pose significant risks.

Anemarrhena asphodeloides extract (AAE) has been used for the treatment of inflammatory diseases and its anti-inflammatory effects have been reported. In this feasibility study, the hepato-protective effect of AAE was evaluated in a rat liver cirrhosis model by a combination of biochemical analysis and electrical tissue conductivity. Liver cirrhosis was induced by dimethylnitrosamine (DMN) injection. A total of 32 Sprague–Dawley rats were divided into four groups such as normal liver, cirrhotic liver, cirrhotic liver with AAE treatment, and cirrhotic liver with lactulose treatment. Effects of AAE were compared with those of lactulose. Cirrhotic liver with both AAE and lactulose treatments showed increased body weight, decreased levels of aspartate aminotransferase and alanine aminotransferase, and increased albumin level compared with cirrhotic liver (p < 0.05). The expression levels of α-smooth muscle actin (α-SMA) and cyclooxygenase-2 (COX-2) in immunohistochemical analysis showed reduced fibrosis and inflammatory response in both AAE and lactulose treatments compared with cirrhotic liver (p < 0.05). The levels of AAE treatment were relatively lower than those of lactulose. The western blot analysis of α-SMA and COX-2 protein in both AAE and lactulose treatments was similar to that of normal liver. When comparing electrical conductivity to normal liver, difference in conductivity was 21.2%, 11.5%, and 7.7% in cirrhotic liver, lactulose treatment, and AAE treatment, respectively. These results suggest that the anti-inflammatory effect of AAE may delay or prevent the progress from liver fibrosis to cirrhosis. In summary, a more precise analysis of tissue conditions following the induction of liver cirrhosis was possible by combining electrical tissue conductivity with conventional biochemical analysis.

Localized aortic dissection at the sinus of Valsalva is a rare finding in patients with Stanford type A dissections. This condition can be fatal and difficult to diagnose. In this study, we report a case of a 69-year-old man with aortic dissection at the sinus of Valsalva, which was accurately diagnosed with multiplanar reformatted images of coronary computed tomography angiography, and later confirmed at surgery.

Electrical stimulation such as transcranial direct current stimulation (tDCS) is widely used to treat neuropsychiatric diseases and neurological disorders. Computational modeling is an important approach to understand the mechanisms underlying tDCS and optimize treatment planning. When applying computational modeling to treatment planning, uncertainties exist due to insufficient conductivity information inside the brain. In this feasibility study, we performed in vivo MR-based conductivity tensor imaging (CTI) experiments on the entire brain to precisely estimate the tissue response to the electrical stimulation. A recent CTI method was applied to obtain low-frequency conductivity tensor images. Subject-specific three-dimensional finite element models (FEMs) of the head were implemented by segmenting anatomical MR images and integrating a conductivity tensor distribution. The electric field and current density of brain tissues following electrical stimulation were calculated using a conductivity tensor-based model and compared to results using an isotropic conductivity model from literature values. The current density by the conductivity tensor was different from the isotropic conductivity model, with an average relative difference |rD| of 52 to 73%, respectively, across two normal volunteers. When applied to two tDCS electrode montages of C3-FP2 and F4-F3, the current density showed a focused distribution with high signal intensity which is consistent with the current flowing from the anode to the cathode electrodes through the white matter. The gray matter tended to carry larger amounts of current densities regardless of directional information. We suggest this CTI-based subject-specific model can provide detailed information on tissue responses for personalized tDCS treatment planning. [ABSTRACT FROM AUTHOR]

Non-invasive quantification of radiation-induced damage is an important factor in radiation therapy to maximize radiation dose to cancer cells while minimizing damage to surrounding healthy surrounding tissue. The development of imaging biomarkers to accurately assess post-radiation therapy effects at an early stage is essential for better prognosis and to individualize the examination of brain tumors. MR-based electrical conductivity imaging provides novel contrast information based on the concentration and mobility of ions constituting tissue. It can exhibit high sensitivity in quantifying the therapeutic effect of ionizing radiation in cancer treatment. In this preclinical study, we analyzed the change in conductivity at different doses and quantified the response of the rat brain tissue to irradiation. The variation in conductivity with the elapsed time shows potential as a tool to monitor the therapeutic effect of radiation. The potential of MR-based conductivity imaging in future clinical studies might be beneficial. [ABSTRACT FROM AUTHOR]

Reversible splenial lesion syndrome can be caused by viral infection. Rubella generally occurs in childhood, and it is rarely accompanied by neurological complications in adulthood. A 35-year-old man visited our hospital due to conjunctival injection, mild fever, and headache 3 days after experiencing skin rash. Brain magnetic resonance imaging (MRI) revealed distinct lesions involving white matter in the splenium of the corpus callosum approximately 3 days following the onset of symptoms. Enzyme immunoassay performed on serum and CSF samples was positive for rubella virus IgM. A follow-up brain MRI was performed 24 days after the onset of symptoms, and reduced lesion size with decreased signals were observed on diffusion weighted image. This case showed that rubella infection can result in reversible splenial lesion accompanied by only mild neurological symptoms. [ABSTRACT FROM AUTHOR]