Pancreatic Adenocarcinoma: Imaging Modalities and the Role of Artificial Intelligence in Analyzing CT and MRI Images

Pancreatic ductal adenocarcinoma (PDAC) stands out as the predominant malignant neoplasm affecting the pancreas, characterized by a poor prognosis, in most cases patients being diagnosed in a nonresectable stage. Image-based artificial intelligence (AI) models implemented in tumor detection, segmentation, and classification could improve diagnosis with better treatment options and increased survival. This review included papers published in the last five years and describes the current trends in AI algorithms used in PDAC. We analyzed the applications of AI in the detection of PDAC, segmentation of the lesion, and classification algorithms used in differential diagnosis, prognosis, and histopathological and genomic prediction. The results show a lack of multi-institutional collaboration and stresses the need for bigger datasets in order for AI models to be implemented in a clinically relevant manner.

Liver Transplant in Patients with Hepatocarcinoma: Imaging Guidelines and Future Perspectives Using Artificial Intelligence

Hepatocellular carcinoma is the most common primary malignant hepatic tumor and occurs most often in the setting of chronic liver disease. Liver transplantation is a curative treatment option and is an ideal solution because it solves the chronic underlying liver disorder while removing the malignant lesion. However, due to organ shortages, this treatment can only be applied to carefully selected patients according to clinical guidelines. Artificial intelligence is an emerging technology with multiple applications in medicine with a predilection for domains that work with medical imaging, like radiology. With the help of these technologies, laborious tasks can be automated, and new lesion imaging criteria can be developed based on pixel-level analysis. Our objectives are to review the developing AI applications that could be implemented to better stratify liver transplant candidates. The papers analysed applied AI for liver segmentation, evaluation of steatosis, sarcopenia assessment, lesion detection, segmentation, and characterization. A liver transplant is an optimal treatment for patients with hepatocellular carcinoma in the setting of chronic liver disease. Furthermore, AI could provide solutions for improving the management of liver transplant candidates to improve survival.

Assessment of Minimal Hepatic Encephalopathy with Brain MRI and EncephalApp Stroop Test

Background: Minimal hepatic encephalopathy (MHE) consists of subtle cognitive deficits that are not apparent on a standard neurological examination. Minimal hepatic encephalopathy has been reported in up to 80% of cirrhotic patients and is associated with decreased job performance, poor driving performance, impaired quality of life, and poor survival. In parallel, brain magnetic resonance imaging (MRI) abnormalities are known to occur in liver cirrhotic patients in the form of T1 globus pallidus hyperintensities. In recent years, a new psychometric test for diagnosing MHE has been developed as an app for smartphones and tablets (EncephalApp Stroop test). A translated version of the app is available in Romanian language. Aim:To use EncephalApp Stroop test for MHE diagnosis in our cirrhotic patients; to describe the main brain MRI abnormalities encountered in these patients; and to establish if Stroop test results correlate with imaging findings, clinical neurologic findings, and liver function parameters or prognosis. Material and methods:Cross-sectional study over a one-year period, involving 30 adult patients with liver cirrhosis. Subjects were evaluated through a standard neurological examination, psychometric testing using EncephalApp Stroop test, electroencephalogram and brain MRI. In parallel, 40 adult healthy controls were also recruited and evaluated with the EncephalApp Stroop test using the same methodology. Results:Age distribution was similar between the two groups (p=0.6). The mean age of patients was 50±10 years and that of controls 51±12 years. Mean Stroop result was 171±26 seconds for the patient group and 143±20 seconds for the control group (p<0.0001). There was a direct correlation between Stroop test results and age in the control group (R=0.69, p<0.0001) but not also in the patient group (R=0.28, p=0.13). Statistically significant results were obtained by using the Fischer exact test for both cut-off values: 145 seconds in patients < 45-year-old (p<0.001) and 190 seconds in those ≥45 years-old (p=0.03). MRI T1-hyperintensities of the basal ganglia, blood ammonia levels and electroencephalographic changes were not associated with poorer results. Conclusion:Our pilot study, although small, confirmed that patients with liver cirrhosis may have subtle deficits in cognitive areas like attention, concentration or reaction time. This can be assessed easily with the EncephalApp Stroop test which is readily available for use on smartphones or tablets.

Acute confusional state in a patient with bilateral thalamic ischemic stroke

The acute confusional state is one of the most common reasons for neurologic consultation in the hospital setting and the plethora of causes can truly be daunting. The etiology can vary from structural, metabolic, toxic to systemic infections. Our purpose is to present a rare case of acute confusional state in a patient with bilateral thalamic ischemic stroke due to occlusion of the artery of Percheron (AOP). A 79-year-old woman with a history of hypertension and surgery for lumbar disc herniation, managed on antiplatelet therapy, angiotensin receptor blocker and diuretics, was admitted for acute confusion and paresthesia of all four limbs. She had disorientation in time and space, abnormal behavior, decreased muscle strength in both lower limbs (paraparesis 2/5 MRC since the surgery), paresthesia in all four limbs and was unable to walk due to generalized weakness. Laboratory analysis showed high blood levels of cholesterol and glucose. Both head CT and cerebral MRI showed bilateral ischemic changes in the thalami, suggesting an infarct along the artery of Percheron territory. However, no clear cause for the stroke could be identified. Screening for coagulation abnormalities and autoimmune disorders (lupus anticoagulant, anti-beta-2 glycoprotein, anti-cardiolipin, anti-nuclear and anti-ds DNA antibodies) came back negative. There were no pathological finds on the echocardiogram and electrocardiogram, while cervical Doppler ultrasound showed atherosclerosis without stenosis.

Tuberous sclerosis with negative genetic testing and multiple cerebral cavernomas: A new association (Case report)

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder with multisystemic involvement usually resulting from mutations in the tuberous sclerosis 1 (TSC1) or TSC2 genes. However, 10 to 25% of patients do not exhibit these mutations. Cerebral cavernous malformations (CCMs) are capillary-venous malformations that can be asymptomatic or cause variable neurological manifestations, including seizures. Familial CCMs are recognized. In both conditions, specific dermatological lesions are associated. We present the case of a 31-year-old female with TSC diagnosed at the age of 18 years who presented with negative genetic testing. She was admitted to our department in 2019 for a sudden increased frequency of focal seizures. Patient examination revealed multiple facial and intraoral angiofibroma, diplopia, right hemihypoesthesia, brisk deep tendon reflexes, and distal leg paresthesia. VideoEEG indicated a frontal paramedian epileptogenic focus. Cerebral magnetic resonance imaging (MRI) and angioMRI identified multiple fronto-parietal cortical tubers, as well as multiple CCMs, with evidence of bleeding in one. Under antiepileptic drug (AED) and mTOR inhibitor treatment, the seizure frequency significantly improved in a short period of time. This is the first reported case of tuberous sclerosis with negative genetic testing associated with multiple cerebral cavernoma. Such complex patients require multidisciplinary management and detailed genetic testing for increasing knowledge on neuro-cutaneous disorders.

First Report of a pCys194Arg Notch 3 Mutation in a Romanian CADASIL Patient with Transient Ischemic Attacks and Patent Foramen Ovale - Case Report and Brief Review

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease caused by mutations in NOTCH3 gene, characterized by accumulation of a toxic protein in the small and medium size arterioles. Clinical manifestations of CADASIL include lacunar infarcts or, less frequently, large artery ischemic strokes, transient ischemic attacks, dementia, migraine and psychiatric disorders. Brain magnetic resonance imaging (MRI) usually shows multiple lacunar infarcts, diffuse leukoencephalopathy and cerebral microbleeds. The authors report the case of a 39-year-old Romanian woman who presented two transient ischemic attacks manifested with aphasia, headache and mild cognitive impairment. Brain MRI showed multiple isolated and confluent bilateral supratentorial hyperintense fluid-attenuated inversion recovery (FLAIR) and apparent diffusion coefficient (ADC) areas involving the subcortical and deep white matter, but also lenticular and caudate regions and normal aspects of the brain arteries on magnetic resonance angiography (MR-angiography). Differential diagnosis with other disorders affecting small cerebral vessels was performed. Transesophageal echocardiography showed presence of patent foramen ovale (PFO), with right-to-left shunt and contrast passage at Valsalva maneuver. Genetic testing revealed a pCys194Arg heterozygous mutation with C580T>C nucleotide's change on exon 4 of NOTCH 3 gene. The authors discuss the association of CADASIL to PFO and mild cognitive impairment as well as ongoing research for a therapeutic strategy.

The Pivotal Role of the Glutamate - glutamine Cycle in Minimal Hepatic Encephalopathy. An experimental magnetic resonance spectroscopy study

The glutamate-glutamine cycle is essential for sustaining the neuronal secretion of the excitatory neurotransmitter glutamate. Hepatic encephalopathy, even in its most discreet form, minimal hepatic encephalopathy (MHE), interferes with the glutamate and glutamine balance due to the increase in ammonia levels in the central nervous system (CNS), induced by a combination of liver dysfunction, increased blood-brain barrier permeability and many other factors. An experimental study on 21 patients with chronic liver disease and 11 healthy volunteers was performed. Magnetic resonance spectroscopy demonstrated an increase of the glutamate-glutamine complex peak, with high predictive value for MHE, especially when the metabolites are referenced to creatine, a stabile metabolite in the CNS. This paper also explores the pathophysiology of MHE with emphasis on the involvement of the glutamate-glutamine cycle in the development of this complication.

Lymphocytes B population profile in a case of multiple sclerosis presenting with sudden sensorineural hearing loss caused by a demyelinating pontine lesion

Sudden sensorineural hearing loss (SSHL) is a rare manifestation of multiple sclerosis, typically appearing in the early stages of the disease, especially in female subjects. SSHL is produced by the involvement of auditory tract, vestibulocochlear nerve and possibly cochlear structures and rarely due to a single lesion. The authors report the case of a young woman in which the onset of multiple sclerosis presented with SSHL caused by a pontine lesion. Oligoclonal bands in the cerebrospinal fluid (CSF) were absent at the disease onset and appeared during disease progression. Immunophenotyping of cells showed low cellularity of CD19+ cells in the CSF and expression of CD38+ on the majority of CD19+, CD20+ B cells in the peripheral blood, suggesting that many of them were mature B lymphocytes.

Neurological complications of hematopoietic cell transplantation in children and adults

Hematopoietic cell transplantation (HCT) is widely performed for neoplastic and non-neoplastic diseases. HCT involves intravenous infusion of hematopoietic progenitor cells from human leukocyte antigen (HLA)-matched donor (allogeneic) or from the patient (autologous). Before HCT, the patient is prepared with high dose chemotherapy and/or radiotherapy to destroy residual malignant cells and to reduce immunologic resistance. After HCT, chemotherapy is used to prevent graft rejection and graft versus host disease (GvHD). Neurological complications are related to the type of HCT, underlying disease, toxicity of the conditioning regimens, immunosuppression caused by conditioning regimens, vascular complications generated by thrombocytopenia and/or coagulopathy, GvHD and inappropriate immune response. In this review, neurological complications are presented according to time of onset after HCT: (1) early complications (in the first month) - related to harvesting of stem cells, during conditioning (drug toxicity, posterior reversible encephalopathy syndrome), related to pancytopenia, (2) intermediate phase complications (second to sixth month) - central nervous system infections caused by prolonged neutropenia and progressive multifocal leukoencephalopathy due to JC virus, (3) late phase complications (after sixth month) - neurological complications of GvHD, second neoplasms and relapses of the original disease.

ESTABLISHING THE CORRECT MANAGEMENT IN A PATIENT WITH MULTIPLE CRYPTOGENIC STROKES: ANTIPLATELET VS ANTICOAGULANT THERAPY

Cryptogenic strokes represent a category of ischemic strokes in which there is no well-defined cause identified. For that matter, choosing between antiplatelet and anticoagulant therapy can be challenging. We present the case of a 44 year old Caucasian male with a history of multiple ischemic strokes, with thrombophilia, but no atrial fi brillation or known cardio-embolic sources, who initially received anticoagulant treatment, which was switched in 2015 with Clopidogrel. Aspirin was added in 2017 after having a TIA in the left MCA territory. Despite dual antiplatelet therapy, the patient developed ischemic stroke in the left MCA territory, for which re-initiation of anticoagulant treatment was decided. Holter ECG, transthoracic and transesophageal echocardiography were performed, but failed to identify a cause.

Fibrolamellar hepatocellular carcinoma with ovarian metastasis - an unusual presentation

AIM

Fibrolamellar carcinoma (FLC) has been considered a distinct clinical entity vs. hepatocellular carcinoma, with respect to its epidemiology, etiology, and prognosis.

CASE PRESENTATION

We describe the unusual case of a 23-year-old female patient with FLC and ovarian (Krukenberg) and peritoneal metastases, clinically mimicking an ovarian carcinoma. Multiple recurrences occurred despite initial R0 resection and chemotherapy, requiring surgical treatment. The patient survived five years and died from generalized disease.

DISCUSSION

The particularities of our case are discussed by comparison with the other two similar cases and other date from the literature.

CONCLUSIONS

To our knowledge, the ovarian involvement encountered in our case is the third case published in literature, being explained by the superficial location of the liver tumor.

Current Stance of Magnetic Resonance Imaging in the Diagnosis and Monitoring of Hepatic Encephalopathy

OBJECTIVES

Hepatic encephalopathy is a complex of neuropsychiatric manifestations in patients with acute or chronic liver insufficiency and/or porto-systemic shunts.

MATERIAL AND METHODS

The diagnostic can be sustained by various elements, clinical and paraclinical. Selected patients with hepatic encephalopathy have been investigated by Magnetic Resonance, in parallel with specific biochemical analysis.

OUTCOMES

This paper emphasizes the importance of Magnetic Resonance Imaging in an accurate diagnosis and patient monitoring after treatment.

CONCLUSIONS

Magnetic Resonance Spectroscopy has a substantial role, showing even minute metabolite ratio changes, with a potential in investigating minimal hepatic encephalopathy.

Minimal hepatic encephalopathy diagnosis by magnetic resonance spectroscopy. A case report

Minimal Hepatic Encephalopathy (MHE) is a potentially reversible spectrum of neuro-psychiatric alterations in patients with acute or chronic liver disease, in the presence of a normal neurological examination. Studies demonstrated that early diagnosis and treatment of this complication increases the quality of life of the patients and leads to an overall better liver disease management. Currently, a practical method of diagnosing MHE is through psychological tests, with modest accuracy. A highly sensible and specific non-invasive method of diagnosis is Magnetic Resonance Spectroscopy (MRS) which identifies the key neuro-biochemical profile of hepatic encephalopathy. In selected cases of equivocal psychological test results, MRS is justified and adequate according to the authors' opinion.

Persistent repeated measurements by magnetic resonance spectroscopy demonstrate minimal hepatic encephalopathy: a case report

Minimal Hepatic Encephalopathy (MHE), previously referred to as infraclinical or subclinical is a precursor in the development of clinical hepatic encephalopathy (HE). The demonstration of MHE is done through neuropsychological testing in the absence of clinical evidence of HE, patients showing only a mild cognitive impairment. Neuropsychological tests employed consist of Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and portosystemic encephalopathy (PSE) test score. Unfortunately, there are numerous occasions when the tests prove irrelevant: in the situation of inexperienced investigators, the patient's poor education, vision problems or concurring central nervous system disease, all of which may delay or deviate from the correct diagnosis.

Magnetic resonance spectroscopy--a non-invasive method in evaluating focal and diffuse central nervous system disease

Magnetic Resonance Spectroscopy is a non-invasive method, which can be performed following a routine Magnetic Resonance investigation within the same examination, and can provide very useful molecular information related to the metabolism and function of the normal and pathological structures of the brain. Its role is increasing in the establishment of a clear diagnosis, in both focal and diffuse central nervous system diseases, and the tendency is to replace the histopathology test, in certain cases, with similar or sometimes better diagnostic accuracy. This paper summarizes the principle, method, and main clinical applications, standing as a guide to procedure performing and results interpretation.

Updates in CT characterization of thymic epithelial tumors in patients with myasthenia gravis

Thymic epithelial tumors have been traditionally classified into two main types: noninvasive and invasive thymoma. Several classifications have been proposed for thymic tumors, but according to these classifications, the prognosis of patients with thymomas varies considerably. Our purpose is to present different CT aspects according to various subtypes of thymic epithelial neoplasms based on the simplified World Health Organization classification. In this article, we will discuss and illustrate histologic and functional features of the thymus and a spectrum of thymic tumors associated with Myasthenia Gravis. Smooth contours and a round shape are the most suggestive of type A thymic epithelial tumors, whereas irregular contours and heterogeneous enhancement are the most suggestive of type C tumors. Calcifications are suggestive of type B tumors. CT findings may serve as predictors of postoperative recurrence or metastasis for the thymic epithelial tumors.

Updates in MRI characterization of the thymus in myasthenic patients

PURPOSE

To evaluate the imaging appearance of the thymus in the myasthenic patients by using chemical shift magnetic resonance imaging, and, to correlate the chemical shift ratio (CSR) with pathologic findings after surgical excision.

MATERIALS AND METHODS

In the past year, a total of 11 myasthenic patients (4 males, 7 females; age range of 26-65 years), have been investigated by MRI centered at the thymic lodge. Our protocol included a Dual-Echo technique, T1-weighted In-phase/Opposed-phase MR images in all patients. A chemical shift ratio (CSR) was calculated by comparing the signal intensity of the thymus gland with that of the chest wall muscle for quantitative analysis. For this purpose, we have used standard region-of-interest electronic cursors at a slice level of the maximum axial surface of the thymus. We have identified two patients groups: a thymic hyperplasia group and a thymic tumoral group.

RESULTS

With the decrease in the signal intensity of the thymus gland at chemical shift, the MR imaging was evident only in the hyperplasia group. The mean CSR in the hyperplasia group was considerably lower than that in the tumor group, 0,4964 ± 0,1841, compared with 1,0398 ± 0,0244. The difference in CSR between the hyperplasia and tumor groups was statistically significant (P=0,0028).

CONCLUSION

MR imaging using T1-weighted In-phase/Opposed-phase images could be a useful diagnostic tool in the preoperative assessment of the thymic lodge and may help differentiate thymic hyperplasia from tumors of the thymus gland.

The thymus in myasthenic patients: correlation between mediastinal CT imaging and histopathological findings

PURPOSE

To correlate computed tomographic (CT) appearance of the thymus with results from histologic examination of thymic tissue in myasthenic patients who underwent thymectomy.

MATERIALS AND METHODS

A retrospective study, based on case series report, between January 2000 and December 2010 on 247 patients with generalized myasthenia gravis or myasthenic syndrome explored by CT using a specific protocol, in the Radiology and Medical Imaging Department of Fundeni Clinical Institute. All subjects in the study were operated and had a histologic evaluation.

RESULTS

CT examinations of these 247 subjects showed remaining thymic mass, remnant of thymic tissue, fatty infiltration of the thymus and tumoral thymus or focal thymic mass. The results of histologic examination showed normal thymus, thymic lymphoid follicular hyperplasia, thymic atrophy, fatty infiltration and thymoma.

CONCLUSION

It was a 100% correlation between CT examinations and intra-operative findings regarding the presents of focal thymic masses in our study. In the diagnostic of focal thymic mass, the only inter-disciplinary correlation is between radiological and macroscopic aspects. CT examination has a limited value in differential diagnosis between thymic lymphoid follicular hyperplasia and thymoma.

Tissue specific MR contrast media role in the differential diagnosis of cirrhotic liver nodules

State-of-the-art magnetic resonance (MR) imaging using tissue specific contrast media facilitates detection and characterization in most cases of hepatic nodules. According to the currently used nomenclature, in liver cirrhosis there are only two major types of hepatocellular nodular lesions: regenerative lesions and dysplastic or neoplastic lesions. The purpose of this clinical imaging review is to provide information on the properties of tissue-specific MR contrast agents and on their usefulness in the demonstration of the pathologic changes that take place at the level of the hepatobiliary and reticuloendothelial systems during the carcinogenesis in liver cirrhosis.

Spiral computed tomography and magnetic resonance angiography evaluation in Budd-Chiari syndrome

Budd-Chiari syndrome is caused by the obstruction of the hepatic venous outflow at the level of the hepatic venules, large hepatic veins, and inferior vena cava up to the confluence with the right atrium. When it is untreated, the mortality rate for patients is high. Because the clinical presentation of this syndrome is nonspecific, imaging investigation--computed tomography and magnetic resonance--are important diagnostic steps. Contrast-enhanced multiphase spiral computed tomography (CT) and magnetic resonance (MR) angiography permits morphologic and functional assessment of parenchymatous liver changes in this particular entity. In this review, we present the spectrum of vascular and hepatic parenchymal abnormalities in Budd-Chiari syndrome observed on multiphase contrast enhanced spiral CT and MR angiography.