Administration Of Contrast Agent Research Articles

Asymptomatic Apical Hypertrophic Cardiomyopathy: Case Report and Review of Literature

Apical hypertrophic cardiomyopathy (AHCM) is a known entity since its first introduction by Sakamoto and Yamaguchi. However, unlike classical hypertrophic cardiomyopathy (HCM), it is less explored in terms of its associated diagnosis and long-term outcomes. Given the increased availability and utilization of ultra-sophisticated cardiac imaging modalities, AHCM will be increasingly recognized as a distinct, clinically significant variant of classical HCM. It is associated with a wide spectrum of presentation ranging from asymptomatic course with incidental findings on imaging to rarely being associated with ventricular arrhythmias, syncope and sudden cardiac death (SCD). Contrast echocardiography is the most effective and diagnostic study when performed in the right setting with high suspicion on clinical and typical electrocardiogram (ECG) findings. Cardiac magnetic resonance imaging (CMR) has an equal diagnostic yield as a contrast echocardiogram. We are presenting a unique case report of a 57-year old gentleman with asymptomatic AHCM which was distinctly delineated after utilizing contrast tuned imaging (CnTI) echocardiography sans administration of intravenous contrast agents. This is a first case report of AHCM portrayed by this ingenious technology.
 Keywords: Apical Hypertrophic Cardiomyopathy, LV Contrast Echocardiography, Contrast Tuned Imaging, 4Dimensional XStrain Echocardiography.

CT-guided Retrograde Urography as a Diagnostic Tool for Post-kidney Transplantation Evaluation: A Case Report

The vast majority of urological complications occur at the ureterovesical junction and usually occur early after transplantation. The aim of this study is to enhance the quality of medical care provided to patients who undergo kidney transplantation. Cystography was conducted on renal transplant recipients utilizing computed tomography. The utilization of changes in the patient’s position and reconstructed images of the bladder can serve as a diagnostic tool to assess the normal functioning of the urinary tract system subsequent to kidney transplantation. To ensure adequate filling of the bladder and ureter, it is necessary to introduce varying amounts of contrast medium through the urinary catheter into these structures. This diagnostic procedure aims to verify the existence of stenosis or leakage occurring at the vesicoureteral junction. The evaluation and diagnosis of urinary tract problems subsequent to kidney transplantation can be effectively conducted. Furthermore, it has the potential to mitigate the adverse effects and alleviate the strain on the renal system resulting from the administration of contrast agents in computed tomography urography. CT-guided cystography can enhance the medical quality and comfort of Kidney transplantation patients.

Contrast Agent Administration as a Source of Liability: A Legal Database Analysis.

Background Radiology ranks high in terms of specialties implicated in medical malpractice claims. While most radiologists understand the risks of liability for missed findings or lapses of communication, liability for the use of contrast agents in imaging procedures may be underappreciated. Purpose To review the clinical context and outcomes of lawsuits alleging medical malpractice for contrast-related imaging procedures. Materials and Methods Two large U.S. legal databases were queried using the terms "Contrast" and "Radiology OR Radiologist" from database inception to October 31, 2022, to identify cases with published decisions or settlements related to medical malpractice in patients who underwent contrast-related imaging procedures. The search results were screened to include only those cases involving the practice area of health care law where there was at least one claim of medical negligence against a health care institution or provider. Data on the medical complications alleged by patients after contrast agent administration and on the trial were extracted and reported using descriptive statistics. Results A total of 151 published case summaries were included in the analysis. Anaphylactic reaction following contrast agent administration was the most common medical complication observed (30% [45 of 151 cases]), of which failure to diagnose developing anaphylaxis or failure to treat the anaphylactic reaction made up the majority of allegations (93% [42 of 45]). Inappropriate management of contrast media extravasation (27% [41 of 151]) and alleged contrast agent-induced acute kidney injury (13% [19 of 151]) were the next most frequent causes of lawsuits. Of the 11 cases of alleged kidney injury that went to trial, all resulted in a judgment in favor of the defense. Conclusion This study highlights the key reasons for medical malpractice lawsuits associated with use of contrast media and outcomes from these lawsuits. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Trop in this issue.

Modified bare-back micro-retrograde tibial arterial access to facilitate peripheral endovascular therapy.

Patients with critical limb threatening ischemia often present with complex segmental peripheral arterial chronic total occlusions, which might not be amenable to traditional antegrade revascularization techniques. For these patients, alternative retrograde revascularization techniques could be necessary. In the present report, we describe a novel modified retrograde cannulation technique using a bare back technique that eliminates the need for conventional tibial access sheath placement and, instead, facilitates distal arterial blood sampling, blood pressure monitoring, retrograde administration of contrast agents and vasoactive substances, and a rapid-exchange strategy. This cannulation strategy can serve as part of the armamentarium in the treatment of patients with complex peripheral arterial occlusions.

Effect of Contrast Agent on Renal Functions in Patients with Renal Impairment Undergoing Percutaneous Coronary Intervention

Abstract Background Contrast induced nephropathy is one of the most important clinical complications associated with IV administration of radio-contrast media. This prospective study evaluating incidence and predictors of contrast induced nephropathy after administration of contrast agent in patients with renal impairment undergoing percutaneous coronary intervention. Objective To predict the effect of contrast agents on renal functions in patients with renal impairment undergoing percutaneous coronary intervention. Patients and Methods A prospective study that included 120 patients who underwent percutanous coronary intervention with glomerular filtration rate below 90 ml/min. All patients were subjected to full history, examination and investigation. Results were recorded using serum creatinine and glomerluar filtration rate before and 72 hours after procedure. Results CIN had occurred in 26.67% of studied group where these was high incidence of occurrence of CIN with elderly (p = 0.009), obese patients (p = 0.039), hypertensive (p = 0.004), Diabetics (p = 0.000) and amount of dye received (p = 0.000). 50% of patients who developed CIN where males and 50% where females which was non significant with p = 0.165. Conclusion CIN in patients with preexisting renal damage or risk factors for the development of kidney dysfunction is a potentially serious complication after PCI with increased short and longterm morbidity and mortality. Appropriate management of patients at risk is crucial for the prevention of CIN. Although a specific treatment for CIN is not available removal of modifiable risk factors and implementation of periprocedural measures such as CM reduction and intravenous hydration can significantly lower the risk of CIN in selected patients.

Penatalaksanaan Pemeriksaan MRI Cervical Pada Kasus Syringomyelia Pada Medulla Spinalis Di Rumah Sakit Primaya Tangerang

Management of Cervical MRI Examination in Cases of Syringomyelia in the Spinal Medulla at Primaya Hospital Tangerang. Magnetic Resonance Imaging (MRI) is a state-of-the-art diagnostic tool for examining and detecting the body using a large magnetic field and radio frequency waves, without the use of X-rays or radioactive materials, which produces cross-sectional images of the human body/organs using a magnetic field. strength between 0.064 – 1.5 tesla (1 tesla = 1000 Gauss) and vibrational resonance of the hydrogen atom nucleus. MRI can produce images of the vertebral column, spinal cord, and also the CSF. The MRI screening procedure is ideal for the differential diagnosis of structural disorders that can affect the spinal roots and spinal cord. This examination is used in carrying out a vertebral examination at once, namely scanning starting directly from the cervical vertebrae and also up to the sacrum. So this examination can directly diagnose the cervical, thoracic, lumbar, sacral vertebrae and also includes the coccyx. The purpose of this study was to determine the management of cervical MRI examination with clinical syringomyelia. This research is descriptive qualitative with a case study approach. The subject is a patient with clinical syringomyelia. All subjects underwent Cervical MRI examination at 1.5 tesla to find out the sequence and procedure and sequence information used. From the research results obtained according to the theory using T1-weighted imaging with administration of contrast agent. While in the field using the cervical MRI protocol without contrast, it is sufficient to establish a diagnosis using an examination procedure with a localizer sequence design, sagittal T1, Axial T1 FSE, Axial T2, Axial 2D marge, sagittal T2 fat sat, Axial T2 thoracic 2-3, myelo 2D. The T2 fat sat sagittal sequence section makes it possible to see the anatomy, namely syringomyelia.

Radiomics analysis from magnetic resonance imaging in predicting the grade of nonfunctioning pancreatic neuroendocrine tumors: a multicenter study

ObjectivesTo explore the potential of radiomics features to predict the histologic grade of nonfunctioning pancreatic neuroendocrine tumor (NF-PNET) patients using non-contrast sequence based on MRI.MethodsTwo hundred twenty-eight patients with NF-PNETs undergoing MRI at 5 centers were retrospectively analyzed. Data from center 1 (n = 115) constituted the training cohort, and data from centers 2–5 (n = 113) constituted the testing cohort. Radiomics features were extracted from T2-weighted images and the apparent diffusion coefficient. The least absolute shrinkage and selection operator was applied to select the most important features and to develop radiomics signatures. The area under receiver operating characteristic curve (AUC) was performed to assess models.ResultsTumor boundary, enhancement homogeneity, and vascular invasion were used to construct the radiological model to stratify NF-PNET patients into grade 1 and 2/3 groups, which yielded AUC of 0.884 and 0.684 in the training and testing groups. A radiomics model including 4 features was constructed, with an AUC of 0.941 and 0.871 in the training and testing cohorts. The fusion model combining the radiomics signature and radiological characteristics showed good performance in the training set (AUC = 0.956) and in the testing set (AUC = 0.864), respectively.ConclusionThe developed model that integrates radiomics features with radiological characteristics could be used as a non-invasive, dependable, and accurate tool for the preoperative prediction of grade in NF-PNETs.Clinical relevance statementOur study revealed that the fusion model based on a non-contrast MR sequence can be used to predict the histologic grade before operation. The radiomics model may be a new and effective biological marker in NF-PNETs.Key PointsThe diagnostic performance of the radiomics model and fusion model was better than that of the model based on clinical information and radiological features in predicting grade 1 and 2/3 of nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs).Good performance of the model in the four external testing cohorts indicated that the radiomics model and fusion model for predicting the grades of NF-PNETs were robust and reliable, indicating the two models could be used in the clinical setting and facilitate the surgeons’ decision on risk stratification.The radiomics features were selected from non-contrast T2-weighted images (T2WI) and diffusion-weighted imaging (DWI) sequence, which means that the administration of contrast agent was not needed in grading the NF-PNETs.

NEIM-15 AN EXCEPTION TO THE METASTATIC RULE: A NON-ENHANCING MIDBRAIN LESION DUE TO METASTATIC FIBROMYXOID SARCOMA WITH EXTENSIVEINFLAMMATORY INFILTRATE

Abstract Metastases from extra-CNS sites typically enhance on MR after the administration of gadolinium-based contrast agents due to disruption of the blood-brain barrier. Fibromyxoid sarcoma involving the brain is extremely rare, with only a few reported cases manifesting as well-circumscribed enhancing masses. Here, we report an extremely rare non-enhancing brain metastasis secondary to an already rare sarcoma. A 44-year-old woman with gluteal fibromyxoid sarcoma metastatic to cervical paraspinal muscles and adrenal gland treated with ipilimumab/nivolumab presented with diplopia and was found to have an 8 mm T2-hyperintense midbrain lesion without enhancement or mass effect. An inflammatory etiology associated with checkpoint inhibitor therapy was suspected, and she was treated with IV methylprednisolone 1 g daily for 3 days followed by an oral prednisone taper, IV immunoglobulin, and plasma exchange without improvement. The midbrain lesion steadily grew over 15 months of follow up, eventually involving the bilateral medial thalami and demonstrating diffusion restriction in the midbrain, but never showing gadolinium enhancement. The imaging was reminiscent of peripheral brainstem non-enhancing band-like lesions reported in leptomeningeal lung cancer, however CSF cytology was repeatedly normal, as was extensive infectious and inflammatory testing. Her neurologic disability continued to progress, with development of bilateral oculomotor nerve palsies, dysarthria, and depressed level of alertness, devolving into non-convulsive status epilepticus requiring intubation. She died six months after onset of neurologic symptoms. At autopsy, histologic and immunohistochemical evaluation revealed fibromyxoid sarcoma (MUC-4 positive, TAOK1-FUS fusion) centered on the periventricular aqueduct with accompanying disseminated single-cell infiltration throughout the midbrain. The background midbrain and periventricular parenchyma were notable for voluminous microglial activation and histiocytic infiltrate. In sum, this case represents a radiographically unique sarcoma brain metastasis which on pathologic exam showed robust inflammatory changes far out of proportion to the tumor present.

Glymphatic transport is reduced in rats with spontaneous pituitary tumor.

Pituitary tumor in patients induces adverse alterations in the brain, accompanied by cognitive deficits. Dysfunction of glymphatic waste clearance results in accumulation of neurotoxic products within the brain, leading to cognitive impairment. However, the status of glymphatic function in the brain with pituitary tumor is unknown. Using magnetic resonance imaging (MRI) and an advanced mathematical modeling, we investigated the changes of glymphatic transport in the rats carrying spontaneous pituitary tumor. Rats (22-24 months, female, Wistar) with and without pituitary tumor (n = 7/per group) underwent the identical experimental protocol. MRI measurements, including T2-weighted imaging and dynamic 3D T1-weighted imaging with intracisternal administration of contrast agent, were performed on each animal. The contrast-induced enhancement in the circle of Willis and in the glymphatic influx nodes were observed on the dynamic images and verified with time-signal-curves (TSCs). Model-derived parameters of infusion rate and clearance rate that characterize the kinetics of glymphatic tracer transport were evaluated in multiple representative brain regions. Our imaging data demonstrated a higher incidence of partially enhanced circle of Willis (86 vs. 14%; p < 0.033) and a lower incidence of enhancement in glymphatic influx nodes of pituitary (71 vs. 100%) and pineal (57 vs. 86%) recesses in the rats with pituitary tumor than in the rats with normal appearance of pituitary gland, indicating an intensification of impaired peri-vascular pathway and impeded glymphatic transport due to the presence of pituitary tumor. Consistently, our kinetic modeling and regional cerebral tissue quantification revealed significantly lower infusion and clearance rates in all examined regions in rats with spontaneous pituitary tumor than in non-tumor rats, representing a suppressed glymphatic transport in the brain with pituitary tumor. Our study demonstrates the compromised glymphatic transport in the rat brain with spontaneous pituitary tumor. The reduced efficiency in cerebral waste clearance increases the risk for neurodegeneration in the brain that may underlie the cognitive impairment commonly seen in patients with pituitary tumors.

Arterial Spin Labeling (ASL) in Neuroradiological Diagnostics - Methodological Overview and Use Cases.

Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI)-based technique using labeled blood-water of the brain-feeding arteries as an endogenous tracer to derive information about brain perfusion. It enables the assessment of cerebral blood flow (CBF). This review aims to provide a methodological and technical overview of ASL techniques, and to give examples of clinical use cases for various diseases affecting the central nervous system (CNS). There is a special focus on recent developments including super-selective ASL (ssASL) and time-resolved ASL-based magnetic resonance angiography (MRA) and on diseases commonly not leading to characteristic alterations on conventional structural MRI (e. g., concussion or migraine). ASL-derived CBF may represent a clinically relevant parameter in various pathologies such as cerebrovascular diseases, neoplasms, or neurodegenerative diseases. Furthermore, ASL has also been used to investigate CBF in mild traumatic brain injury or migraine, potentially leading to the establishment of imaging-based biomarkers. Recent advances made possible the acquisition of ssASL by selective labeling of single brain-feeding arteries, enabling spatial perfusion territory mapping dependent on blood flow of a specific preselected artery. Furthermore, ASL-based MRA has been introduced, providing time-resolved delineation of single intracranial vessels. Perfusion imaging by ASL has shown promise in various diseases of the CNS. Given that ASL does not require intravenous administration of a gadolinium-based contrast agent, it may be of particular interest for investigations in pediatric cohorts, patients with impaired kidney function, patients with relevant allergies, or patients that undergo serial MRI for clinical indications such as disease monitoring. · ASL is an MRI technique that uses labeled blood-water as an endogenous tracer for brain perfusion imaging.. · It allows the assessment of CBF without the need for administration of a gadolinium-based contrast agent.. · CBF quantification by ASL has been used in several pathologies including brain tumors or neurodegenerative diseases.. · Vessel-selective ASL methods can provide brain perfusion territory mapping in cerebrovascular diseases.. · ASL may be of particular interest in patient cohorts with caveats concerning gadolinium administration..

Noninvasive investigations of human glymphatic dynamics in a diseased model.

To explore human glymphatic dynamics in a diseased model via a noninvasive technique. Patients with reversible vasoconstriction syndrome (RCVS) presenting with blood-brain barrier disruption, i.e., para-arterial gadolinium leakage on 3-T 3-dimensional isotropic contrast-enhanced T2-fluid-attenuated inversion recovery (CE-T2-FLAIR) magnetic resonance imaging (MRI), were prospectively enrolled. Consecutive 9-min-CE-T2-FLAIR for 5-6 times (early panel) after intravenous gadolinium-based contrast agent (GBCA) administration and one time-varying deferred scan of noncontrast T2-FLAIR (delayed panel) were performed. In Bundle 1, we measured the calibrated signal intensities (cSIs) of 10 different anatomical locations. In Bundle 2, brain-wide measurements of para-arterial glymphatic volumes, means, and medians of the signal intensities were conducted. We defined mean (mCoIs) or median (mnCoIs) concentration indices as products of volumes and signal intensities. Eleven subjects were analyzed. The cSIs demonstrated early increase (9min) in perineural spaces: (cranial nerve [CN] V, p = 0.008; CN VII + VII, p = 0.003), choroid plexus (p = 0.003), white matter (p = 0.004) and parasagittal dura (p = 0.004). The volumes, mCoIs, and mnCoIs demonstrated increasing rates of enhancement after 9 to 18min and decreasing rates after 45 to 54min. The GBCA was transported centrifugally and completely removed within 961-1086min after administration. The exogenous GBCA leaked into the para-arterial glymphatics could be completely cleared around 961 to 1086min after administration in a human model of BBB disruption. The tracer enhancement started variously in different intracranial regions but was eventually cleared centrifugally to brain convexity, probably towards glymphatic-meningeal lymphatics exits. Glymphatic clearance time intervals and the centrifugal directions assessed by a noninvasive approach may have implications for clinical glymphatic evaluation in the near future. • This study aimed to investigate the human glymphatic dynamics in a noninvasive diseased model. • The intracranial MR-detectable gadolinium-based contrast agents were removed centrifugally within 961 to 1086min. • The glymphatic dynamics was demonstrable by enhancing MRI in an in vivo diseased model noninvasively.

Dual-Mode 1-D Linear Ultrasound Array for Image-Guided Drug Delivery Enhancement Without Ultrasound Contrast Agents.

Pulsed high-intensity focused ultrasound (pHIFU) uses nonlinearly distorted millisecond-long ultrasound pulses of moderate intensity to induce inertial cavitation in tissue without administration of contrast agents. The resulting mechanical disruption permeabilizes the tissue and enhances the diffusion of systemically administered drugs. This is especially beneficial for tissues with poor perfusion such as pancreatic tumors. Here, we characterize the performance of a dual-mode ultrasound array designed for image-guided pHIFU therapies in producing inertial cavitation and ultrasound imaging. The 64-element linear array (1.071 MHz, an aperture of 14.8×51.2 mm, and a pitch of 0.8 mm) with an elevational focal length of 50 mm was driven by the Verasonics V-1 ultrasound system with extended burst option. The attainable focal pressures and electronic steering range in linear and nonlinear operating regimes (relevant to pHIFU treatments) were characterized through hydrophone measurements, acoustic holography, and numerical simulations. The steering range at ±10% from the nominal focal pressure was found to be ±6 mm axially and ±11 mm azimuthally. Focal waveforms with shock fronts of up to 45 MPa and peak negative pressures up to 9 MPa were achieved at focusing distances of 38-75 mm from the array. Cavitation behaviors induced by isolated 1-ms pHIFU pulses in optically transparent agarose gel phantoms were observed by high-speed photography across a range of excitation amplitudes and focal distances. For all focusing configurations, the appearance of sparse, stationary cavitation bubbles occurred at the same P- threshold of 2 MPa. As the output level increased, a qualitative change in cavitation behavior occurred, to pairs and sets of proliferating bubbles. The pressure P- at which this transition was observed corresponded to substantial nonlinear distortion and shock formation in the focal region and was thus dependent on the focal distance of the beam ranging within 3-4 MPa for azimuthal F -numbers of 0.74-1.5. The array was capable of B-mode imaging at 1.5 MHz of centimeter-sized targets in phantoms and in vivo pig tissues at depths of 3-7 cm, relevant to pHIFU applications in abdominal targets.

Assessment of hepatic function employing hepatocyte specific contrast agent concentrations to multifactorially evaluate fibrotic remodeling.

Diffuse parenchymal liver diseases are contributing substantially to global morbidity and represent major causes of deaths worldwide. The aim of our study is to assess whether established hepatic fat and iron quantitation and relaxometry-based quantification of hepatocyte-specific contrast material as surrogate for liver function estimation allows to evaluate liver fibrosis. Retrospective consecutive study. Seventy-two healthy patients (mean age: 53 years) without known liver disease, 21 patients with temporary elevated liver enzymes (mean: 65 years) and 109 patients with biopsy proven liver fibrosis or cirrhosis (mean: 61 years), who underwent liver magnetic resonance imaging (MRI) with a hepatocyte-specific contrast agent [gadoxetate disodium, gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA), 0.25 mmol/mL Primovist, Bayer AG, Leverkusen, Germany] at 1.5 T (n=133) and at 3 T (n=69), were included. Fibrosis was classified using the histopathological meta-analysis of histological data in viral hepatitis (METAVIR) and the clinical Child-Pugh scores. Gd-concentration were quantified using T1 map-based calculations. Gd-concentration mapping was performed by using a Look-Locker approach prior to and 912±159 s after intravenous administration of hepatocyte specific contrast agent. Additionally, parenchymal fat fraction, R2*, bilirubin, gender and age were defined as predicting factors. Diagnostic accuracy was calculated in a monoparametric (linear regression, predictor: Gd-concentration) and multiparametric model (predictors: age, bilirubin level, iron overload, liver fat fraction, Gd concentration in the left and right liver lobe). Mean Gd-concentration in the liver parenchyma was significantly higher for healthy patients ([Gd] =0.51 µmol/L) than for those with liver fibrosis or cirrhosis ([Gd] =0.31 µmol/L; P<0.0001) and with acute liver disease ([Gd] =0.28 µmol/L), though there were no significant differences for the latter two groups. There was a significant moderate negative correlation for the mean Gd-concentration and the METAVIR score (ρ=-0.44, P<0.0001) as well as for the Child-Pugh stage (ρ=-0.35, P<0.0001). There was a significant strong correlation between the bilirubin concentration and the Gd-concentration (ρ=-0.61, P<0.0001). The diagnostic accuracy for the discrimination of healthy patients and patients with known fibrosis or cirrhosis was 0.74 (0.71/0.60 sensitivity/specificity) in a monoparametric and 0.76 (0.85/0.61 sensitivity/specificity) in a machine learning based multiparametric model. T1 mapping-based quantification of hepatic Gd-EOB-DTPA concentrations performed in a multiparametric model shows promising diagnostic accuracy for the detection of fibrotic changes. Liver biopsy might be replaced by imaging examinations.

Comparison of MRI Sequences to Predict ATRX Status Using Radiomics-Based Machine Learning.

ATRX is an important molecular marker according to the 2021 WHO classification of adult-type diffuse glioma. We aim to predict the ATRX mutation status non-invasively using radiomics-based machine learning models on MRI and to determine which MRI sequence is best suited for this purpose. In this retrospective study, we used MRI images of patients with histologically confirmed glioma, including the sequences T1w without and with the administration of contrast agent, T2w, and the FLAIR. Radiomics features were extracted from the corresponding MRI images by hand-delineated regions of interest. Data partitioning into training data and independent test data was repeated 100 times to avoid random effects. Feature preselection and subsequent model development were performed using Lasso regression. The T2w sequence was found to be the most suitable and the FLAIR sequence the least suitable for predicting ATRX mutations using radiomics-based machine learning models. For the T2w sequence, our seven-feature model developed with Lasso regression achieved a mean AUC of 0.831, a mean accuracy of 0.746, a mean sensitivity of 0.772, and a mean specificity of 0.697. In conclusion, for the prediction of ATRX mutation using radiomics-based machine learning models, the T2w sequence is the most suitable among the commonly used MRI sequences.

MRI-Cavernosography: A New Diagnostic Tool for Erectile Dysfunction Due to Venous Leakage: A Diagnostic Chance.

Erectile dysfunction caused by venous leakage is a vascular disease in which blood fails to accumulate in the corpora cavernosa due to the abrupt drainage of blood from the penis secondary to an abnormal venous network that affects 1 to 2% of men under 25 years old and about 10 to 20% over 60 years old, who do not raise a sufficient erection for penetrative sex. The study of the venous leak and its characterization in young patients with erectile dysfunction represent a diagnostic challenge, and imaging remains the best way to diagnose this condition. In the article, it is described the methods of execution and the diagnostic role of the cavernous MRI in the study of vasogenic erectile dysfunction from the venous leak, proposing it as a good alternative to the cavernous CT, considering the satisfactory results in terms of diagnostic interpretation, the absence of ionizing radiation, the higher soft tissue resolution of the imaging method and the lower administration of contrast agent.

A deep-learning approach for myocardial fibrosis detection in early contrast-enhanced cardiac CT images.

Diagnosis of myocardial fibrosis is commonly performed with late gadolinium contrast-enhanced (CE) cardiac magnetic resonance (CMR), which might be contraindicated or unavailable. Coronary computed tomography (CCT) is emerging as an alternative to CMR. We sought to evaluate whether a deep learning (DL) model could allow identification of myocardial fibrosis from routine early CE-CCT images. Fifty consecutive patients with known left ventricular (LV) dysfunction (LVD) underwent both CE-CMR and (early and late) CE-CCT. According to the CE-CMR patterns, patients were classified as ischemic (n = 15, 30%) or non-ischemic (n = 35, 70%) LVD. Delayed enhancement regions were manually traced on late CE-CCT using CE-CMR as reference. On early CE-CCT images, the myocardial sectors were extracted according to AHA 16-segment model and labeled as with scar or not, based on the late CE-CCT manual tracing. A DL model was developed to classify each segment. A total of 44,187 LV segments were analyzed, resulting in accuracy of 71% and area under the ROC curve of 76% (95% CI: 72%-81%), while, with the bull's eye segmental comparison of CE-CMR and respective early CE-CCT findings, an 89% agreement was achieved. DL on early CE-CCT acquisition may allow detection of LV sectors affected with myocardial fibrosis, thus without additional contrast-agent administration or radiational dose. Such tool might reduce the user interaction and visual inspection with benefit in both efforts and time.

A deep learning approach to predict myocardial fibrosis in early contrast-enhanced CCT images

Abstract Funding Acknowledgements Type of funding sources: None. Background Late gadolinium enhancement (LGE) derived from cardiac magnetic resonance (CMR) has become a method of choice for the evaluation of myocardial tissue composition and detection of myocardial fibrosis. Advances in cardiac computed tomography (CCT) imaging have led to its growing role as possible alternative to CMR, because of its wider availability and suitability for patients with contraindication. Purpose To develop a myocardial fibrosis detection method from early contrast-enhanced CCT (CE-CCT) imaging using a deep learning (DL) approach. Methods Fifty consecutive patients (age: 62±10 y, male 84%) with known left ventricular dysfunction were enrolled. All patients underwent both LGE-CMR and early and delayed CE-CCT. According to the LGE-CMR patterns, patients were classified as ischemic (n=15, 30%) or non-ischemic (n=35, 70%). Scar regions were manually traced on delayed CE-CCT using LGE-CMR as reference. On early CE-CCT images, segments were extracted according to American Heart Association (AHA) 16-segment model and labeled (scar/no scar) based on the delayed CE-CCT manual tracing. A DL model was developed for automatic segmental classification. Results Based on 44187 segments analyzed, 71% of accuracy (ischemic: 66%; non-ischemic: 74%) for detecting scar on early CE-CCT images was achieved (Picture 1). In a per-segment analysis of the 16-segment AHA model, an accuracy of 91% (ischemic: 87%; non-ischemic: 93%) was obtained from early CE-CCT compared to the LGE-CMR. Conclusions DL on early CE-CCT acquisition may allow the detection of myocardial fibrosis without additional contrast-agent administration or radiation exposure, thus reducing the user interaction and visual inspection with benefit in both efforts and time.

CEST2022: Amide proton transfer-weighted MRI improves the diagnostic performance of multiparametric non-contrast-enhanced MRI techniques in patients with post-treatment high-grade gliomas

New or enlarged lesions in malignant gliomas after surgery and chemoradiation can be associated with tumor recurrence or treatment effect. Due to similar radiographic characteristics, conventional—and even some advanced MRI techniques—are limited in distinguishing these two pathologies. Amide proton transfer-weighted (APTw) MRI, a protein-based molecular imaging technique that does not require the administration of any exogenous contrast agent, was recently introduced into the clinical setting. In this study, we evaluated and compared the diagnostic performances of APTw MRI with several non-contrast-enhanced MRI sequences, such as diffusion-weighted imaging, susceptibility-weighted imaging, and pseudo-continuous arterial spin labeling. Thirty-nine scans from 28 glioma patients were obtained on a 3 T MRI scanner. A histogram analysis approach was employed to extract parameters from each tumor area. Statistically significant parameters (P < 0.05) were selected to train multivariate logistic regression models to evaluate the performance of MRI sequences. Multiple histogram parameters, particularly from APTw and pseudo-continuous arterial spin labeling images, demonstrated significant differences between treatment effect and recurrent tumor. The regression model trained on the combination of all significant histogram parameters achieved the best result (area under the curve = 0.89). We found that APTw images added value to other advanced MR images for the differentiation of treatment effect and tumor recurrence.

Photoacoustic imaging on its way toward clinical utility: a tutorial review focusing on practical application in medicine.

Photoacoustic imaging (PAI) enables the visualization of optical contrast with ultrasonic imaging. It is a field of intense research, with great promise for clinical application. Understanding the principles of PAI is important for engineering research and image interpretation. In this tutorial review, we lay out the imaging physics, instrumentation requirements, standardization, and some practical examples for (junior) researchers, who have an interest in developing PAI systems and applications for clinical translation or applying PAI in clinical research. We discuss PAI principles and implementation in a shared context, emphasizing technical solutions that are amenable to broad clinical deployment, considering factors such as robustness, mobility, and cost in addition to image quality and quantification. Photoacoustics, capitalizing on endogenous contrast or administered contrast agents that are approved for human use, yields highly informative images in clinical settings, which can support diagnosis and interventions in the future. PAI offers unique image contrast that has been demonstrated in a broad set of clinical scenarios. The transition of PAI from a "nice-to-have" to a "need-to-have" modality will require dedicated clinical studies that evaluate therapeutic decision-making based on PAI and consideration of the actual value for patients and clinicians, compared with the associated cost.

Diagnostic utility of contrast-enhanced FLAIR MRI in imaging of demyelinating and infectious brain lesions

BackgroundContrast-enhanced MRI is frequently used as a baseline modality and indispensable tool for early diagnosis and follow-up of different brain lesions. Herein, we aimed to evaluate the diagnostic impact of contrast-enhanced FLAIR compared to the widely used post-contrast T1W sequence in terms of demyelinating and infectious brain lesions detection in clinical practice and explore its value in monitoring disease activity for selecting appropriate therapy. MR Imaging was performed using 1.5 Tesla device. Both T1W and FLAIR sequences were obtained prior to and after administration of intravenous gadolinium-based contrast agent. Both qualitative and quantitative approaches were used for image analysis by two independent radiologists.ResultsSixty patients were prospectively enrolled in this study. Our participants were subdivided into two categories, either demyelinating (45 multiple sclerosis) or infectious lesions (13 meningitis/meningoencephalitis and 2 pyogenic abscess). By comparing the two post-contrast sequences, CE-FLAIR revealed greater enhancement in 38 cases (63.34%), equal enhancement in 17 cases (28.33%) and less enhancement in 5 cases (8.33%). For lesion conspicuity: good delineation observed in (61.67%), fair delineation in (25%) and no delineation in (13.33%). Lesion-to-background contrast ratio was statistically significant in CE-FLAIR with excellent inter-class correlation.ConclusionCE-FLAIR should be added in conjunction with or as a superior alternative to conventional CE-T1W sequence to optimize lesion detection and improve diagnostic reliability particularly in demyelinating and infectious lesions.