Complications of thoracic endovascular aneurysm repair (TEVAR): A pictorial review.

Thoracic endovascular aneurysm repair (TEVAR) has replaced open surgical repair as the treatment of choice for several aortic conditions. Despite its lower morbidity and mortality, several TEVAR-related complications can occur and some of which may necessitate surgical or endovascular re-intervention. The current article reviews common and rare complications of TEVAR procedure with emphasis on complications identifiable on cross-sectional imaging and potential pitfalls of pre-procedural planning.

A Concise Review of the Multimodality Imaging Features of Renal Cell Carcinoma.

The evaluation of renal cell carcinoma (RCC) is routinely performed using the multimodality imaging approach, including ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). Ultrasonography is the most frequently used imaging modality for the initial diagnosis of renal masses. The modality of choice for the characterization of the renal mass is multiphasic CT. Recent advances in CT technology have led to its widespread use as a powerful tool for preoperative planning, reducing the need for catheter angiography for the evaluation of vascular invasion. CT is also the standard imaging modality for staging and follow-up. MRI serves as a problem-solving tool in selected cases of undefined renal lesions. Newer MRI techniques, such as arterial spin labeling and diffusion-weighted imaging, have the potential to characterize renal lesions without contrast media, but these techniques warrant further investigation. PET may be a useful tool for evaluating patients with suspected metastatic disease, but it has modest sensitivity in the diagnosis and staging of RCC. The newer radiotracers may increase the accuracy of PET for RCC diagnosis and staging. In summary, the main imaging modality used for the characterization, staging, and surveillance of RCC is multiphasic CT. Other imaging modalities, such as MRI and PET, are used for selected indications.

Detecting recurrent prostate Cancer using multiparametric MRI, influence of PSA and Gleason grade.

BACKGROUND: The utility of multiparametric MRI (mpMRI) in detecting suspected local recurrence post radical prostatectomy (RP) may be associated with PSA and Gleason grade. The purpose of the study was to evaluate the likelihood of detecting locally recurrent prostate cancer utilizing mpMRI in patients with suspected recurrence following radical prostatectomy (RP) parsed by PSA and Gleason grade. METHODS: One hundred ninety five patients with suspected local recurrence were imaged on a 1.5 T MRI with torso array and endorectal coil in this retrospective study. mpMRI interpretations were stratified by PSA and lower (Gleason < 7) vs. higher grade tumors (Gleason 8-10). Recursive partitioning was used to determine whether mpMRI interpretations could be classified as positive or negative. RESULTS: The majority of mpMRI interpretations in patients with lower Gleason grade tumors and PSA < 0.5 ng/mL were negative (68/78, 87.2%, p = 0.004). The majority of mpMRI interpretations in patients with higher Gleason grade tumors and PSA > 1.5 ng/mL were positive (8/9, 88.9%, p = 0.003). Findings were corroborated by recursive partitioning, which identified a PSA = 0.5 ng/ml in patients with lower grade tumors and a PSA = 1.5 ng/mL in patients with higher grade tumors as differentiating negative and positive mpMRIs. CONCLUSION: In the setting of suspected recurrence after RP, mpMRI results are associated with PSA and Gleason grade, both of which can help guide when mpMRI may find utility. mpMRI is likely to be low diagnostic yield and negative for recurrence (87%) in the setting of lower Gleason grade tumors and PSA < 0.5 ng/mL. mpMRI is likely to be of low diagnostic value and positive for recurrence (89%) in the setting of PSA > 1.5 ng/mL and higher grade tumors; in this case, mpMRI findings may be more useful for directing biopsy and local therapy. Between these extremes, PSA > 0.5 ng/mL and lower grade tumors or PSA < 1.5 ng/mL and higher grade tumors, mpMRI results are less predictable, suggesting greater diagnostic value for detecting recurrence post prostatectomy.

An Under-Recognized Sequela of Myocardial Infarction: Lipomatous Metaplasia.

Lipomatous metaplasia is an infrequently discussed condition characterized by adipose tissue replacing scar tissue from ischemic events. Lipomatous metaplasia specifically of the myocardium is an adverse physiological result of myocardial infarction. In the past, several different imaging and diagnostic techniques were utilized to recognize lipomatous metaplasia of the myocardium. The aim of this study is to discuss an individual case with this condition to highlight several key aspects that are under-discussed in current literature, such as determining the most suitable modality for the recognition of lipomatous metaplasia.

Uterineintravenous leiomyomatosis with cardiac involvement.

Intravenous leiomyomatosis is a histologically benign smooth muscle tumor that arises either by direct extension of a uterine leiomyoma into the adjacent veins or by vascular intimal smooth muscle proliferation. Herein, we report the case of a 60-year-old female who was noted to have suspected cardiac mass on elective echocardiography done electively for abnormal electrocardiographic findings. Computed tomography and cardiac magnetic resonance indicated the presence of an intravenous leiomyoma originating from the uterus and extending to the inferior vena cava and right atrium. The patient was managed with a single-stage surgery involving cardiopulmonary bypass and excision of the right atrial mass, excision of the inferior vena cava tumor thrombus, and total abdominal hysterectomy and bilateral salpingo-oophorectomy.

Multidetector Computed Tomography (MDCT) Angiography in the Pre-Procedural Assessment of Patients Undergoing Transcatheter Aortic Valve Replacement.

Transcatheter aortic valve replacement (TAVR) initially emerged as an alternative option to surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis who were considered either inoperable or high-risk for surgery. However, since its advent the role of TAVR has been continuously evolving on the basis of clinical trials which showed that TAVR is non-inferior to SAVR in patients with moderate as well as low-risk for surgery. Because of recent technological advances, multidetector computer tomography (MDCT) is inherently suitable for the pre-procedural assessment of patients being considered for TAVR within a very short imaging time, MDCT can measure the diameter of the aortic annulus, provide detailed information regarding the status of the entire thoracoabdominal aorta, and assess the caliber of the peripheral vasculature used for transcatheter heart valve delivery. This information helps interventionists make optimal pre-procedural decisions and avoid complications. To familiarize non-imaging specialists with the role of MDCT in TAVR, we provide a concise overview of our approach to using this modality for the pre-procedural assessment of TAVR candidates.

Hepatic hemangioendothelioma: CT, MR, and FDG-PET-CT in 67 patients-a bi-institutional comprehensive cancer center review.

OBJECTIVE: To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT. METHODS: Bi-institutional review identified 67 adults (mean age, 47 years; 23 M/44 F) with pathologically proven HEH and pretreatment multiphasic CT (n = 67) and/or MR (n = 30) and/or FDG-PET-CT (n = 13). RESULTS: HEHs were multifocal in 88% (59/67). Mean size of the dominant mass was 4.1 cm (range, 1.4-19 cm). The tumors were located in the peripheral, subcapsular regions of the liver in 96% (64/67). Capsular retraction was present in 81% (54/67 cases) and tumors were coalescent in 61% (41/67). HEH demonstrated peripheral ring enhancement on arterial phase imaging in 33% (21/64) and target appearance on the portal venous phase in 69% (46/67). Persistent peripheral enhancement on the delayed phase was seen in 49% (31/63). On MR, multilayered target appearance was seen on the T2-weighted sequences in 67% (20/30) and on the diffusion-weighted sequences in 61% (11/18). Target appearance on hepatobiliary phase of MRI was seen in 57% (4/7). On pre-therapy FDG-PET-CT, increased FDG uptake above the background liver parenchyma was seen in 62% (8/13). CONCLUSION: HEHs typically manifest as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. Peripheral arterial ring enhancement and target appearance on portal venous phase are commonly seen on CT. Similarly, multilayered target appearance correlating with its histopathological composition is typically seen on multiple sequences of MR including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced multiphasic MR. KEY POINTS: • Hepatic epithelioid hemangioendotheliomas manifest on CT and MR as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. • Enhancement pattern on contrast-enhanced CT and MR can vary but peripheral ring enhancement on arterial phase and target appearance on portal venous phase are commonly seen. • Retrospective two-center study showed that cross-sectional imaging may help in the diagnosis.

Relationships between visceral/subcutaneous adipose tissue FABP4 expression and coronary atherosclerosis in patients with metabolic syndrome.

BACKGROUND: Cytoplasmic fatty acid-binding proteins facilitate the transport of lipids to specific compartments in cells. Fatty acid-binding protein 4 (FABP4), also known as aP2 or A-FABP, plays a key role in the development of atherosclerosis, insulin resistance, obesity, and metabolic syndrome (MS). The FABP4 polymorphisms are associated with protein expression changes in vitro and metabolic and vascular alterations in vivo. The aim of this study was to investigate the association between FABP4 messenger ribonucleic acid (mRNA) expression levels in epicardial (EAT), pericardial (PAT), and subcutaneous adipose tissues (SAT), and the extent of coronary atherosclerosis in coronary artery disease (CAD) patients with MS. Furthermore, the relationship between the extent of coronary atherosclerosis and epicardial adipose tissue volume (EATV) and FABP4 gene variations was evaluated. PATIENTS AND METHODS: A total of 37 patients undergoing coronary artery bypass grafting because of CAD (MS CAD group) and 23 non-MS patients undergoing heart valve surgery (control group) were included. Coronary angiography was performed for all patients and the extent of coronary atherosclerosis was assessed using the Sullivan's scoring system. The mRNA expression levels of FABP4 gene in EAT, PAT, and SAT, and FABP4 polymorphisms were analyzed using the quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: An increased FABP4 expression was observed in EAT and PAT of MS CAD group compared to controls. In the MS CAD group, FABP4 mRNA expression levels in EAT was 2.8-fold higher compared to PAT. The expression of FABP4 in EAT was positively correlated with the extent of atherosclerosis and EATV in MS CAD group (r = 0.588, P= 0.001, r = 0.174, P = 0.001, respectively). There were no correlations between PAT and SAT versus the extent of atherosclerosis and EATV. The FABP4 EAT mRNA expression levels were found to significantly increase in mutant allele carriers of rs1054135, whereas they significantly decreased in mutant allele carriers of rs77878271 (T-87C) in MS CAD group (P < 0.05). The extent of atherosclerosis was also found to be significantly associated with rs1054135 (P < 0.05). A cut-off point of 57.5 cm3 EATV was used indicating the presence of CAD with a significant area under the curve of 0.783%, 98% sensitivity, and 100% specificity (95% CI 0.620-0.880; P < 0.05). CONCLUSIONS: Our study results suggest that FABP4 expression in EAT is strongly associated with the extent of atherosclerosis and EATV in MS CAD patients.

Computed Tomography Imaging Findings of Acute Aortic Pathologies.

Acute aortic syndromes (AAS) encompass a spectrum of life-threatening conditions characterized by acute aortic pain. AAS include acute aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm rupture. The prognosis of AAS is clearly related to prompt diagnosis and appropriate management. The different types of AAS cannot be reliably differentiated solely based on clinical presentation since the clinical features are indistinguishable. Multidetector-row computed tomography (MDCT) with electrocardiographic gating (ECG-gated MDCT) has been used in the acute emergency setting as a powerful clinical tool, which enables rapid and specific diagnosis of aortic pathologies. ECG-gated MDCT significantly reduces motion artifact and avoids potential pitfalls in the diagnosis of AAS. The aim of this review is to evaluate the role of MDCT imaging in the assessment of AAS and to discuss the differentiation of this spectrum of aortic diseases with reference to the key imaging findings.

David Versus Goliath: The Clinical Consequences of an Influenza A Viral Infection in an Unvaccinated Patient.

Acute influenza virus (AIV) infection can manifest as a severe life-threating illness in patients who are not vaccinated, and furthermore, have comorbidities that place them at risk for rapid respiratory decompensation. Each year influenza causes death in individuals with high risk for contracting this infection, although the illness is preventable by vaccination. Complications of AIV infection, such as bacterial pneumonia are treatable, but other severe complications such as acute respiratory distress syndrome (ARDS) leading to diffuse alveolar damage (DAD) are limited to supportive therapy and self-resolution. In most cases, ARDS leading to DAD is fatal, due to the insidious severity of symptoms which lead to rapid oxygen desaturation without correction, and despite supportive therapy. Regardless of a poor prognosis, the clinical signs and symptoms are congruent with imaging and attest to the importance of vaccination, which protect against high mortality rates.

Right Ventricular Outflow Tract Tachycardia: a Common Rhythm due to an Uncommon Etiology.

Right ventricular outflow tract (RVOT) aneurysm is a rare cause of RVOT ventricular tachycardia (RVOT-VT). We present a very unusual case of RVOT-VT due to an RVOT aneurysm diagnosed by cardiovascular magnetic resonance imaging.

Role of Dual-Energy Computed Tomography in Thoracic Oncology.

Dual-energy CT (DECT) is an emerging technology that has potential to enhance diagnostic performance and radiologists' confidence in the evaluation of thoracic malignancies. DECT clinical applications include characterization of solitary pulmonary nodule, lung masses and mediastinal tumors. DECT-derived iodine uptake quantification may assist in characterization of tumor differentiation and gene expression. The use DECT in oncology has potential to improve lung cancer staging, therapy planning, and assessment of response to therapy as well as detection of incidental pulmonary embolism.

CT perfusion in normal liver and liver metastases from neuroendocrine tumors treated with targeted antivascular agents.

OBJECTIVE: To assess the effects of bevacizumab and everolimus, individually and combined, on CT perfusion (CTp) parameters in liver metastases from neuroendocrine tumors (mNET) and normal liver. METHODS: This retrospective study comprised 27 evaluable patients with mNETs who had participated in a two-arm randomized clinical trial of mono-therapy with bevacizumab (Arm B) or everolimus (Arm E) for 3 weeks, followed by combination of both targeted agents. CTp was undertaken at baseline, 3 and 9 weeks, to evaluate blood flow (BF), blood volume (BV), mean transit time (MTT), permeability surface area product (PS), and hepatic arterial fraction (HAF) of mNET and normal liver, using a dual-input distributed parameter physiological model. Linear mixed models were used to estimate and compare CTp parameter values between time-points. RESULTS: In tumor, mono-therapy with bevacizumab significantly reduced BV (p = 0.05); everolimus had no effects on CTp parameters. Following dual-therapy, BV and BF were significantly lower than baseline in both arms (p ≤ 0.04), and PS was significantly lower in Arm E (p < 0.0001). In normal liver, mono-therapy with either agent had no significant effects on CTp parameters: dual-therapy significantly reduced BV, MTT, and PS, and increased HAF, relative to baseline in Arm E (p ≤ 0.04); in Arm B, only PS reduced (p = 0.04). CONCLUSIONS: Bevacizumab and everolimus, individually and when combined, have significant and differential effects on CTp parameters in mNETs and normal liver, which is evident soon after starting therapy. CTp may offer an early non-invasive means to investigate the effects of drugs in tumor and normal tissue.

Periosteal mesenchymal chondrosarcoma of the tibia with multifocal bone metastases: a case report.

Mesenchymal chondrosarcoma of bone is a rare high-grade variant of chondrosarcoma, which typically has central intramedullary location. The tumor is characterized by admixture of highly anaplastic small round malignant cells and islands of mineralized low-grade hyaline cartilage. It is most unusual for this tumor to arise on the surface of a long bone. We describe a patient with periosteal mesenchymal chondrosarcoma that arose at the surface of the right tibia with multifocal bone metastases. Radiographic, CT, MRI, and PET-CT features of this unusual tumor are presented.

Prostate magnetic resonance imaging for brachytherapists: Anatomy and technique.

PURPOSE: To present an overview of mp MRI techniques necessary for high-resolution imaging of prostate. METHODS: We summarize examples from our clinical experience and concepts from the current literature that illustrate normal prostate anatomy on multiparametric MRI (mp MRI). RESULTS: Our experience regarding optimal mp MRI image acquisition is provided, as well as a summary of prostate and periprostatic anatomy and anatomical variants that pose challenges for BT. CONCLUSIONS: mp MRI provides unparalleled assessment of the prostate and periprostatic anatomy, making it the most appropriate imaging modality to facilitate prostate BT treatment planning, implantation, and followup. This work provides an introduction to prostate mp MR imaging, anatomy, and anatomical variants essential for successful integration mp MRI into prostate brachytherapy practice.

Prostate magnetic resonance imaging for brachytherapists: Diagnosis, imaging pitfalls, and post-therapy assessment.

Optimal integration of multiparametric MRI (mp MRI) into prostate brachytherapy practice necessitates an understanding of imaging findings pertinent to prostate cancer detection and staging. This review will summarize prostate cancer imaging findings and tumor staging on mp MRI, including an overview of the Prostate Imaging Reporting and Data System (PIRADS)-structured reporting schema, mp MRI findings observed in the post-therapy setting including cases of post-treatment recurrence, and MRI concepts integral to successful salvage brachytherapy.

Outcomes of unselected patients with metastatic clear-cell renal cell carcinoma treated with first-line pazopanib therapy followed by vascular endothelial growth factor receptor tyrosine kinase inhibitors or mammalian target of rapamycin inhibitors: a single institution experience.

OBJECTIVE: To explore the efficacy and safety of pazopanib in a 'real-world' setting in unselected patients, as data regarding unselected patients with metastatic clear-cell renal cell carcinoma (ccRCC) treated with first-line pazopanib are limited. PATIENTS AND METHODS: We reviewed records of patients with metastatic ccRCC treated with first-line pazopanib from 1 November 2009 through to 1 November 2012. Cox models were fitted to evaluate the association of progression-free survival (PFS) and overall survival (OS) with patient co-variables. RESULTS: In all, 88 patients were identified; 74 were evaluable for response: two (3%) had a complete response, 27 (36%) a partial response, 36 (49%) had stable disease and nine (12%) had progressive disease. The median PFS was 13.7 months [95% confidence interval (CI) 8.7-18.3]. PFS was correlated with a Karnofsky Performance Status score of <80 [hazard ratio (HR) 3.26, P < 0.001] and serum lactate dehydrogenase of >1.5 × upper limit of normal (HR 3.25, P = 0.014). The median OS was 29.1 months (95% CI 20.2-not reached). The OS was correlated with brain metastasis (HR 2.55, P = 0.009), neutrophilia (HR 1.179, P = 0.018), and anaemia (HR 3.51, P < 0.001). There were no treatment-related deaths. In all, 53 patients received second-line therapy [vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKI) in 22 patients, mammalian target of rapamycin inhibitors (mTORi) in 22 patients, and other therapy in nine patients]; the median PFS was 8.6 months (95% CI 3.3-25.7) with VEGFR-TKI and 5 months (95% CI 3.5-15.2) with mTORi (P = 0.41); the median OS was 19.9 months (95% CI 12.9-not reached) and 14.2 months (95% CI 8.1-not reached), from initiation of second-line VEGFR-TKI or mTORi, respectively (P = 0.37). CONCLUSIONS: In this retrospective study, first-line pazopanib confirmed its efficacy in metastatic ccRCC. Trends for longer PFS and OS were seen with VEGFR-TKI compared with mTORi after first-line pazopanib.

Comparison of Low-Dose Higher-Relaxivity and Standard-Dose Lower-Relaxivity Contrast Media for Delayed-Enhancement MRI: A Blinded Randomized Crossover Study.

OBJECTIVE: The gadolinium-based MRI contrast agent gadobenate dimeglumine has nearly twice the MR relaxivity of gadopentetate dimeglumine at 1.5 T. The purpose of this study was to determine whether a lower dose (0.1 mmol/kg) of gadobenate dimeglumine can be used to obtain delayed-enhancement MR images comparable to those obtained with a standard dose (0.2 mmol/kg) of gadopentetate dimeglumine. SUBJECTS AND METHODS: In this blinded randomized crossover study, 20 patients with known myocardial infarction underwent two separate delayed-enhancement MRI examinations after receiving 0.1 mmol/kg gadobenate dimeglumine and 0.2 mmol/kg gadopentetate dimeglumine (random administration). The conspicuity of lesion enhancement 5, 10, and 20 minutes after contrast administration was quantified as relative enhancement ratio (RER). RESULTS: With either gadolinium-based contrast agent, damaged myocardium had higher signal intensity than normal remote myocardium (RER > 4) on delayed-enhancement MR images, and the blood RER declined over time after contrast administration. The blood RER was not significantly higher for gadobenate dimeglumine than for gadopentetate dimeglumine at 5 and 10 minutes. Nevertheless, there was a larger reduction in blood RER for gadobenate dimeglumine than for gadopentetate dimeglumine between 5 and 10 minutes and between 10 and 20 minutes. The volumes of enhancement were similar for gadobenate dimeglumine (13.6 ± 8.8 cm(3)) and gadopentetate dimeglumine (13.5 ± 8.9 cm(3)) (p = 0.98). The mean difference in Bland-Altman analysis for delayed-enhancement volume between the agents was 0.1 cm(3). CONCLUSION: Qualitatively and quantitatively, delayed-enhancement MR images of ischemic myocardium obtained with 0.1 mmol/kg gadobenate dimeglumine are comparable to those obtained with 0.2 mmol/kg gadopentetate dimeglumine 5, 10, and 20 minutes after contrast administration.