Advanced Diagnostic Imaging Research Articles

Quadricuspid Aortic Valve: A Report of 12 Cases and a Review of the Literature

Quadricuspid aortic valve (QAV) is rare and its diagnosis, clinical course, and management are less well defined relative to other aortic valve abnormalities. Advances in diagnostic imaging, notably in ultrasound, have increased clinical awareness of this anomaly and prompted this review of our experience with 12 new patients and a compilation of previously reported patients to further characterize this condition.

Reviewing the standard of care in pancreatic adenocarcinoma: A critical appraisal

Treatment of pancreatic adenocarcinoma is still a great challenge to the surgeon. Although recent investigation and treatment protocols have redefined the limits of resectability and adjuvant care, survival outcome still remains dismally low. Because surgical resection of localized disease remains the only hope for curing pancreatic adenocarcinoma, all advances in diagnostic imaging and perioperative care have been aimed at improving the surgical outcome. In the present article, we discuss new developments and the existing controversies in the diagnosis, staging, determination of resectability, and the progress in surgical technique, palliation and, importantly, adjuvant and neoadjuvant therapy, and highlight the latest standard of care wherever possible. Where consensus is lacking, available literature is discussed to narrow the debate and provide a working formula for the readers at large. It is finally understood that for the best outcome, treatment should be tailored to the patient. Although surgical outcome improves in expert hands, the overall survival remains poor irrespective of centres.

TC multimodal en el diagnóstico del código ictus

Stroke results in significant morbidity and mortality. Recent years have seen a revolution in the diagnosis and treatment of stroke, with advances in diagnostic imaging and improvements in early and specific treatment. Multimodal CT (unenhanced CT, perfusion CT, and CT angiography) is widely available, fast, and efficacious, all of which give it a key role in the early diagnosis of stroke and in the selection of patients who will benefit from thrombolytic treatment. Unenhanced CT is useful for ruling out hemorrhage or lesions that simulate stroke and for evaluating the presence of early signs. Perfusion CT enables us to know the presence and extension of infarcted ischemic tissue (irrecoverable) and of penumbra (tissue at risk that is potentially recoverable), thus ensuring more appropriate selection of candidates for treatment. Finally, CT angiography makes it possible to evaluate the intra- and extra-cranial circulation, to know the vascular alteration that originated the stroke, and to guide treatment (intra-arterial or mechanical thrombolysis).

Management of Papillary Thyroid Cancer Patients in Absence of Postoperative Radioiodine Remnant Ablation: Tailoring Follow-Up by Neck Sonography

Throughout the world, small, differentiated thyroid cancers—papillary thyroid carcinomas (PTC) for the most part—are being diagnosed with growing frequency, an effect that can be attributed largely to technological advances in diagnostic imaging and greater diagnostic scrutiny (1). In most cases, the risk of disease recurrence and tumor-related mortality after total or near-total thyroidectomy appears to be quite low, and for this reason postoperative radioiodine remnant ablation (RRA) is being omitted in an increasingly large percentage of patients with PTC (2). This strategy, which tailors case management to individual risk levels, is in keeping with the 2009 American Thyroid Association (ATA) guidelines (3), which encourage more selective use of postoperative RRA. The challenge, however, is to find an effective approach for the postoperative follow-up of patients who have undergone total or near-total thyroidectomy without RRA. Although the outcome of these “low risk” PTC is almost invariably favorable, the patients still require regular, long-term surveillance. Indeed, persistent or recurrent disease can also occur in patients with early-stage tumors, and relapses have been reported as late as 10 yr after diagnosis (4). Effective postsurgical follow-up of patients thought to be disease-free should be capable of detecting recurrences: 1) early (when the chances of a cure are greatest); 2) with high sensitivity and specificity; and 3) with a high negative predictive value. Ideally, it should also allow us to identify—at some point—cases with a low enough likelihood of recurrence to justify less intensive surveillance, which would be not only more cost-effective but also easier on the patient (physically and psychologically). The 2009 ATA guidelines recommend that periodic serum thyroglobulin assay and neck ultrasonography (US) “be considered” during the follow-up of patients whose differentiated thyroid cancers have been managed with subtotal thyroidectomy or with total thyroidectomy not followed by RRA (recommendation 44) (3). However, little distinction is made between these two methods, and few details are offered on their respective merits or shortcomings and how and when each might be used. Serum thyroglobulin assays after exogenous or endogenous TSH stimulation are considered the mainstay cornerstone of postoperative surveillance programs for patients with PTC (3). Indeed, detectable TSH-stimulated thyroglobulin levels or increases over time in their values are a highly specific marker of residual/recurrent disease for patients treated with postoperative RRA (3, 5); until recently, this included virtually all of those who were treated for PTC. What we know about the diagnostic value of serum thyroglobulin assays is largely based on their performance in this population after TSH stimulation. But for patients who do notundergoRRA,theseassaysaremoredifficult to interpret. Detectable thyroglobulin production in these cases may well originate exclusively from the remnant of normal thyroid tissue leftafter surgery,andtheboundariesbetween“normal and neoplastic production” have never been specifically investigated in this population. Consequently, for a rapidly growing subset of PTC patients, serum thyroglobulin assays currently have some important limitations as postoperative follow-up tools. By contrast, neck sonography has a number of features that are valuable in the postoperative follow-up of PTC patients (5–8). Persistent or recurrent disease is almost always associated with spread to the cervical lymph nodes,

Variations on brain microglial gene expression of MMPs, RECK, and TIMPs in inflammatory and non-inflammatory diseases in dogs

Matrix metalloproteinases (MMPs), MMP inhibitors (TIMPs, tissue inhibitors of matrix metalloproteinases), and the membrane-anchored glycoprotein RECK (reversion-inducing cysteine-rich protein with Kazal motifs) contribute to the pathogenesis of many CNS diseases. To assess the potential pathogenetic roles of microglial MMP, TIMP, and RECK generation in extracellular matrix breakdown, opening of the blood brain barrier (BBB) and subsequent recruitment of leukocytes in the CNS, twenty-four dogs suffering from spontaneously occurring different intracranial and extracranial (control group) diseases were examined. Microglia cells were isolated ex vivo by density gradient centrifugation and their expressions of MMP-2, MMP-9, MMP-12, MMP-13, MMP-14, TIMP-1, TIMP-2, and RECK were examined via quantitative real-time polymerase chain reaction (qPCR). Zymography on CNS tissues in selected cases was performed to assess differences at the protein level. Dogs were grouped in different disease categories according to histopathological examinations, in groups with or without inflammatory reactions, and in groups with/without contrast enhancement in advanced diagnostic imaging as a function of BBB breakdown. The results showed a significant up-regulation of MMP-9 in dogs with inflammation in the nervous system compared to dogs with non-inflammatory diseases. An increased expression of MMP-9 might lead to a facilitated invasion of white blood cells. Furthermore, down-regulation of MMP-13 was found in dogs with contrast enhancement. Zymographical data reflected MMP-2 qPCR data. In conclusion, differential expression of MMPs and their inhibitors, but not of RECK, which might crucially influence the pathogenesis of a given disease, could be demonstrated in canine microglia. This reflects a further pathway in the microglial repertoire to respond to various disease conditions in the CNS, a characteristic that might be of particular relevance as a target for specific treatments.

Advances in diagnostic imaging of the larynx and pharynx

SummaryImaging of the larynx and pharynx has traditionally been limited to upper airway endoscopy and radiography. Recently, ultrasonography, magnetic resonance imaging and computed tomography have become used more widely. These modalities have increased our diagnostic yield when investigating disorders of the upper airway. The Case Report in this issue (Koenig et al. 2012) describes the diagnosis and biopsy of a laryngeal mass using ultrasonography illustrating one novel application of laryngeal ultrasonography. Increased use of laryngeal ultrasonography and advanced imaging of the larynx and pharynx will hopefully lead to a better understanding of conditions of the upper airway and improved treatment strategies.

Transient Ischemic Attack: Definition, Diagnosis, and Risk Stratification

Transient ischemic attack (TIA) can convey a high imminent risk for the development of a major stroke and is therefore considered to be a medical emergency. Recent evidence indicates that TIA with imaging proof of brain infarction represents an extremely unstable condition with early risk of stroke that is as much as 20 times higher than the risk after TIA without tissue damage. The use of neuroimaging in TIA is therefore critical not only for diagnosis but also for accurate risk stratification. In this article, recent advances in diagnostic imaging, categorizations, and risk stratification in TIA are discussed.

The Effect of Self-Referral on Utilization of Advanced Diagnostic Imaging

This article reviews the evidence on the relationship between recent increases in utilization of diagnostic imaging and self-referral. The evidence shows that self-referral invariably leads to higher utilization and the attendant higher costs. Because most physicians do not own advanced imaging equipment, their own best interests are being thwarted by the practice of self-referral. Congress and the Centers for Medicare and Medicaid Services should restrict the in-office ancillary services exception to the Stark laws as it applies to advanced imaging.

Osseous cyst-like lesions/subchondral bone cysts of the phalanges

Summary In the horse, the phalanges are the second most common location for the occurrence of osseous cyst-like lesions (OCLLs) after the medial femoral condyle of the stifle. Phalangeal OCLLs occur in a variety of locations, most of which are adjacent to, if not communicating with, a joint. The aetiology of these lesions is considered to be multifactorial by most authors. Horses with OCLLs demonstrate lameness of varying severity. Diagnostic analgesia should be used to localise the lameness. After localisation of the lameness, standard radiographic views of the isolated area should be performed. The radiographic characteristics of OCLLs are dependent on the stage of development of the OCLL; OCLLs may first be identified as a small lucent flattening or depression in the articular surface; however, they may progress to a circular, oval or conical single or multi chambered radiolucency within the bone. There may be a rim of radiodense sclerosis around the lucency. Diagnosis of some OCLLs may only be achieved using nonstandard radiographic views or may require advanced diagnostic imaging modalities such as computed tomography or magnetic resonance imaging. Treatment of phalangeal cysts may be conservative or surgical. Surgical treatment options generally aim to prevent cyst enlargement and promote filling of the lesion with osseous material. Depending on the cyst, this can be performed arthroscopically or via an extra-articular approach. Occasionally, the severity of proximal interphalangeal joint OCLLs warrants surgical arthrodesis. Overall the prognosis for return to performance for horses with OCLLs ranges from 30–90% but is dependent on the breed, age and intended use of the horse, surface area of weightbearing cartilage affected, concurrent osteoarthritis within the joint and treatment administered.

Imaging Phenotype Versus Genotype in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common monogenetic cardiac disease with a prevalence of 0.2%1 that usually is inherited as an autosomal dominant trait with variable penetrance and expression. Clinically, HCM is defined by the presence of left ventricular (LV) hypertrophy (LVH) unexplained by abnormal loading conditions.1 The natural history varies from an asymptomatic course to drug-refractory angina/dyspnea, sudden cardiac death (SCD), and end-stage heart failure. The incidence of HCM-related SCD is approximately 1% to 2% in children and adolescents and 0.5% to 1% in adults.2,3 In this review, we examine the impact of advanced diagnostic imaging technologies on HCM, with particular emphasis on the detection of particular genetic subtypes. In ≈60% of cases, HCM is inherited as an autosomal dominant trait caused by mutations in genes coding for cardiac sarcomere proteins (Figure 1).4–7 Mutations in genes encoding Z-disc proteins and proteins involved in calcium regulation account for <5% of cases. The absence of sarcomeric gene mutations can be explained by limitations of current mutation detection techniques or mutations in as yet unidentified genes, but in some cases, hypertrophy is caused by other diseases that mimic the phenotype of sarcomeric protein disease. Table 1 lists genetic disorders associated with HCM. Figure 1. A schematic illustration of a cardiac sarcomere. View this table: Table 1. Currently Known Genes Implicated in HCM More than 600 different sarcomeric gene mutations are reported in patients with HCM.8–16 The majority are missense mutations, but nonsense, frameshift, and in-frame insertion/deletion mutations also occur. Most mutations are characterized by incomplete penetrance and variable clinical expression likely due to locus heterogeneity and the effect of mutations at different locations within the same gene. Most mutations probably have a dominant negative effect on sarcomere function, but in some cases, haploinsufficiency (ie, only a single functional …

Clinical value of 18F-FDG PET/CT in postoperative monitoring for patients with colorectal carcinoma

Objective: To evaluate the clinical value of 18F-FDG PET/CT in postoperative monitoring for patients with colorectal carcinoma. Methods: 66 postoperative patients with colorectal carcinoma underwent whole-body FDG PET/CT. The final histopathological and formal clinical follow-up findings were used as gold standard to determine the sensitivity and specificity of FDG PET/CT and enhanced CT of the same periods. Results: The sensitivity and specificity of FDG PET/CT in detecting recurrence are 96.30%, 94.87% (while enhanced CT are 70.37% and 87.18% respectively). The sensitivity and specificity in detecting metastasis are 95.35%, 82.61% (enhanced CT are 61.90%, 75.00%). SUVmax was significantly higher in malignant lesions [range 4.16–22.00, mean±standard deviation (x±s) 8.06±4.30] than in benign ones (range1.18–6.25, x±s 2.82±1.02). Conclusion: At present, whole-body 18F-FDG PET/CT is an advanced diagnostic imaging technique in detecting loco-regional recurrence and metastasis in postoperative patients with colorectal carcinoma for its higher sensitivity and specificity.

Evidence Requirements for Innovative Imaging Devices: From Concept to Adoption

Changes in the regulatory and reimbursement environment for advances in imaging in the United States are leading to increasing requirements for formal clinical evidence of efficacy, effectiveness, and safety. The authors describe 5 phases of an imaging product's lifecycle: design, regulatory clearance and approval, early adoption, reimbursement, and full adoption. Each phase has distinct needs for clinical evidence. With increasing costs of clinical evidence generation, the question of ownership of the responsibility to gather clinical evidence at each successive phase becomes important. Mismatch between the pace of advances in imaging technologies and the time required to do formal clinical trials to clear regulatory and reimbursement evidence requirements threatens patient access to the benefits of innovation such as reduction in exposure to radiation. Public and payer requirements for clinical evidence must also be evaluated for their impact on incremental design improvements, which have historically characterized advances in diagnostic imaging.

Palliative therapy for osteosarcoma

Despite advances in diagnostic imaging, the evolution of neoadjuvant chemotherapy and the refinements in limb-salvage surgery, the progression-free survival rate remains poor for patients with metastatic, recurrent or unresectable osteosaroma. Different therapeutic strategies for these subgroups of patients have been employed to control disease and prolong survival. Treatment options are limited and controversial, including systemic and localized therapies. Surgical resection, whenever feasible, is still the standard treatment in advanced osteosarcoma. The role of chemotherapy is unclear while the use of radiotherapy, embolization and thermal ablation is increasing. New therapeutic experimental approaches and novel target therapies are needed to improve the outcome of these subgroups of patients.

Imaging in thromboembolic disease

Venous thromboembolic disease is common, but is difficult to diagnose clinically. Diagnostic imaging therefore plays a central and increasing role in its diagnosis. Many modalities are available and there are many published guidelines on how to work-up patients suspected of venous thromboembolic disease. This article summarizes the findings on the various diagnostic imaging techniques and the accuracies of the modalities available. Guidelines are provided for the work-up of patients, including special patient populations, such as intensive care patients, patients with contrast allergy or patients of childbearing age. Future perspectives on venous thromboembolism work-up and advanced diagnostic imaging are also discussed.

Radiation Dose Escalation in Stage III Non-Small-Cell Lung Cancer

For patients with stage III non-small-cell lung cancer with unresectable or inoperable tumors, definitive chemoradiotherapy is often utilized. Historically, local control and overall survival rates have been poor. In an effort to improve local control, new chemotherapeutic agents in combination with higher doses of radiotherapy have been investigated. Early dose escalation trials date back to the 1980s, and the feasibility and efficacy of dose escalation for patients with inoperable stage III lung cancer continue to be topics of investigation. Herein, we review the evolution of chemotherapy as it relates to treatment of unresectable stage III lung cancer, and we outline the early and the more recent dose escalation studies. While dose escalation appears to provide a modest benefit in terms of preventing local failure and improving overall survival, advances in diagnostic imaging and radiotherapy treatment have possibly resulted in selection of a more favorable patient population. These variables make statements regarding the benefit of dose escalation challenging.

A Prior Authorization Program of a Radiology Benefits Management Company and How It Has Affected Utilization of Advanced Diagnostic Imaging

A Prior Authorization Program of a Radiology Benefits Management Company and How It Has Affected Utilization of Advanced Diagnostic Imaging

Advances in diagnostic imaging for peripheral arterial disease

Refinements in both noninvasive and invasive imaging techniques have led to significant improvements in both the diagnosis and treatment of peripheral arterial disease. Multiple complementary imaging modalities are available for evaluating these patients. This article reviews the advantages, disadvantages and recent advances in the commonly used clinical applications of duplex ultrasonography, magnetic resonance angiography, computed tomographic angiography, digital subtraction angiography and intravascular ultrasound for arterial imaging in the lower extremities. It also discusses experimental imaging techniques more recently applied to peripheral arterial disease such as PET, hyperspectral imaging and molecular imaging of atherosclerosis. As more is understood about both lesion and patient characteristics that affect their response to peripheral interventions, clinician selection of the various imaging modalities as well as different peripheral interventions will allow for more effective treatment of patients with peripheral arterial disease.

Finite element modelling of maxillofacial surgery and facial expressions—a preliminary study

Recent advances in diagnostic imaging and associated software have enabled the transformation of anatomical structures into finite element (FE) models facilitating computerized facial modelling. The work presented employs personalized imaging data of facial anatomical structures for use in planning and predicting the outcome of maxillofacial surgery. The current process relies on either freehand planning and/or commercial two-dimensional (2D) and three-dimensional (3D) surgical planning software packages, but the validity of these software packages has been questioned. In this paper, the finite element technique was used to predict the outcome of maxillofacial surgery. A finite element facial model was created, based on patient specific bone and skin image data, combined with generic muscle data. The model was used for two distinct purposes: simulation of the maxillofacial surgery and simulation of facial expressions pre- and post-surgery. This combination allowed for an improved prediction of surgery outcome. Commercial software was used for creating the FE facial model from the original image data, and LS-DYNA(®) was the analysis code used for the purpose of the FE simulation. The results from the simulation of maxillofacial surgery showed an overall agreement of 85% with the patient data at 6 months post-surgery and the error was generally contained within a ± 2 mm threshold. The results show that the approach of using commercial FE software tools to create a detailed and anatomically accurate patient specific model for simulation of maxillofacial surgery, as well as facial expressions, can be applied in facial surgery planning. As the study was based on data collected from one patient, further work is needed in which additional subjects can be assessed.

Magnetic Resonance Imaging of the Knee: Optimizing 3 Tesla Imaging

Magnetic resonance imaging (MRI), with its multiplanar capabilities and excellent soft-tissue contrast, has established itself as the leading modality for noninvasive evaluation of the musculoskeletal system (1-5). It is regarded as the top imaging and diagnostic tool for the knee joint as a result of its ability to evaluate a wide range of anatomy and pathology varying from ligamentous injuries to articular cartilage lesions. Imaging of the knee requires excellent contrast, high resolution and the ability to visualize very small structures, all of which can be provided by MR imaging. The development of advanced diagnostic MR imaging tools for the joints is of increased clinical importance as it has been recently shown that musculoskeletal imaging is the most rapidly growing field in MR imaging, second only to neuroradiology applications (6). Currently, most clinical evaluation of the musculoskeletal system is performed at intermediate field strengths of 1.5 T or lower. High field systems, like 3.0 T, are now becoming increasingly available for clinical use. Although at first used primarily for neurological imaging, an increasing number of studies have demonstrated the abilities and advantages of 3.0 T systems in musculoskeletal imaging (7-10). The most notable advantage includes an increased signal-to-noise ratio (SNR) which can lead to a shorter imaging time or improved image resolution. However, with the increase to a 3.0 T field strength comes a various number of considerations that must be dealt with in order to optimize its intrinsically superior imaging capabilities.

Spontaneous Rectus Sheath Hematoma Pregnancy: Case Report and Review of the Literature

Rectus sheath hematoma (RSH) is a rare, but important potential cause of acute upper abdominal pain in pregnancy. We report a patient with history of hemolysis, elevated liver enzymes, low platelets syndrome who presented with upper abdominal pain, hypotension, elevated hepatic transaminase levels, and a visibly enlarging right costal margin mass at 33 weeks' gestation. She underwent emergent cesarean delivery and upper abdominal exploration with findings of a large hematoma involving the entire right rectus sheath. The current case illustrates that the diagnosis of an RSH in pregnancy can be difficult as its presentation can mimic many common causes of abdominal pain seen outside of pregnancy, as well as many specific to pregnancy. Review of the published cases from the past 20 years shows that correct diagnosis remains difficult in pregnancy despite advances in diagnostic imaging. Although management of an RSH outside of pregnancy is frequently conservative, it is very often treated surgically in pregnant patients and often leads to preterm delivery.