The evolving role of the division psychiatrist

With the recent restructuring of Army infantry divisions in the new brigade combat team model, division psychiatrists are facing new and unique demands. This article outlines the varying perspectives of the position and the duties and responsibilities of a division psychiatrist. It provides guidance on how to negotiate the myriad of challenges unique to the position. Discussion includes planning and supervision, providing command consultation, educational efforts, fulfilling the roles of an officer and leader, and future directions for the position.     

The evolving role of coronary CT angiography in Acute Coronary Syndromes

In the United States, non-obstructive coronary disease has been on the rise, and each year, nearly one million adults suffer myocardial infarction, 70% of which are non-ST-segment elevation myocardial infarction (NSTEMI). In addition, approximately 15% of patients suffering NSTEMI will have subsequent readmission for a recurrent acute coronary syndrome (ACS). While invasive angiography remains the standard of care in the diagnostic and therapeutic approach to these patients, these methods have limitations that include procedural complications, uncertain specificity in diagnosis of the culprit lesion in patients with multi-vessel coronary artery disease (CAD), and challenges in following coronary disease over time. The role of coronary computed tomography angiography (CCTA) for evaluating patients with both stable and acute chest pain has seen a paramount upshift in the last decade. This paper reviews the established role of CCTA for the rapid exclusion of obstructive plaque in troponin negative acute chest pain, while exploring opportunities to address challenges in the current approach to evaluating NSTEMI.     

The role of radiology in dive-related disorders

Recreational scuba diving has continued to grow in popularity in the past several decades, and military diving remains an integral part of ship husbandry, explosives and ordinance disposal, and special warfare. Although relatively uncommon, disorders such as decompression sickness and arterial gas embolism can be fatal, whereas disorders such as ear baro-trauma and dysbaric osteonecrosis are not fatal but can cause significant morbidity. An extensive literature search was performed to comprehensively examine the current role of diagnostic radiology with respect to diving medicine. In selected cases, diagnostic imaging can be of potential benefit for evaluation. Diagnostic imaging plays a useful role in the screening of certain individuals for future fitness to dive. Radiological imaging has also been of paramount importance in postmortem evaluation of dive casualties.     

MRI of rectal disorders

OBJECTIVE: The objective of this pictorial essay is to provide a review of the diseases involving the rectal wall with an emphasis on the key clinical and radiologic differentiating features. CONCLUSION: A wide spectrum of disease processes can involve the rectum in adults. MRI is the technique of choice in the definitive diagnosis of these disease conditions, mainly because of its superior tissue contrast differentiation.     

Targeting the vulnerable plaque: The evolving role of nuclear imaging

The majority of acute ischemic events relating to atherosclerosis are caused by plaque rupture and ensuing thrombosis. The risk of plaque rupture is dictated in part by plaque morphology, which in turn is influenced by pathophysiologic mechanisms at the cellular and molecular level. Anatomic imaging modalities such as intravascular ultrasound, high-resolution magnetic resonance imaging, and multislice computed tomography can identify morphologic features of the vulnerable plaque, such as a large lipid core and thin fibrous cap, but give little or no information regarding molecular and cellular mechanisms, such as endothelial function, macrophage activation, lipid transport and metabolism, and cell death. Recent studies suggest that nuclear imaging may be able to provide images of sufficient quality to identify and quantify some of these molecular and cellular pathophysiologic processes. In the future this could allow for the early identification and noninvasive monitoring of vulnerable plaque.     

The role of MR imaging in scaphoid disorders

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser’s disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings.     

The role of MRI in diseases of the kidney

The role of MRI in evaluating renal diseases has not yet been fully defined. Despite some inherent limitations due to motion and failure to confidently define calcifications, MRI can display normal and pathologic anatomy with great clarity. MRI is useful in the staging of renal carcinoma, especially in the evaluation of vascular invasion. Bulky tumors are best depicted with MRI, especially when the organ or origin is in question. Contrast agents, fast scan techniques, and spectroscopy hold great promise for the future.     

The role of MRI in the diagnosis of endometriosis

Aim

The aim of this study is to evaluate the accuracy of the magnetic resonance imaging in diagnosis of endometriosis especially in non-apparent types as tubal and cul de sac endometriosis.

Patients and methods

MRI obtained between January 2007 and June 2009 for 34 premenopausal women complaining of dysmenorrhea, menorrhagia and infertility and the diagnosis of endometriosis were included in the differential diagnosis. T1 weighted fat saturated and T2 weighted images were done for every patient, we evaluated the MR images for the presence of T1 bright signal suggesting endometriosis. Transvaginal US was performed in two perpendicular planes for the detection of focal areas with ill defined borders or abnormal echo texture. Suspicious cases which become negative by laparoscopy were excluded from the study.

Results

MRI diagnosed endometriosis in the uterus in 18 patients, ovarian endometriosis in 13 patients, tubal in two patients, and cul de sac in one patient.

Conclusion

It is concluded that MRI is superior in the diagnosis of endometriosis than transvaginal ultrasound.     

The role of MRI in the diagnosis of MS

Magnetic resonance imaging (MRI) is the most widely used imaging technique in the investigation of multiple sclerosis (MS). Although MS remains a clinical diagnosis, MRI has become an invaluable tool in understanding and monitoring the disease, and is commonly used to confirm the clinical diagnosis. Various imaging techniques can be used but T2-weighted brain imaging remains the standard tool. The officially endorsed imaging criteria for MS places greater emphasis on the spatial and temporal distribution of lesions than on their individual appearance. This review focuses on the more typical findings in MS, and considers the current role of MRI in the diagnosis.     

The role of MRI in screening for neurogenic hypertension

Neurovascular compression (NVC) of the left ventrolateral medulla (VLM) has been implicated as a cause of essential hypertension. We investigated whether high-resolution MRI of the posterior cranial fossa could identify patients with essential hypertension who may benefit from surgery. A retrospective analysis of imaging and clinical records from 162 patients was performed. There were 38 patients with essential hypertension and 124 who were normotensive. Contact or compression of the VLM was present in 42.1 % (16/38) of the hypertensive group on the left and 47.3 % (18/38) on the right. In the normotensive group it was seen in 32.2 % (40/124) on the left and 26.6 % (33/124) on the right. There was no significant difference between the hypertensive and control groups with regard to contact or compression of the left VLM. The results support the contention that neurovascular compression (NVC) of the left or right VLM is a common finding on MRI in normotensive individuals. We therefore believe that high-resolution MRI cannot be used as a screening tool to identify patients who may benefit from surgery. Received: 26 April 1999/Accepted: 19 May 1999     

The evolving role of coronary computed tomography in understanding sex differences in coronary atherosclerosis

Our understanding of sex differences in subclinical atherosclerosis and plaque composition and characteristics have greatly improved with the use of coronary computed tomography (CCTA) over the past years. CCTA has emerged as an important frontline diagnostic test for women, especially as we continue to understand the impact of non-obstructive atherosclerosis as well as diffuse, high risk plaque as precursors of acute cardiac events in women.Based on its ability to identify complex plaque morphology such as low attenuation plaque, high risk non calcified plaque, positive remodeling, fibrous cap, CCTA can be used to assess plaque characteristics. CCTA can avoid false positive of other imaging studies, if included earlier in assessment of ischemic symptoms. In the contemporary clinical setting, CCTA will prove useful in further understanding and managing cardiovascular disease in women and those without traditional obstructive coronary disease.     

MRI of bone marrow disorders

Four factors can be used in MR of bone marrow: fat–water distribution, artifacts induced by bone trabeculae, diffusion, and uptake of contrast media. Fat–water is imaged using T1-weighted spin-echo, short tau inversion recovery (STIR), and fast STIR, in- and out-of-phase gradient echo, and fat pre-saturation sequences; bone trabeculae by gradient echo with long TE; diffusion by single-shot spin-echo. The injection of contrast media is a more easy and efficient way to improve the specificity. The value and limitations of those sequences are discussed in marrow replacements (metastases, lymphoma, leukemia) and in myeloid hyperplasia or depletion.     

Restriction spectrum imaging: An evolving imaging biomarker in prostate MRI

Restriction spectrum imaging (RSI) is a novel diffusion‐weighted MRI technique that uses the mathematically distinct behavior of water diffusion in separable microscopic tissue compartments to highlight key aspects of the tissue microarchitecture with high conspicuity. RSI can be acquired in less than 5 min on modern scanners using a surface coil. Multiple field gradients and high b‐values in combination with postprocessing techniques allow the simultaneous resolution of length‐scale and geometric information, as well as compartmental and nuclear volume fraction filtering. RSI also uses a distortion correction technique and can thus be fused to high resolution T2‐weighted images for detailed localization, which improves delineation of disease extension into critical anatomic structures. In this review, we discuss the acquisition, postprocessing, and interpretation of RSI for prostate MRI. We also summarize existing data demonstrating the applicability of RSI for prostate cancer detection, in vivo characterization, localization, and targeting. Level of Evidence: 5 J. Magn. Reson. Imaging 2017;45:323–336.