Principal Imaging Modality Research Articles

Multimodality Imaging of Giant Prolapsing Left Atrial Myxoma

Through a case of a very large left atrial myxoma diagnosed in a 53-year old woman, we feature the complementary value of multimodality imaging. Two-dimensional echocardiography continues to be the principal imaging modality for intracardiac masses due to its accessibility and ability to provide basic information on mass morphology, position, and mobility. Real-time three-dimensional echocardiography offers more precise assessment of tumor size and attachment. Cardiac magnetic resonance allows superior tissue characterization, particularly important in differentiating a myxoma from a thrombus. Appropriate use of these various non-invasive imaging modalities is a safe and comprehensive preoperative diagnostic approach for patients with intracardiac masses.

Intestinal Fibrosis in Crohns Disease: Medical Treatment or Surgery?

Crohn's disease (CD) is a chronic panenteric disease of unknown aethiology tending to progress, inspite medical or surgical treatment. Intestinal fibrosis is among the most common complications of CD, resulting in stricture formation in the small intestine and colon. About 75% of CD patients will undergo surgery at least once over the course of their disease and fibrotic strictures represents the main indication for surgery and the first cause of hospitalization and costs for CD patients. Clinical management of intestinal strictures depends on the type of stricture: inflammatory strictures are treated medically and are usually responsive to treatment, while fibrotic strictures require surgery. Clinical decisions regarding the right treatment choice for such conditions require proper knowledge on what to expect from the emerging drug strategies and surgical techniques. To achieve optimal results in patients management an approach combining the expertise of both gastroenterologist and colorectal surgeon is essential. This review aims at providing clinicians with an overview on fibrotic strictures in CD patients particular focus will be placed on the principal imaging modalities, and the medical, endoscopic and surgical treatment options with relative indications, according to the most recent evidence available.

Imaging colorectal trauma using 64-MDCT technology

Computed tomography has evolved to become the principal imaging modality in the evaluation of colorectal trauma. Direct signs of colorectal trauma are usually highly specific but relatively insensitive and, therefore, indirect signs are important in the diagnostic of colorectal injuries. In addition, prompt recognition of colorectal injury is crucial as even short delays in its diagnosis have been shown to significantly increase both morbidity and mortality. All these things make colorectal injury a challenge for radiologists. The purpose of this review is to describe and analyze the various computed tomography (CT) findings of colorectal injuries in both penetrating and blunt trauma using 64-multirow detector computed tomography technology, based on our experience in a level I trauma center. Additionally, the CT protocol methods specific to colorectal injuries are detailed.

Localization of Parathyroid Adenomas by Sonography and Technetium Tc 99m Sestamibi Single-Photon Emission Computed Tomography Before Minimally Invasive Parathyroidectomy

The purpose of this study was to determine the utility of radiologist-performed sonography as the principal modality for parathyroid localization before minimally invasive parathyroidectomy. Both sonography and technetium Tc 99m sestamibi single-photon emission computed tomography (SPECT) are commonly performed during imaging evaluation of patients with primary hyperparathyroidism (HPTH). Sonographic examinations ordered during the study period were performed by 1 author (M.E.T.), and results were immediately reported. Findings of a subsequent Tc 99m sestamibi study were recorded blinded to the sonographic results. The sensitivity and specificity of sonography and Tc 99m sestamibi SPECT were assessed with the use of surgery and pathology reports as a reference standard. The 2007 global Medicare reimbursement rates were used to assess the costs of preoperative localization. Parathyroidectomy was performed in 144 of 172 patients evaluated by both modalities. The sensitivity, specificity, and positive predictive value of sonography for identifying abnormal parathyroid glands were 74%, 96%, and 90%, respectively. Sonography correctly localized a single adenoma or suggested multiglandular disease in 112 of 144 patients (78%). The sensitivity, specificity, and positive predictive value of SPECT were 58%, 96%, and 89%. Technetium 99m sestamibi SPECT correctly predicted an adenoma or multiglandular disease in 88 of 144 patients (61%). Five patients with negative sonographic findings were shown to have uniglandular disease on Tc 99m sestamibi SPECT. Selective use of Tc 99m sestamibi SPECT (ie, when sonographic findings were negative or equivocal) would have decreased the cost of imaging by 53%. Radiologist-performed sonography may potentially be used as a principal imaging modality for patients with HPTH. Selective use of Tc 99m sestamibi in cases with negative or equivocal sonographic findings can decrease the cost of imaging before parathyroid resection considerably.

P.1.e.002 A case of transient global amnesia with high signal intensities at the both hippocampi on diffusion-weighted MRI

Magnetic resonance imaging (MRI) serves as the principal imaging modality to diagnose and plan treatment for children with cutaneous vascular anomalies. While routine MRI protocols can lead to the correct diagnosis in the majority of cases, the imaging appearances can sometimes be nonspecific or confusing, yielding more than one possible diagnosis. This review highlights specific MRI sequence recommendations and scanning tips that can optimize the imaging protocol to increase diagnostic confidence.

Central pulmonary embolism diagnosed by real-time endobronchial ultrasound

Introduction: Life threatening central pulmonary embolism (PE) is defined as thrombotic occlusion of the main pulmonary trunk or of main or lobar pulmonary artery. These vessels accompany the trachea, the main and lobar bronchi at a distance of less than 5mm. Chest-CT enhanced with iv contrast (Angio-CT) has become the principal imaging modality to evaluate suspected, central PE. Here we report imaging of central PE using real-time endobronchial ultrasound (rtEBUS).

Magnetic resonance angiography and vascular corrosion casting as tools in biomedical research: application to transgenic mice modeling Alzheimer's disease

In vivo imaging technologies are presently receiving considerable attention in the biomedical and pharmaceutical research areas. One of the principal imaging modalities is magnetic resonance imaging (MRI). The multiparametric nature of MRI enables anatomical, functional and even molecular information to be obtained non-invasively from intact organisms at high spatial resolution. Here we describe the use of one MRI modality, namely angiography (MRA), to non-invasively study the arterial vascular architecture of APP23 transgenic mice modeling Alzheimer's disease. Because the spatial resolution of the technique is limited, the in vivo studies are complemented by a powerful analysis of the vasculature using vascular corrosion casting. Both techniques revealed age-dependent blood flow alterations and cerebrovascular abnormalities in these mice. Our experience suggests that MRA complemented by cast analysis are important tools to describe vascular alterations and test new therapy concepts in animal models of AD. Furthermore, being non-invasive, MRA can also be applied to studies in patients suffering from this disease.

Controversies in emergency radiology: acute appendicitis in children--the case for CT.

Acute appendicitis is the most common condition requiring surgical intervention in childhood. The clinical diagnosis of acute appendicitis is often not straightforward and can be challenging. Approximately one-third of children with the condition have atypical clinical findings and are initially managed nonoperatively. There is currently great variability in the utilization of imaging for the assessment of suspected acute appendicitis in children. The principal imaging modalities utilized are graded-compression sonography and CT. Sonography has important diagnostic limitations that are addressed by CT. The principal advantages of CT include its operator independency, with resultant higher diagnostic accuracy, enhanced delineation of disease extent in perforated appendicitis, and improved patient outcomes including decreased negative laparotomy and perforation rates.

Imaging appearances of metastases from neuroendocrine tumours of the pancreas.

Endocrine tumours of the pancreas (ETPs) are rare neoplasms that are frequently malignant. Despite their usual slow growth, metastases do occur and have a major impact on prognosis. Metastases may be the first manifestation of disease, and recognition of particular radiological features of these hypervascular metastases should suggest their possible neuroendocrine origin. Although somatostatin receptor scintigraphy has changed the imaging strategy for these tumours and has become their principal imaging modality, radiological techniques are still required for precise localization of scintigraphic hot spots and monitoring of response to therapy. This pictorial review shows the typical radiological features of ETP metastases and emphasizes the role of different imaging modalities.

Fluorine-18 fluorodeoxyglucose positron emission tomography in the staging and follow-up of lymphoma: is it time to shift gears?

Positron emission tomography (PET) imaging has become a very useful technique for staging and monitoring therapy response in lymphoma, providing unique information about the biological behavior of disease. Increased fluorine-18 fluorodeoxyglucose (FDG) uptake in lymphoma is based on elevated glycolysis and longer residence time of FDG in malignant cells compared with most normal tissues. The metabolic information provided by this technique suggests that FDG-PET may be more sensitive than the anatomical imaging modalities. Computed tomography (CT) is the principal imaging modality for the staging and restaging of lymphoma. Nonetheless, this technique has significant shortcomings, particularly in the post-therapy setting. Gallium-67 scintigraphy has played an important role in monitoring response to therapy and follow-up of patients; however, the sensitivity of 67Ga depends on the subtype of lymphoma and the size and location of disease. Published results strongly indicate that FDG-PET is superior to 67Ga imaging and may be equal or superior to CT for the detection of nodal as well as extranodal involvement in lymphoma.

MRI appearance of cervical incompetence in a pregnant patient

Ultrasonography is currently the principal imaging modality for diagnosing cervical incompetence during pregnancy. Various technical factors, both patient and technologist/transducer related, may limit its evaluation for cervical incompetence. MRI is not dependent on these technical considerations. MRI may demonstrate a higher degree of soft tissue contrast than ultrasonography for depicting uterine anatomy. MRI may, in some instances, be more accurate in depicting cervical incompetence in the gravid patient. We present the first case of cervical incompetence in a pregnant patient diagnosed by MRI, in which ultrasonography failed to provide conclusive evidence of extra-uterine herniation of the amniotic sac.

Lack of utility of (111)In-pentetreotide scintigraphy in localizing ectopic ACTH producing tumors: follow-up of 18 patients.

Octreotide scintigraphy has been advocated as the principal imaging modality for localizing ectopic ACTH-secreting tumors in Cushing's syndrome. To assess its usefulness we reviewed the course of 18 consecutive patients with ectopic ACTH-producing tumor. Imaging included (111)In-pentetreotide scintigraphy, computed tomography (CT), and/or magnetic resonance imaging (MRI). Tumor was detected initially in 7/18 patients, and in 3/18 during follow-up. No ACTH-secreting tumor was detected by octreotide scintigraphy when CT/ MRI were negative. Seventeen of forty octreotide scintigrams were abnormal. CT and/or MRI confirmed tumors in 10, but demonstrated nonendocrine lesions in association with 6 false positive octreotide scintigrams. Hepatic venous sampling for ACTH refuted one lesion detected by octreotide and CT scans. Twenty-three of forty octreotide scintigrams were normal. Of these, 8 were false negative, as CT and/or MRI detected tumor; 10 agreed with negative CT and MRI, and 5 correctly refuted false positive CT and/or MRI scans. Repeated CT/ MR, but not octreotide scintigraphy, led to tumor resection in 2 patients. We conclude that octreotide scintigraphy does not offer greater sensitivity than CT/MRI and that false positive scans are common. Although octreotide scintigraphy may be helpful in selected cases, it is not a significant advance over conventional imaging for ectopic ACTH-secreting tumors.

Coronary Intravascular Ultrasound

Abstract For several decades, contrast angiography has served as the principal imaging modality used to assess the anatomic severity of coronary artery disease. Recent technical advances in acoustics and microelectonics have permitted development and refinement of miniaturized ultrasound devices capable of real-time tomographic coronary imaging. This approach, intravascular ultrasound, represents an emerging alternative to angiography for direct visualization of coronary anatomy during diagnostic and interventional catheterization. Clinical studies comparing angiography to intravascular ultrasound have demonstrated frequent differences in quantitative or qualitative findings. Accordingly, intraluminal ultrasound imaging is increasingly utilized to confirm, refute, or supplement angiographie data in patients with coronary disease. The discrepancies between angiography and intravascular ultrasound can be explained by the characteristics of these two different imaging techniques. Angiography, which portrays the vessel as a silhouette of the lumen, whereas ultrasound depicts the coronary from a tomographic perspective, providing cross-sectional images that portray not only the lumen, but also the deeper intramural structures.

Computed Tomography in the Early Detection of Skeletal Involvement With Multiple Myeloma

IT IS generally accepted that approximately 25% to 50% of the trabecular spongiosum in the vertebrae must be resorbed or destroyed to be detected by conventional roentgenography. 1 Radionuclide bone scanning is more sensitive in detecting focal osseous destruction based on the dynamic state of reactive osteoblastic activity and/or increased regional bone blood flow. Specifically, however, in multiple myeloma, bone scans are frequently falsely negative, and conventional roentgenography continues to be the principal imaging modality to assess skeletal involvement. 2-4 This case illustrates a potentially sensitive method of detecting early skeletal destruction in multiple myeloma using high-resolution computed tomography (CT). Report of a Case A 43-year-old woman with known multiple myeloma had low-back pain and sciatica. Conventional roentgenograms of the lumbosacral spine demonstrated mild generalized demineralization but no focal abnormalities (Fig 1); CT of the lumbar spine was performed to evaluate lumbar disk disease. Serial scans disclosed a protruding disk