Matthew T. Heller

Superphysiologic FDG Uptake in the Non-Paralyzed Vocal Cord. Resolution of a False-Positive PET Result with Combined PET-CT Imaging.

The application of positron emission tomography imaging with 18F-fluorodeoxyglucose (FDG) to the extracranial head and neck has been proven to be effective in the detection and staging of malignancy. The FDG uptake of normal laryngeal tissue is symmetric and low, while benign lesions typically have only slight increases in FDG uptake. We report a case of asymmetric, superphysiologic FDG uptake in the contralateral vocal cord of a patient with a unilateral vocal cord paralysis secondary to sacrifice of the recurrent laryngeal nerve during pneumonectomy for lung cancer. The FDG uptake of the non-paralyzed vocal cord was increased multiple-fold, placing it well within the range of malignancy. Use of unique, combined PET-CT imaging localized the high FDG uptake to the non-paralyzed vocal cord, and laryngoscopy confirmed no evidence of malignancy in the vocal cord. This case demonstrates that a benign cause of false-positive FDG-PET imaging may be encountered during evaluation of the extracranial head and neck for malignancy. We aim to alert the reader to this potential pitfall in the interpretation of FDG-PET imaging, which can be resolved with the use of combined PET-CT imaging and clinical correlation.

NCI Workshop Report: Clinical and Computational Requirements for Correlating Imaging Phenotypes with Genomics Signatures.

The National Cancer Institute (NCI) Cancer Imaging Program organized two related workshops on June 26–27, 2013, entitled “Correlating Imaging Phenotypes with Genomics Signatures Research” and “Scalable Computational Resources as Required for Imaging-Genomics Decision Support Systems.” The first workshop focused on clinical and scientific requirements, exploring our knowledge of phenotypic characteristics of cancer biological properties to determine whether the field is sufficiently advanced to correlate with imaging phenotypes that underpin genomics and clinical outcomes, and exploring new scientific methods to extract phenotypic features from medical images and relate them to genomics analyses. The second workshop focused on computational methods that explore informatics and computational requirements to extract phenotypic features from medical images and relate them to genomics analyses and improve the accessibility and speed of dissemination of existing NIH resources. These workshops linked clinical and scientific requirements of currently known phenotypic and genotypic cancer biology characteristics with imaging phenotypes that underpin genomics and clinical outcomes. The group generated a set of recommendations to NCI leadership and the research community that encourage and support development of the emerging radiogenomics research field to address short-and longer-term goals in cancer research.

Hepatic transplantation: postoperative complications

Advances in surgical techniques and immunosuppression have made orthotopic liver transplantation a first-line treatment for many patients with end-stage liver disease. The early detection and treatment of postoperative complications has contributed significantly to improved graft and patient survival with imaging playing a critical role in detection. Complications that can lead to graft failure or patient mortality include vascular abnormalities, biliary abnormalities, allograft rejection, and recurrent or post-transplant malignancy. Vascular abnormalities include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava, as well as hepatic artery pseudoaneurysm, arteriovenous fistula, and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not used to diagnose allograft rejection, it plays an important role in identifying complications that can mimic rejection. Ultrasound is routinely performed as the initial imaging modality for the detection and follow-up of both early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are used to characterize biliary complications and computed tomography is used to confirm abnormal findings on ultrasound or for the evaluation of postoperative collections. The purpose of this article is to describe and illustrate the imaging appearances and management of complications associated with liver transplantation.

Imaging of the Female Perineum in Adults

The female perineum is a diamond-shaped structure inferior to the pelvic diaphragm and between the symphysis pubis and coccyx. The perineum is divided into the anterior urogenital triangle and the posterior anal triangle; the vulva represents the external genitalia. A wide array of diseases affect the female perineum in adults. Vulvar trauma, infection (including Fournier gangrene), developmental lesions, and thrombophlebitis can be investigated with various imaging modalities; vulvar malignancies are best imaged with magnetic resonance (MR) imaging to identify local-regional extent of disease. MR imaging is also the modality of choice for imaging of the distal urethra, although imaging of a urethral diverticulum also includes voiding cystourethrography and ultrasonography. The distal vagina at the level of the introitus is best imaged with MR imaging for assessment of Bartholin gland cysts and malignancies. Diseases encountered in the anus include anal carcinoma, fistula-in-ano, and anovaginal fistula, which can all be imaged with various modalities offering different sensitivities and fields of view. Lastly, musculoskeletal neoplasms affecting the perineum and vulva include mesenchymal, lipomatous, nerve sheath, and osseous neoplasms. These neoplasms can be imaged with both computed tomography and MR imaging, although the latter provides higher soft-tissue contrast and greater anatomic detail for diagnosis and determination of the extent of necessary surgery. Familiarity with the anatomy of the female perineum and appropriate selection of imaging modalities facilitate prompt and accurate diagnosis and treatment.

Infiltrative Hepatocellular Carcinoma: What Radiologists Need to Know

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The macroscopic growth pattern of HCC is subdivided into three categories: nodular, massive, and infiltrative. Infiltrative HCC accounts for 7%-20% of HCC cases and is confirmed at pathologic analysis on the basis of the spread of minute tumor nodules throughout large regions of the liver. Infiltrative HCC may represent a diagnostic challenge because it is often difficult to distinguish from background changes in cirrhosis at imaging. Infiltrative HCC usually spreads over multiple hepatic segments, occupying an entire hepatic lobe or the entire liver, and it is frequently associated with portal vein tumor thrombosis. The tumor is usually ill defined at ultrasonography and shows minimal and inconsistent arterial enhancement and heterogeneous washout at contrast material-enhanced computed tomography and magnetic resonance (MR) imaging. The tumor may be more visible among the surrounding liver parenchyma at diffusion-, T1-, and T2-weighted MR imaging. Several liver diseases can mimic the infiltrative appearance of this malignancy, including focal confluent fibrosis, hepatic fat deposition, hepatic microabscesses, intrahepatic cholangiocarcinoma, and diffuse metastatic disease (pseudocirrhosis). The prognosis for patients with infiltrative HCC is poor because the tumor is often markedly advanced and associated with vascular invasion at presentation. Survival after surgical resection is decreased; thus, infiltrative HCC is a contraindication for resection and transplantation. Knowledge of the key tumor characteristics and imaging findings will help radiologists formulate a correct and timely diagnosis to improve patient management.

Imaging of Neuroendocrine Tumors

Neuroendocrine tumors (NETs) constitute a large group of diverse neoplasms with a wide spectrum of clinical, imaging, and pathologic findings. Imaging diagnosis of NETs can be challenging, and several complementary imaging modalities may be needed during the diagnostic workup. Accurate interpretation of the imaging findings is important to facilitate diagnosis and contribute to patient management. This article discusses the gastrointestinal site-specific features and the tumor-specific features of several NETs and the role of several imaging modalities such as computed tomography, MR imaging, ultrasonography, and positron emission tomography in the evaluation of these NETs.

The Role of Ultrasonography in the Evaluation of Diffuse Liver Disease

The use of ultrasonography (US) to detect and characterize diffuse liver disease can be challenging, but remains a useful tool for the diagnosis and management of many diffuse parenchymal liver diseases such as cirrhosis, steatosis, and malignancies. Newer techniques, such as elastography, are proving useful for earlier detection of hepatic parenchymal changes. The role of US in the assessment of possible biliary ductal obstruction is well established, and Doppler US may provide additional physiologic information regarding hepatic blood flow. US plays a central role in target selection and guidance of percutaneous liver biopsies.

MDCT of renal trauma: correlation to AAST organ injury scale

Renal injuries affect 8-10% of patients presenting with blunt abdominal trauma. Imaging with multidetector computed tomography (MDCT) is the preferred modality at most trauma centers. Renal injuries have been categorized by several grading schemes in the literature. The classification proposed by the American Association for the Surgery of Trauma (AAST) predicts clinical outcome with reasonable accuracy. Although the AAST classification for renal injury is primarily based on findings during surgery, it has a strong correlation with MDCT findings.

Cystic Hepatic Lesions: A Review and an Algorithmic Approach

OBJECTIVE The purpose of this article is to review the different cystic hepatic lesions, with an emphasis on the imaging features that help to differentiate them, and to propose a practical algorithm for approaching the diagnosis of these lesions. CONCLUSION The number and morphology of the lesions and determination of whether there is a solid component are key imaging features that are helpful for approaching the diagnosis of cystic hepatic lesions. Familiarity with these features and knowledge of the clinical associations will help the radiologist to establish a definitive diagnosis or provide a reasonable differential diagnosis.

Academic Radiology in the New Health Care Delivery Environment

RATIONALE AND OBJECTIVES Ongoing concerns over the rising cost of health care are driving large-scale changes in the way that health care is practiced and reimbursed in the United States. MATERIALS AND METHODS To effectively implement and thrive within this new health care delivery environment, academic medical institutions will need to modify financial and business models and adapt institutional cultures. In this article, we review the expected features of the new health care environment from the perspective of academic radiology departments. CONCLUSIONS Our review will include background on accountable care organizations, identify challenges associated with the new managed care model, and outline key strategies-including expanding the use of existing information technology infrastructure, promoting continued medical innovation, balancing academic research with clinical care, and exploring new roles for radiologists in efficient patient management-that will ensure continued success for academic radiology.