Deborah L. Reede

Internal jugular vein thrombosis

Internal jugular vein thrombosis is a vascular disorder that is easily overlooked or misdiagnosed. It occurs in a variety or clinical settings which disrupt normal blood flow through the internal jugular vein. Intravenous drug abusers represent a high risk group in this study. Diagnosis is readily made by computed tomography. Seven patients are presented, with discussion of the pathogenesis, clinical findings, radiologic features, potential complications, and treatment rationale.

Vascular Lesions of the Orbit: More than Meets the Eye

Vascular lesions of the orbit may be classified on the basis of their natural history, growth pattern, and histologic composition as capillary hemangiomas, venous vascular malformations, venous lymphatic malformations, arterial and arteriovenous lesions, or neoplasms. Most follow a characteristic pattern of clinical development and have one or more specific imaging features that allow diagnosis. Hemangiomas typically manifest at or soon after birth and subsequently involute. They are nonencapsulated, poorly circumscribed, often lobulated, and largely extraconal in location. Cavernous malformations are septate and well circumscribed, may exhibit progressive enhancement on delayed images, and do not involute. Orbital varices appear distended on images obtained with the patient prone or during the Valsalva maneuver. Venous lymphatic malformations show multiple fluid-fluid levels, enlarge during viral infections, and may manifest as chocolate-colored cysts after an acute hemorrhage. Arteriovenous malformations, fistulas, and aneurysms have typical angiographic features. Hemangiopericytomas arise from the paranasal sinuses and show early tumor blush and persistent staining on angiographic images. Hemangioblastomas appear as enhancing mural nodules with associated cysts and serpentine flow voids on magnetic resonance (MR) images. Choroidal hemangiomas and melanomas can be differentiated on the basis of their appearances on T2-weighted MR images. Patients with vascular orbital and ocular metastases commonly have a history of breast or lung primary tumors.

Diagnosis of surgical sinusitis using nasal endoscopy and computerized tomography

The ability to identify surgical sinus disease using diagnostic nasal endoscopy and coronal CT scanning of the paranasal sinuses is studied prospectively. Fifty consecutive patients with symptoms of chronic sinusitis lacking surgical indications by traditional work‐up comprise the patient population. Sixty percent had endoscopic or CT indications for surgery. There was a 90% correlation between endoscopy and CT examination with the combined work‐up being more accurate than either modality alone. Functional endoscopic sinus surgery was performed in 18 cases. There were no major complications. Approximately 89% of the postoperative group report significant improvement, with 55.6% reporting total relief of symptoms.

Radiographic imaging for the cochlear implant.

Imaging plays an essential role in evaluating the cochlear implant candidate and the results of implantation. Eighteen candidates for cochlear implantation were reviewed for this study. Fourteen received implants; all but one, intracochlear devices. Based on the trial use of multiple techniques, a protocol has been established for the use of radiography in implant studies. The protocol suggests preoperative high resolution semiaxial computed tomographic scanning, intraoperative anteroposterior transorbital plain films if there is doubt concerning the electrode placement, and postoperative plain films in cases of unexpected poor device performance. In cases with complications, postoperative CT scanning may be required.

Correlation of fine needle aspiration biopsy and ct scanning of parotid masses

Preoperative evaluation of parotid tumors still poses difficult problems for the head and neck surgeon. The complex anatomy of the parotid space leads to difficulty in localizing these tumors. In addition, physical examination will rarely determine whether a parotid lesion is benign or malignant. High resolution CT scanning with contrast and fine needle aspiration can provide enough preoperative information to enable the surgeon to counsel his patient concerning possible risks and the extent of surgery that may be indicated. We are able to determine tumor location, multiple or bilateral masses, associated adenopathy, and often specific tumor histology. Forty‐two parotid aspirates and 26 CT scans were reviewed and correlated with their postoperative pathology specimen. Parotid aspiration cytology was found to be a highly accurate and safe procedure for preoperative determination of parotid pathology. However, the CT scan was specific only in defining the anatomic localization and extent of a parotid mass.

Cholesteatoma vs. Cholesterol Granuloma of the Petrous Apex

Lesions involving the petrous apex are rarely encountered in clinical practice. This directly affects the ability of the otolaryngologist to diagnose and effectively treat these lesions. Greater physician awareness and increased technologic capability are leading to more effective management of pathologic conditions involving this area of the temporal bone.

Computed tomography of spinal chordomas

Computed tomography of 16 spinal chordomas revealed lytic lesions, or lytic and blastic lesions, of 2 or more adjacent vertebrae and a fairly well-delineated soft tissue mass in 16 patients. Intravenous contrast enhancement revealed multiple zones of hypodensity in 5 tumors pathologically proved to contain areas of cystic degeneration. Invasion of the epidural space was noted on computed tomography in 2 vertebral and 7 sacral lesions, and on myelography in 7 vertebral lesions. Computed tomography is ideal for delineation of the soft tissue component of these lesions, detection of sacral lesions at an early stage, planning of surgical excision or irradiation treatment, and detection of recurrence.

Interpretive Error in Radiology

OBJECTIVE Although imaging technology has advanced significantly since the work of Garland in 1949, interpretive error rates remain unchanged. In addition to patient harm, interpretive errors are a major cause of litigation and distress to radiologists. In this article, we discuss the mechanics involved in searching an image, categorize omission errors, and discuss factors influencing diagnostic accuracy. Potential individual- and system-based solutions to mitigate or eliminate errors are also discussed. CONCLUSION Radiologists use visual detection, pattern recognition, memory, and cognitive reasoning to synthesize final interpretations of radiologic studies. This synthesis is performed in an environment in which there are numerous extrinsic distractors, increasing workloads and fatigue. Given the ultimately human task of perception, some degree of error is likely inevitable even with experienced observers. However, an understanding of the causes of interpretive errors can help in the development of tools to mitigate errors and improve patient safety.

Computerized Axial Tomography in the Diagnosis and Management of Thyroid and Parathyroid Disorders

Computerized axial tomography (CAT) was used to study 39 patients with known thyroid disease and 14 patients with primary hyperparathyroidism. In all, CAT was performed only when information that was required for diagnosis or therapy was not available from other less expensive techniques. The greatest value was found in the evaluation of cryptic symptoms or structures in the neck after surgery for thyroid cancer, the assessment of the extent of thyroid cancer, the localization of aberrant thyroid tissue, the etiology of unexplained recurrent laryngeal nerve paralysis and the identification and delineation of mediastinal goiter. In six of 14 patients undergoing neck exploration for primary hyperparathroidism CAT correctly localized the site of the enlarged parathyroid glands including one mediastinal parathyroid adenoma and one patient with two parathyroid adenomas.

The use of computed tomography in evaluating chest wall pathology

Forty-nine patients with chest wall lesions were evaluated by computed tomography (CT) and conventional radiography. Computed tomography was found to be indispensable for detecting and precisely localizing these lesions. It revealed unsuspected bone destruction and lung, pleural, and mediastinal involvement, as well as invasion of the spinal canal. In more than two thirds of the patients, CT provided additional information of clinical importance in management and, in one third, treatment was altered or the surgical approach modified because of the CT findings. Computed tomography is an essential diagnostic modality in evaluating chest wall lesions.