Direct sagittal CT in the evaluation of temporal bone disease

The human temporal bone is an extremely complex structure. Direct axial and coronal CT sections are quite satisfactory for imaging the anatomy of the temporal bone; however, many relationships of the normal and pathologic anatomic detail of the temporal bone are better seen with direct sagittal CT sections. The sagittal projection is of interest to surgeons, as it has the advantage of following the plane of surgical approach. This article describes the advantages of using direct sagittal sections for studying various diseases of the temporal bone. The CT sections were obtained with the aid of a new head holder added to our GE CT 9800 scanner. The direct sagittal projection was found to be extremely useful for evaluating diseases involving the vertical segment of the facial nerve canal, vestibular aqueduct, tegmen tympani, sigmoid sinus plate, sinodural angle, carotid canal, jugular fossa, external auditory canal, middle ear cavity, infra- and supralabyrinthine air cells, and temporomandibular joint.

Orbital space-occupying lesions: role of computed tomography and magnetic resonance imaging. An analysis of 145 cases

CT and MRI of the orbit have significantly enhanced the diagnosis of orbital lesions. Because of these techniques, disorders of the globe, structures within the bony orbit, surrounding structures of the eye, and optic pathways can now be diagnosed with much more certainty than before.

Malignant uveal melanoma and simulating lesions: MR imaging evaluation

Twenty-one patients with intraocular disease were studied by magnetic resonance (MR) imaging and computed tomography (CT). In 13 cases, malignant uveal melanoma was considered the likely diagnosis. Both imaging methods were accurate in determining the location and size of uveal melanomas. MR imaging was superior for the assessment of possible associated retinal detachment, for assessment of vitreous change, and for differentiating uveal melanoma from choroidal hemangioma and choroidal detachment. A case of retinal gliosis could not be differentiated from uveal melanoma by either technique. Uveal melanomas appeared as hyperintense lesions on T1-weighted images and as hypointense lesions on T2-weighted images. High signal intensity of the vitreous was observed in patients with vitritis and in those who were thought to have protein leaking into the vitreous as a result of impairment of the retinal-blood barrier.

Magnetic resonance imaging in the diagnosis of nonsquamous tumors of the head and neck

Nonsquamous cell tumors of the head and neck can be reliably evaluated by MRI. In certain pathologic entities, it appears that MRI can provide more information than CT scan.

Chronic otomastoiditis: a conceptual understanding of CT findings

Inflammation of the middle ear cleft is a disease of great interest from both clinical and radiologic points of view. The attic floor (tympanic diaphragm), the tympanic isthmus, and the aditus ad antrum play important roles in inflammatory processes of the middle ear cleft. The anatomy of the temporal bone at this level was examined by studying microdissections of 250 fresh temporal bones and reviewing over 1,000 high-resolution computed tomography (CT) scans of the temporal bones. The pertinent anatomy is described, and the role of the tympanic diaphragm and isthmus in determining the degree to which middle ear disease may progress is stressed. The appearances on CT scans of chronic otomastoiditis, tympanosclerosis, cholesterol granuloma, attic retraction pocket, and acquired cholesteatoma are reviewed and illustrated.

CT in the evaluation of the orbit and the bony interorbital distance

The distance between the orbits and their individual dimensions are important in the diagnosis of craniofacial anomalies. Most observers rely on standard radiographs for measuring the bony interorbital distance. Tomography of the skull base and orbital computed tomography (CT) can also be used. This article describes the normal range of the bony interorbital distance and other useful orbital linear and angular measurements as determined from a series of CT scans of the orbits in 400 adults who had CT for other purposes. The normal interorbital distance measured at the posterior border of the frontal processes of the maxilla on nonrotated scans, in the plane of the optic nerve, ranges from 2.29 to 3.21 cm (average, 2.67 cm) in men and 2.29 to 3.20 cm (average, 2.56 cm) in women. The widest interorbital distance lies behind the posterior poles of the globes. This ranges from 3.16 to 4.10 cm (average, 3.37 cm) in men and 2.93 to 3.67 cm (average, 3.20 cm) in women.

Use of CT in the evaluation of cochlear otosclerosis

Otosclerosis (otospongiosis) occurs when the hard endochondral bone of the otic capsule is replaced by spongy vascular foci of haversian bone. Using computed tomography (CT), we studied the ears of 32 selected patients with mixed or sensorineural hearing loss (one patient had normal hearing); 24 were suspected of having otosclerosis. CT proved valuable in detecting cochlear otosclerosis, foci of demineralization, and changes in bony texture and enables the easy recognition of subtle radiographic findings. Our paper also reports the CT findings of temporal bones in osteogenesis imperfecta and Paget disease.

Cartilage involvement in laryngeal carcinoma: correlation of CT and pathologic macrosection studies

Fifteen patients with laryngeal epidermoid carcinoma underwent CT of the larynx prior to surgery. Whole mount sections of the extirpated larynx cut in the horizontal plane were compared with the corresponding level of the preoperative CT sections. This study in particular was designed to evaluate the accuracy of diagnosing cartilage involvement by CT and to correlate CT findings with histologic involvement. Our results indicate that CT correlates well with anatomic location of gross cartilage involvement by the tumor; however, small macroscopic invasion of the laryngeal cartilages may be difficult to diagnose with CT. Microscopic involvement of the cartilages cannot be diagnosed with CT. Decisions regarding conservation surgery cannot be based on CT evaluation alone.

CT in the evaluation of the vestibulocochlear nerves and their central pathways. Evaluation of neurotologic disorders

CT has evolved to become an important technique for the diagnosis of neurotologic disorders. By obtaining thin sections, the central pathway of the vestibulocochlear nerve can be rather properly evaluated with satisfactory clinical correlation when pathology exists. The validity of central vestibular and audiometric signs can be best substantiated with CT. The functional neuroanatomy of the vestibulocochlear and vestibulo-oculomotor systems is discussed. Results of the assessment of endocranial lesions involving the vestibulocochlear system are presented.

Congenital sensorineural hearing loss

The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems.

Work in progress: intra-arterial P-32 chromic phosphate for prevention of postoperative liver metastases in high-risk colorectal cancer patients

Eight patients with locally extensive colorectal cancer were treated with colloidal P-32 chromic phosphate via the superior mesenteric artery following resection to prevent development of liver metastases. Less than 2% of the injected dose was found in the right atrial blood following the first pass through the liver and less than 1% in the urine. Therapy was tolerated well by all patients, with no acute complications. Long-term follow-up is needed to determine the effect of P-32 on the liver and the frequency of hepatic metastases.

Computed tomography of the larynx: correlation with anatomic and pathologic studies in cases of laryngeal carcinoma

Seven patients with known carcinoma of the larynx underwent computed tomography (CT) of the larynx prior to surgery. Whole-mount sections of the extirpated larynx cut in the horizontal plane were compared with the corresponding level of the preoperative CT sections to demonstrate the validity of CT scanning in the evaluation of tumors of the larynx. The results indicate that CT scanning accurately demonstrates the anatomic location and gross size of laryngeal tumor, although early invasion of the laryngeal cartilages may be difficult to diagnose with CT. It is concluded that preoperative CT scanning of the larynx is the radiologic procedure of choice for evaluating carcinoma of the larynx.

Computed air myelography of the lumbosacral spine

Plain computed tomography (CT) of the lumbosacral spine may be a reliable method for diagnosing herniated disk when abundant epidural fat is present. When epidural fat is not sufficient, CT after the administration of nonionic contrast medium (170 mg I/ml) and/or regular metrizamide myelography have been used. Ten patients were studied by CT enhanced with air injected as a negative contrast agent. The findings were correlated with plain and contrast-enhanced (metrizamide) CT as well as conventional myelography. The technique is described and advantages and disadvantages of the method are discussed. Air-contrast CT is useful in the evaluation of herniated disk in cases with equivocal findings on plain CT and in patients with a history of allergic reaction to iodinated contrast media.

Computed tomography in the evaluation of patients with persistent hyperplastic primary vitreous (PHPV)

The computed tomographic (CT) findings in 5 patients with proven persistent hyperplastic primary vitreous (PHPV) are described. PHPV arises when the embryonic hyaloid vascular system fails to regress normally. Clinically, this condition usually manifests as unilateral or bilateral leukokoria and is one of the more important and frequent conditions mimicking retinoblastoma. The spectrum of CT findings include: (a) soft-tissue replacement (infiltration) of the vitreous body; (b) retrolental soft tissue along the Cloquet canal; (c) absence of abnormal calcification within the orbit; (d) microphthalmus; (e) retrohyaloid layered blood; and (f) hypervascularity of the vitreous humor.

Comparison of intravenous and intramuscular sincalide (C-terminal octapeptide of cholecystokinin) on gallbladder contraction in man

The effects of intramuscular and intravenous sincalide on gallbladder contraction and visualization of the bile ducts were compared in a group of 37 subjects referred for oral cholecystography. The maximum reduction in gallbladder size observed after sincalide 400 ng/kg intramuscular, 54.7 +/- 7.2% (mean +/- SEM), occurred 25 min after injection and was significantly greater than that observed after sincalide 20 ng/kg intravenous, 26.5 +/- 8.2%. Maximum reduction after sincalide 100 ng/kg intramuscular was 47.3 +/- 8.2%. The common bile duct was visualized in 60 and 45% of subjects after intramuscular and intravenous sincalide, respectively. The use of intramuscular sincalide 400 ng/kg intramuscular is an effective and convenient adjunct to oral cholecystography when significant gallbladder contraction and visualization of the common bile duct is desired.

Ultrasonography of blood during stasis and coagulation

A series of in vitro and animal experiments were performed to determine ultrasonic features of blood during stasis and coagulation. Liquid whole blood became echogenic within a few seconds to 3 minutes following the onset of stasis. This occurred in citrated human blood allowed to stand and in occluded segments of vena cava and aorta of dogs. Mechanical agitation of the blood in stasis caused a disappearance of echoes. This echogenicity occurred with gray-scale and real-time ultrasonography using 7.5-mHz transducers, but was not observed with 3.5-mHz transducer used in real-time scanning. Whole blood clot was echogenic both with 7.5- and 3.5-mHz scanning. Fibrin clot was sonolucent. Echogenicity with stasis did not occur with plasma, serum, or packed erythrocytes. The development of echogenicity required the presence of fibrinogen or its products plus erythrocytes. The echogenicity of blood during stasis detectable by high-frequency ultrasonography probably was related to physical layering of blood products. The disappearance of reflective echoes following agitation suggested that the layering could be readily disrupted.

Real-time ultrasonography during biliary surgery

High resolution real-time B-mode ultrasound scanning using a sterile 7.5 MHz transducer was performed during operations on the biliary tract. Ultrasound is useful for locating the common bile duct in the presence of acute inflammation and other abnormal anatomy, detecting small calculi in the gallbladder with a thickened wall, measuring the caliber of the common bile duct, and identifying calculi in the common bile duct. Intraoperative ultrasonography can permit earlier and more precise appraisal of operative findings and, thereby, decrease operative time.

Partial splenic embolization in the treatment of hypersplenism

Transcatheter embolization of the spleen has been associated with serious complications, such as splenic abscess, rupture of the spleen, pneumonia, and septicemia. These complications, with their grave consequences, have prevented the use of this procedure as an alternative to operative splenectomy in selected cases. A detailed description of our method, which consists of partial splenic embolization, antibiotic prophylaxis, adequate pain control, and careful pre- and postembolization, is reported. Thirteen patients with hypersplenism were successfully treated with transcatheter partial embolization of their spleen.

Diagnosis of urine extravasation after renal transplantation

Urine extravasation in the early postoperative period after renal transplantation is a serious complication requiring expedient surgical intervention. Whereas clinical and laboratory findings are inconclusive, radiologic diagnostic studies have definite value. Routine ultrasound and radioisotope studies were performed on 111 renal transplant patients. In the eight who developed urine extravasation, ultrasound and/or radioisotope studies identified the extravasation in seven cases. Four of the eight were studied by intravenous pyelography and another two were studied by cystography. All results were positive. We recommend use of radioisotope and ultrasound studies for routine postoperative screening with invasive techniques reserved for inconclusive cases.

Percutaneous biopsy of renal transplants using ultrasonographic guidance

The transplanted kidney is an ideal organ for study by ultrasonic methods because it is located superficially in the iliac fossa and it is free of superimposed echoes from the intestines. Therefore, it is possible to localize the transplant accurately, measure the distance from the skin to the surface of the kidney and determine with precision the angle of the intended pathway of the needle.

Skin necrosis following extravasation during peripheral phlebography

Skin necrosis is an unusual complication following venography of the legs. The authors have found only four cases in the English literature. Two cases of skin necrosis following extravasation of contrast medium are reported. Their pathogenesis, clinical course, and treatment are discussed along with methods of prevention.

Mycobacterium bovis infection in baboons (Papio papio)

Two tuberculin-positive baboons in a primate colony were found to have grossly visible tuberculous lesions in the liver, spleen, lung, and mediastinal lymph nodes on necropsy. Results of histopathologic examination of the tissues showed granulomas with Langhans giant cells. An acid-fast organism was isolated from tissues of each baboon; the isolates were identified as Mycobacterium bovis by being negative for niacin production and nitrate reduction and by their susceptibility to thiophen-2-carbosylic acid hydrazide and to 5% glycerol.