RESUMEN
BACKGROUND AND PURPOSE: With a 64-channel multidetector row CT, imaging acquisition during speech, swallowing, or phonation has become feasible. However, the actual benefit of these additional focused images should be critically evaluated with respect to radiation dose. The purpose of this study was to determine if dedicated laryngeal CT using breath-holding and straw-blowing improved the accuracy of TNM-staging for patients with biopsy-proved laryngeal carcinomas in comparison with a standard neck CT. MATERIALS AND METHODS: A total of 27 patients underwent a standard neck CT and a laryngeal CT with additional images acquired while patients held their breath or blew through a straw. Two radiologists interpreted the neck CT and later the laryngeal CT and assigned a TNM-stage for each case. These interpretations were compared with a TNM-stage determined by surgery and/or clinical examination for the individual patients. The accuracy of standard neck CT was compared with the accuracy of laryngeal CT. RESULTS: The overall accuracy was not significantly different between standard neck CT and the additional laryngeal CT and was, in fact, lower in cases with additional larynx images. The accuracy of staging was slightly improved with the additional laryngeal CT for glottic cancers; however, it was decreased for supraglottic cancers. The accuracy of a dichotomous diagnosis of early-versus-advanced-stage cancer was 0.86 for the standard neck CT and 0.80 for the laryngeal CT. The readers' confidence levels did not improve with the use of the additional images. CONCLUSIONS: In the era of isovoxel multidetector CT technology and judicious monitoring of radiation dose, a standard neck CT with coronal and sagittal reformats should suffice for the staging of laryngeal cancer.
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Neoplasias Laríngeas/diagnóstico por imagen , Estadificación de Neoplasias/normas , Tomografía Computarizada por Rayos X/normas , Anciano , Anciano de 80 o más Años , Biopsia , Glotis/diagnóstico por imagen , Humanos , Neoplasias Laríngeas/patología , Neoplasias Laríngeas/cirugía , Laringe/diagnóstico por imagen , Masculino , Cuello/diagnóstico por imagen , Estadificación de Neoplasias/métodos , Estadificación de Neoplasias/estadística & datos numéricos , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Mecánica Respiratoria , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada por Rayos X/estadística & datos numéricosRESUMEN
Fibrous orbital tumors present clinically and radiographically in a broad spectrum ranging from a benign mass, to locally aggressive tumor, to invasive malignancy. Pathologic analysis and diagnosis are often challenging, usually based on a combination of light microscopy, immunohistochemistry, and electron microscopic findings. Some light microscopic and immunohistochemical findings, however, are relatively characteristic. A storiform or cartwheel pattern and vimentin staining are characteristic of fibrous histiocytoma. A herringbone pattern is usually found in fibrosarcoma. A "patternless pattern" and CD34 staining is found most commonly in solitary fibrous tumor. CT and MR imaging findings, as well as clinical presentation, in fibrous orbital lesions are often difficult to distinguish from those of other orbital masses, although there may be useful clues. Benign fibrous lesions are usually well-circumscribed and may chronically remodel bone, whereas more aggressive malignant fibrous tumors tend to have infiltrating margins and may destroy bone on CT or MR imaging. With malignant fibrous masses, enhancement patterns on CT or MR imaging may be more inhomogeneous, with avascular or necrotic nonenhancing regions. At MR imaging, benign lesions tend to be homogeneous on T1, T2, and postgadolinium T1-weighted images, whereas malignant soft tissue lesions may change their pattern from homogeneous on T1-weighted images to heterogeneous with low signal septations on T2-weighted images. Low T2 signal comprising part or all of a fibrous lesion correlates with dense collagen fibers, with a less cellular matrix. Areas of hyperintensity on T2-weighted images correspond with a more cellular matrix of fibroblasts and other cells. Calcification within a tumor, however, may give a similar appearance. Thus, if a lesion has predominantly low signal on T2-weighted images, or less specifically has low signal septations, then a fibrous orbital lesion with high collagen content may be ranked higher in the differential diagnosis (see Figs. 2E and 3B). When T2 signal is intermediate-to-high, then one has a difficult time narrowing the differential diagnosis. Radiographically, distinguishing these lesions from other fibrous orbital lesions, as well as from other varieties of orbital masses, is difficult. Differential diagnosis of fibrous orbital masses includes all the fibrous lesions described in this article, in addition to schwannoma (Fig. 7), neurofibroma (Figs. 4 and 8), hemangiopericytoma (Figs. 9 and 10), rhabdomyosarcoma, meningioma, lymphoma, and metastasis (Figs. 11 and 12). A history of prior orbital irradiation for retinoblastoma or other tumors may raise the possibility of radiation-induced secondary tumors, such as MFH, fibrosarcoma, and osteosarcoma. Determining the extent of orbital involvement remains the primary goal of the radiologist. The final diagnosis still rests with the pathologist.
Asunto(s)
Histiocitoma Fibroso Benigno/diagnóstico , Neoplasias de Tejido Fibroso/diagnóstico , Neoplasias Orbitales/diagnóstico , Biomarcadores de Tumor/análisis , Colágeno/análisis , Diagnóstico Diferencial , Histiocitoma Fibroso Benigno/patología , Humanos , Aumento de la Imagen/métodos , Inmunohistoquímica , Imagen por Resonancia Magnética/métodos , Microscopía Electrónica , Neoplasias de Tejido Fibroso/patología , Neoplasias Inducidas por Radiación/diagnóstico , Neoplasias Primarias Secundarias/diagnóstico , Neoplasias Orbitales/patología , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: To compare the abilities of magnetic resonance (MR) imaging and computed tomography (CT) in detection of lymph node metastasis from head and neck squamous cell carcinoma. MATERIALS AND METHODS: MR imaging and CT were performed with standard protocols in patients with known carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx. Histopathologic examination was performed to validate imaging findings. Between 1991 and 1994, 213 patients undergoing 311 neck dissections were accrued at three institutions. RESULTS: For the upper jugular and spinal accessory regions, the areas under the receiver operating characteristic curves for combined information on size and internal abnormality were 0.80 for CT and 0.75 for MR imaging. Sensitivities, specificities, negative predictive values (NPVs), and positive predictive values (PPVs) were calculated for various size criteria with and without internal abnormality information. With use of a 1-cm size or an internal abnormality to indicate a positive node, CT had an NPV of 84% and a PPV of 50%, and MR imaging had an NPV of 79% and a PPV of 52%. CT achieved an NPV of 90%, correlating with a PPV of 44%, with use of 5-mm size as an indicator of a positive node. CONCLUSION: CT performed slightly better than MR imaging for all interpretative criteria. However, a high NPV was achieved only when a low size criterion was used and was therefore associated with a relatively low PPV.
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Carcinoma de Células Escamosas/secundario , Neoplasias de Cabeza y Cuello/patología , Metástasis Linfática/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/patología , Femenino , Humanos , Metástasis Linfática/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cuello , Estadificación de Neoplasias , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
The anatomy of the thoracic inlet and lesions of the thyroid gland, parathyroid glands, and brachial plexus are discussed in depth in other articles in this issue. The focus of this article is to review lesions of the remaining structures and spaces that abut or traverse through the plane of the thoracic inlet. Although this junction of the neck with the chest is relatively easy to define on coronal or sagittal MR, determining this level with axial CT and MR is actually a bit of a challenge. Depending on neck length, degree of neck extension, shoulder thickness, arm position, thoracic kyphosis, and scan angle, the appearance of this area is extremely variable. For the purpose of this article, the thoracic inlet is better regarded as a zone or volume extending several centimeters both above and below this plane. In addition, this zone is very prone to CT beam hardening artifacts from the thickness of the shoulders as well as MR pulsation, respiratory, and bulk susceptibility artifacts, often resulting in less than esthetic images.
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Diagnóstico por Imagen , Enfermedades Torácicas/diagnóstico , HumanosRESUMEN
PURPOSE: To devise a practical technique for high-resolution evaluation of the anterior optic apparatus using a phased-array surface coil system, and to evaluate this system in patients with suspected optic pathway abnormalities. METHODS: A four-element phased-array coil pair was placed on each side of the head, and signal-to-noise measurements were obtained using a head phantom. Comparison between the phased-array coil, the quadrature coil, and a single-turn 12.7-cm (5-in) surface coil was done. T1 spin-echo and T2 fast spin-echo sequences were obtained in the oblique axial and oblique sagittal planes, to approximate the long axis of the optic nerves and the nonoblique coronal plane. RESULTS: The phantom signal-to-noise measurements at simulated locations of the optic nerve head, optic canal, and optic chiasm revealed an improvement of at least 30% using the phased-array system. Of 24 imaged cases, 9 had trauma, 5 had suspected neoplasms, and 2 had optic neuritis. In 3 patients, an unexpected diagnosis of optic pathway contusion or infarction was made. The remaining 8 patients had various suspected visual pathway lesions. CONCLUSION: Phased-array surface coils allow rapid, thin-section imaging of the entire anterior optic pathway, with improved signal-to-noise ratio. This may improve evaluation of optic pathway lesions over conventional techniques.
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Lesiones Encefálicas/diagnóstico , Imagen por Resonancia Magnética/instrumentación , Nervio Óptico/patología , Neuritis Óptica/diagnóstico , Órbita/patología , Fracturas Orbitales/diagnóstico , Neoplasias Orbitales/diagnóstico , Adolescente , Adulto , Niño , Contusiones/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Esclerosis Múltiple/diagnóstico , Síndromes de Compresión Nerviosa/diagnóstico , Traumatismos del Nervio Óptico , Sarcoidosis/diagnóstico , Vías Visuales/lesiones , Vías Visuales/patología , Heridas por Arma de Fuego/diagnósticoRESUMEN
Functional endoscopic sinus surgery (FESS) is being advocated to treat children with chronic sinusitis. The surgeon performing FESS needs an intimate understanding of the anatomy to adequately treat disease and avoid complications. One hundred thirty-six patients who had endoscopic sinus surgery were reviewed. Preoperative direct coronal computed tomography scans were available for review in 114 patients. Several nasal and paranasal sinus anomalies were uncovered during this evaluation. The most common was hypoplasia of the maxillary sinuses. All hypoplastic maxillary sinuses had diseased mucosa. Eleven patients were found to have a laterally deviated uncinate process and abnormal anatomy of the maxillary ostia. Other anomalies such as concha bullosa, Haller's cells, and paradoxic curvature of the middle turbinate were found, and their respective frequencies in this population were determined.
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Nariz/anomalías , Senos Paranasales/anomalías , Sinusitis/complicaciones , Adolescente , Adulto , Cartílago/anomalías , Cartílago/patología , Niño , Preescolar , Enfermedad Crónica , Endoscopía , Femenino , Humanos , Lactante , Masculino , Seno Maxilar/anomalías , Sinusitis Maxilar/complicaciones , Sinusitis Maxilar/cirugía , Membrana Mucosa/patología , Mucosa Nasal/patología , Nariz/diagnóstico por imagen , Senos Paranasales/diagnóstico por imagen , Estudios Retrospectivos , Sinusitis/diagnóstico por imagen , Sinusitis/cirugía , Tomografía Computarizada por Rayos X , Cornetes Nasales/anomalías , Cornetes Nasales/patologíaRESUMEN
Cerebral vasospasm is a major determinant of outcome after subarachnoid hemorrhage (SAH). Brain SPECT with 99mTc-HMPAO was obtained before and after cerebral angioplasty in 10 patients with delayed ischemia due to vasospasm. Eight patients had clinically evident neurologic improvement after the procedure. Visual interpretation and an internal-reference (cerebellum), manual, semi-quantitative region of interest (ROI) analysis revealed improvement of regional cerebral blood flow (rCBF) in 9 out of 10. There were disagreements between the visual and ROI analysis in the two that did not improve clinically. For all 10, the average increase per anterior circulation vessel dilated (n = 17) was 8.8% by comparison of the corticocerebellar ratios. For the eight that improved, the average increase was 10.5%. Brain SPECT is valuable for evaluating delayed cerebral ischemia caused by vasospasm after SAH and is useful to document the changes in rCBF induced by angioplasty. It is possible that SPECT may be useful to detect critical reductions in perfusion before clinical deficits develop, thereby offering the potential to identify candidates for early treatment with angioplasty.
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Angioplastia de Balón , Encéfalo/diagnóstico por imagen , Ataque Isquémico Transitorio/diagnóstico por imagen , Ataque Isquémico Transitorio/terapia , Hemorragia Subaracnoidea/complicaciones , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Circulación Cerebrovascular/fisiología , Humanos , Ataque Isquémico Transitorio/etiología , Persona de Mediana Edad , Examen Neurológico , Compuestos de Organotecnecio , Oximas , Exametazima de Tecnecio Tc 99m , Factores de TiempoAsunto(s)
Mejilla/lesiones , Traumatismos Craneocerebrales/diagnóstico por imagen , Cuerpos Extraños/complicaciones , Tomografía Computarizada por Rayos X , Heridas Penetrantes/diagnóstico por imagen , Adulto , Traumatismos del Nervio Craneal , Traumatismos Craneocerebrales/cirugía , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía , Humanos , Venas Yugulares/lesiones , Masculino , Parálisis/etiología , Heridas Penetrantes/cirugíaRESUMEN
To determine whether long TR MR imaging is best performed before or after IV administration of gadopentetate dimeglumine, we obtained spin-density- and T2-weighted images before and after contrast administration in 21 patients with known intracranial enhancing lesions. Of 25 lesions demonstrating enhancement on T1-weighted sequences, 21 showed mild or moderate enhancement on spin-density-weighted sequences and 20 showed mild enhancement on T2-weighted sequences. Importantly, no spin-density or T2 information was obscured by the administration of gadopentetate dimeglumine, and no T2 shortening effects were visible. Two new foci of enhancement were visible on postcontrast spin-density- and T2-weighted images that were missed on postcontrast T1-weighted images and on precontrast spin-density- and T2-weighted studies. Visualization of new areas of enhancement is the main advantage provided by the long TR images obtained after IV injection of gadopentetate dimeglumine. The most likely reason for the appearance of these newly visualized lesions is thought to be delayed enhancement. This imaging protocol also allows the display of adjacent edema or gliosis and enhancing lesions on a single image. Additionally, in three cases, posterior fossa phase-shift artifacts raised the suspicion of an enhancing lesion on postcontrast T1-weighted images, but the cerebellum was shown to be normal on the postcontrast spin-density- and T2-weighted studies. On the basis of our results, we recommend obtaining long TR images after rather than before the administration of gadopentetate dimeglumine in patients with intracranial enhancing lesions.
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Encefalopatías/diagnóstico , Encéfalo/patología , Imagen por Resonancia Magnética , Meglumina , Compuestos Organometálicos , Ácido Pentético , Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Hemorragia Cerebral/diagnóstico , Medios de Contraste , Combinación de Medicamentos , Gadolinio DTPA , Humanos , Recurrencia Local de NeoplasiaRESUMEN
Magnetic resonance (MR) imaging was used to evaluate myocutaneous flap viability in an animal model. Bilateral myocutaneous panniculus carnosus groin flaps were created in 14 piglets. Eight of the piglets underwent early occlusion of the vascular pedicle to one flap that resulted in flap failure in all cases. Six piglets underwent late occlusion of the vascular pedicle to one flap that resulted in flap survival in all cases. Spin-echo T1- and T2-weighted MR images were obtained from all piglets 2 and 24 hours after occlusion. Additional gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced serial T1-weighted images were obtained in four piglets who underwent early occlusion and in four piglets who underwent late occlusion of the pedicle. The T2-weighted images showed increased signal intensity in both occluded and control flaps and thus did not help predict flap viability. Gd-DTPA-enhanced images enabled accurate prediction of flap viability. The images of early-occluded (non-viable) flaps demonstrated no contrast material enhancement, while both the late-occluded (viable) flaps and the control flaps were contrast enhanced. The authors conclude that Gd-DTPA-enhanced MR imaging can help predict myocutaneous flap viability in piglets.
Asunto(s)
Imagen por Resonancia Magnética , Colgajos Quirúrgicos , Supervivencia Tisular , Animales , Medios de Contraste , Gadolinio DTPA , Compuestos Organometálicos , Ácido Pentético , Flujo Sanguíneo Regional , Porcinos , Grado de Desobstrucción VascularRESUMEN
A case is presented that illustrates the magnetic resonance appearance of supratentorial hemangioblastomas both prior to and following intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Spinal cord hemangioblastomas were also present and were visualized only after Gd-DTPA administration. Pathological verification of the multiple tumoral lesions was obtained.
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Gadolinio , Hemangiosarcoma/diagnóstico , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética , Neoplasias Primarias Múltiples/diagnóstico , Neoplasias de la Médula Espinal/diagnóstico , Neoplasias Supratentoriales/diagnóstico , Adulto , Hemangiosarcoma/patología , Humanos , Masculino , Neoplasias Primarias Múltiples/patología , Neoplasias de la Médula Espinal/patología , Neoplasias Supratentoriales/patologíaRESUMEN
Globe tenting is a change in the posterior globe configuration that results in a tented or conical appearance and is objectively defined as a posterior globe angle of less than 130 degrees. Globe tenting is caused by an acute/subacute intraorbital mass effect producing significant proptosis with tethering of the globe by the stretched optic nerve. In this series of 10 patients, globe tenting was produced by subperiosteal abscess (five cases), hemorrhage into a lymphangioma (two cases), a varix (one case), traumatic carotid hemorrhage into a lymphangioma (two cases), a varix (one case), traumatic carotid cavernous fistula (one case), and multiple epithelial implantation cysts (one case). Progressive narrowing of the posterior globe angle correlated with an increase in proptosis and in optic nerve length, as well as with more severe visual impairment. Tenting with a posterior globe angle of 120-130 degrees correlated with mild visual symptoms and a good recovery. A posterior globe angle of less than 120 degrees with acute proptosis constitutes a surgical emergency; a delay in surgical decompression in these patients may prevent complete recovery of visual function. CT is useful in providing good characterization of globe tenting and, thus, in helping to determine the clinical significance of this abnormality.
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Exoftalmia/diagnóstico por imagen , Ojo/diagnóstico por imagen , Órbita/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Niño , Preescolar , Exoftalmia/etiología , Exoftalmia/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Órbita/fisiopatologíaRESUMEN
This report describes the radiographic features in a case of sarcoidosis involving both the frontal calvaria and the petrous bone. The plain radiographic and nuclear medicine findings were consistent with previous descriptions. High resolution CT demonstrated concentric growth with a lucent advancing margin, ghost-like remnant of partially replaced bone, crossing of suture lines, invasion of contiguous bones, and lack of associated soft tissue mass.
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Enfermedades Óseas/diagnóstico por imagen , Hueso Petroso/diagnóstico por imagen , Sarcoidosis/diagnóstico por imagen , Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Femenino , Humanos , Persona de Mediana Edad , Cintigrafía , Medronato de Tecnecio Tc 99mRESUMEN
Twenty-one previously reported cases of aneurysms of the anterior inferior cerebellar artery (AICA) were reviewed. They often present acutely with subarachnoid hemorrhage due to rupture, or less frequently with an insidious onset, as a cerebellopontine angle (CPA) mass. Rupture of the aneurysm is usually not difficult to diagnose because of the acute symptoms and the subarachnoid hemorrhage, which can easily be detected by CT or lumbar puncture. However, caution must be exercised in those lesions presenting as a CPA mass clinically, which on CT appear unusually dense with contrast enhancement. Erosion of the internal auditory canal may be present but is non-specific. If an enhancing CPA mass appears atypical and dynamic CT confirms rapid enhancement, vertebrobasilar angiography is essential to establish an AICA aneurysm as the cause.
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Aneurisma Intracraneal/diagnóstico por imagen , Neuroma Acústico/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Arteria Basilar/diagnóstico por imagen , Ángulo Pontocerebeloso/diagnóstico por imagen , Diagnóstico Diferencial , Femenino , Humanos , Aneurisma Intracraneal/patología , Aneurisma Intracraneal/cirugíaRESUMEN
In this report we document the clinical, radiologic, surgical, and pathologic features of a cerebellopontine angle (CPA) lipoma, including the CT visualization of the seventh and eighth cranial nerves passing through the middle of the lesion, a feature previously undescribed. Comparison is made with other reported CPA lipomas.
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Neoplasias Cerebelosas/diagnóstico por imagen , Ángulo Pontocerebeloso , Lipoma/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Humanos , MasculinoRESUMEN
The authors present an illustrative case of progressive and severe shortening of the colon complicating chronic ulcerative colitis. The term brachycolon is defined and proposed as a useful differential diagnostic sign of ulcerative colitis.