Trans-sphenoidal spread of rhinopharyngeal neoplasms. Correlations between computerized tomography and magnetic resonance

In 1957 Teoh observed, in an autopsic series of 31 patients with nasopharyngeal carcinoma, 3 cases of neoplastic spread through the marrow spaces of the base of the skull, without macroscopic bone alterations. In order to demonstrate in vivo this kind of neoplastic spread, CT and MR examinations of 35 patients with nasopharyngeal carcinoma were reviewed. In 3/26 cases the invasion of the marrow spaces of the clivus was demonstrated. In these cases CT showed only minimal alterations in spongiosa and cortices of the clivus, associated with intracranial soft-tissue tumoral components. MR imaging demonstrated, with great accuracy, the replacement of bone marrow in the clivus by neoplastic tissue of intermediate signal intensity on T1-weighted images. Tumor tissue was characterized by high signal intensity on T2-weighted images. The authors stress the greater utility of MR imaging in evaluating the permeative involvement of the base of the skull.     

Vertebral infection

Vertebral infection represents 2-4% of all cases of osteomyelitis. An increase in the incidence of pyogenic as well as granulomatous spondylitis has been noticed. Early radiological diagnosis is of great importance for prompt treatment and prevention of clinically significant consequences which include neural compromise and late spinal deformities. The most frequent causative pyogenic micro-organisms are gram-negative bacteria especially Staphylococcus aureus. An important form of nonpyogenic granulomatous infection is tuberculous spondylitis which represents the most common form of extrapulmonary tuberculosis. The routes of spinal infection include hematogenous spread, postoperative infections, direct implantation during spinal punctures and spread from a contiguous focus. The role of imaging is an early diagnosis, evaluation of extent of infection with special regard to potential neural compromise, differential diagnosis, guidance of diagnostic biopsy, planning of eventual operative procedures and assessment of therapeutic response. Imaging modalities include bone scintigraphy, radiography, CT and MRI. In practice, usually a combination of a sensitive and a specific method is utilised. The only imaging modality which combines high sensitivity with satisfactory specificity is MRI. This is the reason that MRI frequently has become the first imaging modality in clinically suspect spinal infection. The MRI is the method of choice for direct demonstration of extension of infection, especially of eventual epidural abscess or phlegmon and consecutive neural compression. Using MRI monitoring of therapeutic efficiency is possible.     

Diagnosis of osteomyelitis in the presence of soft-tissue infection and radiologic evidence of osseous abnormalities: value of leukocyte scintigraphy

To evaluate the usefulness of 111In-leukocyte scintigraphy for identifying osteomyelitis in the presence of soft-tissue infection, we prospectively studied 45 bone sites adjacent to soft-tissue infection in patients with abnormal findings on radiographs and 99mTc bone scans that were suggestive of osteomyelitis. 111In-leukocyte scans were analyzed in terms of the intensity of abnormal uptake and its location relative to bone. The diagnosis of osteomyelitis was established from results of percutaneous bone biopsy culture (n = 35), histologic examination of surgical specimens (n = 8), and clinical follow-up (n = 2). Osteomyelitis was present at 22 sites, including 16 of 18 sites with increased leukocyte uptake in bone, resulting in a sensitivity of 73%, specificity of 91%, and positive predictive value of 89% for this finding. Osteomyelitis was present at four of 17 sites with predominantly soft-tissue localization of leukocyte activity in the region of bone, none of seven sites with normal leukocyte scans, and two of three sites with diminished leukocyte uptake in bone. Although not helpful in distinguishing infectious from noninfectious bone abnormalities, 3- and especially 24-hr bone scans viewed in conjunction with leukocyte studies provided important correlation to aid in estimating the location of focal abnormal leukocyte uptake. The finding of soft-tissue infection with increased uptake of labeled leukocytes that extends to involve adjacent bone strongly suggests concurrent osteomyelitis. When the presence of abnormal leukocyte uptake in bone is uncertain, additional imaging and possibly biopsy may be required to establish or exclude the diagnosis of osteomyelitis.     

Actinomycosis: CT findings in six patients

Actinomycosis is an uncommon disease with clinical and radiographic findings that overlap those of other inflammatory and neoplastic conditions. A retrospective review of CT scans in six proved cases revealed a spectrum of findings, including soft-tissue mass with various degrees of infiltration and abscess formation. Administration of IV contrast material was helpful in defining the loculations of the abscess in two cases. Areas of involvement included the neck (two cases), liver (one case), abdominal wall (one case), thorax (one case) and kidney and retroperitoneum (one case). CT findings of a soft-tissue mass in the neck, lungs, or abdomen, with or without a draining sinus or fistula, raise the possibility of actinomycosis in patients with clinical findings that suggest a subacute or chronic inflammatory process.     

骨肉瘤的X线、CT及MRI比较分析(附61例分析)

目的:探讨原发性骨肉瘤的X线、CT和MRI表现及诊断价值.方法:经穿刺或手术病理证实的61例骨肉瘤患者,52例行X线检查,39例行CT检查,55例行MRI检查,其中23例行MRI动态增强检查.回顾性分析其影像学表现并与病理学表现进行对照分析.结果:本组61例骨肉瘤中成骨型13例,溶骨型21例,混合型27例.52例X线检...     

CT in pyogenic osteomyelitis of the spine

Six patients with bacteriologically proven pyogenic osteomyelitis of the spine were followed serially with computed tomography (CT). Initial evaluation of the involved vertebral bodies and adjacent soft tissues showed a drop in CT numbers when compared to normal cancellous bone and soft tissues. A soft-tissue mass was seen in all cases. After appropriate antibiotic therapy, all six patients showed an increase in bone density and a diminution of the soft-tissue mass (p less than 0.05). Five of the six patients showed a further decrease in soft-tissue CT numbers.     

Computed tomography of the osseous pelvis.

Computed tomography (CT) was used for study of the osseous pelvis in 43 patients with definitive pathological or clinical follow-up. CT accurately characterized and determined extent of bone and soft-tissue involvement; neoplasms and other disease processes, such as sacroiliac joint disease, were well localized. In cases of trauma, CT was able to identify, localize, and characterize fracture fragments and bone or joint displacement. CT was judged "useful" or "definitive" in 80% of all lesions and 96% of neoplasms studied.     

Soft-tissue masses of the locomotor system: comparison of MR imaging with CT

Magnetic resonance (MR) images and computed tomographic (CT) scans of histologically characterized soft-tissue masses of the locomotor system in 35 patients were compared for image contrast, demonstration of bone destruction, and display of extent and anatomic relationships of the masses. Subjective criteria for predicting malignancy were tested. T1 measurements were made in a few cases. Intensities of masses relative to those of fat and muscle in spin-echo T1-weighted and highly T2-weighted images were evaluated for correlation with tissue type. Subjective value of using coronal and sagittal images was assessed. Because of its superior inherent image contrast and its ability to provide direct sagittal and coronal images, MR was better than CT in demonstrating size and extent of most tumors and their relationships to vascular and nonvascular structures. However, bone destruction was more difficult to see with MR. Except for fatty tumors, MR was not helpful in identifying tissue type. Subjective criteria were of limited value in distinguishing benign from malignant lesions. Moreover, there is currently no credible evidence that T1 or T2 measurements are helpful in this regard. Study results suggest that MR is superior to CT in evaluating soft-tissue masses of the locomotor system. If an MR examination is performed, CT may not be necessary in certain cases unless bone involvement is suspected.     

MR imaging features of nasopharyngeal tuberculosis: report of three cases and literature review

The MR imaging appearances in three cases of nasopharyngeal tuberculosis are reported, and the findings are combined with three additional cases from a review of the literature. Two patterns of nasopharyngeal tuberculosis were identified. The first pattern is a discrete polypoid mass in the adenoids, and the second pattern is a more diffuse soft-tissue thickening of one or two of the walls of the nasopharynx. Extension outside the confines of the nasopharynx was not a feature, except in one case with early involvement of the prevertebral muscles.     

Early diagnosis of single segment vertebral osteomyelitis--MR pattern and its characteristics.

Nine cases of single segment vertebral osteomyelitis were included based on the single level of vertebral body involvement according to the MR findings. They were 3 cases with tuberculous infection and 6 cases with pyogenic infection. The vertebral body involvement was presented as abnormal signal changes (100%) and heterogenous enhancement (77.7%). They usually caused the cortical disruption in its anterior aspect (100%). It goes along the upward subligamentous spread (100%) most often, then the upper disc involvement (66.6%) and downward subligamentous spread (55.5%). The lower disc involvement is least common (11.1%). By using these criteria, the single segment vertebral osteomyelitis could be earlier diagnosed.     

Cervical osteomyelitis due to i.v. heroin use: radiologic findings in 14 patients

We reviewed the radiographs of 14 patients who had cervical osteomyelitis and were IV heroin users. Eleven were men and three were women. Their age range was 33-48 years (mean, 39 years). Eleven regularly used the jugular vein access, and three alternated between the jugular and femoral veins. Initial radiographs of the cervical spine in 13 patients showed destruction of two or more vertebral bodies and the adjacent intervertebral disk, as well as a prevertebral soft-tissue mass. In one patient, findings on initial radiographs were normal, but marked destruction at two contiguous intervertebral levels and a large prevertebral abscess were identified 2 weeks later. All the patients had positive results on cultures of joint aspirates or bone biopsy materials (10 patients) or blood (four patients). Ten grew Staphylococcus aureus; two, Staphylococcus epidermidis; one, Streptococcus viridans; and one, Pseudomonas aeruginosa. CT in nine patients showed inflammatory reaction adjacent to the carotid sheath resulting from the repeated jugular injections and delineated the extent of prevertebral abscess and bone destruction. Scintigrams were of minimal value in establishing the diagnosis. Advanced vertebral body destruction, disk space infection, prevertebral abscess, and anterior cervical inflammatory reaction appear to be typical findings on radiographs in heroin abusers with cervical osteomyelitis.     

Skeletal lymphoma

The records of forty-two patients with lymphoma of bone [.11 with Hodgkin disease (HD), 31 with non-Hodgkin lymphoma (NHL)] were retrospectively reviewed to correlate histologic type with sites of osseous involvement, radiographic patterns of bone destruction, and prognosis. The vertebral column was the most frequent site of axial involvement and the femur was the commonest site overall. In HD, the most frequent radiographic pattern was vertebral sclerosis, while periosteal reaction was noted in two focal femoral lesions and hypertrophic pulmonary osteoarthropathy in one patient. In NHL, permeative destruction predominated, while unusual layered periosteal reaction and eccentric cortical destruction were each seen in two patients. Radiographic patterns of bone involvement alone cannot be used to predict histologic type or prognosis. Staging remains the most important prognostic indicator. For skeletal lymphoma, instead of the traditional Ann Arbor Staging System, we prefer the more specific Mayo Staging System which relates the temporal appearance of osseous disease to nodal or soft-tissue disease or both.     

External auditory canal cholesteatoma: clinical and imaging spectrum

BACKGROUND AND PURPOSE: Cholesteatoma is an inflammatory lesion of the temporal bone that uncommonly involves the external auditory canal (EAC). In this large case series, we aimed to define its imaging features and to determine the characteristics most important to its clinical management. METHODS: Thirteen cases of EAC cholesteatoma (EACC) were retrospectively reviewed. Clinical data were reviewed for the history, presentation, and physical examination findings. High-resolution temporal bone CT scans were examined for a soft-tissue mass in the EAC, erosion of adjacent bone, and bone fragments in the mass. The middle ear cavity, mastoid, facial nerve canal, and tegmen tympani were evaluated for involvement. RESULTS: Patients presented with otorrhea, otalgia, or hearing loss. Eight cases were spontaneous, and five were postsurgical or post-traumatic. CT imaging in all 13 cases showed a soft-tissue mass with adjacent bone erosion. Intramural bone fragments were identified in seven cases. This mass most often arose inferiorly (n = 8) or posteriorly (n = 8), but it was circumferential in two cases. We noted middle ear extension (n = 5), mastoid involvement (n = 4), facial canal erosion (n = 2), and tegmen tympani dehiscence (n = 1). CONCLUSION: Temporal bone CT shows EACC as a soft-tissue mass within the EAC, with adjacent bone erosion. Bone fragments may be present within the mass. The cholesteatoma may extend into the mastoid or middle ear, or it may involve the facial nerve canal or tegmen tympani. Recognition of this entity and its possible extension is important because it may influence clinical management.     

MRI of aseptic lymphocytic vasculitis-associated lesions in metal-on-metal hip replacements

OBJECTIVE: The aim of this review is to describe the clinical, histopathologic, and MRI features of aseptic lymphocytic vasculitis-associated lesions in total hip replacements. CONCLUSION: The introduction of modern metal-on-metal hip arthroplasty has been accompanied by a newly described disease, aseptic lymphocytic vasculitis-associated lesions, which is characterized histologically by bland necrosis and dense perivascular lymphocytic infiltrates. Conventional radiographic findings are often normal, but the typical MRI findings include periprosthetic fluid collections, soft-tissue masses, gluteal tendon avulsion, bone loss, periosteal stripping, neurovascular involvement, and periprosthetic fractures. The severity of the histologic and MRI appearances can be graded according to defined published criteria.     

The cervicocranium: its radiographic assessment

Acute injuries of the cervicocranium (from the occiput to the second cervical intervertebral disk) may be radiographically obscure due to minimal displacement of fracture fragments, minor alterations of normal anatomic relationships (occipitoatlantal subluxation), or superimposition of normal skeletal structures. With the nasooropharynx adequately distended with air, the normal cervicocranial prevertebral soft-tissue contour is congruent with the anterior cortical margin of the cervicocranium; namely, concave above, convex anterior to, and concave below the anterior tubercle of C1. Alterations of the normal cervicocranial prevertebral soft-tissue contour due to hemorrhage into the retropharyngeal fascial space from subtle fractures or ligamentous injuries should prompt further assessment of the cervicocranium by means of computed tomography (CT). Cervicocranial CT prompted by an abnormal cervicocranial prevertebral soft-tissue contour has yielded a 16% positive injury rate, approximately three times the rate of acute cervical spine injuries reported in the literature.     

Vertebral osteomyelitis without disc involvement

Vertebral osteomyelitis is most commonly due to pyogenic or granulomatous infection and typically results in the combined involvement of the intervertebral disc and adjacent vertebral bodies. Non-infective causes include the related conditions of chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. Occasionally, these conditions may present purely within the vertebral body, resulting in various combinations of vertebral marrow oedema and sclerosis, destructive lesions of the vertebral body and pathological vertebral collapse, thus mimicking neoplastic disease. This review illustrates the imaging features of vertebral osteomyelitis without disc involvement, with emphasis on magnetic resonance imaging (MRI) findings.     

Forefoot pain involving the metatarsal region: differential diagnosis with MR imaging.

Many disorders produce discomfort in the metatarsal region of the forefoot. These disorders include traumatic lesions of the soft tissues and bones (eg, turf toe, plantar plate disruption, sesamoiditis, stress fracture, stress response), Freiberg infraction, infection, arthritis, tendon disorders (eg, tendinosis, tenosynovitis, tendon rupture), nonneoplastic soft-tissue masses (eg, ganglia, bursitis, granuloma, Morton neuroma), and, less frequently, soft-tissue and bone neoplasms. Prior to the advent of magnetic resonance (MR) imaging, many of these disorders were not diagnosed noninvasively, and radiologic involvement in the evaluation of affected patients was limited. However, MR imaging has proved useful in detecting the numerous soft-tissue and early bone and joint processes that occur in this portion of the foot but are not depicted or as well characterized with other imaging modalities. Frequently, MR imaging allows a specific diagnosis based on the location, signal intensity characteristics, and morphologic features of the abnormality. Consequently, MR imaging is increasingly being used to evaluate patients with forefoot complaints. Radiologists should be familiar with the differential diagnosis and MR imaging features of disorders that can produce discomfort in this region.     

MR imaging of infectious spondylitis

MR images of 14 patients with pyogenic and three patients with tuberculous infectious spondylitis were studied to develop criteria for diagnosis. T1-weighted scans, 800/20 (TR/TE), were obtained in 17 patients and T2-weighted scans, greater than 2000/30,80, were obtained in 14. In seven patients, T2*-weighted scans (gradient-recalled acquisition into steady state, 25/15/5-7 degrees [TR/TE/flip angle]) and short-T1 inversion-recovery scans (STIR), 1400/150/40 (TR/TI/TE), as well as fat and water images (using a suppression technique), were obtained. Unenhanced and gadopentetate-dimeglumine-enhanced scans were obtained in four patients. In all but two patients with pyogenic infectious spondylitis, the T1-weighted sagittal scan showed characteristic findings: narrowed disk space, low signal intensity in the marrow of at least two adjacent vertebrae, subligamentous or epidural soft-tissue masses, and erosion of cortical bone. In one patient the T1-weighted scan was normal and abnormalities could be detected only on the T2-weighted scan. The remaining patient had abnormal marrow signal on the T1-weighted scan but only in one vertebral body. On T2-weighted images the major findings were a narrowed disk space with variable signal changes, abnormal high signal in marrow of at least two adjacent vertebrae, high-signal subligamentous or epidural masses, and cortical bone erosion. The findings in the three patients with tuberculous spondylitis included areas of increased and decreased signal intensity in vertebrae on T1-weighted images. Disk spaces were relatively spared given the extent of disease. Extraosseous soft-tissue components could be large. Bone erosion was best seen on the first echo of a T2-weighted sequence and on a water image; the latter was most reliable since it had no chemical-shift artifact. The use of gadopentetate dimeglumine could obscure or clarify MR findings, depending on the situation. T1- and T2-weighted MR images should be obtained for assessment of infectious spondylitis. STIR scans are particularly helpful. Fat images can be useful in subtle presentations, since they are very sensitive to marrow replacement, and gadopentetate dimeglumine may be helpful for epidural delineation of disease.     

Langerhans' cell histiocytosis of the temporal bone in pediatric patients: imaging and follow-up

OBJECTIVE: The purpose of this study was to review the initial clinical and radiologic manifestations and the follow-up of pediatric patients with Langerhans' cell histiocytosis affecting the temporal bone. MATERIALS AND METHODS: We retrospectively studied 14 patients with Langerhans' cell histiocytosis affecting the temporal bone. All patients were examined initially and sequentially with CT. In six patients, MR imaging was also done. RESULTS: Temporal bone involvement was the initial form of presentation in 12 patients. In eight patients, temporal bone involvement presented as an isolated manifestation, and in four it was associated with multisystemic involvement. In the remaining two patients, temporal bone involvement appeared during the course of the Langerhans' cell histiocytosis. Bilateral involvement was seen in four patients. In two patients, the temporal bone was affected only at the petrous apex. CT showed destruction of bone in all 14 patients and an associated soft-tissue homogeneous mass after injection of i.v. contrast material in 12 patients. CT showed a heterogeneous appearance of the soft-tissue mass in two patients. The average period of follow-up was 5 years. In seven of the 14 patients, the disease had a satisfactory evolution in which the bony lesions of the temporal bone reossified and remodeled over the course of a year. CONCLUSION: In Langerhans' cell histiocytosis, involvement of the temporal bone is usually seen on radiographs as extensive lytic lesions associated with soft-tissue masses. The lesions that remit show early disappearance of the soft-tissue mass, followed by reossification and remodeling of the involved bone. Patients with limited initial involvement of the temporal bone have a better prognosis on long-term follow-up than do patients with the multisystemic form.