Rocky Mountain spotted fever encephalitis: MR findings.

We describe a case of Rocky Mountain spotted fever encephalitis and present the associated findings of an MR examination of the brain, which showed increased signal intensity in the distribution of perivascular spaces. Resolution of the MR abnormalities coincided with clinical improvement.     

The chest radiograph in Rocky Mountain spotted fever

Chest radiographs of 43 patients with Rocky Mountain spotted fever were reviewed to elucidate the frequency and types of involvement of the lower respiratory tract. The abnormal radiographic patterns included localized and diffuse infiltrates of both interstitial and alveolar type. Autopsies were performed in five cases, and findings in several of these are described to help provide radiologic-pathologic correlation. An association of lung involvement (as evidenced by diffuse infiltrates on chest radiographs) and increased mortality was demonstrated.     

Salivary duct carcinomas: clinical and CT and MR imaging features in 20 patients

Introduction

Salivary duct carcinoma (SDC) is an uncommon high grade adenocarcinoma of the salivary gland with a grave prognosis. The aim of this study was to investigate the clinical and CT and MR imaging features of SDC.

Methods

We retrospectively evaluated the clinical and CT and MR imaging findings in 20 patients (14 men and six women; mean age, 59?years) with histologically proved SDC. We also tried to correlate clinicoradiological tumor staging with pathologic tumor staging in 17 patients who underwent surgery.

Results

The tumor originated in the parotid gland (n?=?11; 55%), the submandibular gland (n?=?7; 35%) and the buccal space along the distal Stensen's duct (n?=?2; 10%). Locoregional recurrence occurred in 41% and distant metastasis in 47%. Fifty-eight percent died of the disease with a mean survival period of 32?months after diagnosis. On CT and MR images, SDC was mostly seen as an ill-defined (85%) and infiltrative (60%) mass with frequent calcification (50%) and necrosis (80%). Although various signal intensities were seen on MR images, six of nine tumors contained the areas of marked hypointensity on T2-weighted images. Clinicoradiological tumor staging correlated well with pathologic tumor staging in 82% of the patients.

Conclusion

Ill-defined, infiltrative mass with calcification on CT scans and the areas of marked hypointensity on T2-weighted MR images may be useful radiologic features to suggest the diagnosis of SDC. CT and MR imaging are useful for staging of SDC.     

Idiopathic inflammatory pseudotumour of the orbit: CT features correlated with clinical outcome.

Idiopathic orbital pseudotumour is an inflammatory condition which usually presents as an orbital mass. The response to treatment is variable and often unpredictable. In this study we have assessed the spectrum of computed tomographic (CT) appearances in 17 patients. Four categories of orbital pseudotumour were identified by CT based on the location and extent of the inflammatory process within the orbit. Patients within each of the four categories had broadly similar clinical outcomes. CT was valuable in identifying certain prognostic features enabling better clinical and therapeutic planning.     

Comparison of MR imaging and CT in patients with intracranial aneurysm clips

CT and MR imaging of the brain were performed without complications in 16 patients who had undergone surgery for a ruptured aneurysm with the use of nonferromagnetic Yasargil 316 or Sugita Elgiloy clips. MR was performed on a 0.3-T Fonar beta-3000M imaging system. The artifacts caused by the clips were smaller on MR than on CT, and, therefore, anatomic structures such as the brainstem and temporal lobes were better visualized on MR. Brain-tissue lesions corresponding to the frontotemporal surgical approach were seen with MR in seven patients and with CT in six. In three patients temporal-lobe lesions seen on MR were not seen on CT because of beam-hardening artifacts. Lesions unrelated to the region of surgery were seen with MR in nine patients and with CT in five. In conclusion, MR was safe and superior to CT both in demonstrating anatomic details and in detecting tissue lesions in patients with aneurysm clips.     

Intracranial hemangiopericytomas: MR and CT features.

PURPOSETo describe the MR and CT imaging features of hemangiopericytoma and to identify the characteristics that might distinguish them from meningioma.METHODSWe retrospectively reviewed the CT and MR findings in 34 pathologically proved cases of hemangiopericytoma. We evaluated the size, shape, and location of the tumor; the presence of hydrocephalus, edema, and mass effect; the type of dural attachment (broad-based or narrow-based) and bone changes (erosion, hyperostosis); and the tumor''s density, signal, and contrast-enhancement characteristics.RESULTSThirty of 34 tumors were 4 cm or more in greatest dimension, 32 were lobular, and only seven were in the posterior fossa. Hydrocephalus was present in 18, edema in 30, and mass effect in 33. Twenty-three had broad-based dural attachment and 11 had narrow-based attachment. All 26 unenhanced CT scans showed hyperdense tumors; 19 were heterogeneous and seven homogeneous. All 27 contrast-enhanced CT scans showed enhancement; 17 were heterogeneous and 10 homogeneous. Bone erosion was present in 17 of 29 hemangiopericytomas imaged with CT. None had hyperostosis or tumor calcifications. On T1-weighted MR images, 13 of 17 tumors were isointense with cortical gray matter; on T2-weighted image, 10 of 17 were isointense. All 14 tumors imaged with contrast enhanced T1-weighted MR imaging showed enhancement, and 13 of these were heterogeneous; eight of the 14 had a "dural tail" sign.CONCLUSIONIntracranial hemangiopericytomas are multilobulated, extraaxial tumors, sometimes associated with narrow-based dural attachment and bone erosion. Unlike with meningiomas, hyperostosis and intratumoral calcification are not present.     

颅底沟通性肿瘤的临床特点及其CT、MRI诊断价值比较

目的 :探讨颅底沟通性肿瘤的临床特点及其CT、MRI诊断价值。方法 :回顾性分析我院经CT、MRI和组织病理学确诊的颅底沟通性肿瘤64例,比较不同病变部位患者的一般临床资料、CT和MRI特点,以及CT和MRI对颅底沟通性肿瘤、侵犯周围骨质、侵犯周围软组织诊断符合率的差异。结果:颅底沟通性肿瘤沟通部位位于前颅窝32例(50.00%),中颅窝26例(40.62%),后颅窝6例(9.38%);等密度45例(70.31%),稍高密度13例(20.31%),高密度6例(9.38%);信号均匀13例(20.31%),不均匀41例(64.06%),混杂10例(15.62%);中等强化49例(76.56%),高度强化15例(23.44%);钙化或骨化35例(54.69%)。CT对颅底沟通性肿瘤的诊断准确率与MRI差异无统计学意义(P0.05)。CT对颅底沟通性肿瘤侵犯周围骨质及周围软组织的诊断符合率与MRI比较差异均有统计学意义(均P0.05)。结论:CT、MRI能准确显示颅底沟通性肿瘤的病变特征,两者在诊断准确率和符合率方面各有优势。     

CT and MR imaging features of adnexal torsion.

In adnexal torsion, the ovary, ipsilateral fallopian tube, or both twist with the vascular pedicle, resulting in vascular compromise. Unrelieved torsion is likely to cause hemorrhagic infarction as the degree of arterial occlusion increases. Therefore, early diagnosis is important to preserve the affected ovary. Adnexal torsion commonly accompanies an ipsilateral ovarian neoplasm or cyst but can also occur in normal ovaries, usually in children. Although ultrasonography is typically the initial emergent examination, computed tomography (CT) and magnetic resonance (MR) imaging may also be useful diagnostic tools. Common CT and MR imaging features of adnexal torsion include fallopian tube thickening, smooth wall thickening of the twisted adnexal cystic mass, ascites, and uterine deviation to the twisted side. Uncommon imaging findings in adnexal torsion that are specific to hemorrhagic infarction include hemorrhage in the thickened fallopian tube, hemorrhage within the twisted ovarian mass, and hemoperitoneum. Additional imaging findings that can suggest hemorrhagic infarction include eccentric smooth wall thickening exceeding 10 mm in a cystic ovarian mass converging on the thickened fallopian tube and lack of contrast enhancement of the internal solid component or thickened wall of the twisted ovarian mass. Early diagnosis can help prevent irreversible structural damage and may allow conservative, ovary-sparing treatment.     

Juvenile Huntington disease: CT and MR features.

PURPOSETo describe the clinical and radiologic manifestations of juvenile Huntington disease and to determine whether adult imaging criteria for Huntington disease are helpful for pediatric patients.METHODSSix patients (3 to 18 years of age; mean age, 9.8 +/- 5.6 years; 3 female, 3 male) with juvenile Huntington disease were studied with CT (n = 6) and/or MR (n = 3). CT and MR studies were evaluated for frontal horn distance/intercaudate distance and bicaudate ratios, which were compared with those of 24 age-matched healthy children and 12 age-matched patients with Leigh (n = 9) or Wilson (n = 3) disease.RESULTSAtrophy of the caudate nuclei was identified in all Huntington patients. The frontal horn distance/intercaudate distance (1.64 +/- 0.39) and bicaudate (0.205 +/- 0.060) ratios of the patients with juvenile Huntington disease were found to be significantly different from those of healthy children and that of those patients with Leigh/Wilson disease. The 3 patients with Huntington disease who underwent MR evaluation were noted to have increased proton density- and T2-weighted signal in the caudate nuclei and putamina.CONCLUSIONAs in adult patients, the use of frontal horn distance/intercaudate distance and bicaudate ratios are helpful for the diagnosis of Huntington disease in pediatric patients. On MR, increased proton density- and T2-weighted signal in the atrophic caudate nuclei and putamina are additional features of juvenile Huntington disease.     

Acute disseminated encephalomyelitis: MR and CT features.

We describe three cases of acute disseminated encephalomyelitis (an immune-mediated inflammatory demyelinating disease of the central nervous system) and their histology, showing different radiological features. One appearance is a few ring-shaped enhancing lesions, which are found predominantly in the supratentorial white matter, the other is solid disseminated lesions.     

Anorectal gastrointestinal stromal tumors: CT and MR imaging features with clinical and pathologic correlation

OBJECTIVE: The purpose of this study was to describe the imaging features of anorectal gastrointestinal stromal tumors with clinical and pathologic correlation. CONCLUSION: Anorectal gastrointestinal stromal tumors are mesenchymal neoplasms that typically arise in the muscularis propria of the intestinal wall. The cross-sectional imaging appearance is that of a well-defined mural mass that may have an exophytic component and may invade adjacent structures. A prominent intraluminal component is a rare feature.     

急性播散性脑脊髓炎的临床、病理及CT和MRI表现

急性播散性脑脊髓炎(ADEM)是一种急性脱髓鞘性病变，常继发于感染和免疫接种后，主要累及脑白质，也可累及灰质，其临床表现、脑脊液改变及影像学表现有一定特点，但均无特异性，目前还没有一个很好的诊断标准，与其它病变如多发性硬化(MS)等鉴别困难，最后诊断有赖于临床表现、各种检查及一定时间的随访观察。     

节细胞神经瘤的影像学表现

目的 探讨节细胞神经瘤的CT和MR表现.方法 回顾性分析18例经手术病理证实的节细胞神经瘤的CT、MR影像学资料,所有患者均接受CT平扫及增强扫描,2例接受MR平扫.结果 节细胞神经瘤好发于中青年,位于后纵隔8例,肾上腺5例,腹膜后4例,颈部1例.均为单发病灶、边界清楚,嵌入式生长可呈多种形态.CT平扫:12例为均匀低密度,平均CT值22～37 HU;6例密度不均,平均CT值13～46 HU,其中2例伴有坏死、囊变.2例见斑点状钙化.增强扫描:肿瘤各期均无强化4例,仅动脉期轻度强化5例,仅静脉期轻度强化2例,静脉期及延迟期呈轻、中度渐进性强化1例,三期呈渐进性强化6例;坏死及囊变部分未见强化.2例肿瘤内见肋间后动脉穿行,1例见腰动脉穿行并见细小分支滋养肿瘤.2例下腔静脉推挤受压移位,1例见颈部大血管被包绕.MR平扫:1例信号均匀,1例信号不均;T1WI表现为低信号,T2 WI呈高信号为主,脂肪抑制(SPIR)及扩散加权成像(DWI)呈高信号.结论 节细胞神经瘤的CT及MR表现具有一定特征性,尤其是CT示肿瘤为均匀低密度、伴有斑点状钙化、肿瘤内血管穿行但未受侵,增强扫描动脉期无明显强化或轻度强化,呈渐进性强化方式,DWI示肿瘤呈高信号时,应考虑节细胞神经瘤的可能.     

Multiple glioblastomas: CT and MR features

The aim of this study was to analyze the CT and MR features of multiple glioblastomas, and to determine the best imaging modality for the initial diagnosis. The CT (four exams) and MR imaging (eight exams) of eight patients with proven multiple glioblastomas were reviewed by two neuroradiologists. The lesions were always hypo- or isodense on CT and hyperintense on T2-weighted images (100 %). They were usually hypo- or isointense on T1-weighted images (90 %). Edema and mass effect were very variable. After contrast media administration, the enhancement was mostly strong (71 % on CT and 70 % on MR), often either heterogeneous or ring-like. The different lesions of a patient often had a different pattern on MR (75 % of cases). Meningeal or ventricular enhancement, suggestive of a possible way of dissemination, was rare. In case of multiple cerebral masses, multiple glioblastomas should be considered as a possible diagnosis in addition to the better known diagnosis of brain metastases, abscesses, or multifocal lymphomas. Moderate edema and mass effect on MR associated with strong and heterogeneous enhancement are suggestive of feature of multiple glioblastomas. Magnetic resonance allows rarely the visualization of a dissemination route. Received: 10 March 2000 Revised: 18 May 2000 Accepted: 22 May 2000     

MR appearance of autologous chondrocyte implantation in the knee: correlation with the knee features and clinical outcome

Objective To relate the magnetic resonance imaging (MRI) appearance of autologous chondrocyte implantation (ACI) in the knee in the 1st postoperative year with other knee features on MRI and with clinical outcome. Design and methods Forty-nine examinations were performed in 49 patients at 1 year after ACI in the knee. Forty-one preoperative magnetic resonance (MR) examinations were also available. The grafts were assessed for smoothness, thickness in comparison with that of adjacent cartilage, signal intensity, integration to underlying bone and adjacent cartilage, and congruity of subchondral bone. Presence of overgrowth and bone marrow appearance beneath the graft were also assessed. Presence of osteophyte formation, further cartilage defects, appearance of the cruciate ligaments and the menisci were also recorded. An overall graft score was constructed, using the graft appearances. This was correlated with the knee features and the Lysholm score, a clinical self-assessment score. The data were analysed by a Kruskal–Wallis H test followed by a Mann–Whitney U test with Bonferroni correction as post-hoc test. Results Of 49 grafts, 32 (65%) demonstrated complete defect filling 1 year postoperatively. General overgrowth was seen in eight grafts (16%), and partial overgrowth in 13 grafts (26%). Bone marrow change underneath the graft was seen; oedema was seen in 23 grafts (47%), cysts in six grafts (12%) and sclerosis in two grafts (4%). Mean graft score was 8.7 (of maximal 12) (95% CI 8.0–9.5). Knees without osteophyte formation or additional other cartilage defects (other than the graft site) had a significantly higher graft score than knees with multiple osteophytes (P=0.0057) or multiple further cartilage defects (P=0.014). At 1 year follow-up improvement in the clinical scores was not significantly different for any subgroup. Knees with a graft score of 8 points or greater had a better improvement of the clinical score than those of 7 points or fewer. Conclusions At 1 year follow-up after ACI, higher graft scores are associated with an overall better preserved knee joint. ACI improves the clinical outcome, but there is no statistically significant correlation of graft score and clinical outcome.