糖尿病性肌梗死的磁共振表现(一例报告及文献分析)

目的 :探讨糖尿病性肌梗死 (DMI)的MRI表现、相关病理基础及MRI的诊断价值。方法 :报道 1例发生于右侧胸大肌的DMI病案 ,并对文献报道的 3 4例DMI病案进行回顾性分析。结果 :DMI在MRI平扫上表现为受累肌肉增大水肿 ,肌内灶性梗死和 /或出血 ,伴肌间脂肪间隔模糊 ,肌筋膜下积液和皮下水肿 ;增强扫描时肌肉呈现弥漫性强化和 /或灶性环状强化。其中 ,除灶性出血的显示率为 17.1%外 ,其它征象的显示率均在 5 0 %以上。结论 :DMI是糖尿病的一种罕见并发症 ,在MRI上有比较典型的表现。MRI是诊断和随访本病的首选影像学检查方法。MRI与临床表现相结合可以使多数病例得到确诊 ,从而避免了活检或手术可能带来的不良后果     

MRI diagnosis of diabetic muscle infarction: report of two cases

 Diabetic muscle infarction (DMI) is a rare complication of diabetes mellitus occurring in patients with poorly controlled insulin-dependent diabetes. In previous reports, the diagnosis of this condition was based on the pathologic studies, although MRI examinations were performed in a few patients as part of the diagnostic work-up. In this report, we describe two additional cases of DMI where the diagnosis was based on the MRI findings in conjunction with the clinical picture and laboratory studies. The patients usually present with thigh or calf pain and swelling, are afebrile, and have normal white blood cell count. MRI examination typically shows diffuse swelling and increased signal intensity on T2-weighted images in the affected muscles, with no focal fluid collections. In the proper clinical setting, these findings are diagnostic of DMI and patients should be spared unnecessary invasive diagnostic examinations such as lower extremity venograms and biopsies.     

Intramuscular plasmacytoma

Objective

In multiple myeloma, secondary infiltration of adjacent muscles from bone lesions is common. However, plasmacytoma directly arising within the skeletal musculature is rare. Imaging findings of this rare entity have been described only sporadically. The purpose of this study was to identify the clinical signs and radiological features of intramuscular plasmacytoma (IP).

Materials and methods

Eleven patients with IP were retrospectively identified in the pathological and radiological databases of our institution. Computed tomography (CT) was performed in nine patients and magnetic resonance imaging (MRI) in four cases.

Results

IP presented clinically with local pain in four patients. In one case with involvement of the rectus lateralis muscle of the eye, the patient showed a painless bulbus proptosis. In another patient, IP manifested as a massive bilateral forearm swelling with compartment syndrome. In four patients, IP was identified incidentally on computed tomography during staging examination. On imaging, two patterns of IP were found: intramuscular mass (n?=?5) or diffuse muscle infiltration (n?=?6). On CT with contrast, IP showed a moderate enhancement. With MRI on T1-weighted images, IP was isointense in comparison to the unaffected musculature, whereas on T2-weighted images, IP showed high signal intensity. After intravenous administration of contrast medium, a slight-to-moderate inhomogeneous enhancement was seen in all cases.

Conclusions

IP should be considered in the differential diagnosis of muscle tumors. It manifests with two radiological patterns, either as intramuscular mass or as diffuse muscle infiltration.     

The role of MRI in facial swelling due to presumed salivary gland disease.

50 consecutive patients presenting with facial swelling thought clinically to be due to salivary gland disease underwent MRI. Examinations were interpreted by one radiologist without access to previous investigations. Records were reviewed to determine the reliability and role of MRI in patient management, and the contribution of other prior or subsequent investigations. MRI findings were verified against operative findings, percutaneous biopsy or clinical follow-up (periods ranging from 8-58 months). A mass was found in 27 patients; in 11 of these patients, disease was extrinsic to the salivary gland. MRI diagnosis of tumour was correct in all patients and MRI was a reliable investigation for planning surgical resection. No mass was found in 23 patients, 8 of whom had normal appearances. Evidence of salivary duct dilatation was seen in 12 patients and fatty infiltration was seen in 3. MRI findings appeared correct in all patients. Prior investigation was undertaken in 29 patients, including orthopantomography, ultrasound and sialography; none provided additional information. Sialography was carried out in three patients after MRI and concurred with MRI in all cases. MRI was an adequate basis for management in all patients and therefore appears to be an effective first line investigation of facial swelling. It is reasonable for patients to undergo preliminary investigation for dental sepsis, this being the most common cause of facial swelling. Further study is required to determine whether MRI can completely replace invasive sialography.     

Osteomyelitis of the clavicle: clinical,radiologic, and bacteriologic findings in ten patients

Most lesions of the clavicle are traumatic and pose few diagnostic difficulties. Nontraumatic clavicular lesions, on the other hand, are rare and frequently present problems in diagnosis. This report reviews the clinical, radiologic, and bacteriologic findings in ten patients, six of whom were diagnosed as having acute osteomyelitis and four chronic osteomyelitis. The differential diagnosis of clavicular osteomyelitis is also discussed. The clinical duration of the infectious process in these patients ranged from 2 weeks to 1.5 years. All patients presented with pain; six had fever, three had localized swelling or a mass, and three had soft tissue abscesses. The radiographic findings also varied: the lesion was predominantly sclerotic in four patients, lytic in three, and mixed in two patients; in the one patient in whom magnetic resonance imaging was the only imaging study performed, these features could not be properly evaluated. Periosteal reaction was detected in three patients. Staphylococcus aureus was the causal organism in four patients, while in the remaining six patients different microorganisms were cultured, including Coccidioides immitis and Mycobacterium tuberculosis. Six patients required biopsy for final diagnosis. Although clavicular osteomyelitis is rare, particularly in adults, it should be considered in the differential diagnosis of a clavicular lesion. The final diagnosis often depends on the results of biopsy and cultures.     

Unsuspected lower extremity deep venous thrombosis simulating musculoskeletal pathology

Objective The purpose of this study was to highlight the critical role that MRI may play in diagnosing unsuspected lower extremity deep venous thrombosis and to stress the importance of scrutinizing MRI studies of the lower extremity showing apparently non-specific muscle edema for any evidence of intramuscular venous thrombosis.Design and patients The imaging studies of four patients in whom deep venous thrombosis was unsuspected on clinical grounds, and first diagnosed on the basis of MRI findings, were reviewed by two musculoskeletal radiologists in consensus. In all four patients the initial clinical suspicion was within the scope of musculoskeletal injuries (gastrocnemius strain, n=3; ruptured Baker cyst, n=1), explaining the choice of MRI over ultrasound as the first diagnostic modality.Results All patients showed marked reactive edema in the surrounding soft tissues or muscles. Three patients showed MR evidence of branching rim-enhancing structures within intramuscular plexuses characteristic of venous thrombosis (gastrocnemius, n=1; sural, n=2); one patient showed a distended popliteal vein. Ultrasound was able to duplicate the MRI findings in three patients: one patient showed above-the-knee extension on ultrasound; neither of the two patients with intramuscular thrombosis demonstrated on ultrasound showed extension to the deep venous trunks.Conclusion Intramuscular venous thrombosis can present as marked edema-like muscle changes on MRI, simulating primary musculoskeletal conditions. In the absence of clinical suspicion for deep venous thrombosis, only the identification of rim-enhancing branching intramuscular tubular structures will allow the correct diagnosis to be made.     

Pancreatic masses with inconclusive findings on spiral CT: Is there a role for MRI?

This prospective study evaluates the ability of MRI using T1-weighted fat-suppressed spin-echo (T1FS) and dynamic gadolinium chelate (Gd) enhanced spoiled-gradient echo (SGE) to detect the presence of pancreatic tumor in patients in whom spiral CT findings are inconclusive. Sixteen consecutive patients who underwent spiral CT and had findings that were considered inconclusive for pancreatic tumor underwent MR within 2 weeks of CT. Spiral CT and MR images were interpreted in a prospective fashion by separate individual investigators blinded to the results of the other imaging modality. CT was performed on a spiral CT scanner. MRI was performed on a 1.5-T MR machine. Imaging sequences included T1FS pre-Gd and post-Gd and SGE pre-Gd and immediately post-Gd. Data were analyzed using receiver operating characteristic (ROC) analysis. Confirmation was obtained by pancreatic biopsy (n = 4), surgical resection (n = 1), and clinical imaging (n = 4) or clinical follow-up (n = 7). MRI was superior to spiral CT (P = .027) in this selected patient group at detecting or excluding pancreatic tumor by ROC analysis, with areas under the curve of .982 and .764, respectively, which was significant (P = .041). The greatest advantage of MRI was in patients in whom spiral CT demonstrated enlargement of the pancreatic head without clear definition of tumor, which was significant (P = .033). In 10 patients with this CT appearance, MRI demonstrated a high confidence for presence of tumor in four and a high confidence of absence in six. Association of imaging findings with patient diagnosis was significant for MRI (P = .001) but not significant for CT (P = .148). The results of our study suggest that MRI may add significant diagnostic information in patients in whom spiral CT is inconclusive for the presence of pancreatic tumor. The greatest advantage of MRI was in the evaluation of patients in whom spiral CT findings revealed an indeterminate enlarged pancreatic head.     

Imaging of Intracystic Papillary Carcinoma

OBJECTIVETo describe the clinical, imaging, and histopathologic findings of intracystic papillary carcinoma (IPC) of the breast.MATERIALS AND METHODSFollowing institutional review board approval, a database at a single institution was searched to identify cases of patients who received a diagnosis of IPC from 1999-2013 and who had undergone preoperative imaging with mammography, sonography, or MRI. The clinical, mammographic, sonographic, and MRI features of IPC were compared and analyzed using the BI-RADS mammography, ultrasound, and MRI lexicons.RESULTSThe study sample included 40 patients, 36 females and 4 males. The most common clinical presentation was a palpable mass. Mammographic data was assessed in 31 patients. A tumor was mammographically occult in one patient. The predominant features were oval shape of 17 tumors (57%), obscured margins of 12 (40%), and high density of 20 (67%). Ultrasound data of 37 patients revealed 20 oval masses, 13 irregular masses, and 4 round masses. Fourteen complex solid and cystic masses were identified. One patient underwent MRI that showed a complex, enhancing mass with washout kinetics. Ultrasound guided biopsy was performed on 33 of the 37 masses. Core needle biopsy and fine needle aspiration (FNA) biopsy were most commonly performed on the solid components of the complex solid and cystic masses. IPC was diagnosed by stereotactic biopsy in 1 patient with a suspicious mass on mammography with no correlate on sonography and 6 patients had surgical excision without imaging-guided biopsy.Pathology showed in situ IPC in 31/40 tumors and 11 were solid and cystic complex masses on ultrasound. Pathology revealed invasive IPC in 9 tumors and five had an irregular mass on ultrasound.CONCLUSIONOur study reveals no specific imaging features to differentiate in situ vs invasive IPC. The most common ultrasound feature in biopsy proven IPC was an oval mass, however, we identified that a complex solid and cystic mass is more often associated with the diagnosis of in situ IPC and an irregular mass is more often associated with the diagnosis of invasive IPC. Future studies with larger cohorts are needed to further define the clinical and imaging features of this rare malignancy.     

Spinal osteoblastoma: relationship between paravertebral muscle abnormalities and scoliosis

 Objective. To illustrate the variety of paravertebral muscle abnormalities as seen on computed tomography (CT) or magnetic resonance imaging (MRI) in association with spinal osteoblastomas and correlate the findings with the presence of scoliosis. Design. In a retrospective study the clinical notes, plain radiographic, CT and/or MRI features were reviewed for the presence of scoliosis and paravertebral muscle abnormality (either inflammation or atrophy). Patients. Twelve patients (7 male, 5 female) with a mean age of 17 years were studied. Three lesions occurred in the cervical spine, five in the thoracic spine and four in the lumbar spine. Results and conclusions. Nine patients had scoliosis. All patients with a thoracic or lumbar lesion and scoliosis (n=8) had an associated abnormality of the paravertebral muscles (usually atrophy with fatty replacement). One patient with a lumbar lesion and no scoliosis had normal paravertebral muscles. One patient with a cervical lesion had thoracic scoliosis but no muscle abnormality in the cervical region, while two patients with cervical lesions and no scoliosis showed muscle abnormalities. The results support the clinical hypothesis that scoliosis in patients with spinal osteoblastoma is due to paravertebral muscle spasm, although this would not appear to be the case for cervical lesions.     

糖尿病患者肌肉梗死的MRI诊断

目的 探讨糖尿病性肌肉梗死（DMI）的MRI表现。资料与方法 对3例行MRI和彩超检查,临床诊断DMI的患者进行回顾性分析。3例均为男性,平均年龄63．7岁,平均糖尿病病程为7．3年,所有患者均单一肢体发病。结果 MRI示受累肌肉明显肿胀,体积增大,T1WI信号减低,T2WI信号增高;可显示部分脂肪间隔消失、筋膜下积液等征象,皮下组织水肿。病变在T2WI上最敏感。结论 糖尿病伴随突发下肢肌肉肿胀疼痛,MRI示受累肌肉弥漫肿胀、水肿即可提示本病的诊断。     

Pseudoaneurysm following vertebral biopsy and treatment with percutaneous thrombin injection

We present a case of a pseudoaneurysm within the lumbar musculature. This occurred following a computed tomography (CT)-guided vertebral biopsy in a 79-year-old male patient and was successfully treated with percutaneous ultrasound-guided thrombin injection. The patient initially presented with severe back pain. The plain radiographs and Magnetic resonance imaging (MRI) showed destruction of the L1 and L2 end plates, with marked narrowing of the disc space, suggestive of infective discitis. CT-guided biopsy was performed by the right paravertebral approach. Methicillin-resistant Staphylococcus aureus (MRSA) was grown, following culture of the specimen. Twenty days later, the patient developed a palpable swelling in the right lumbar region, with worsening of the back pain. MRI and ultrasound imaging showed a 3 cm pseudoaneurysm within the right lumbar musculature. The pseudoaneurysm was successfully treated following percutaneous ultrasound-guided injection of thrombin.     

Magnetic resonance imaging: a cost-effective alternative to bone scintigraphy in the evaluation of patients with suspected hip fractures

Objective. To evaluate the cost-effectiveness of magnetic resonance imaging (MRI) compared with radionuclide bone scan in the evaluation of patients with clinically suspected hip fractures. Design. The medical records of all patients who had been seen in the emergency room over a 4-year period with a clinically suspected hip fracture, negative or equivocal plain films, and either a subsequent bone scan or MRI examination were retrospectively reviewed. The time to diagnosis, admission rate, and time to surgery were determined. A two-sample t-test was used to assess the statistical significance of the results. A theoretical cost analysis was performed using current charges to estimate all expenses. Patients. Forty patients (11 male, 29 female; age 28–99 years) satisfied our inclusion criteria. Results and conclusions. Twenty-one patients had bone scans (six with fractures), and 19 had MRI (four with fractures). The time to diagnosis was 2.24±1.30 days for bone scanning and 0.368±0.597 days for MRI (P<0.0001). Twenty patients in the bone scan group were admitted compared with 13 in the MRI group. The time to surgery was at least 1 day longer in patients undergoing bone scanning. Bone scanning resulted in higher patient costs compared with MRI because of the delay in diagnosis. In the evaluation of patients with suspected hip fractures, early MRI is more cost-effective than delayed bone scanning. Further prospective studies comparing the cost-effectiveness of early MRI with early bone scanning are needed.     

Skeletal muscle disease: patterns of MRI appearances

Although the presumptive diagnosis of skeletal muscle disease (myopathy) may be made on the basis of clinical–radiological correlation in many cases, muscle biopsy remains the cornerstone of diagnosis. Myopathy is suspected when patients complain that the involved muscle is painful and tender, when they experience difficulty performing tasks that require muscle strength or when they develop various systemic manifestations. Because the cause of musculoskeletal pain may be difficult to determine clinically in many cases, MRI is increasingly utilised to assess the anatomical location, extent and severity of several pathological conditions affecting muscle. Infectious, inflammatory, traumatic, neurological, neoplastic and iatrogenic conditions can cause abnormal signal intensity on MRI. Although diverse, some diseases have similar MRI appearances, whereas others present distinct patterns of signal intensity abnormality. In general, alterations in muscle signal intensity fall into one of three cardinal patterns: muscle oedema, fatty infiltration and mass lesion. Because some of the muscular disorders may require medical or surgical treatment, correct diagnosis is essential. In this regard, MRI features, when correlated with clinical and laboratory findings as well as findings from other methods such as electromyography, may facilitate correct diagnosis. This article will review and illustrate the spectrum of MRI appearances in several primary and systemic disorders affecting muscle, both common and uncommon. The aim of this article is to provide radiologists and clinicians with a collective, yet succinct and useful, guide to a wide array of myopathies.Skeletal muscle disorders have a wide variety of causes, treatments and prognoses, and are commonly seen in orthopaedic, neurology or internal medicine practices. The diagnosis of muscle disease (myopathy) has traditionally relied on clinical examination, coupled with histological analysis of a muscle biopsy specimen in complex cases that may be clinically obscure. Because patients with these conditions present with vague symptoms of myalgia, weakness, fatigue and disability, the abnormalities are often initially overlooked or even underestimated as a source of pathology [1,2]. Furthermore, clinical assessment of the integrity and performance of skeletal muscle can be problematic, owing to the complex compartmental anatomy and several anatomical variations in muscle [3]. Early recognition of abnormalities is, however, critical to implementing an appropriate management regimen that facilitates patients'' prompt and safe return to function and activity.Given the relatively non-specific clinical presentation of the spectacular array of primary and systemic disorders affecting skeletal muscles, imaging plays a key role in achieving the correct diagnosis. Although radiography allows for evaluation of certain muscle derangements (e.g. infection, heterotopic ossification), it is limited by relatively poor sensitivity and lack of anatomical detail [4,5]. CT facilitates the diagnosis of conditions similar to those detected by radiography in a cross-sectional display, but it provides limited contrast resolution for muscle. MRI has emerged as the advanced imaging method of choice for skeletal muscle, providing excellent soft-tissue contrast resolution and multiplanar tomographic display. Although many of the disorders affecting muscle may manifest with non-specific imaging signs, MRI allows detection and characterisation of these lesions, which helps to formulate a reasonable diagnosis or to establish a limited differential diagnosis. Furthermore, MRI can depict selective abnormality within individual muscles that may be challenging to detect clinically because of the presence of unaffected synergistic muscles [6]. We present the MRI findings seen with a wide range of primary and systemic neuromuscular and orthopaedic disorders that can aid the clinician when assessing the cause of pain and dysfunction in muscle. Although this work is not an exhaustive presentation of muscular pathology, we aim at presenting a concise, helpful and practical imaging review of the basic MRI findings associated with common and uncommon musculoskeletal disease processes.     

Florid reactive periostitis and bizarre parosteal osteochondromatous proliferation: pre-biopsy imaging evolution, treatment and outcome

Objective. To report on the imaging evolution of florid reactive periostitis (FRP) and bizarre parosteal osteochondromatous proliferation (BPOP) of the phalanges of the hands from prospective diagnosis to operation and on postsurgical outcome. Design and patients. Three patients (2 female, 1 male; age range 11–34 years) presented with a swollen digit of the hand. Following presumptive radiographic diagnosis of FRP, they were closely observed both clinically and radiographically until operation. All three patients had radiographs of the involved digit, and one patient had an MR imaging examination. The interval between presumptive diagnosis and operation ranged from 2 to 8 months. Following operation, the patients have been clinically followed for 9–13 months (mean 10 months). Results. In each of the patients, maturing of periosteal reaction without bone destruction was observed within 1–2 weeks of the presumptive diagnosis of FRP. Periosteal reaction was initially minimal in relation to the extent of soft tissue swelling and subsequently became more florid. In one patient, the lesion ossified, became adherent to the phalanx, and had an ”osteochondromatous” appearance. In another patient, periosteal reaction was seen on both sides of the phalanx with an intact phalanx. In the sole patient who had MR imaging, edema was seen in the phalanx distal to the symptomatic site and the metacarpal proximal to the symptomatic site. Conclusions. Close clinical and radiographic correlation permits an accurate pre-biopsy diagnosis of FRP. The first follow-up radiograph taken within 2 weeks usually provides reassurance of the accuracy of the diagnosis. FRP may progress to BPOP. Arbitrary antibiotic treatment can be avoided, and a planned surgical approach can be adopted. Received: 21 August 2000 Revision requested: 8 December 2000 Revision received: 26 December 2000 Accepted: 26 December 2000     

Multiparametric Magnetic Resonance Imaging Characteristics of Prostate Tuberculosis

ObjectiveTo describe the multiparametric magnetic resonance imaging (MRI) appearance of prostate tuberculosis.ResultsThe histopathological results were obtained from biopsies in four men and from transurethral resection of the prostate in two men after the MRI examination. Nodular (33%, 2/6 patients) and diffuse lesions (67%, 4/6 patients) were seen on MRI. The nodular lesions were featured by extremely low signal intensity (similar to that of muscle) on T2-weighted imaging (T2WI). The T2WI signal intensity of the diffuse lesions was low but higher than that of muscle, which showed high signal intensity on diffusion weighted imaging and low signal intensity on an apparent diffusion coefficient map. MR spectroscopic imaging of this type showed a normal-like spectrum. Abscesses were found in one patient with the nodular type and in one with the diffuse type.ConclusionThe appearance of prostate tuberculosis on MRI can be separated into multiple nodular and diffuse types. Multiparametric MRI may offer useful information for diagnosing prostate tuberculosis.     

Type I Gaucher disease: extraosseous extension of skeletal disease

Objective. To investigate the frequency and morphology of extraosseous extension in patients with Gaucher disease type I. Design and patients. MRI examinations of the lower extremities were analyzed in 70 patients with Gaucher disease type I. Additionally, the thoracic spine and the midface were investigated on MRI in two patients. Results. Four cases are presented in which patients with Gaucher disease type I and severe skeletal involvement developed destruction or protrusion of the cortex with extraosseous extension into soft tissues. In one patient, Gaucher cell deposits destroyed the cortex of the mandible and extended into the masseter muscle. In the second patient, multiple paravertebral masses with localized destruction of the cortex were apparent in the thoracic spine. In the third and fourth patient, cortical destruction with extraosseous tissue extending into soft tissues was seen in the lower limbs. Conclusions. Extraosseous extension is a rare manifestation of Gaucher bone disease. While an increased risk of cancer, especially hematopoietic in origin, is known in patients with Gaucher disease, these extraosseous benign manifestations that may mimic malignant processes should be considered in the differential diagnosis of extraosseous extension into soft tissues. A narrow neck of tissue was apparent in all cases connecting bone and extraosseous extensions. Received: 19 July 1999 Revision requested: 8 September 1999 Revision received: 7 October 1999 Accepted: 14 October 1999     

Gadopentetate-dimeglumine-enhanced MR imaging of osteonecrosis and osteochondritis dissecans of the elbow: initial experience

Magnetic resonance imaging (MRI) was performed on seven patients with aseptic osteonecrosis (n=4) and osteochondritis dissecans (OCD;n=3) of the elbow. Precontrast MRI was superior to plain radiographs, which did not show any abnormality in three cases of osteonecrosis. On gadopentetate-dimeglumine-enhanced T1-weighted images, which were obtained in three patients with osteonecrosis and three patients with OCD, all cases of osteonecrosis demonstrated homogeneous enhancement of the lesions. All cases of OCD were diagnosed on plain radiographs. On MRI one showed significant enhancement of the loose body. In another case an incompletely enhancing loose body was surrounded by a diffusely enhancing region. In the third patient only a small marginal enhancement of the defect was observed. Our results suggest that MRI can improve the accuracy in diagnosis of aseptic osteonecrosis of the elbow. The use of gadopentetate dimeglumine allows the viability of the lesions or the loose bodies to be demonstrated and reparative tissue to be detected.     

Superior orbital fissure syndrome and its mimics: What the radiologist should know?

Aim of this study

The aim of this study was to assess the rule of imaging in the superior orbital fissure syndrome (SOFS) and to identify the rule of the radiologist in guidance of the management.

Material and methods

This study was conducted on 7 patients with clinical diagnosis of SOFS. Contrast enhanced MRI was used in examination of all patients. With exception of metastatic lesions, follow up MRI study was performed to all lesions. Final diagnosis was reached either by dramatic response to cortico-steroid therapy, tissue biopsy or by correlation with clinical and other imaging data.

Results

In all patients enhancing abnormal T1 and T2 intermediate intensities are seen localized to the anatomical site of the superior orbital fissure (SOF). Four patients presented with sheet like enhancement casting the SOF. Nodular enhancement is noted along the medial aspect of the SOF in one case. Two patients presented with sizable destructive space occupying lesions at SOF.

Conclusion

In management of SOFS, if there is a dramatic clinical and radiological response to corticosteroid therapy, we recommend MRI follow-up study after 6 week interval. As the symptoms were resolving, the potential risks associated with tissue biopsy from that area will be unacceptable.     

Congenital absence and aberrant course of the internal carotid artery

We retrospectively reviewed the imaging features of an aberrant course of the internal carotid artery (ICA) in one patient and its unilateral absence in four. Absence of the ICA was initially detected by MRI and MR angiography in both patients who underwent these examinations. CT revealed an abnormal or absent carotid canal in all cases. Radiological diagnosis by MRI and MR angiography could play an important role in the diagnosis. Correspondence to: S. Takahashi     

Magnetic resonance imaging in coccidioidal arthritis

 Objective. The authors assessed the MRI findings of appendicular coccidioidal arthritis. Design. T1- and T2-weighted MR images of affected joints, both with and without intravenous gadopentetate dimeglumine, were performed in nine adult patients (ten studies) and evaluated by three masted readers, using a four-point certainty scale for: synovial abnormality, articular cartilage loss, subarticular bone loss, abnormal marrow signal, enhancement of osseous and articular structures, and assessment of disease activity. Findings were correlated with biopsy results or clinical course. Results. Eight patients had active and one had inactive arthritis, involving the knee (five patients), ankle (two patients), and elbow (one patient). Synovial complex was the most common finding in active arthritis (P<0.025). Cartilage and subarticular bone loss were seen 56% and 89% of patients with active disease, respectively. Abnormal marrow signal was uncommon (two patients). All cases showed synovial and/or osseus enhancement. Conclusions. MRI findings in coccidiodal arthritis are described. Enhancement of thickened synovium and erosions was seen after intravenous gadopentetate.