Ganglion cysts at the gastrocnemius origin: a series of ten cases

Objective To describe ganglion cysts arising close to the origin of the medial and lateral head of gastrocnemius as identified on magnetic resonance (MR) imaging. Design and patients We present a series of ten cases of ganglion cysts arising close to the gastrocnemius origin from the medial and lateral femoral condyles. These were collected over a 6-year period from our imaging database. All patients attended for routine MR imaging of the knee with a variety of clinical presentations. Data collected included patient demographics, ganglion size, ganglion site, clinical presentation and ancillary MR imaging findings. The ten patients in this series consisted of seven males and three females, five right and five left knees, age range 27–68 years, mean age 40.6 years. Results The mean maximal dimension of the ganglion cysts was 26 mm, range 15–40 mm. The medial gastrocnemius origin was involved in eight patients and the lateral origin in two patients. The MR imaging findings consisted of both uni- and multi-loculated cysts, often containing numerous septations with fluid signal characteristics. The cysts were extra-capsular with no clear communication with the joint. One patient presented with a popliteal soft tissue mass and none of the cases required surgical intervention for cyst removal. Conclusions MR imaging may identify ganglion cysts arising in an intra- or extra-articular site around the knee. This series documents the MR imaging characteristics of ganglion cysts arising close to the gastrocnemius origin and discusses the relevance of this imaging finding.     

Peroneal nerve injury in three patients with knee trauma: MR imaging and correlation with anatomic findings in volunteers and anatomic specimens

The aim of this article is to report on three patients with injuries of the peroneal nerve along the posterolateral aspect of the knee. Injuries in this area are less common than the injuries occurring at the level of the fibular head. In this article we report on three patients with posterolateral knee trauma who had peroneal nerve dysfunction. To better understand the precise location of the nerve on MR images, we performed MR imaging in five volunteers, and studied the position of the nerve on anatomic dissection (n=1) and anatomic slices (n=1). The common peroneal nerve is easily depicted on MR images and has a typical location along the posterior margin of the biceps tendon. Non-visualisation of the peroneal nerve at the posterolateral aspect of the knee, as seen on MR images, is consistent with nerve injury. Scar tissue at the posterolateral aspect of the knee indicates injury of this specific area, and involvement of the peroneal nerve is likely.     

The MRI appearance of cystic lesions around the knee

This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus–tibial collateral ligament, iliotibial and fibular collateral ligament–biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate.     

Advanced imaging of melorheostosis with emphasis on MRI

Objective: To describe the CT and MR imaging appearance of both osseous and extraosseous manifestations of melorheostosis. Design and patients: We retrospectively reviewed the CT (n=7) and/or MR imaging findings (n=12) of 17 patients with characteristic radiographic findings of melorheostosis (undulating cortical hyperostosis with marked uptake on radionuclide bone scintigraphy). Results: CT and MR imaging revealed cortical hyperostosis as high attenuation and low signal intensity on all MR pulse sequences, respectively. Encroachment on the marrow space was seen in all cases resulting from endosteal involvement. Thirteen patients demonstrated 14 soft tissue masses with infiltrative margins in 80% of cases and seven showed extensive mineralization on CT or MR imaging (low intensity on all pulse sequences). Seven soft tissue masses were predominantly nonmineralized with intermediate signal intensity on T1-weighted and intermediate to high signal on T2-weighted MR images corresponding to vascularized fibrous tissue with variable collagen content pathologically. Enhancement after intravenous gadolinium was seen in all patients imaged with soft tissue masses (n=2). Two patients demonstrated muscle atrophy resulting from nerve involvement. Conclusions: The osseous abnormalities in melorheostosis are identical on advanced imaging and radiographs. Mineralized or nonmineralized soft tissue masses should be recognized as another manifestation of this disease as opposed to a more ominous finding, making biopsy unwarrranted. Received: 16 January 2001 Accepted: 21 February 2001     

MR imaging of lipoma arborescens and the associated lesions

Objective To describe the typical features of lipoma arborescens on MR imaging with pathologic correlation and to evaluate the associated lesions within the joints.Design and patients The MR imaging findings of 32 patients with the diagnosis of lipoma arborescens of the knee (n=32) and shoulder (n=1) were reviewed. The diagnosis of lipoma arborescens was confirmed by the histologic findings in 12 cases and the other 21 cases were diagnosed by the characteristic MR imaging features. One patient had bilateral lipoma arborescens of the knee joint.Results MR imaging showed a typical pattern of villous lipomatous proliferation of the synovium in all cases, as a diffuse pattern in 79% (26/33) of cases and as a dominant mass-like lesion in 21% (7/33) of cases. The associated MR pathology in the knee was (n=32): joint effusion (100%), degenerative changes (87%), meniscal tear (72%), synovial cysts (38%), bone erosions (25%), chondromatosis (13%), patellar subluxation (6%) and discoid meniscus (3%). In all cases except two there was associated pathology of the knee. MR imaging showed an associated rotator cuff tear in the lipoma arborescens of the shoulder.Conclusion The characteristic MR features of lipoma arborescens allows an accurate diagnosis of this rare lesion, which is almost always associated with other chronic pathology of the joint in the elderly.     

Ganglion cyst at the proximal tibiofibular joint - A rare cause of compression neuropathy of the peroneal nerve

Ganglion cysts are fluid filled sacs which develop near joints and tendons and are usually asymptomatic. Lower limb ganglion cysts are rare occurrences especially those situated around joint spaces causing nerve compression. We present the case of a 68 year-old female with history of progressive swelling in the left antero-lateral leg, associated with pain, and neurological symptoms of peroneal nerve compression. Magnetic resonance imaging (MRI) revealed a large proximal tibiofibular joint ganglion cyst causing peroneal nerve compression. One year following the left sided presentation, the patient presented with similar but less severe symptoms in her right antero-lateral leg. MRI revealed a small juxta-articular ganglion cyst in the right proximal tibiofibular joint space. We discuss etiology, symptoms, and management of lower limb ganglion cysts.     

Evaluation of ganglion cysts using vastly undersampled isotropic projection reconstruction (VIPR)

For some atypical para-articular ganglia, the presence of a joint connection is highly controversial. The proper preoperative diagnosis and identification of this joint connection for ganglion cysts is important for patient treatment and outcome. MRI is the imaging modality of choice when evaluating such lesions, but the detection of subtle joint connections remains difficult with conventional MR protocols. We investigated the utility of a steady-state free-precession acquisition with isotropic high resolution using the vastly undersampled isotropic projection reconstruction (VIPR) pulse sequence to determine if joint connections for ganglion cysts could be seen more effectively, using the knee region as a model. We evaluated four patients: two with peroneal intraneural ganglion cysts, one with adventitial cystic disease of the popliteal artery, and one patient with a more typical extraneural (intramuscular) cyst. Both conventional MR and VIPR techniques were used. In our clinical experience, we found VIPR to be superior to conventional MR techniques in detecting and depicting joint connections in typical and atypical ganglion cysts around the knee.     

CT and MR of neurofibromatosis of the bladder.

Neurofibromatosis of the genitourinary system is rare. We present the CT and MR findings of neurofibromas of the bladder in three patients with von Recklinghausen disease (neurofibromatosis, Type 1). In one case, genitourinary involvement was the primary presentation of the disease. Both CT and MR imaging revealed diffuse and nodular bladder wall involvement, along with pelvic sidewall and adjacent soft tissue abnormalities. The CT attenuation coefficients measured near soft tissue density. On T1-weighted spin echo MR images the tumors revealed signal intensity slightly greater than that of skeletal muscle. Neurofibromas showed markedly increased signal intensity on T2-weighted images relative to the surrounding soft tissues, with marked enhancement in two cases imaged following Gd-DTPA administration. Obstructive hydronephrosis was present in all cases, presumably due to neurofibromas involving the trigonal region. Pelvic sidewall tumors were visualized as rounded, nodular masses extending into the obturator foramina. In the evaluation of patients with von Recklinghausen disease, MR imaging, compared with CT, more clearly defined tumor extent within the bladder, pelvic sidewalls, and surrounding soft tissues.     

Ganglion cysts of the cruciate ligaments

Purpose:
To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings. Material and Methods:
We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations. Results:
Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment. Conclusion:
MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations.     

Synovial hemangioma: imaging features in eight histologically proven cases,review of the literature,and differential diagnosis

Objective This study was undertaken to describe the imaging characteristics of synovial hemangioma, with the goal of improving the disappointing rate (22%) of clinical diagnosis of this condition. A review of the literature and the differential diagnosis of intra-articular lesions, including synovial osteochondromatosis and pigmented villonodular synovitis, are also presented.Patients The subjects of the study were 8 patients (4 males, 4 females; age range: 5–47 years; mean age: 19 years) with histologically confirmed synovial hemangioma involving the knee (n=7) or wrist (n=1). We retrospectively examined the imaging studies performed in these patients, including plain radiography (n=8), magnetic resonance imaging (MRI; n=4), angiography (n=3), arthrography (n=2), and contrast-enhanced computed tomography (CT; n=2).Results Plain radiographs showed a soft tissue density suggesting either joint effusion or a mass in all patients. Phleboliths and bone erosions on plain films in four patients with extra-articular soft tissue involvement pointed to the correct diagnosis. Angiography, showing fine-caliber, smooth-walled vessels, contrast pooling in dilated vascular spaces, and early visualization of venous structures, was diagnostic in two patients. Neither arthrography nor CT yielded specific enough findings. MRI was consistently effective in allowing the correct diagnosis to be made preoperatively, showing an intra-articular or juxta-articular mass of intermediate signal intensity on T1-weighted images and of high signal intensity on T2or T2^*-weighted images with low-signal channels or septa within it. A fluid-fluid level was found in two patients with a cavernous-type lesion.Conclusion Despite the limited nature of this study, it shows clearly that MRI is the procedure of choice whenever an intra-articular vascular lesion such as synovial hemangioma is suspected. Nonetheless, phleboliths and evidence of extra-articular extension on plain radiographs point to angiography as an effective procedure of first resort because it can be combined with embolotherapy.     

MRI findings in patients with tibial nerve compression near the knee

The soleus sling has been recently identified as a site of compression of the tibial nerve resulting in tibial neuropathy. Diagnosis of soleal sling syndrome is difficult, and has been based mainly on clinical examination. Advances in MR imaging with high-resolution 3-Tesla scanners have made direct visualization of nerve pathology possible. With the use of high-resolution imaging and fat-suppression protocols, tibial nerve compression at the soleal fascial arch can be demonstrated in a subset of patients presenting with idiopathic tibial neuropathy. The purpose of this paper is to confirm the ability of MR imaging to demonstrate pathologic changes in the tibial nerve in patients presenting with soleal sling syndrome. Additionally, patients presenting with tibial neuropathy and ganglion cysts, both extra- and intraneural, were examined to determine if the site of compression corresponded to the region of the soleus sling. Nine patients were included in the study, two with idiopathic soleus sling syndrome, four with extraneural, and three with intraneural ganglion cysts. In the patients presenting with idiopathic soleus sling syndrome, MR imaging demonstrated a thickened soleus sling with T2 hyperintensity of the tibial nerve at the level of the sling and denervation changes in muscles of the posterior compartment of the leg. In patients with extraneural ganglion cysts, MR imaging demonstrated a “sandwich”-like compression of the tibial nerve between the cyst and the soleus sling with corresponding tibial nerve T2 hyperintensity and denervation change in posterior compartment muscles. No compression of the tibial nerve at the soleus sling was found in the intraneural ganglion population. We conclude that MR imaging is effective in demonstrating pathologic changes in the tibial nerve at the soleus sling. Based on the MRI findings, we also believe that the soleus sling is a component of the compression when patients present with extraneural ganglion cysts and tibial neuropathy near the knee; in these patients, we recommend release of the soleus sling as part of the definitive management.     

颞骨内面神经病变的影像学表现

目的总结分析面神经病变的影像学检查方法和表现,提高诊断准确性。资料与方法回顾性分析31例经手术病理或临床跟踪随访证实的面神经病变的CT和MRI表现,31例行MR扫描,其中28例行平扫和增强扫描,3例仅行平扫;19例行CT扫描。结果（1）面神经损伤13例,8例行CT扫描,6例显示面神经管骨折,2例表现正常;13例MRI扫描均表现为面神经增粗,其中10例增强扫描显示面神经明显强化。（2）面神经炎14例,7例行CT扫描,1例因岩尖胆脂瘤致面神经管迷路段、前膝部、鼓室段前部骨质破坏,6例面神经管未见异常;14例MRI增强扫描显示面神经节段性异常强化。（3）面神经鞘瘤4例,CT表现为受累面神经管骨质破坏和软组织肿块;MRI表现为面神经节段性增粗,呈长T1、长T2信号,信号不均匀,增强后不均匀强化。经统计学处理,MRI显示颞骨内面神经病变明显优于CT（P＜0．01）。结论HRCT可显示面神经管的异常,MRI尤其是MR增强扫描可显示面神经病变的形态、部位、范围及强化表现,有助于病变的诊断和鉴别诊断。     

Normal and pathological MR findings in osteochondral autografts with longitudinal follow-up

The purpose of this study was to analyze normal and pathological MR findings in osteochondral autograft transfer systems (OATS) of the knee and ankle in the longitudinal follow-up and in relation to the clinical findings. MR imaging was performed in 55 patients (21 females: 34 males; mean age 34.5±12.1 years) after OATS procedures in the knee (n=45) and ankle (n=10). MR sequences were obtained with and without intravenous Gd-DTPA administration within the first year post-operatively, in 30 patients within the second and in 13 patients in the third year. One hundred and five OATS cylinders were implanted. MR findings consistent with osteonecroses were detected in eight cylinders (n=6 in the knee and n=2 in the ankle) in six patients; four out of eight were demonstrated during the first year and four/eight in the second year. Edema around and/or in the cylinders was found in 28/55 of the patients within the first year, five/30 in the second year and in two/13 in the third year. No substantial changes in the cartilage signal intensity or the cartilage-cartilage interface were demonstrated in the longitudinal follow-up within the first three years. Clinical and MR findings were not consistently associated in particular in the patients with osteochondral autograft necroses.     

MRI of the pediatric shoulder: nontraumatic lesions

Magnetic resonance imaging is an established technique for imaging the shoulder because it demonstrates clearly the articular surfaces, medullary canal and the extra-articular soft tissues which can be affected in shoulder disorders. The value of MR imaging in the evaluation of the traumatized shoulder has been described [1]; however, few cases of MR imaging in nontraumatic disorders in children have been reported. We reviewed the findings in 55 children undergoing MRI of the shoulder for nontraumatic conditions and included selected cases showing a broad range of imaging findings. Received 13 November 1995; Revision received 23 February 1996; Accepted 23 May 1996     

Imaging of the collateral ligament injuries of the knee

The role of routine and advanced imaging techniques after suspected injury to the collateral ligaments of the knee is to augment the findings on physical examination. Although radiographs may disclose avulsion injuries, the limited soft tissue contrast does not permit accurate assessment of the collateral ligaments and associated soft tissue structures. Because of its superior soft tissue contrast and multiplanar capabilities, magnetic resonance (MR) imaging has largely replaced conventional imaging techniques. Using high-contrast pulse sequences, MR imaging permits localization of the site of ligamentous trauma, as well as associated soft tissue injury, including meniscal tears, cruciate ligament tears, and injury to the structures of the posterolateral corner. Although secondary signs of ligamentous injury, including adjacent soft tissue edema and bony contusions, may be helpful in localizing the site of injury, the most important criteria remains direct visualization of the ligament, with focal discontinuity. Using such criteria, accurate preoperative assessment of the injured extremity may be made, thereby aiding in the clinical management of the patient.     

Alveolar soft part sarcoma: MR and angiographic findings

Objective. To present the MR and angiographic findings of alveolar soft part sarcoma (ASPS). Design and patients. MR examinations (12 tumors of 10 patients) of ASPS performed at multiple hospitals were retrospectively reviewed. The tumors were found in the thigh (n=4), lower leg (n=4), femur (n=2, local metastasis), scalp (n=1) and arm (n=1). The MR signal characteristics including signal intensity, homogeneity and signal void of lesions and bony invasion including direct invasion or local metastasis were evaluated. Angiographic findings (n=4) and post-embolotherapy follow-up MR imaging (n=2) findings were also assessed. Results. Local bony metastasis was found in two cases. Seven tumors showed heterogeneous high signal intensity on T1- and T2-weighted images with good enhancement. One tumor had a very high signal on T1-weighted images. Eight tumors (67%) showed numerous signal voids in or near the tumors. All four angiographic studies showed numerous enlarged vessels, arteriovenous shunts and delayed washout. Two cases mimicked arteriovenous malformations on angiographic studies but MR images demonstrated solid soft tissue components as well as tortuous vessels. Conclusions. High signal on T1-weighted image and numerous signal voids are highly suggestive of ASPS, although they are not universal as has been suggested and arteriovenous malformation should be included in the differential diagnosis. Local bony metastases in ASPS were seen in two cases and should be carefully investigated. Received: 12 April 2000 Revision requested: 27 June 2000, 8 August 2000 Revision received: 2 August 2000, 21 August 2000 Accepted: 22 August 2000     

Intra-articular ganglion cysts of the knee: clinical and MR imaging features

The purpose of this study was to present clinical and MR imaging features of intra-articular ganglion cysts of the knee. Retrospective review of 1685 consecutive medical records and MR examinations of the knee performed at three imaging centers allowed identification of 20 patients (13 men and 7 women; mean age 35 years), in whom evidence of intra-articular ganglion cyst was seen. Of the 20 ganglion cysts, 5 were found in the infrapatellar fat pad, 10 arose from the posterior cruciate ligament, and 5 from the anterior cruciate ligament. Three of five patients with ganglion cyst in the infrapatellar fat pad had a palpable mass. In 7 of 15 patients with ganglion cyst in the intercondylar notch, exacerbation of pain occurred in a squatting position. On four MR arthrographies, ganglion cysts were an intra-articular round, lobulated, low signal intensity lesion. Five cases of fat-suppressed contrast-enhanced T1-weighted SE images demonstrated peripheral thin rim enhancement. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. The MR appearance of intra-articular ganglion cyst is characteristic and usually associated with the cruciate ligament or the infrapatellar fat pad. Magnetic resonance arthrography has no definite advantage over conventional MR in the evaluation of the lesion. For intra-articular ganglion cyst in the infrapatellar fat pad, fat-suppressed contrast-enhanced MR imaging could be useful, because a thin, rim-enhancing feature of intra-articular ganglion cyst allows it to be distinguished from synovial hemangioma and synovial sarcoma. Received: 29 June 2000 Revised: 13 September 2000 Accepted: 15 September 2000     

Magnetic resonance imaging findings in anterolateral impingement of the ankle

Objective. To demonstrate the MR imaging findings of anterolateral impingement (ALI) of the ankle. Design and patients. Nine patients with a history of ankle inversion injury and chronic lateral ankle pain were imaged with MR imaging, and the findings correlated with the results of arthroscopy. Three additional patients with clinically suspected ALI of the ankle were also included. Ankle MR imaging studies from 20 control patients in whom ALI was not suspected clinically were examined for similar findings to the patient group. Results. MR imaging findings in the patients with ALI included a soft tissue signal mass in the anterolateral gutter of the ankle in 12 of 12 (100%) cases, corresponding to the synovial hypertrophy and soft tissue mass found at arthroscopy in the nine patients who underwent arthroscopy. Disruption, attenuation, or marked thickening of the anterior talofibular ligament was seen in all cases. Additional findings included signs of synovial hypertrophy elsewhere in the tibiotalar joint in seven of 12 patients (58%) and bony and cartilaginous injuries to the tibiotalar joint in five of 12 (42%). None of the control patients demonstrated MR imaging evidence of a soft tissue mass in the anterolateral gutter. Conclusions. ALI of the ankle is a common cause for chronic lateral ankle pain. It has been well described in the orthopedic literature but its imaging findings have not been clearly elucidated. The MR imaging findings, along with the appropriate clinical history, can be used to direct arthroscopic examination and subsequent debridement. Received: 22 July 1999 Revision requested: 20 September 1999 Revision received: 7 October 1999 Accepted: 8 October 1999     

慢性侵袭性真菌性鼻窦炎的CT和MRI诊断

目的探讨慢性侵袭性真菌性鼻窦炎的CT和MRI表现及诊断价值。方法回顾性分析经手术、组织病理学证实的10例慢性侵袭性真菌性鼻窦炎的影像学资料。结果慢性侵袭性真菌性鼻窦炎发生于蝶窦5例，上颌窦3例，筛窦2例。CT表现：受累窦腔内充以软组织影，其中1例伴斑点状钙化；窦壁骨质破坏，同时伴周围骨质增生肥厚。MRI表现：T1WI为低信号（与脑实质比较，以下相同）2例，等信号7例；T2WI信号不均匀，7例以低信号为主，2例以高信号为主；增强后病变明显强化。侵犯邻近结构：眼眶9例，其中6例累及眶尖区，可见不规则软组织肿块影，与邻近眼外肌分界不清楚，7例包绕视神经；6例侵犯海绵窦，可见形态不一的软组织影；脑膜增厚、强化5例，3例侵犯脑实质，表现为水肿1例，肉芽肿2例；4例侵犯翼腭窝及颞下窝；3例鼻咽部软组织增厚；2例上颌神经和1例下颌神经明显增粗、强化；3例面颊部软组织肿胀；1例硬腭骨质破坏。结论窦壁骨质破坏伴硬化、MR T2WI低信号、易侵犯眶尖及海绵窦为本病特征性影像学表现。结合CT和MRI2种检查方法能够对本病的诊断、鉴别和治疗提供更可靠的信息。     

MR imaging features of foot involvement in ankylosing spondylitis

OBJECTIVE: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. MATERIALS AND METHOD: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22%). CONCLUSION: In our experience, MR imaging may detect inflammatory and/or erosive bone, soft tissue, cartilage, tendon, and joint abnormalities in AS patients, even if AS patients did not have clinical signs and symptoms of foot involvement. If these data prove to be confirmed in further MR studies, MR imaging may be of importance especially in early diagnosis of inflammatory changes in the foot.