Pre- and postoperative MR imaging of the craniocervical junction in rheumatoid arthritis

Ten patients with severe chronic rheumatoid arthritis with atlantoaxial subluxation were examined with conventional radiography and MR imaging of the cervical spine before and at an average of 6 months after posterior occipitocervical fusion. Periodontoid pannus formation was revealed by MR preoperatively in nine patients, all with mobile horizontal atlantoaxial subluxation. Compression of the medulla and/or upper cervical cord, due to subluxation and periodontoid pannus bulging into the spinal canal, was seen in seven patients. After the stabilizing surgery the periodontoid pannus had decreased in size in all patients with preoperative pannus. This reduction in the pannus seems to be the result of the atlantoaxial immobility achieved by the posterior fusion. Postoperatively, three patients had some remaining compression of the medulla and/or cord secondary to immobile subluxation, while the pannus posterior to the odontoid process had disappeared. Artifacts from the surgical stainless steel fixation material were confined to the posterior part of the neck on short TR/short TE MR images and did not interfere with the evaluation of the periodontoid region and the anterior part of the medulla/cervical cord. We found that flexion and extension lateral radiographs, combined with sagittal short TR/short TE MR images in the neutral position, enable preoperative evaluation of patients with rheumatoid arthritis in the cervical spine. Postoperative MR should be performed only if there are residual or new symptoms.     

Aortic anastomotic pseudoaneurysms: US, CT, MR, and angiography.

Correlation of imaging and anatomic findings in seven men with abdominal aortic graft prostheses (four "end-to-end" anastomoses and three "end-to-side" anastomoses) was done to compare the value of different imaging modalities in detecting postoperative complications, especially aortic anastomotic pseudoaneurysms (AAPs). In all cases, angiographic and CT studies were carried out. In six patients ultrasound and MR examinations were also performed. Anatomic verification was obtained by surgery in six patients and autopsy in one case. Five patients had an AAP (four at surgery and one at autopsy), one had a true abdominal aortic aneurysm above the anastomosis, and one a nondetectable abnormality of the aortic suture line. Digital subtraction angiography diagnosed one of five AAPs, missed the true aneurysm in the sixth patient, and was normal in the patient without any aneurysm. Computed tomography correctly diagnosed the five AAPs and the true aneurysm and was normal in the last patient. Ultrasound correctly diagnosed the AAPs in three of four patients, incorrectly diagnosed an AAP in the patient who had the true aneurysm, and was normal in the patient without any aneurysm. Magnetic resonance diagnosed four of four AAPs and the true aneurysm and was normal in the last patient. Computed tomography seems to be the best imaging modality with which to diagnose and evaluate an aortic AAP in patients with aortoiliofemoral graft prosthesis.     

Pre- and postcontrast MR studies in tuberous sclerosis.

The MR findings in eight patients with intracranial manifestations of tuberous sclerosis are reported. There were subependymal lesions in seven patients and peripheral lesions (i.e., cortical and subcortical) in all patients. All lesions were supratentorial. We emphasize two findings that have not been previously stressed. The signal intensity patterns of the subependymal lesions varied from patient to patient, but in all patients receiving intravenous contrast medium, the majority of these lesions enhanced. Although this finding may signify early breakdown of the blood-brain barrier with potential for lesion growth, the high frequency of enhancement challenges earlier concepts of equating this phenomenon with existence of actively growing giant cell astrocytomas. The peripheral lesions were more numerous than subependymal lesions. These lesions were nearly always hyperintense in the proton density weighted and T2-weighted images. Most notable is the fact that, in half of the lesions, signal intensity was also elevated in the T1-weighted image, an observation that has not been emphasized in previous reports. Although not pathologically confirmed this signal pattern may represent early stages of calcification within these lesions. Finally, unlike subependymal lesions, none of the peripheral lesions showed contrast enhancement.     

Metastatic involvement of the heart and pericardium: CT and MR imaging.

Metastases to the heart and pericardium are much more common than primary cardiac tumors and are generally associated with a poor prognosis. Tumors that are most likely to involve the heart and pericardium include cancers of the lung and breast, melanoma, and lymphoma. Tumor may involve the heart and pericardium by one of four pathways: retrograde lymphatic extension, hematogenous spread, direct contiguous extension, or transvenous extension. Metastatic involvement of the heart and pericardium may go unrecognized until autopsy. Impairment of cardiac function occurs in approximately 30% of patients and is usually attributable to pericardial effusion. The clinical presentation includes shortness of breath, which may be out of proportion to radiographic findings in patients with pericardial effusion or may be the result of associated pleural effusion. Patients may also present with cough, anterior thoracic pain, pleuritic chest pain, or peripheral edema. The differential diagnosis of pericardial effusion in a patient with known malignancy includes malignant pericardial effusion, radiation-induced pericarditis, drug-induced pericarditis, and idiopathic pericarditis. Any disease process that causes thickening or nodularity of the pericardium or myocardium or masses within the cardiac chambers can mimic metastatic disease.     

Technical considerations: CT and MR imaging in the postoperative orthopedic patient

Cross-sectional imaging utilizing computed tomography (CT) and magnetic resonance (MR) imaging have become routine components in the imaging assessment of patients with musculoskeletal disease. Unfortunately, in the setting of a postoperative orthopedic patient with associated orthopedic metallic instrumentation, these imaging techniques are prone to artifacts resulting in image quality degradation. An understanding of the physical basis of such metal-related artifacts, and their appearance on CT and MR imaging, has led investigators to the implementation of a series of techniques and modifications to imaging protocols to decrease CT and MR imaging artifacts in the vicinity of metallic instrumentation. Utilizing such modified imaging techniques, consistent, improved CT and MR image quality may be achieved in imaging of the postoperative orthopedic patient.     

Preoperative and postoperative MR evaluation of congenital heart disease in children

Cardiovascular magnetic resonance imaging (CMR) plays an important role in the preoperative and postoperative evaluation of congenital heart disease with newer techniques enabling faster and more comprehensive evaluation of the pediatric patient. This article reviews the clinical applications of CMR before and after surgery in the most common congenital heart anomalies in pediatric patients.     

MR imaging of pseudoaneurysms in aortocoronary bypass graft

Aneurysm formation may complicate aortocoronary saphenous vein bypass grafts. Because of multiplanar imaging capabilities and the potential for flow evaluation, magnetic resonance (MR) is useful as a noninvasive diagnostic technique. Two cases of pseudoaneurysm formation were evaluated by MR and demonstrate the clinical value of this modality.     

Pre- and postoperative irradiation of the mammary carcinoma

There are different indications for the pre-, per- and postoperative treatment of mammary carcinomas with certain or doubtful operability. Based on clinical examinations, the clinical effect of pre- and postoperative irradiation on the incidence of loco-regional recurrences and distant metastases is explained. The resulting therapy suggestions are discussed. Instead of radical surgery or modified radical surgery in case of subclinical and little carcinomas less than 3 cm, a simple ablation of the tumor with adequate subsequent irradiation is recommended. The therapy results of conservative treatments published hitherto are presented.     

Comparison of myelography, CT myelography and magnetic resonance imaging in cervical spondylosis and disk herniation. Pre- and postoperative findings

Twenty-six patients with cervical radiculopathy and/or myelopathy caused by spondylosis or disk herniation were examined with myelography, CT myelography and MR. Fourteen of the patients were operated upon and 11 of them underwent postoperative MR and CT. The three radiologic methods provided comparable information about narrowing of the subarachnoid space and compression of the spinal cord. It was more difficult to distinguish bone from soft tissue with MR only, but the combination of MR and conventional radiography gave sufficient information for this differentiation. When radiologic nerve root sheath deformity was compared with clinical radiculopathy, myelography, CT myelography and MR had similar sensitivity and accuracy. Postoperative MR could reveal remaining indentation on the thecal sac and the cord but CT without contrast medium was useful as a complement to determine the aetiology of the indentation. Because MR has several practical advantages, it is well suited as the primary imaging modality, together with conventional radiography, for the preoperative radiologic evaluation of patients with cervical radiculopathy and/or myelopathy. Postoperative MR is useful in patients with persistent or new symptoms.     

Biomechanics of the arch of the foot. Pre- and postoperative radiological examination

The human foot is a complex biomechanical structure. The arch of the foot is formed by the bony and articular structure of the midfoot and supported by strong ligaments and tendons. The normal arch develops in childhood. Tendon and ligament rupture and degeneration often lead to flattening of the arch. Frequent painful conditions include hallux valgus deformity and rupture of the posterior tibial tendon both leading to flat feet. Radiological examination is necessary in a standardized, full weight bearing standing position. The standing dorsoplantar view shows hallux valgus angle and intermetatarsal 1/2 angle. The side view shows Lisfranc joint instability and decrease of the talometatarsal angle. Talonavicular instability is a frequent secondary sign of spring ligament and posterior tibial tendon lesion. After failure of conservative therapy, corrective surgery with osteotomy and realignment procedure of the malpositioned bones in combination with tendon and ligament reconstruction is the state of the art procedure. In postoperative follow-up a standing X-ray of the foot is again the standard tool. Additional MRI and CT examinations help to detect bone and cartilage lesions and tendon/ligament ruptures.     

Recurrent postoperative sciatica: evaluation with MR imaging and enhanced CT

Magnetic resonance (MR) imaging and computed tomography enhanced with intravenous iodine injection (ECT) were prospectively compared in 80 patients in the diagnosis of recurrent postoperative sciatica. Diagnostic accuracy was determined with surgical verification. Isolated fibrosis was considered a contraindication to surgery. A decision to operate was made in 56 of the 80 patients on the basis of MR imaging findings; in 21 of the 56, the decision was also made on the basis of ECT findings. Of the 80 patients, 45 underwent surgery, In all but one of these patients, the diagnosis made on the basis of MR imaging findings was confirmed with surgical analysis. The only surgical finding that did not agree with MR imaging findings was a calcification of the common posterior ligament. The 21 diagnoses of disk herniation based on ECT findings were confirmed surgically, but among the 24 diagnoses of fibrosis made with the help of ECT, there were actually 19 recurrent herniations, four herniations with fibrosis, and one herniation at the level above the previously resected disk. MR imaging seems to be the investigation of choice in diagnosing the cause of recurrent postoperative sciatica.     

Pre- and postoperative evaluation of urethral diverticulum

OBJECTIVE: The purpose of this article is to review the diagnostic imaging findings, differential diagnosis, complications, and postoperative imaging appearance of urethral diverticulum. CONCLUSION: With increased clinical awareness and advanced imaging techniques, diagnoses of urethral diverticula are more frequent, and radiologists need to be aware of the pre- and postoperative imaging appearances of this disorder.     

Cranial CT and MR in the Klippel-Trenaunay-Weber syndrome.

This report describes the intracranial CT and MR findings in two cases of Klippel-Trenaunay-Weber Syndrome. The findings are 1) markedly enhancing choroid plexuses, 2) severe cerebral atrophy, 3) cerebral calcifications, and 4) angiomatous leptomeningeal enhancement. The findings may resemble those seen in cases of bilateral Sturge-Weber syndrome. The two diseases should be distinguishable by the external stigmata. The authors raise the question of a spectrum of involvement in the angiodysplasias of Klippel-Trenaunay-Weber syndrome and Sturge-Weber syndrome with considerable overlap.     

MR and CT in the assessment of Poland syndrome.

Seven cases of Poland syndrome were investigated with CT and/or MR to assess the extent of the muscle abnormalities of the shoulder girdle. In all cases the absence of the sternocostal head of the pectoralis major was clearly shown, as were any associated abnormalities of the pectoralis minor, serratus anterior, and latissimus dorsi. The latissimus dorsi muscle has an important role in reconstructive surgery and can be difficult to assess clinically. Cross-sectional imaging with CT or MR will give useful information in patients with Poland syndrome requesting anterior axillary reconstruction and breast mound formation.     

Pre- and posttreatment MR imaging findings in lead encephalopathy

A 41-year-old man suspected of having lead poisoning was evaluated with MR imaging before and after British antilewisite therapy. The MR imaging findings showed bilateral symmetric involvement of the occipital lobe, affecting predominantly the gray-white matter junction and the subcortical white matter. A right cerebellar lesion was noted, with focal hyperintensities involving the gray-white matter. Similar lesions were seen in the temporal, parietal, and frontal regions. These lesions resolved after chelation therapy.     

Assessment of ischemic heart disease with electron-beam CT and MR imaging

Anatomical and functional information derived from diagnostic modalities is essential in cardiac imaging. Electron-beam CT and MR imaging have played a role in the assessment of cardiac function, and recent developments in both modalities have permitted non-invasive visualization of coronary artery stenosis, which previously had been demonstrated exclusively by catheter coronary angiography. In this article, coronary artery imaging and cardiac functional imaging were reviewed by focusing on new technical developments in the screening of coronary atherosclerosis leading to acute coronary syndrome. Quantitative assessment of coronary calcifications by electron-beam CT has already become one of the most useful techniques for predicting the degree of coronary atherosclerosis and the risk of coronary events in individual patients. Electron-beam CT and MR imaging have also provided non-invasive clinical tools with which to demonstrate coronary artery stenosis. Visualization and characterization of atheromatous plaque at the coronary artery has recently been attempted with MR imaging, since this might lead to the detection of coronary artery plaque that was likely to rupture, thereby possibly predicting and preventing acute coronary syndrome in asymptomatic individuals. Although electron-beam CT and MR imaging have not been fully incorporated into routine clinical practice, each could serve as a comprehensive modality for the assessment of ischemic heart disease.     

Pre- and postoperative radiotherapy of operable carcinoma of the rectum

This was a non-randomized prospective study on the "sandwich" radiosurgical treatment of resectable rectal and rectosigmoid carcinomas. From December 1984 to December 1989, 100 patients were treated 86 of them are now evaluable. Mean follow-up was 38 months (range: 9-69). Surgery was abdomino-perineal resection in 33 cases and anterior resection in 53 cases. Radiotherapy was preoperative pelvic irradiation, with a single 500-Gy fraction, the day before surgery. To stages B2, C1 and C2 patients (Astler and Coller) postoperative radiotherapy was administered for a total dose of 4500 Gy (180 Gy/fraction, 5 fractions/week), with box technique, from a Co 60 unit or Linear Accelerator (photon 18 MV). Preliminary results indicate 8% (7/86) local recurrences and 9.3% (8/86) distant metastases. Five-year actuarial disease-free survival is 63.2% +/- 8 for stage B1, 55.6% +/- 19 for stage B2, and 40.2% +/- 13 for stages C1 + C2. Overall 5-year actuarial disease-free survival is 53% +/- 10. No lethal or severe complications were observed following treatment.     

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.     

CT and MRI features of pseudoaneurysms of the mitral-aortic intervalvular fibrosa

ObjectiveTo describe the CT and MR features of pseudoaneurysms of the mitral-aortic intervalvular fibrosa (PMAIVF).Materials and methodsThis retrospective study included 9 patients with a diagnosis of PMAIVF who had CT or MRI within 3 months of echocardiography. Echocardiography images were reviewed by a cardiologist and CT and MRI images were reviewed by two experienced cardiothoracic radiologists.ResultsRecognizable imaging features of PMAIVFs were communication with the Left ventricular outflow tract, location between the anterior leaflet of the mitral valve and the aortic valve, systolic expansion and diastolic collapse.ConclusionCT and MRI show characteristic appearances of PMAIVFs and are complementary to echocardiography.