Magnetic resonance direct thrombus imaging of the evolution of acute deep vein thrombosis of the leg.

BACKGROUND: Accurate diagnosis of acute recurrent deep vein thrombosis (DVT) is relevant to avoid improper diagnosis and unnecessary life-long anticoagulant treatment. Compression ultrasound has high accuracy for a first episode of DVT, but is often unreliable in suspected recurrent disease. Magnetic resonance direct thrombus imaging (MR DTI) has been shown to accurately detect acute DVT. The purpose of this prospective study was to determine the MR signal change during 6 months follow-up in patients with acute DVT. PATIENTS/METHODS: This study was a prospective study of 43 consecutive patients with a first episode of acute DVT demonstrated by compression ultrasound. All patients underwent MR DTI. Follow-up was performed with MR-DTI and compression ultrasound at 3 and 6 months respectively. All data were coded, stored and assessed by two blinded observers. RESULTS: MR direct thrombus imaging identified acute DVT in 41 of 43 patients (sensitivity 95%). There was no abnormal MR-signal in controls, or in the contralateral extremity of patients with DVT (specificity 100%). In none of the 39 patients available at 6 months follow-up was the abnormal MR-signal at the initial acute DVT observed, whereas in 12 of these patients (30.8%) compression ultrasound was still abnormal. CONCLUSION: Magnetic resonance direct thrombus imaging normalizes over a period of 6 months in all patients with diagnosed DVT, while compression ultrasound remains abnormal in a third of these patients. MR-DTI may potentially allow for accurate detection in patients with acute suspected recurrent DVT, and this should be studied prospectively.

Heterotropic mesenteric ossification: a case report (2004:10b).

Heterotropic mesenteric ossification is a rare entity. Only a few cases have been described in the literature. We report a case of heterotropic mesenteric ossification in a patient who underwent several laparotomies, after suffering from multiple gunshot wounds. We discuss the radiographic findings of this disease that can easily be misdiagnosed, and review the literature.

MR urography for the preoperative evaluation of living renal donors.

The purpose of this study was to assess the image quality and diagnostic value of MR urography in detecting abnormalities of the urinary collecting system relevant for the preoperative evaluation of living renal donors. Study subjects were selected from the existing intravenous urography (IVU) reports: 18 consecutive patients with a duplication or another abnormality of the collecting system and 20 consecutive patients with normal anatomy. They underwent a respiratory-triggered 3D T2-weighted fast spin-echo acquisition after oral administration of furosemide, without and with abdominal compression. The MR images were evaluated by two independent blinded observers. The IVU was used as the standard of reference. Image quality of the MR urograms with compression was overall better than those without compression, and the former were regarded as adequate for the evaluation of small filling defects and deformities of the pelvis and calyces in 76-81% of the kidneys and 74-79% of the patients. Both observers correctly diagnosed all 13 kidneys with a partial or complete duplication. The image quality of MR urography was inadequate to evaluate the calyces and pelvis for small filling defects or deformities in approximately 25% of the patients; however, the technique was accurate in the detection of abnormalities of the urinary collecting system relevant for the preoperative evaluation of living renal donors.

Some complications of common treatment schemes of thoracolumbar spine fractures can be predicted with magnetic resonance imaging: prospective study of 53 patients with 71 fractures.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To study the predictive value of magnetic resonance imaging (MRI) findings of thoracolumbar spine fractures concerning the radiologic and clinical outcome. SUMMARY OF BACKGROUND DATA: Disagreement about the proper treatment of thoracolumbar spine fractures is caused by insufficiency of conventional imaging techniques. Previous studies have shown that MRI is capable of distinguishing injury to all structures of the fractured spine and thus may help develop schemes with higher predictive power. METHODS: A total of 53 patients with 71 fractures were studied with MRI in a prospective fashion. A total of 24 patients with 39 fractures were treated conservatively and 29 patients with 32 fractures were treated operatively after a protocol concerning the treatment options. MRI scans were obtained within 1 week of injury and at the 2-year follow-up. Pain scores were obtained at the 2-year follow-up. Previously described MRI schemes concerning the trauma and post-trauma conditions were used. RESULTS AND CONCLUSIONS: An unfavorable outcome in the conservative group was related to the progression of kyphosis, which in most cases was predictable with the use of trauma MRI findings concerning the endplate comminution and vertebral body involvement. In the operatively treated group, recurrence of the kyphotic deformity was predictable by the lesion of the posterior longitudinal ligamentary complex together with endplate comminution and vertebral body involvement as seen on trauma MRI. The authors recommend the use of MRI to develop reliable prognostic criteria for these injuries.

Validity and reproducibility of ultrasonography for the measurement of intra-abdominal adipose tissue.

OBJECTIVE: We studied the validity and reproducibility of a new abdominal ultrasound protocol for the assessment of intra-abdominal adipose tissue. MEASUREMENTS: Intra-abdominal adipose tissue was assessed by CT, MRI, anthropometry and ultrasonography on a single day. By ultrasonography the distance between peritoneum and lumbar spine was measured using a strict protocol, including the location of the measurements, pressure on the transducer and respiration. All measurements were repeated after 3 months. RESULTS: The study population consisted of 19 overweight patients with a body mass index (BMI) of 32.9 kg/m(2) (s.d. 3.7), intra-abdominal adipose tissue on CT 140.1 cm(2) (s.d. 55.9), and a mean ultrasound distance of 9.8 cm (s.d. 2.5). There was a strong association between the CT and ultrasonographic measures: Pearson correlation coefficient was 0.81 (P<0.001). The correlation between ultrasound and waist circumference was 0.74 (P<0.001), the correlation between CT and waist circumference was 0.57 (P=0.01). Ultrasound appeared a good method to diagnose intra-abdominal obesity: the area under the ROC curve was 0.98. During the follow-up period of 3 months, the patients lost on average almost 3 kg of body weight. The correlation coefficient between changes in intra-abdominal adipose tissue assessed by CT and ultrasound was 0.74 (P<0.001). The correlation coefficient of the mean ultrasound distance assessed by two different sonographers at baseline was 0.94 (P<0.001), the mean difference 0.4 cm (s.d. 0.9), and the coefficient of variation 5.4%, indicating good reproducibility of the ultrasound measurements. CONCLUSIONS: The results of this validation study show that abdominal ultrasound, using a strict protocol, is a reliable and reproducible method to assess the amount of intra-abdominal adipose tissue and to diagnose intra-abdominal obesity.

Assessing the subtalar joint: the Brodén view revisited.

We prospectively evaluated subtalar inversion stress views (Brodén view) with inversion stress views on helical CT in a group of 10 patients with unilateral instability. The contralateral, asymptomatic ankle was used as control. All patients were examined with inversion stress views on plain stress radiography and helical CT. Subtalar tilt was demonstrated in all cases on conventional stress radiography. Helical CT didn't show tilting in any of the patients except in the subluxated posteromedial part of the subtalar joint. Our data do not support prior reports that the Brodén view is useful for screening patients with subtalar instability.

[Diagnostic image (33). Segond fracture with anterior cruciate ligament rupture]. / Diagnose in beeld (33). Segond-fractuur en ruptuur van de voorste kruisband.

A 23-year-old man fell on his bent left knee and developed a Segond fracture with a rupture of the anterior cruciate ligament.

Posttraumatic subchondral bone contusions and fractures of the talotibial joint: occurrence of "kissing" lesions.

OBJECTIVE: The objective of this study was to determine the presence and location of subchondral bone contusions, fractures, and "kissing" lesions of the talotibial joint after a sprain of the ankle shown on MR imaging. MATERIALS AND METHODS: We retrospectively reviewed the images of all consecutive patients who underwent MR imaging of the ankle after acute or recurrent sprain occurring between January and December 1997. The number and location of subchondral contusions or fractures revealed on MR imaging were recorded, and a comparison was made with the radiographs obtained for each patient. RESULTS: Of the 146 ankles, 42 osteochondral lesions were revealed on MR imaging in 26 ankles (18%) involving 23 patients. Twenty-three lesions were localized in the dome of the talus and 19, in the tibiofibular plafond. In 16 (11%) of the 146 ankles, the lesions were present in the opposing bones of the joint ("kissing" lesions). Only six of the 12 talar fractures and none of the tibial fractures involving the 26 ankles were seen on conventional radiography. CONCLUSION: Subchondral lesions in the talus and tibia are relatively common after ankle trauma, occurring in 18% of patients in our series. Kissing lesions were present in more than half of the lesions in these patients.

MRI dynamic color mapping: a new quantitative technique for imaging soft tissue motion in the orbit.

PURPOSE: To investigate both feasibility and clinical potential of magnetic resonance imaging-dynamic color mapping (MRI-DCM) in measuring the motion of soft tissues in the orbit and in the diagnosis of orbital disorders by detecting changes in motion. METHODS: Sequences of MRI scans were acquired (acquisition time, 5 seconds) in a shoot-stop manner, while the patient fixated at a sequence of 13 gaze positions (8 degrees intervals). Motion was quantified off-line (in millimeters per degree of gaze change) using an optical flow algorithm. The motion was displayed in a color-coded image in which color saturation of a pixel shows the displacement and the hue the displacement's orientation. Six healthy volunteers and four patients (two with an orbital mass and two with acrylic ball implant after enucleation) were studied. RESULTS: The technique was found to be clinically feasible. For a gaze change of 1 degrees, orbital tissues moved between 0.0 and 0.25 mm/deg, depending on the type of tissue and location in the orbit. In the patients with an orbital mass, motion of the mass was similar to that of the medial rectus muscle, suggesting disease of muscular origin. In the enucleated orbits, soft tissue motion was decreased. One eye showed attachment of the optic nerve to the implant, which could be verified by biopsy. CONCLUSIONS: MRI-DCM allows noninvasive and quantitative measurement of soft tissue motion and the changes in motion due to pathologic conditions. In cases in which the diagnosis of a tumor in the apex is in doubt, it may reduce the need for biopsy. In contrast to static computed tomographic (CT) scans and MRIs, it can differentiate between juxtaposition and continuity and may be a new and promising tool in the differential diagnosis of intraorbital lesions.

Reversed palmaris longus muscle on MRI: report of four cases.

Muscle anomalies around the wrist, in particular the palmaris longus muscle, may cause effort-related median nerve compression. A search of the medical records at our university hospital between 1994 and 1999 revealed four patients with an effort-related median nerve compression due to a reversed palmaris longus muscle. Magnetic resonance imaging was used in the patient work-up and showed an anomalous muscle in each case that had been missed initially. All four patients were free of pain after simple excision of the anomalous muscle. Awareness of muscle anomalies at the wrist on MR imaging is essential in evaluating patients with nerve compressions at the wrist. The purpose of this article is to heighten this awareness in radiologists.

Vascularization of head and neck paragangliomas: comparison of three MR angiographic techniques with digital subtraction angiography.

BACKGROUND AND PURPOSE: MR angiography of the head and neck region has been studied widely, but few studies have been performed concerning the efficacy of MR angiography for the identification of the specific vascular supply of the highly vascular head and neck paragangliomas. In this study, we compared three MR angiography techniques with respect to visualization of branch arteries in the neck and identification of tumor feeders in patients with paragangliomas. METHODS: Fourteen patients with 29 paragangliomas were examined at 1.5 T using 3D phase-contrast (PC), 2D time-of-flight (2D TOF), and multi-slab 3D TOF MR angiography. In the first part of the study, two radiologists independently evaluated the visibility of first-, second-, and third-order branch arteries in the neck. In the second part of the study, the number of feeding arteries for every paraganglioma was determined and compared with digital subtraction angiography (DSA), the standard of reference in this study. RESULTS: Three-dimensional TOF angiography was superior to the other MR angiography techniques studied (P < .05) for depicting branch arteries of the external carotid artery in the neck, but only first- and second-order vessels were reliably shown. DSA showed a total of 78 feeding arteries in the group of patients with 29 paragangliomas, which was superior to what was revealed by all MR angiography techniques studied. More tumor feeders were identified with 3D TOF and 2D TOF angiography than with 3D PC MR angiography (P < .05), with a sensitivity/specificity of 61%/98%, 54%/95%, and 31%/95%, respectively. Sensitivity was lowest for carotid body tumors. CONCLUSION: Compared with intra-arterial DSA, the 3D TOF MR angiography technique was superior to 3D PC and 2D TOF MR angiography for identifying the first- and second-order vessels in the neck. With 3D TOF angiography, more tumor feeders were identified than with the other MR angiography techniques studied. The sensitivity of MR angiography, however, is not high enough to reveal important vascularization. The sensitivity of MR angiography is too low to replace DSA, especially in the presence of carotid body tumors.

MRI findings of thoracolumbar spine fractures: a categorisation based on MRI examinations of 100 fractures.

OBJECTIVE: To define the state of different structures of the fractured thoracolumbar spine which may play a role in the immediate and long-term mechanical stability on MR images and to investigate the relationship of these findings with the AO classification of spinal injuries. DESIGN: The state of the anterior longitudinal ligament, posterior longitudinal ligament, posterior ligamentous complex, cranial and caudal endplates, cranial and caudal discs and the vertebral body were defined using clinical, experimental and radiological data. The state of these structures was reported for each fracture on the MRI examinations and the different MRI features appropriate for different fracture classes were defined. PATIENTS: MRI examinations of 70 patients with 100 fractures of the thoracolumbar spine were used for this study. RESULTS: Wide variations were seen in the state of the structures studied. We could not find a definite pattern to relate these findings with the AO classification scheme. CONCLUSIONS: MR findings should be integrated into future classification schemes of thoracolumbar spine fractures. This would enable specific data about the structures involved in the stability of the spine to be acquired. Prospective studies using the criteria developed in this study may help resolve some of the controversies concerning the diagnosis and prognosis of these injuries as well as the development of new classification systems.

Acromegaly: report of two patients with an unusual presentation.

The presenting features of functionally active pituitary tumours depend on the specific hormone which is overproduced. Growth hormone (GH) producing tumours usually present with the clinical manifestations of acromegaly due to excessive GH secretion or symptoms resulting from mass effects of the enlarging tumour. The changes in physical features and the increase in tumour size are usually insidiously slow and therefore, recognition of the disease is delayed. In this report two patients with acromegaly are described with an atypical presentation due to acute onset of symptoms. The first patient presented with central diabetes insipidus. The diagnosis acromegaly was made on physical examination. The second patient presented with a generalized seizure during sleep. On CT-scanning a large tumour protruding into the left temporal lobe connected to the pituitary gland was seen. Immunohistochemistry of the tumour after partial transcranial resection confirmed the clinical diagnosis of acromegaly. At a later stage transsphenoidal resection of the pituitary tumour was performed with full recovery and without loss of pituitary function.

Color Doppler imaging of paragangliomas in the neck.

PURPOSE: In this study, we describe the color Doppler imaging findings in carotid body tumors and vagal body tumors. METHODS: B-mode and color Doppler imaging were performed on 17 patients who had a total of 25 previously diagnosed paragangliomas (14 carotid body tumors and 11 vagal body tumors). RESULTS: Nineteen of 25 tumors were depicted. Five small vagal body tumors in the region of the nodose ganglion and 1 carotid body tumor could not be depicted. With B-mode imaging, paragangliomas appeared as well-defined, solid, hypoechoic masses. With color Doppler imaging, hypervascularity with a low-resistance flow pattern was demonstrated in all but 1 of the 19 tumors. CONCLUSIONS: The use of color Doppler imaging in the workup of an ambiguous neck mass is advocated.

Stress radiography and stress examination of the talocrural and subtalar joint on helical computed tomography.

The main objective of this study was to compare subtalar inversion stress views using the Brodén view with inversion stress views on helical computed tomography (CT). One of the drawbacks of routine radiography is the imaging of three-dimensional structures in a two-dimensional plane. We investigated whether the use of helical CT would lead to a more objective and clearer measurable method to determine the amount of tilt in the subtalar joint. A group of 15 patients with unilateral chronic instability complaints and clinically suspected subtalar instability was examined. The contralateral asymptomatic foot was used as control. A variable amount of subtalar tilt (range, 4 degrees to 18 degrees) was demonstrated in all cases on stress radiographs, without finding significant difference between the symptomatic and asymptomatic feet. However, contrary to the findings at the talocrural level, subtalar tilt was found in none of the patients using helical CT. Thus, we now doubt that the tilt seen during stress examination using the Brodén view is the true amount of tilt. It may be that the lateral opening, seen on these radiographs, largely results from imaging two planes that have made a translatory and rotary movement relative to each other in an oblique direction. It is concluded that the Brodén stress examination might not be useful for screening patients with subtalar instability. Associated anomalies not visible on the radiographs were detected by helical CT. In four cases, narrowing of the articular cartilage and irregular and hypertrophic bone formation at the middle facet joint of the subtalar joints were found. It is likely that these changes cause disturbance of function of this joint and it is suggested that the subjective complaint of instability with "giving way" is not only caused by hypermobility, but can be caused by other disturbance of normal motion.

Carcinoid tumor of the jugulo-tympanic region.

Increased levels of 5-hydroxyindole acetic acid (5-HIAA) were found in a patient with a tumor arising in the middle ear. Iodine-123-metaiodobenzylguanidine ([123I]MIBG) scintigraphy and biochemical analysis showed evidence of serotonin production by the tumor. Immunohistochemistry of the tumor showed reactivity with antibodies directed against serotonin, chromogranin, leu-7 and neuron-specific enolase; S-100, met-enkephalin, leu-enkephalin and glial fibrillary acid protein were negative. This case suggests a close relationship between functioning paragangliomas and carcinoid tumors because a strong clinical and endocrinological resemblance exists. The hormonal activity found is discussed in relation to extra-adrenal paragangliomas. We recommend urinary screening not only for detection of increased levels of catecholamines, but also of 5-HIAA in all patients with paragangliomas of the head and neck. When elevated levels are found, [123I]MIBG scintigraphy should be performed to localize the areas of increased uptake in or outside the head and neck region.

From medical history and biochemical tests to presymptomatic treatment in a large MEN 2A family.

An extensive study was published in 1959 in the Netherlands on a large family, which initially attracted attention because of a family history of attacks of shaking. Clinical investigation revealed phaeochromocytomas in four family members. In 1975, the family was identified to be a MEN 2A family, and since then, the members were examined annually using measurement of catecholamine metabolites in 24-h excreted urine and C-cell stimulation tests. In 1993, the RET proto-oncogene on chromosome 10q11 was found to be associated with MEN 2A and a specific mutation in this gene was identified in the family. In this family, 32 MEN 2A patients were detected. Since screening started in 1975, no patient died of phaeochromocytoma; however, two patients died of metastasized medullary thyroid carcinoma (MTC) (mean age 46 years). Twelve patients were operated on for phaeochromocytoma, and 13 for MTC. The results of DNA-analysis revealed the failures of the biochemical tests to identify affected family members. Six disease gene carriers with normal C-cell stimulation test results appeared to have small multifocal MTCs. Two carriers with normal excretion levels of catecholamines had a small phaeochromocytoma. DNA-analysis enables the unambiguous diagnosis of MEN 2A gene carrier-ship, allowing presymptomatic surgery for MTC.