Heterotopic calcification and tears of the ulnar collateral ligament: radiographic and MR imaging findings.

OBJECTIVE: The purpose of this paper is to describe the radiographic and MR imaging appearance of heterotopic calcification in the ulnar collateral ligament. MATERIALS AND METHODS: Retrospective radiographic review of 710 patients examined for elbow pain yielded 42 individuals (age range, 16-38 years) with heterotopic calcification in the ulnar collateral ligament. Radiographic and MR imaging findings were compared with surgical findings. RESULTS: Fifty-one heterotopic calcifications were identified in 42 patients; nine patients had two sites of heterotopic calcification. Average initial calcification size in the craniocaudal dimension was 4 mm (range, 1-12 mm) and in the transverse dimension was 1 mm (range, 1-4 mm). Five of 42 patients had enlargement of the calcification on follow-up radiography. The largest heterotopic calcification that was not visualized on MR imaging measured 5 x 4 mm in craniocaudal and transverse dimensions. Of 34 patients with heterotopic calcification who underwent surgery, 26 patients (76%) had either partial or complete tears of the ulnar collateral ligament. CONCLUSION: Heterotopic calcification in the ulnar collateral ligament may be associated with partial or complete tears. The MR imaging detection of heterotopic calcification is less sensitive than that of radiography of the elbow.

Aortoiliac disease: two-dimensional inflow MR angiography with lipid suppression.

A magnetic resonance (MR) imaging strategy, SLIP (spatially separated lipid presaturation), which can be incorporated into existing MR imaging and MR angiographic techniques, has been developed to suppress lipid signal. The authors report the clinical application of this technique, with a triple comparison of two-dimensional inflow MR angiography, with and without SLIP, and x-ray angiography in patients with aortoiliac disease. SLIP improved visualization of arterial segments, with 50 of 63 (79%) arterial segments visualized versus 41 of 63 (65%) for non-SLIP MR angiography. The SLIP strategy aids in the depiction of slow or turbulent flow, because the lipid signal is suppressed while the intravascular signal is left undisturbed. Image quality improves because of the combination of decreased background lipid signal intensity and use of the maximum-intensity-projection algorithm. Compared with x-ray arteriography, non-SLIP MR angiography had a sensitivity and specificity of 60% and 56%, respectively, for detection of lesions with 50%-100% diameter reduction, while SLIP MR angiography had a sensitivity and specificity, respectively, of 53% and 67%.

Duplex assessment of the portal venous system.

The clinical applications of duplex ultrasound and color Doppler imaging in the evaluation of the portal venous system and hepatic vasculature are quite diverse and widespread. These include identification of portal vein thrombosis, portal venous hypertension, and hepatic veno-occlusive disease as well as a role in the preoperative and postoperative treatment of patients who are candidates for portosystemic shunts or for liver allografts. As technological improvements continue, the current applications will almost certainly be refined, with resultant improvements in sensitivity, specificities, and accuracy rates.

Duplex assessment of the splanchnic vasculature.

The role of duplex ultrasound and color Doppler imaging in the evaluation of patients with suspected splanchnic vasculature obstructive disease and chronic mesenteric ischemia is not clearly defined. In this report the examination technique, as well as normal and abnormal findings, is discussed. Limitations are also described.

Duplex evaluation of native renal vessels and renal allografts.

Duplex ultrasound and color duplex imaging are useful in evaluating the renal vasculature. Investigation of native renal vessels includes the diagnosis of renal artery stenosis and occlusion and renal vein thrombosis. The sonographic examination of renal allografts may detect vascular complications and peritransplant fluid collections, both of which may impair allograft function. In order to perform and interpret renal vascular sonography, knowledge of pertinent vascular anatomy and proper duplex technique is essential. Renal arterial and venous examination with gray-scale, Doppler, and color duplex imaging is reviewed, comparing their performance with other methods of assessing renal vessels when appropriate.

Outflow refreshment angiography: a bright blood, bright static tissue technique.

A new "bright blood" strategy, outflow refreshment imaging, is introduced in which a number of overlapping slices are excited in rapid succession. Flowing spins that refresh each overlapped slice portion contribute a bright signal. Additionally, static tissue in each non-overlapped slice portion also yields a bright signal. However, the flow/static contrast is comparable to that produced in inflow refreshment images, and angiograms can be generated by conventional maximum intensity projection processing. The dual ability to visualize angiograms and static tissue images is a major benefit of the strategy. Computer simulations of flow sensitivities and in vivo results are presented which compare the outflow and inflow refreshment imaging strategies.

Peripheral arterial occlusive disease: prospective comparison of MR angiography and color duplex US with conventional angiography.

Conventional angiography, two-dimensional inflow magnetic resonance (MR) angiography, and color duplex ultrasound (US) were performed on 12 patients in a blinded, prospective study. The ability to grade arterial lesions and plan revascularization interventions were compared. Arterial lesions were categorized as nonsignificant (0%-49% diameter reduction) or significant (50%-100% diameter reduction). Determination of nonsignificant and significant lesions with MR angiography was in agreement with that at conventional angiography in 100 of 140 lesions (71%). Agreement between results of conventional angiography and color duplex US occurred with 114 of 123 infrainguinal lesions (93%). Twenty-one vascular interventions were planned by using conventional angiography; there was agreement with color duplex US in 11 cases and MR angiography in five. Color duplex US performed well in the assessment of infrainguinal disease but was limited in the evaluation of iliac segments because of nonvisualization. The iliac region was visualized in more patients with MR angiography than with color duplex US, but image quality with MR angiography was inconsistent. Strategies to improve MR angiography of the peripheral vasculature merit further study.

MRI of internal derangement of the knee with arthroscopic correlation.

MRI has assumed a major role in investigating disorders of the knee, especially internal derangement. We correlated the MRI report and arthroscopic findings of 18 patients with suspected meniscal or ligament injury. The results are presented and compared with other series. A particularly important asset of MRI is its very high negative predictive value.

CT and MR imaging in the evaluation of retroperitoneal fibrosis.

We have performed CT and MR on five patients with biopsy proven retroperitoneal fibrosis (RPF). Magnetic resonance (MR) accurately displayed a retroperitoneal mass of low signal intensity on T1-weighted scans and of heterogeneous medium signal intensity on T2-weighted scans. The coronal MR views demonstrated a retroperitoneal mass: the shape, signal intensity, and effects on the ureters and major vessels appear characteristic of RPF.

Bochdalek hernia of diaphragm in the adult. Diagnosis by computed tomography.

Two cases of asymptomatic Bochdalek hernia in adults with identical roentgenographic findings are reported. Computed tomography (CT) in each case revealed a round mass with a low attenuation coefficient identical to that of adipose tissue, abutting the thoracic surface of the diaphragm and connecting with the subdiaphragmatic density through a diaphragmatic defect. A case of diaphragmatic lipoma was also presented for demonstration of the CT differentiation between lipoma and hernia of the diaphragm. The CT findings for a Bochdalek hernia are characteristic enough for making a definite diagnosis and render other diagnostic modalities unnecessary.