Amyloidoma of the skull: plain radiographs,CT and MRI

Amyloidomas involving bone are rare. The 67-year-old man reported here had a large amyloidoma of the left frontal, parietal, sphenoid (greater wing) and temporal bones causing neural compression. Plain radiographs CT and MRI are shown.     

Venous angiomas: plain and contrast-enhanced MRI and MR angiography

We studied 17 patients with venous angiomas, 4 of whom had associated cavernous angiomas. All underwent MRI with spin-echo T1- and T2-weighted images and T1-weighted images after Gd-DTPA; MR angiography (MRA) was also performed with 3D and 2D time-of-flight technique; 5 patients underwent conventional angiography. Contrast-enhanced MRI demonstrated all the lesions, showing the peripheral medullary veins, the collector and the type of drainage. Both 3D and 2D MRA provided diagnostic information identical to that obtained after infusion of Gd-DTPA. Contrast-enhanced were T1-weighted images and MRA superior in all the cases to images without gadolinium. The possible association with cavernous angiomas (24% in our study) indicates T2-weighted imaging.     

Preoperative evaluation of colorectal liver metastases: comparison between gadoxetic acid-enhanced 3.0-T MRI and contrast-enhanced MDCT with histopathological correlation

Objectives

The aim of this prospective study was to compare the diagnostic performance of 64-row MDCT and gadoxetic-acid-enhanced MRI at 3.0 T in patients with colorectal liver metastases in correlation with histopathological findings.

Methods

Lesions detected at MDCT and MRI were interpreted by three blinded readers and compared with histopathological workup as the term of reference. Two subgroups of lesions were additionally evaluated: (1) metastases smaller than 10 mm and (2) lesions in patients with and without steatosis of the liver, assessed histopathologically.

Results

Surgery and histopathological workup revealed 81 colorectal liver metastases in 35 patients and diffuse metastatic involvement in 3 patients. In a lesion-by-lesion analysis, significant sensitivity differences could only be found for reader 1 (P?=?0.035) and reader 3 (P?=?0.003). For segment-based evaluation, MRI was more sensitive only for reader 3 (P?=?0.012). The number of false-positive results ranged from 3 to 12 for MDCT and 8 to 11 for MRI evaluation. In the group of small lesions, the sensitivity differed significantly between both methods (P?=?0.003). In patients with hepatic steatosis, MRI showed a trend toward better performance than MDCT, but without statistical performance.

Conclusions

The 3.0-T MRI with liver-specific contrast agents is the preferred investigation in the preoperative setting, especially for the assessment of small colorectal liver metastases.

Key Points

? Potential surgical treatment requires accurate radiological assessment of colorectal liver metastases ? Magnetic resonance imaging with gadoxetic acid is the preferred imaging investigation. ? MRI is better than multidetector CT for detecting small liver metastases.     

Magnetic resonance imaging of osteonecrosis in divers: comparison with plain radiographs

Objective. To assess the diagnostic value of magnetic resonance imaging (MRI) as compared with radiographic findings in osteonecrosis in divers. Design and patients. MRI scans and conventional radiographs of the shoulder, hip and knee joints of 23 professional male scuba divers were reviewed together with their clinical findings and personal histories. Correlations between the MRI findings and the radiographic evaluation, clinical symptoms, and personal history were then investigated. Results and conclusions. Lesions found on MRI in 23 divers included 27 in 39 proximal humeri, 17 in 36 proximal femora, 13 in 32 distal femora, and 12 in 32 proximal tibiae. Diffuse, marginated, or irregular patterns were observed. No lesions were seen in epiphyses of the distal femur or proximal tibia. We tried to classify these MRI findings by location and appearance. MRI showed no patients with only one affected bone. A close correlation between the MRI findings and maximum diving depth was observed in the proximal humerus. MRI depicted bone lesions that could not be detected on the radiographs. A routine MRI investigation of the hip joints should be performed in every diver in whom osteonecrosis is diagnosed at another site, for early detection of femoral head osteonecrosis. MRI of the shoulder joint is also the best surveillance in divers who dive deeper than 15?m.     

MRI of pediatric growth plate injury: correlation with plain film radiographs and clinical outcome

Purpose. To evaluate pediatric growth plate injuries with conventional radiographs and magnetic resonance imaging (MRI). To review potential clinical impact of MRI on subsequent patient management and outcome. Methods. Fourteen patients with known or suspected growth plate injury were studied. Each patient underwent imaging by conventional radiography and MRI within 2 weeks of injury. Findings on conventional radiographs and on MR images were compared and then correlated with subsequent management and outcome at a mean of 12 months. Results. Direct visualization of cartilage afforded by MRI improved evaluation of growth plate injury in each case. MRI changed Salter Harris classification or staging in 2 of 9 patients with fractures visualized on conventional radiographs, allowed the detection of radiographically occult fractures in 5 of 14 cases, and resulted in a physical change in management in 5 of the 14 patients studied. Conclusion. MRI has an important role in the evaluation of acute pediatric growth plate injury, particularly when diagnostic uncertainty persists following the evaluation of conventional radiographs. MRI allows detection of occult fractures, may alter Salter Harris staging, and in the reported study it frequently resulted in a change in patient management.     

Enhancement patterns of focal liver masses: discordance between contrast-enhanced sonography and contrast-enhanced CT and MRI

OBJECTIVE: The purpose of this study was to investigate the origin of the infrequent discordance between the contrast enhancement patterns of liver lesions on sonography and those on CT and MRI. Forty-four discordant cases were reviewed retrospectively. CONCLUSION: Four categories of discordance were identified, one of which is unexplained. Contrast agent diffusion caused portal venous phase discordance in malignant tumors (n = 6) whereby CT and MRI contrast material diffused through the vascular endothelium into the tumor interstitium, concealing washout. Sonographic microbubbles were purely intravascular and showed washout. Arterial phase timing discordance occurred in metastatic lesions (n = 10) with hypervascularity and rapid washout on contrast-enhanced sonography. CT arterial imaging performed later showed hypovascularity. Rapidly enhancing hemangiomas (n = 7) exhibited hypervascularity on CT when contrast-enhanced sonography also showed peripheral nodules and fast centripetal progression. Discordance caused by fat in lesions (n = 4) or liver (n = 10) reflected the inherent echogenicity of fat on sonography compared with its low attenuation on CT and low signal intensity on MRI. Infrequent cases of discordance remain unexplained. Recognition of the cause of the infrequent disagreement in enhancement patterns on contrast-enhanced sonography with those on CT and MRI improves diagnostic interpretation.     

Cystic fibrosis: a comparison of computed tomography and plain chest radiographs

In patients with cystic fibrosis, plain chest radiographs may suggest the presence of bronchiectasis, bronchoceles, hilar adenopathy, or pulmonary arterial hypertension. We compared computed tomography (CT) with conventional chest radiography in 12 patients. CT clearly reveals the cause of increased linear markings, nodular lesions, and enlarged hila as seen on plain chest radiographs. It showed that nine patients had hilar adenopathy, five had enlarged pulmonary arteries, and 11 had bronchiectasis. Bronchoceles, a finding that may influence therapy, were seen on seven CT scans but on only four of the plain films.     

Rapid musculoskeletal MRI with phase-sensitive steady-state free precession: comparison with routine knee MRI

OBJECTIVE: The aim of this work was to show the potential utility of a novel rapid 3D fat-suppressed MRI method for joint imaging. CONCLUSION: Phase-sensitive steady-state free precession provides rapid 3D joint imaging with robust fat suppression and excellent cartilage delineation.     

Ferucarbotran-enhanced MRI versus triple-phase MDCT for the preoperative detection of hepatocellular carcinoma

OBJECTIVE: We compared ferucarbotran-enhanced MRI with triple-phase MDCT for the preoperative detection of hepatocellular carcinoma. SUBJECTS AND METHODS: Seventy-three consecutive patients with 121 hepatocellular carcinomas underwent ferucarbotran-enhanced MRI, including a dynamic study, and triple-phase MDCT before hepatic resection. The diagnosis of hepatocellular carcinoma was confirmed in all patients by means of pathologic examination after surgical resection. Three experienced radiologists independently reviewed the MR and CT images on a segment-by-segment basis. The accuracy of these techniques for the detection of hepatocellular carcinoma was assessed by conducting a receiver operating characteristic (ROC) analysis of the observations of 88 resected hepatic segments with at least one hepatocellular carcinoma each and 121 resected hepatic segments without hepatocellular carcinoma. RESULTS: The mean values of the area under the ROC curve (A(z)) for ferucarbotran-enhanced MRI and triple-phase MDCT for all observers were 0.947 and 0.949, respectively; the difference between these two values was not statistically significant (p = 0.799). The mean sensitivities of MRI and triple-phase MDCT were 90.2% and 91.3%, respectively, and their mean specificities were 97.0% and 95.3%, respectively. The differences in the mean sensitivities and specificities of these two imaging techniques were not statistically significant (p > 0.05 in each case). CONCLUSION: Ferucarbotran-enhanced MRI seems to be as accurate as triple-phase MDCT for the preoperative detection of hepatocellular carcinoma.     

MRI of fractures of the distal radius: comparison with conventional radiographs

Objective. To compare the evaluation of fractures of the distal radius with MRI and conventional radiographs. To demonstrate the ability of MRI to detect unsuspected soft tissue derangement accompanying this common injury. Design and patients. Twenty-one consecutive inpatients admitted following fracture of the distal radius underwent preoperative evaluation with both conventional radiographs and MRI. In each case, analysis was made of both the osseous and soft tissue injury. MRI findings were compared with those identified on conventional radiographs and at subsequent surgical fixation. Results. Of 21 patients with fractures of the distal radius, 20 had extension to the radiocarpal articulation, 14 had distal radio-ulnar joint extension and 5 had avulsion of the ulnar styloid.Occult carpal bone fractures accompanying fracture of the distal radius were identified in two patients: one of the capitate and the other of the second metacarpal base. Ten patients (48%) had associated soft tissue injury: six patients had scapholunate ligament rupture, two patients had disruption of the triangular fibrocartilage, one patient had extensor carpi ulnaris tenosynovitis and one patient had a tear of a dorsal radiocarpal ligament. Of five patients with ulnar styloid avulsions, none had evidence of triangular fibrocartilage tears. Conclusion. MRI affords better evaluation of osseous injury accompanying distal radial fractures than conventional radiographs. Intra-articular soft tissue injury accompanies distal radial fractures in almost 50% of cases. Scapholunate ligament disruption commonly accompanies intra-articular fracture through the lunate facet of the distal radius. Fracture of the ulnar styloid is infrequently associated with tear of the triangular fibrocartilage.