Arthroscopic reconstruction of the lateral ankle ligaments: Radiological evaluation and short-term clinical outcome.

PURPOSE: The purpose of this study was to describe the positioning of bone tunnels of arthroscopic anatomical reconstruction of lateral ankle ligaments (AAR-LAL) and identify radiological measurements associated with short-term clinical outcome one year after surgery. MATERIALS AND METHODS: A total of 61 patients were included in this IRB-approved retrospective study. There were 52 men and 9 women, with a mean age of 36.3 ± 10.8 (SD) years. AAR-LAL was performed to treat chronic instability secondary to strain sequelae after failure of conservative treatment. Good short-term clinical outcome was defined by Karlsson-score≥80 (n=40) one year after surgery. Sixteen radiological measurements were studied to characterize the positionings of fibular, talar and calcaneal tunnels (FT, TT and CT, respectively). Feasibility and inter-observer agreement were calculated for each measurement. Receiver operating characteristic curves were used to identify optimal thresholds for measurements associated with outcome at univariate analysis. A binary logistic regression was used to identify independent predictors. RESULTS: Two measurements were associated with good outcome: distance from the proximal FT entrance to the distal end of the fibula on anteroposterior (AP) view (called 'AP distal FT', P=0.005), and the ratio between the distance from TT entrance to the talo-navicular joint and the talus length on lateral view (P=0.009). Optimal thresholds were of >35mm and<0.445, respectively. At multivariate anlysis, only 'AP distal FT'>35mm remained independent predictor of good outcome (P=0.002). CONCLUSION: Radiological evaluation of bone tunnels following AAR-LAL is feasible, reproducible, and helps predict short-term outcome after reconstruction of lateral ankle ligaments.

Iodine contrast agents do not influence Platelet-Rich Plasma function at an early time point in vitro.

BACKGROUND: Iodine contrast agents (ICAs) are routinely used by radiologists to help guide intra-articular infiltrations. The aim of this study was to assess the in vitro effects of ICA on platelet function of human autologous Platelet-Rich Plasma (PRP). METHODS: One hundred thirty-seven consecutive patients with symptomatic femoral-patellar osteoarthritis were included. All were addressed to our institution for a fluoroscopy-guided intra-articular PRP infiltration of the pathological femoral-patellar joint. For each patient, 500 µl of PRP were sampled before intra-articular injection. First, PRP samples were mixed with 50 µl of 2 widely used ICA: Visipaque270® (Iodixanol, n = 58) and Iopamiron200® (Iopamidol, n = 69). PRP concentration ([PRP]) was measured at different delays of incubation (t = 0, 5, 10, 15, 20 and 30 min) enabling to calculate PRP ratio (defined as [PRP](t)/[PRP](0mn)) at each delay, for each mixture, in order to quantitatively assess the influence of ICA on PRP ratio. Second, the PRP samples of 10 additional patients were mixed with Visipaque270®, Visipaque270®, Iopamiron200® and phosphate buffer saline (PBS: control solution) in order to qualitatively assess the influence of ICA on platelet aggregation, using ADP, Collagen, Arachidonic acid and TRAP tests. The surface expression of human P-selectin, a marker of α-granule release, in the PRP + Visipaque270® and PRP + Iopamiron200® mixtures was finally compared. Repeated-measures ANOVA, classical 2-way ANOVA and Wilcoxon matched-pairs test were used to study the influence of ICA on PRP quality. RESULTS: There was no significant change in PRP ratio during the first 30mn of incubation (p = 0.991) whatever the ICA (p = 0.926). Whatever the aggregation test, there was no significant difference in the percentage of platelet aggregation between PRP + PBS, PRP + Visipaque270® and PRP + Iopamiron200® (p = 0.998), nor between PRP + PBS and PRP + Visipaque320® (p = 0.470). Finally, there was no significant difference in P-selectin expression between the PRP + Visipaque270® and PRP + Iopamiron200® mixtures (p = 0.500). CONCLUSION: At early delays of incubation, Visipaque® and Iopamiron®, which are two widely used ICA for intra-articular infiltrations, did not influence the in vitro platelet function nor the quality of PRP.

Homogeneous myxoid liposarcomas mimicking cysts on MRI: A challenging diagnosis.

OBJECTIVES: Myxoid liposarcoma (M-LPS) is the second most frequent subtype of liposarcoma. Foci of fat on MRI are strongly suggestive of this diagnosis. The aims of this study are to (i) assess the prevalence of perfectly homogeneous M-LPS-mimicking cyst and characterize their associated clinical and pathological features and to (ii) identify helpful clues to prevent misdiagnosis when encountered with a cyst-like lesion in soft tissue parts. METHODS: MR images from 32 consecutive pathologically proven M-LPS and round cell liposarcomas (RC-LPS) were retrospectively reviewed independently by two radiologists at our institution. Location, morphology, signals, lesion architecture, heterogeneity, margins and periphery were systematically assessed in each case. Medical records were checked for initial and definitive histopathological diagnosis, therapeutic managements and outcomes. Histopathological specimens of cyst-like M-LPS were reviewed for the study. RESULTS: We have identified seven perfectly homogeneous well-defined cyst mimickers (21.9%) located on the limbs, all but one being deep-seated. These tumors were significantly smaller than the conventional M-LPS (p = 0.0005). Six lesions were initially diagnosed as benign; 4 patients underwent marginal surgical resection without prior diagnosis and 2 cases were put under medical surveillance, one of which progressed towards classical RC-LPS on follow-up MRI. No specific pathological features could be identified nor were any clinical adverse outcomes recorded. CONCLUSION: "Cyst" on MRI, without pathological adjacent joint, necessitates ultrasonography with Doppler and intravenous Gadolinium agent injections as subsets of M-LPS can mimic cyst on MRI. Cyst-like M-LPS, due to their smaller size and relative favorable outcome, could have better prognosis.

Cervical Spinal Cord DTI Is Improved by Reduced FOV with Specific Balance between the Number of Diffusion Gradient Directions and Averages.

BACKGROUND AND PURPOSE: Reduced-FOV DTI is promising for exploring the cervical spinal cord, but the optimal set of parameters needs to be clarified. We hypothesized that the number of excitations should be favored over the number of diffusion gradient directions regarding the strong orientation of the cord in a single rostrocaudal axis. MATERIALS AND METHODS: Fifteen healthy individuals underwent cervical spinal cord MR imaging at 3T, including an anatomic 3D-Multi-Echo Recombined Gradient Echo, high-resolution full-FOV DTI with a NEX of 3 and 20 diffusion gradient directions and 5 sets of reduced-FOV DTIs differently balanced in terms of NEX/number of diffusion gradient directions: (NEX/number of diffusion gradient directions = 3/20, 5/16, 7/12, 9/9, and 12/6). Each DTI sequence lasted 4 minutes 30 seconds, an acceptable duration, to cover C1-C4 in the axial plane. Fractional anisotropy maps and tractograms were reconstructed. Qualitatively, 2 radiologists rated the DTI sets blinded to the sequence. Quantitatively, we compared distortions, SNR, variance of fractional anisotropy values, and numbers of detected fibers. RESULTS: Qualitatively, reduced-FOV DTI sequences with a NEX of ≥5 were significantly better rated than the full-FOV DTI and the reduced-FOV DTI with low NEX (N = 3) and a high number of diffusion gradient directions (D = 20). Quantitatively, the best trade-off was reached by the reduced-FOV DTI with a NEX of 9 and 9 diffusion gradient directions, which provided significantly fewer artifacts, higher SNR on trace at b = 750 s/mm2 and an increased number of fibers tracked while maintaining similar fractional anisotropy values and dispersion. CONCLUSIONS: Optimized reduced-FOV DTI improves spinal cord imaging. The best compromise was obtained with a NEX of 9 and 9 diffusion gradient directions, which emphasizes the need for increasing the NEX at the expense of the number of diffusion gradient directions for spinal cord DTI contrary to brain DTI.

Soft tissue masses with myxoid stroma: Can conventional magnetic resonance imaging differentiate benign from malignant tumors?

OBJECTIVES: To retrospectively evaluate the diagnostic performance of morphological signs observed on conventional magnetic resonance (MR) imaging to differentiate benign from malignant peripheral solid tumors of soft tissue with myxoid stroma. METHODS: MR images from 95 consecutive histopathologically proven tumors (26 benign and 69 malignant) of soft tissues with myxoid components were evaluated in our tertiary referral center. Two radiologists, blind to pathology results, independently reviewed conventional MR sequences including at least a) one T2-weighted sequence with or without fat suppression; b) one T1-weighted sequence without fat suppression; and c) one T1-weighted sequence with gadolinium-complex contrast enhancement and fat suppression. Multiple criteria were defined to analyze morphology, margins, architecture and tumor periphery and evaluated for each lesion. Intra- and inter-observer reproducibility and Odds ratios were calculated for each criterion. RESULTS: The most relevant and reproducible criteria to significantly predict malignancy were: (1) ill-defined tumor margins, (2) a hemorrhagic component, (3) intra-tumoral fat, (4) fibrosis and (5) the "tail sign". A lesion is classified as malignant if any of these 5 criteria is present, and benign if none of them are observed. Therefore, this combination provides a sensitivity of 92.9% and a specificity of 93.3%. CONCLUSION: Conventional MR imaging provides reproducible criteria that can be combined to differentiate between benign and malignant solid tumors of soft tissue with myxoid stroma.

Steatotic hepatocellular adenomas with different phenotypic subtypes: a case report.

Hepatocellular adenomas (HCAs) are heterogeneous group of benign tumors; three pathomolecular subtypes have been identified so far: hepatocyte nuclear factor 1 α-inactivated HCA (H-HCA) (35-40%), inflammatory HCA (I-HCA) (>50%), ß-catenin activated HCA (10%). Ten percent of I-HCA are also ß-catenin activated. We report a rare case of three histologically confirmed steatotic HCAs of three different phenotypes: I-HCA, ß-catenin activated I-HCA, and H-HCA in a 36-year-old woman. This observation outlines that in the same patient, HCA may be of different subtypes. The predisposition to develop different HCA hypothetically caused by a "benign tumorigenic field effect" may result, even rarely, in different genotypes/phenotypes such as H-HCA and I-HCA. Moreover, we illustrate the very high specificity of MR for subtyping HCA.

[Radiotherapy for gliomas in adults: What are the stakes of the follow-up?]. / Radiothérapie des gliomes chez l'adulte : quels sont les enjeux de la surveillance ?

Linked to the difference of prognosis, the terms and conditions of the follow-up of low-grade and high-grade gliomas treated by irradiation differ highly. Patients treated for a low-grade glioma have prolonged survival. In this case, monitoring of toxicities linked to the treatment is a major objective. Opportunistic infections and depression are corticosteroids side effects widely underestimated. Radionecrosis search and differentiation with recurrent disease are done by MRI. Perfusion and spectroscopy showing a choline/creatine ratio increase are in favour of disease recurrence. Cognitive status and quality of life must be evaluated during the follow-up. They have to be evaluated by adapted scales. Cognitive rehabilitation improves interestingly the post-treatment cognitive status. Pseudoprogression rates for high-grade gliomas are near 20%. MRI is the benchmark imaging for its diagnosis. Diffusion weight imaging and spectroscopy are actually the most interesting techniques.

Hepar lobatum carcinomatosum associated with liver metastases from breast cancer: report of five cases.

BACKGROUNDS AND AIMS: Hepar lobatum carcinomatosum (HLC) is an exceptional acquired hepatic distortion which consists in irregularly lobulated hepatic contours seen in patients with known liver metastases, usually from breast carcinoma. We aimed to describe and analyze five similar cases of HLC resulting from metastatic mammary carcinoma in the liver and associated with rapid hepatic failure. METHODS: Five cases of HLC were investigated. Medical (including blood liver tests), radiological and histological data (2 cases) were collected and retrospectively analyzed. All patients were followed up for metastatic invasive ductal carcinoma of the breast and had a common pattern of treatment with combination of targeted therapies (bevacizumab, AVASTIN) and chemotherapy (paclitaxel, TAXOL). RESULTS: All the patients showed rapid hepatic failure after a mean of 9 courses of bevacizumab/paclitaxel. In all cases, liver imaging revealed liver capsule retraction and an irregular lobular margin. An apparent tumor regression of all liver metastases was showed in two cases. Biopsies were consistent with sinusoidal obstruction syndrome (SOS) and, surprisingly, no tumoral cells were found. CONCLUSION: Although rare, such an unusual pattern of liver metastasis may mimick acute cirrhosis and cause rapid hepatic failure in patients, despite possible apparent tumor regression on imaging. The etiology of this pathology is unclear, and may involve multiple pathogenic factors. Direct or indirect vascular injury plays an important role in the development of HLC.

MS lesions are better detected with 3D T1 gradient-echo than with 2D T1 spin-echo gadolinium-enhanced imaging at 3T.

BACKGROUND AND PURPOSE: In multiple sclerosis, gadolinium enhancement is used to classify lesions as active. Regarding the need for a standardized and accurate method for detection of multiple sclerosis activity, we compared 2D-spin-echo with 3D-gradient-echo T1WI for the detection of gadolinium-enhancing MS lesions. MATERIALS AND METHODS: Fifty-eight patients with MS were prospectively imaged at 3T by using both 2D-spin-echo and 3D-gradient recalled-echo T1WI in random order after the injection of gadolinium. Blinded and independent evaluation was performed by a junior and a senior reader to count gadolinium-enhancing lesions and to characterize their location, size, pattern of enhancement, and the relative contrast between enhancing lesions and the adjacent white matter. Finally, the SNR and relative contrast of gadolinium-enhancing lesions were computed for both sequences by using simulations. RESULTS: Significantly more gadolinium-enhancing lesions were reported on 3D-gradient recalled-echo than on 2D-spin-echo (n = 59 versus n = 30 for the junior reader, P = .021; n = 77 versus n = 61 for the senior reader, P = .017). The difference between the 2 readers was significant on 2D-spin-echo (P = .044), for which images were less reproducible (κ = 0.51) than for 3D-gradient recalled-echo (κ = 0.65). Further comparisons showed that there were statistically more small lesions (<5 mm) on 3D-gradient recalled-echo than on 2D-spin-echo (P = .04), while other features were similar. Theoretic results from simulations predicted SNR and lesion contrast for 3D-gradient recalled-echo to be better than for 2D-spin-echo for visualization of small enhancing lesions and were, therefore, consistent with clinical observations. CONCLUSIONS: At 3T, 3D-gradient recalled-echo provides a higher detection rate of gadolinium-enhancing lesions, especially those with smaller size, with a better reproducibility; this finding suggests using 3D-gradient recalled-echo to detect MS activity, with potential impact in initiation, monitoring, and optimization of therapy.

[Abdominopelvic ultrasonography in suspected acute appendicitis: prospective study in adults]. / L'échographie abdominopelvienne en cas de suspicion d'appendicite aiguë: évaluation prospective chez l'adulte.

STUDY AIM: The aim of this prospective descriptive study was to evaluate the accuracy of abdomino-pelvic ultrasonography in suspected acute appendicitis in adults. PATIENTS AND METHODS: From March to July 1998, 100 consecutive patients, 63 women, 37 men (mean age: 25 years), after examination by a visceral surgeon for suspected acute appendicitis, had an abdominal ultrasonography (US) examination with high frequency transducer (7.5 to 9 MHz). The US examination concerned appendice, periappendicular tissues and neighbouring organs. The US data were correlated with the histopathologic findings in operated on patients, and with the clinical and biological follow up in non operated patients. RESULTS: Fourty-seven patients had acute appendicitis; 53 were operated on and 47 non operated. Analysis of US data revealed sensitivity 91.5%, specificity 94.3%, positive predictive value 93.5%, negative predictive value 94.3%, accuracy 93%; 75% of the other diagnosis were found by US. CONCLUSION: Systematic abdominal ultrasonography in suspected acute appendicitis is recommended in adults.

[Ectopic pancreas located in the small bowel: CT-endoscopic appearance. Apropos of two cases]. / Pancréas ectopiques à localisation intestinale: aspects à l'entéroscanner. A propos de deux cas.

Two patients have been diagnosed preoperatively with ectopic pancreas located within the small bowel using CT-enteroclysis. This technique, combining helical CT and small bowel opacification through a naso-jejunal tube, allows detection of small tumors.