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Computed tomography and thymoma: distinctive findings in invasive and noninvasive thymoma and predictive features of recurrence
Abstracts / Clinical Imaging 34 (2010) 324–325 directions. First, oncologic imaging, with detection; characterization and follow-up of lesions. Second, evaluation of diffuse liver diseases, including hepatic fibrosis. The diagnostic impact and role of diffusion-weighted MR imaging remain under investigation, but appear promising. Because of its short acquisition time, sensitivity, and additional information it provides, diffusionweighted MR imaging should be included in routine liver imaging protocols.
Mature and immature ovarian teratomas: US, CT and MR imaging features [in French] Damarey B, Farine MO, Vinatier D, Collinet P, Lucot JP, Kerdraon O, Poncelet E [Imagerie de la femme, Hôpital Jeanne de Flandre, CHRU Lille, avenue Eugène Avinée, F-59037 Lille]. J Radiol 2010;91:27-36. Mature cystic ovarian teratomas, also called dermoid cysts, are one of the most frequent ovarian tumors of younger female patients and are suggested when a fat-containing cystic tumor is identified on imaging. However, the presence of fat is not pathognomonic for dermoid cyst, and it may also be identified in immature teratomas, whose prognosis and treatment are different. Some imaging features are helpful to differentiate between both, rumors, including the presence of enhancement on CT and MRI. Knowledge of the imaging features of these tumors allows for a confident diagnosis to be made in most cases. A few rate and less typical imaging features should also be recognized.
Clinical feasibility of a magnetic resonance tracking system to guide the position of the scan plane during physiologic joint motion Vandevenne J, Pearle A, Lang P, Butts Pauly K, Bergman G [Department of Radiology, Ziekenhuizen Oost-Limburg, Schiepse Bos 6, B-3600 Gent, Belgium]. Radiol Med 2010;115:133-140]. Purpose: Unrestricted physiologic joint motion results in multidirectional displacement of the anatomic structures. When performing real-time magnetic resonance (MR) imaging of such a joint motion, continuous adjustment of the scan plane position may be required. The purpose of this study was to evaluate the clinical feasibility of a method to guide the scan plane position during dynamic-motion MR imaging of freely moving joints. Materials and methods: The location of a small tracker device (dedicated hardware) placed on the patient's skin overlying a joint was determined by an ultrashort MR sequence and used to automatically adjust the scan plane position prior to each dynamic-motion MR image. Using a vertically open MR unit, this MR tracking system was applied in ten dynamic-motion MR examinations to evaluate flexion/extension manoeuvres in the weightbearing knee joint, and in 10 dynamic-motion MR examinations of the shoulder joint to evaluate manoeuvres such as internal/external rotation of the humerus, stress testing of the glenohumeral joint and abduction/ adduction manoeuvres. Average number of manoeuvre repetitions, total number of images and percentage of useful images per manoeuvre were calculated. Imaging time per scan plane for each manoeuvre was recorded. Results: Average repetition of manoeuvres varied between 1.6 and 5.8, with an average number of 7–18 images per manoeuvre. Average percentage of useful images varied between 61% and 89%. Total imaging time per scan plane ranged between 1 min 10 s and 4 min 51 s. Conclusions: The MR tracking system to guide the slice position for each consecutive dynamic-motion MR image of the freely but slowly moving
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shoulder or knee joint was feasible for clinical use, providing a high percentage of useful images for each manoeuvre within a clinically acceptable time frame.
Imaging of giant cell tumor of the tendon sheath Wan JMC, Magarelli N, Pen WCG, Guglielmi G, Shek TWH [S. G.: Dipartimento di Diagnostica per Immagini, Università Cattolica del Sacro Cuore, Policlinico “A. Gemelli”, Largo A. Gemelli 8, I-00168 Roma, Italy]. Radiol Med 2010;115:141-151. Giant cell tumours of the tendon sheath (GCTTS) and pigmented villonodular synovitis (PVNS) are part of a spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae, and tendon sheaths. This review article describes the clinicopathological features and imaging findings in patients with GCTTS. GCTTS usually presents as a soft tissue mass with pressure erosion of the underlying bone. Magnetic resonance (MR) imaging of GCTTS typically shows low to intermediate signal on T1- and T2-weighted spin-echo sequences due to the presence of haemosiderin, which exerts a paramagnetic effect. On gradient-echo sequences, the paramagnetic effect of haemosiderin is further exaggerated, resulting in areas of very low signal due to the blooming artefact. Ultrasonography shows a soft mass related to the tendon sheath that is hypervascular on colour or power Doppler imaging.
Computed tomography and thymoma: distinctive findings in invasive and noninvasive thymoma and predictive features of recurrence Priola AM, Priola SM, Di Franco M, Cataldi A, Durando S, Fava C [Department of Radiology, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, I-10043 Orbassano Turin, Italy]. Radiol Med 2010;115:1-21. Purpose: Our goal was to assess the computed tomography (CT) imaging findings of thymoma and to correlate these features with Masaoka staging system and prognosis. Materials and methods: CT findings of thymoma were analysed in 58 patients who had undergone surgery between January 2002 and September 2007. All cases were classified according to the Masaoka staging system. The presence of various CT findings was correlated with tumour invasiveness and recurrence. In statistical analysis, Pb.05 was interpreted as significant. Results: The study found 26 noninvasive thymomas and 32 invasive thymomas. Invasive thymomas were more likely to be greater in size (Pb.01), with lobulated or irregular contours (Pb.02), a necrotic or cystic component (Pb.04), foci of calcification (Pb.05) and heterogeneous contrast enhancement (Pb.01) than were noninvasive thymomas. Disease progression developed in nine of 58 patients. Tumour recurrence and metastasis correlated with greater size (Pb.04), lobulated or irregular contours (Pb.01), complete mediastinal fat obliteration (Pb.01), great vessel invasion (Pb.01) and pleural implants (Pb.02). Conclusions: CT is useful in differentiating invasive from noninvasive thymomas and plays an important role in evaluating and treating these patients for multimodal therapy with neoadjuvant approaches. Moreover, CT findings may serve as predictors of postoperative recurrence or metastasis.
Mature and immature ovarian teratomas: US, CT and MR imaging features [in French] Damarey B, Farine MO, Vinatier D, Collinet P, Lucot JP, Kerdraon O, Poncelet E [Imagerie de la femme, Hôpital Jeanne de Flandre, CHRU Lille, avenue Eugène Avinée, F-59037 Lille]. J Radiol 2010;91:27-36. Mature cystic ovarian teratomas, also called dermoid cysts, are one of the most frequent ovarian tumors of younger female patients and are suggested when a fat-containing cystic tumor is identified on imaging. However, the presence of fat is not pathognomonic for dermoid cyst, and it may also be identified in immature teratomas, whose prognosis and treatment are different. Some imaging features are helpful to differentiate between both, rumors, including the presence of enhancement on CT and MRI. Knowledge of the imaging features of these tumors allows for a confident diagnosis to be made in most cases. A few rate and less typical imaging features should also be recognized.
Clinical feasibility of a magnetic resonance tracking system to guide the position of the scan plane during physiologic joint motion Vandevenne J, Pearle A, Lang P, Butts Pauly K, Bergman G [Department of Radiology, Ziekenhuizen Oost-Limburg, Schiepse Bos 6, B-3600 Gent, Belgium]. Radiol Med 2010;115:133-140]. Purpose: Unrestricted physiologic joint motion results in multidirectional displacement of the anatomic structures. When performing real-time magnetic resonance (MR) imaging of such a joint motion, continuous adjustment of the scan plane position may be required. The purpose of this study was to evaluate the clinical feasibility of a method to guide the scan plane position during dynamic-motion MR imaging of freely moving joints. Materials and methods: The location of a small tracker device (dedicated hardware) placed on the patient's skin overlying a joint was determined by an ultrashort MR sequence and used to automatically adjust the scan plane position prior to each dynamic-motion MR image. Using a vertically open MR unit, this MR tracking system was applied in ten dynamic-motion MR examinations to evaluate flexion/extension manoeuvres in the weightbearing knee joint, and in 10 dynamic-motion MR examinations of the shoulder joint to evaluate manoeuvres such as internal/external rotation of the humerus, stress testing of the glenohumeral joint and abduction/ adduction manoeuvres. Average number of manoeuvre repetitions, total number of images and percentage of useful images per manoeuvre were calculated. Imaging time per scan plane for each manoeuvre was recorded. Results: Average repetition of manoeuvres varied between 1.6 and 5.8, with an average number of 7–18 images per manoeuvre. Average percentage of useful images varied between 61% and 89%. Total imaging time per scan plane ranged between 1 min 10 s and 4 min 51 s. Conclusions: The MR tracking system to guide the slice position for each consecutive dynamic-motion MR image of the freely but slowly moving
325
shoulder or knee joint was feasible for clinical use, providing a high percentage of useful images for each manoeuvre within a clinically acceptable time frame.
Imaging of giant cell tumor of the tendon sheath Wan JMC, Magarelli N, Pen WCG, Guglielmi G, Shek TWH [S. G.: Dipartimento di Diagnostica per Immagini, Università Cattolica del Sacro Cuore, Policlinico “A. Gemelli”, Largo A. Gemelli 8, I-00168 Roma, Italy]. Radiol Med 2010;115:141-151. Giant cell tumours of the tendon sheath (GCTTS) and pigmented villonodular synovitis (PVNS) are part of a spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae, and tendon sheaths. This review article describes the clinicopathological features and imaging findings in patients with GCTTS. GCTTS usually presents as a soft tissue mass with pressure erosion of the underlying bone. Magnetic resonance (MR) imaging of GCTTS typically shows low to intermediate signal on T1- and T2-weighted spin-echo sequences due to the presence of haemosiderin, which exerts a paramagnetic effect. On gradient-echo sequences, the paramagnetic effect of haemosiderin is further exaggerated, resulting in areas of very low signal due to the blooming artefact. Ultrasonography shows a soft mass related to the tendon sheath that is hypervascular on colour or power Doppler imaging.
Computed tomography and thymoma: distinctive findings in invasive and noninvasive thymoma and predictive features of recurrence Priola AM, Priola SM, Di Franco M, Cataldi A, Durando S, Fava C [Department of Radiology, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, I-10043 Orbassano Turin, Italy]. Radiol Med 2010;115:1-21. Purpose: Our goal was to assess the computed tomography (CT) imaging findings of thymoma and to correlate these features with Masaoka staging system and prognosis. Materials and methods: CT findings of thymoma were analysed in 58 patients who had undergone surgery between January 2002 and September 2007. All cases were classified according to the Masaoka staging system. The presence of various CT findings was correlated with tumour invasiveness and recurrence. In statistical analysis, Pb.05 was interpreted as significant. Results: The study found 26 noninvasive thymomas and 32 invasive thymomas. Invasive thymomas were more likely to be greater in size (Pb.01), with lobulated or irregular contours (Pb.02), a necrotic or cystic component (Pb.04), foci of calcification (Pb.05) and heterogeneous contrast enhancement (Pb.01) than were noninvasive thymomas. Disease progression developed in nine of 58 patients. Tumour recurrence and metastasis correlated with greater size (Pb.04), lobulated or irregular contours (Pb.01), complete mediastinal fat obliteration (Pb.01), great vessel invasion (Pb.01) and pleural implants (Pb.02). Conclusions: CT is useful in differentiating invasive from noninvasive thymomas and plays an important role in evaluating and treating these patients for multimodal therapy with neoadjuvant approaches. Moreover, CT findings may serve as predictors of postoperative recurrence or metastasis.