Valid and reliable diagnostic performance of dual-energy CT in anterior cruciate ligament rupture.

OBJECTIVES: To determine whether dual-energy CT (DECT) can be used to accurately and reliably detect anterior cruciate ligament (ACL) rupture. MATERIALS AND METHODS: Participants with unilateral ACL rupture were prospectively enrolled, and the bilateral knees were scanned by DECT. A tissue-specific mapping algorithm was applied to improve the visualization of the ACLs. The 80-keV CT value, mixed-keV CT value, electron density (Rho), and effective atomic number (Zeff) were measured to quantitatively differentiate torn ACLs from normal ACLs. MRI and arthroscopy served as the reference standards. RESULTS: Fifty-one participants (mean age, 27.0 ± 8.7 years; 31 men) were enrolled. Intact and torn ACLs were explicitly differentiated on color-coded DECT images. The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs (p < 0.001). The optimal cutoff values were an 80-keV CT value of 61.8 HU, a mixed-keV CT value of 60.9 HU, and a Rho of 51.8 HU, with AUCs of 98.0% (95% CI: 97.0-98.9%), 99.2% (95% CI: 98.6-99.7%), and 99.8% (95% CI: 99.6-100.0%), respectively. Overall, DECT had almost perfect reliability and validity in detecting ACL integrity (sensitivity = 97.1% [95% CI: 88.1-99.8%]; specificity = 98.0% [95% CI: 89.5-99.9%]; PPV = 98.0% [95% CI: 93.0-99.8%]; NPV = 97.1% [95% CI: 91.7-99.4%]; accuracy = 97.5% [95% CI: 94.3-99.2%]). There was no evidence of a difference between MRI and DECT in the diagnostic performance (p > 0.99). CONCLUSION: DECT has excellent diagnostic accuracy and reliability in qualitatively and quantitatively diagnosing ACL rupture. CLINICAL RELEVANCE STATEMENT: DECT could validly and reliably diagnose ACL rupture using both qualitative and quantitative methods, which may become a promising substitute for MRI to evaluate the integrity of injured ACLs and the maturity of postoperative ACL autografts. KEY POINTS: • On color-coded DECT images, an uncolored ACL was a reliable sign for qualitatively diagnosing ACL rupture. • The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs, which contributed to the quantitative diagnosis of ACL rupture. • DECT had an almost perfect diagnostic performance for ACL rupture, and diagnostic capability was comparable between MRI and DECT.

[Magnetic Resonance Imaging Features and Their Pathological Mechanisms of Hashimoto's Encephalopathy].

Objective To analyze the routine and functional magnetic resonance imaging(MRI) features and their potential pathological mechanisms of Hashimoto's encephalopathy(HE). Methods The clinical data and routine and functional MRI images of 30 HE patients who were treated in our center from January 2010 to April 2017 were retrospectively reviewed. Among them,15 patients were examined with contrast-enhanced MRI,16 with diffusion-weighed imaging(DWI),8 with magnetic resonance angiography,2 with magnetic resonance spectroscopy,and 1 with both arterial spin labeled perfusion imaging and diffusion tensor imaging. Seven patients had consecutive clinical and imaging data. The distribution,MRI signals,and functional MRI features of HE were analyzed. Results Among 30 HE patients,routine MRI showed negative results in 8 cases and abnormal findings in 22 cases. Among 22 abnormal cases,9 were characterized by small cerebral vascular disease and 13 had non-specific abnormalities;of these 13 cases,12 had lesions mainly located at the supratentorial white matter,11 had multiple lesions,and 2 had lesions complicated with cerebellum atrophy. The lesions were focal or confluent,punctate or small patchy,showing abnormal signal intensity with iso-or hypo-intensity on T1-weighed imaging,hyper-intensity on both T2-weighed imaging and fluid-attenuated inversion recovery. Most of the lesions had no enhancement(12/15). Among 7 cases with abnormalities on DWI,hyper-intensity on DWI and hypo-intensity on apparent diffusion coefficient were seen in 3 sudden acute cases and hyper-intensity on DWI and increased apparent diffusion coefficient value in 4 sub-acute or slow onset cases. Three cases showed localized intracranial artery stenosis. In 2 cases,magnetic resonance spectroscopy revealed significant lower N-acetylaspartate peak,higher choline peak,and visible lactate peak or lipid peak. Of 7 cases with follow-up data,3 cases had no change,4 cases had changes including softening lesions(2/4),remitted and relapsed lesions(1/4),and rapid progression of brain atrophy with negative finding on the initial MRI(1/4). Conclusion Routine MRI combined with functional imaging can show the features of HE from different perspectives. Routine MRI shows multifocal or confluent lesions in the white matter,mostly without enhancement,while functional imaging may reveal pathological characteristics of different phases of acute or chronic ischemia and demyelinating changes of HE. Combined with clinical data,MRI can differentiate HE from other diseases based on routine and functional MRI appearances.

[Clinical features and imaging findings of intravenous leiomyomatosis].

OBJECTIVE: To explore the clinical features and imaging findings of intravenous leiomyomatosis (IVL). METHOD: The clinical features and imaging findings of 9 patients with pathologically confirmed IVL were retrospectively analyzed. RESULTS: Out of these 9 patients, there were 5 first-episode patients and 4 recurrent patients. Five patients had a history of uterine leiomyoma.Inferior vena cava (IVC) were involved in all 9 patients. The tumor extended through IVC into right heart chamber in 7 patients, among whom tumor were initially arisen from pelvic vessels in 6 patients. The first-episode symptoms included chest tightness and shortness of breath (n=4), edema of low extremity (n=2), abdominal distention (n=2), and menorrhagia (n=1). Tumors in pelvis/venous system and right heart cavity appeared as hypoechoic mass under ultrasound examinations, and hypodense mass with mottled enhancement were observed on contrasted CT. Tumors appeared to be isointense to muscles on T1-weighted images and slightly hyperintense on T2-weighted images. CONCLUSIONS: IVL has certain clinical history and lesion locations. Combined imaging examinations are helpful in the early diagnosis, surgery planning, and follow-up of IVL.

Tissue Doppler imaging study of right ventricular myocardial systolic activation in subjects with pulmonary arterial hypertension.

BACKGROUND: Tissue Doppler imaging (TDI) has provided an objective means to quantify global and regional left ventricular (LV) and right ventricular (RV) function with improved accuracy and greater reproducibility than conventional echocardiography. This study was conducted to assess RV myocardial systolic activation by TDI in subjects with pulmonary arterial hypertension (PAH). METHODS: A total of 30 patients with PAH and 30 healthy volunteers, all comparable in age and sex, underwent standard Doppler echo and TDI. Using pulsed Doppler echocardiography combined with TDI, the following regional parameters were evaluated in three different myocardial segments (RV basal lateral wall, basal septal, and LV basal lateral) on apical 4-chamber view: systolic (Sm), early- and late-diastolic (Em and Am) peak velocities. RV myocardial systolic activation delay was defined as the difference in time to peak TDI systolic velocities between the RV basal lateral wall and basal septal. In addition, RV end-diastolic and end-systolic areas were measured to calculate RV fractional area change from the same apical 4-chamber view. RESULTS: Compared with the control group, patients with PAH showed increased RA and RV end-diastolic diameter (RA: (4.5 +/- 1.2) cm vs (3.0 +/- 0.8) cm, P < 0.05 and RV: (4.8 +/- 1.9) cm vs (3.4 +/- 0.5) cm, P < 0.05) and reduced RV fractional area change; (35 +/- 14)% vs (56 +/- 9)%, P < 0.05. These PAH patients showed lower myocardial peak velocities and a significant activation delay compared with controls (P < 0.05). Moreover, a strong correlation between RV myocardial systolic activation delay and RV fractional area change was shown in patients with pulmonary arterial hypertension (r = -0.82). CONCLUSIONS: In PAH, RV myocardial systolic activation was markedly delayed, which was directly related to the RV fractional area change. RV myocardial systolic activation delay assessed by TDI could offer a unique approach to predict RV dysfunction.

[Application of real-time tissue elastography in diagnosis of breast cancer].

OBJECTIVE: To investigate the clinical value of real-time tissue elastography (RTE) in the diagnosis of breast cancer. METHODS: One hundred and twenty patients with breast lumps (135 lesions) were examined with B-mode imaging, color Doppler flowing imaging (CDFI) and RTE. The elastogram was graded using 5-score evaluating method. The postoperative pathological diagnosis was used as gold standard, and the sensitivity, specificity and accuracy of RTE and two-dimensional ultrasonography combined with RTE in diagnosis of breast cancer were calculated. RESULT: When the score >4 was set for cut-off criteria of malignancy, the sensitivity, specificity and accuracy of RTE was 85.45%, 83.75% and 84.4%, respectively. While two-dimensional ultrasonography combined with RTE was used, the sensitivity, specificity and accuracy increased up to 100%, 95% and 97%, respectively. CONCLUSION: RTE combined with two-dimensional ultrasonography can improve the validity in the diagnosis of malignant breast lesions.