Clinical value and feasibility of CT pulmonary angiography with personalized injection of contrast agent in pulmonary embolism.

OBJECTIVE: To determine the clinical value and feasibility of CT pulmonary angiography (CTPA) with personalized injection of contrast agent in pulmonary embolism (PE). METHODS: In the present retrospective study, 130 patients who underwent CTPA examination in our hospital from June 2019 to May 2020 were evaluated. Among them, 67 cases were detected by CTPA with personalized injection of contrast agent as the observation group (Obs group), and 63 cases were detected by CTPA with bolus-tracking (BT) as the control group (Con group). The specificity, sensitivity and accuracy of the detection in the two groups were compared. The image quality score and superior vena cava artifact score of the two diagnostic methods were compared. Additionally, the volumetric CT dose index (CTDIvol) and dose length product (DLP) of the two groups were compared. RESULTS: The Obs group yielded a significantly higher specificity in diagnosing PE than the Con group (P<0.05), but there were no significant differences between the two groups in the sensitivity and accuracy (P>0.05). The image quality score and superior vena cava artifact score of the two groups were not significantly different (P>0.05), and the Obs group showed significantly lower CTDIvol and DLP than the Con group (P<0.05). CONCLUSION: CTPA with personalized injection of contrast agent has good diagnostic value for PE, with good imaging effect and safe profile, and has a lower radiation dose requirement.

The SP-ET index is a new index for assessing the vertical position of patella.

BACKGROUND: Some parameters in previous studies did not better reflect the vertical position of the patella relative to the femoral trochlear. This study aimed to assess the value of the most superior point of patella-entrance of femoral trochlea distance ratio (SP-ET index) as a newer index in defining the vertical position of patella relative to the trochlea, correlate it with the Insall-Salvati ratio, and investigate the effect of the new index on patellar cartilage lesions. METHODS: A total of 99 knees of 77 patients with patellar cartilage lesions were retrospectively analyzed using magnetic resonance imaging (MRI) data. The Insall-Salvati ratio and SP-ET index were measured on MR images. Ninety-nine knees just with meniscus rupture were enrolled as the control group. The two parameters of the patellar cartilage lesions were compared with those of the control group. RESULTS: The Insall-Salvati ratio and SP-ET index in the patellar cartilage lesions group were significantly higher than those in the control group (p < 0.001). The SP-ET index showed a moderate positive correlation with the Insall-Salvati ratio (r = 0.307, p < 0.001). Receiver operating characteristic (ROC) analysis showed that the diagnostic efficiency of the SP-ET index was better than that of the Insall-Salvati ratio in patients with patellar cartilage lesions. CONCLUSION: The SP-ET index may be a useful complement parameter to define the vertical position of the patella relative to the femoral trochlear. Increased SP-ET index may be an important risk factor for patellar cartilage lesions.

Patellar shape is associated with femoral trochlear morphology in individuals with mature skeletal development.

BACKGROUND: As several studies have detected correlations between patellar and femoral trochlear development, this raises the question of whether patellar shape is associated with trochlear developmental outcomes. METHODS: Patellar shape and femoral trochlear morphology were retrospectively analyzed in 183 subjects, of whom 61 each were classified as having Wiberg type I, II, and III patellae (groups A, B, and C, respectively). The sulcus angle (SA), lateral trochlea inclination angle (LTA), medial trochlear inclination angle (MTA), lateral facet length (LFL), medial facet length (MFL), lateral trochlear height (LTH), medial trochlear height (MTH), trochlea sulcus height (TH), and lateral-medial trochlear facet distance (TD) were analyzed as a means of evaluating trochlear morphology. Trochlear depth, trochlear condyle asymmetry, and trochlear facet asymmetry were additionally calculated, and differences in trochlear morphology and correlations between trochlear morphology and patellar shape were evaluated. RESULTS: The femoral trochlear parameters of patients in group A differed significantly from those of patients in groups B and C. No significant differences between groups B and C were evident. Patellar shape was positively correlated with LTA, MTA, MFL, trochlear condyle asymmetry, and trochlear facet asymmetry, and was negatively correlated with SA. CONCLUSIONS: These data indicated that patellar shape and trochlear morphology are related to one another,which suggest normalized patella morphology surgery and trochlear surgery are better choices for patients with patella instability. TRIAL REGISTRATION: Retrospectively registered.

A quantitative MRI investigation of the association between iliotibial band syndrome and patellofemoral malalignment.

BACKGROUND: The iliotibial band (ITB) has a wide patellar insertion that provides lateral restraint to the patella and maintains the patellofemoral joint's stability. There has been limited investigation into the relationship between patellofemoral malalignment and iliotibial band syndrome (ITBS). METHODS: We retrospectively analyzed 47 knees with ITBS by retrieving magnetic resonance imaging (MRI) data collected over an approximately 6-year period from our database. The Insall-Salvati ratio, lateral patellofemoral angle (LPA), lateral patellar tilt (LPT), lateral trochlear length (LTL), angle of the non-weight-bearing facet of the lateral femoral condyle (nwb-LFCA), and the ITB-lateral femoral condyle (IT-LFC) distance were measured on MR images. The knees of 47 age- and gender-matched subjects were enrolled as the normal group. RESULTS: In the ITBS group, over one third (34%, 16/47) of knees had abnormal patellofemoral measurements, including 8 (17%, 8/47) knees with patellar alta, 11 (23.4%, 11/47) knees with an abnormally decreased LPA, and 5 (10.6%, 5/47) knees with an abnormally increased LPT indicating lateral patellar tilt. Moreover, 8 knees had simultaneous combinations of two or three abnormality parameters, and 8 (17%, 8/47) knees presented with superolateral Hoffa's fat pad edema. The Insall-Salvati ratio, LPT, and nwb-LFCA in the ITBS group were significantly higher than those in the normal group (P=0.001, P<0.001, and P<0.001, respectively); the LPA and IT-LFC distances in the ITBS group were significantly lower (P=0.003, P<0.001, respectively) than those in the normal group. There were mild to moderate correlations between the MRI parameters and ITBS (P=0.006, P<0.001, respectively). CONCLUSIONS: This study confirmed that a higher position or lateral tilt of the patella and a steeper morphology of the anterior part of the lateral femoral condyle were associated with the development of ITBS, which is helpful in understanding and further exploring the mechanism of ITBS.

Mechanisms of non-contact anterior cruciate ligament injury as determined by bone contusion location and severity.

BACKGROUND: The location and severity of tibiofemoral bone contusions in magnetic resonance imaging scans in patients with acute non-contact anterior cruciate ligament injuries can reflect the primary mechanisms of anterior cruciate ligament injuries. There has been limited investigation to subdividing the bone contusion model in the medial and lateral directions of the tibial plateau and the femoral condyle. METHODS: A retrospective review of 93 consecutive magnetic resonance imaging examinations of patients with acute non-contact anterior cruciate ligament injuries was conducted to identify bone contusions of the knee. The locations and the severity of the bone contusions were determined using magnetic resonance imaging scans for each anatomic site, including the lateral femoral condyle, the lateral tibial plateau, the medial femoral condyle, and the medial tibial plateau. The bone contusions in the lateral-medial and anterior-posterior directions of four anatomical sites were subdivided into six compartments. The severity of the bone contusions was graded on a scale of 1-4. The location and the severity of bone contusions were accessed in the sagittal and coronal planes on the femoral and tibial sides of the knee using the radiology information system. RESULTS: The prevalence of bone contusions on the magnetic resonance imaging scans was as follows: 78.49% on the lateral femoral condyle, 88.17% on the lateral tibial plateau, 49.46% on the medial femoral condyle, and 69.89% on the medial tibial plateau. The most common and severe compartments of the lateral femoral condyle, the lateral tibial plateau, the medial femoral condyle, and the medial tibial plateau were the central-lateral (CL), the posterior-medial (PM), the CL, and the posterior-lateral (PL) compartments, respectively. CONCLUSIONS: The location patterns and severity of bone contusions in patients indicated that internal tibial rotation, valgus, and the anterior and lateral translation of the tibia were the primary mechanisms of non-contact anterior cruciate ligament injury.

Non-contrast enhanced MRI for assessment of uterine fibroids' early response to ultrasound-guided high-intensity focused ultrasound thermal ablation.

PURPOSE: To examine non-contrast enhanced MRI value to evaluate necrotic area and ablation rate of uterine fibroids after high-intensity focused ultrasound (HIFU) thermal ablation. METHOD: In total, 508 patients with 598 fibroids who underwent HIFU treatment were enrolled. Contrast-enhanced MRI (CE-MRI) with diffusion-weighted imaging (DWI)were performed before treatment and within two days post-treatment. DWI signal performance of post-operative fibroids was observed; apparent diffusion coefficient (ADC) and DWI signal values pre- and post-operation were measured. The volume of post-operative DWI signal change area and post-contrast enhanced fibroid necrosis area were compared. RESULTS: Average ADC and DWI signal values before HIFU treatment were higher than those post-operation; the difference was statistically significant before and after ablation (P < 0.05). After HIFU, 78.09 % (467 / 598) of DWI showed complete regular or irregular high-signal rings and 21.91 % (131 / 598) showed incomplete high-signal rings. No significant difference was noted between the complete high-signal ring volume on DWI and the non-enhanced volume (P > 0.05); however, this difference was statistically significant compared with the incomplete high-signal ring volume on DWI (P < 0.05). Two doctors had good agreements on evaluating the morphology of high-signal rings (κ > 0.75, P < 0.05). CONCLUSIONS: Combined with pre-operative T2WI and post-operative DWI, non-contrast enhanced MRI can effectively evaluate ablation rate for most patients with uterine fibroids.