Sonographic appearances of retained surgical sponges in the abdomen and pelvis.

PURPOSE: To describe the sonographic (ultrasound-US) features of retained surgical sponges (RSSs) and compare them with the pathological findings. METHODS: Ultrasound features of RSSs in nine patients (seven women and two men) identified between June 1996 and July 2015 were retrospectively analyzed. Patient characteristics including gender and age, location of the sponge, time interval until diagnosis, clinical presentation, and patient complaints were evaluated. RESULTS: The US appearances of RSSs could be classified into three types. Type I (five cases): an echogenic arc with a strong posterior shadow; type II (two cases): US appearance mimicked a cystic teratoma; type III (two cases): a cystic mass with zigzag-shaped internal contents. CT and/or MRI showed a mass with density/signal intensity similar to that of the adjacent soft tissues. CONCLUSION: The characteristic US findings along with a history of surgery can help reach a correct diagnosis of RSS.

[Longitudinal evaluation of reparative cartilage after matrix-associated autologous chondrocyte implantation with delayed gadolinium-enhanced MRI of the cartilage].

OBJECTIVE: To estimate zonal variation of GAG content in reparative cartilage after matrix associated autologous chondrocyte implantation (MACI) using delayed gadolinium-enhanced magnetic resonance imaging of the cartilage (dGEMRIC). METHODS: Seven patients (14 cartilage defects) undergoing MACI were recruited for examination with dGEMRIC at 3, 6, and 12 months after the procedure to calculate global and zonal longitudinal relaxivity (Δ R1) of the normal cartilage and reparative cartilage. RESULTS: The mean Δ R1 values of normal cartilage were significantly lower than those of reparative cartilage after MACI. A significant decrease was noted in the mean Δ R1 values from the deep layer to the superficial layer in the reparative cartilage at the 3 examinations. The Δ R1 values of the reparative cartilage showed no significant variation between 3 months and 6 months, but a significant decrease in the Δ R1 values occurred at 12 months. CONCLUSIONS: dGEMRIC is feasible to assess cartilage repair noninvasively following MACI.

[3T magnetic resonance T2 mapping for evaluation of cartilage repair after matrix-associated autologous chondrocyte transplantation].

OBJECTIVE: To assess the value of magnetic resonance imaging (MRI) T2 mapping in quantitative evaluation of cartilage repair following matrix-associated autologous chondrocyte transplantation (MACT). METHODS: Six patients (with 9 plug cartilages) following MACT underwent MRI on a 3.0 Tesla MR scan system at 3, 6 and 12 months after the surgery. The full-thickness and zonal areas (deep and superficial layers) T2 values were calculated for the repaired cartilage and control cartilage. RESULTS: The mean T2 values of the repaired cartilage after MACT were significantly higher than that of the control cartilages at 3 and 6 months (P<0.05), but not at 12 months (P=0.063). At 6 and 12 months, the T2 values of the superficial layers were significantly higher than those of the deep layers in the repaired cartilages (P<0.05). The zonal (deep and superficial layers) T2 values of the repaired cartilages decreased significantly over time at 6 and 12 months as compared to those at 3 months after the surgery (P<0.05). CONCLUSION: MRI T2 mapping can serve as an important modality for assessing the repair of the articular cartilage following MACT.

[Diagnosing radiation-induced liver injury in rabbit using 3.0 Tesla magnetic resonance diffusion-weighted imaging].

OBJECTIVE: To evaluate the clinical value of magnetic resonance (MR) diffusion-weighted imaging (DWI) for diagnosing radiation-induced liver injury (RILI) and detecting changes in hepatic pathology at different post-irradiation times. METHODS: Male New Zealand white rabbits received no irradiation (C0, control group; n = 10) or irradiation of 50 Gy/10F once every other day by virtual three dimensional conformal radiotherapy (3D-CRT) for one day (C1; n = 10), three days (C2; n = 10), two weeks (C3; n = 10), one month (C4; n = 10) or two months (C5; n = 10). One member of all groups were sacrificed for DWI examination and pathologic study on post-irradiation day 1, day 3, week 2, month 1 and month 2. The apparent diffusion coefficient (ADC) values were measured using a range of b values (50, 300, 600, 800 and 1000 s/mm2). RESULTS: Hematoxylin-eosin (H-E) staining showed that livers of rabbits in the C3, C4 and C5 groups had the characteristic features of veno-occlusive disease. DWI examination showed that the irradiated livers of rabbits in C2, C3, C4 and C5 groups had significantly lower ADC values than the livers of the non-irradiated rabbits at b values of 300, 600, 800 and 1000 s/mm2 (P less than 0.05). When the b value was 600 s/mm2, the best negative correlation between ADC values and pathological stage was seen for the irradiated livers (Spearman's rank, r = -0.459, P less than 0.01). The threshold ADC value to distinguish the normal group (C0) from an irradiated group (more than or equal toC1) was 1.955 * 10-3 mm2/s at 600 s/mm2 b value. When the b value was 1000 s/mm2, the threshold ADC value to predict an irradiated group with normal H-E staining (C1) from an irradiated group with abnormal H-E staining (more than or equal toC2) was 1.5250 * 10-3 mm2/s; the ADC threshold value was 1.5150 * 10-3 mm2/s to predict groups C0-2 and groups C3-5. CONCLUSION: DWI has high sensitivity for detecting RILI at three days after irradiation with proper b values. Use of the ADC value is feasible for estimating the evolutionary process of pathological features of RILI damage. DWI may represent an important clinical tool for detection of early pathological changes in RILI.

[Quantitative T2 mapping evaluates the repaired articular cartilage].

OBJECTIVE: To evaluate the value of T2 mapping in monitoring the repaired cartilage after matrix-associated autologous chondrocyte implantation/transplantation (MACI/MACT). METHODS: Four patients (10 plug cartilages) were examined three times by T2 mapping at 1, 3, and 6 months using a 3.0 Tesla MR scan system. Quantitative mean (full-thickness) T2 values were calculated in the transplanted area and control cartilage. Paired t-tests were used to compare the T2 values between transplanted and control cartilage. For analysis of longitudinal T2 values, one-way analyses of variance were performed among 1, 3, and 6 months after MACI. RESULTS: The mean T2 values of the transplanted area at 1, 3, and 6 months after MACI were (82.40±15.23), (71.09±13.06), (53.80±4.86) ms, respectively. There were significant differences between the transplanted and control cartilage at 1 and 3 months (both P<0.01) after MACI, but not at 6 months (P=0.196). There were significant differences among T2 values of 1, 3, and 6 months after MACI in transplanted area (P=0.03). CONCLUSION: T2 mapping provides a useful tool for monitoring the biochemical development of the transplanted cartilage and can be used to evaluate the cartilage repair noninvasively.

[T2 mapping and knee thickness measurement in healthy young adults using quantitative 3.0T magnetic resonance imaging].

OBJECTIVE: To investigate the T2 values and knee thickness in healthy young adults using 3.0 T magnetic resonance imaging(MRI) . METHODS: Totally 40 volunteers(18-30 years old) with body mass index between 18.5-24.0 kg/m(2) were divided into two groups(22 men and 18 women) according to their gender. Also in addition, each group was divided into two subgroups(right knee and left knee) . The T2 values and the thickness of the areas on the medial condyle of femur, the lateral condyle of femur, the medial tibial plateau, the lateral tibial plateau, and the patella of the knee cartilage were measured. RESULTS: The T2 values and the thickness of the right and left knee cartilages showed no significant differences between men and women (P>0.05) . Also, the T2 values in the five parts of the knee cartilage also were not significantly different between men and women (P>0.05) . However, the thickness of the 5 parts of the knee cartilage significantly differed between men and women(P<0.05) . CONCLUSIONS: The thickness of the knee cartilage may different between male and female young adults. The T2 values of the cartilage may be not affected by the gender.

[Research advances in medical imaging for radiation-induced liver injury].

The applications of three dimensional conformal radiotherapy(3-DCRT)in the abdomen has been associated with the increased incidence of radiation-induced liver injury(RILI). Timely and appropriate evaluation of RILI is particularly important for the design and modification of clinical management of tumors. This article reviews the pathological and serological features of RILI, focusing on in the application of medical imaging.

[An experimental study on rabbit liver by 3.0 Tesla magnetic resonance diffusion-weighted imaging].

OBJECTIVE: To explore the methodology as well as the features, quantificational index, and reference standard of 3.0 Tesla magnetic resonance (MR) diffusion-weighted imaging (DWI) on the normal rabbit's liver. METHODS: Twenty New Zealand white rabbits were enrolled and DWI was performed after anesthetics with multi-b values at 3.0 T MR scanner. Apparent diffusion coefficient (ADC) values as well as the difference between maximum and minimum ADC values, signal strength (SH), noise signal (SD), signal to noise ratio (SNR), and quality index (QI) were recorded and analyzed. RESULTS: With b value increased, the ADC values decreased accordingly (P < 0.001). The difference between maximum and minimum ADC values with b = 1000 s/mm2 was the least (good stability), b = 600 s/mm2 was the second least, and b = 300 s/mm2 was greatest (bad stability). The SH decreased at the same time (P < 0.001), but the difference among DWI with b =600, 800, and 1000 s/mm2 was not statistically significant (P > 0.05). The SD decreased at the same time (P < 0.001), but the difference between DWI with b = 800 s/mm2 and b = 1000 s/mm2 was not statistically significant (P > 0.05). The SNR decreased at the same time (P < 0.001), but there were no significant differences between DWI with b = 600 s/mm2 and b = 800 s/mm2 or b = 600 s/mm2 and b = 1000 s/mm2 (P > 0.05). The SNR of DWI with b = 800 s/mm2 and b = 1000 s/mm2 was lower. The QI decreased at the same time (P < 0. 001) , but the difference between DWI with b = 800 s/mm2 and b = 1000 s/mm was not statistically significant (P > 0.05). CONCLUSION: When 3.0 T MR DWI is applied for rabbit liver, it is better to use b = 600 s/mm2 for reducing scanning time and assuring better diffusion weights, quantity of images, and stability of ADC measurement.

[A diffusion tensor magnetic resonance imaging for studying white matter changes in patients with mild cognitive impairment.].

OBJECTIVES: To measure the microstructural differences in the brains of participants with amnestic mild cognitive impairment (aMCI) and compare with a control group using a magnetic resonance diffusion tensor imaging (DTI) technique with fully automated image analysis tools. METHODS: A standardized clinical and neuropsychological evaluation was conducted on each subject. 31 participants (15 participants with aMCI, 16 healthy elderly adults) underwent magnetic resonance imaging (MRI)-based DTI. To control the effects of anatomical variation, the diffusion images of all participants were registered to standard anatomical space. Voxel-by-voxel comparisons showed significant regional reductions in white matter regions of fractional anisotropy (FA) in the participants with aMCI as compared with the controls. RESULTS: Significantly decreased FA value measurements (P < 0.001) were observed in the right frontal white matter in participants with aMCI. Moreover, there was a statistically significant difference between the patients with aMCI and controls in considering the small regions of bilateral superior frontal gyrus white matter (P < 0.001). CONCLUSIONS: White matter damage of frontal lobe may play an important role in histopathologic changes associated with amnestic mild cognitive impairment.

Diffusion-weighted magnetic resonance imaging in diagnosis of Creutzfeldt-Jakob disease.

BACKGROUND: Creutzfeldt-Jakob disease (CJD), a rare disease, is uncharacterized by computed tomography (CT) and magnetic resonance imaging (MRI). This study was aimed to evaluate the diffusion-weighted MRI (DWI) manifestations of CJD and to discuss their diagnostic value. METHODS: The findings of T(1)-weighted MRI (T(1)WI), T(2)-weighted MRI (T(2)WI), DWI and post-contrast MRI in 5 patients (3 patients with biopsy-proven CJD and 2 patients with clinically-proven CJD) were retrospectively analyzed in this study. RESULTS: Four out of the 5 patients had cerebral atrophy of various degrees. One patient showed symmetric high signal intensity at the bilateral globus pallidus and the head of the caudate nucleus, with very high signal in the cerebral cortex on the DWI. This patient only had symmetric slightly high signal at the bilateral globus pallidus and putamen on T(2)WI. One patient had high signal intensity at the basal ganglia and cerebral cortex on DWI, but abnormal T(2) signal intensity at the bilateral paraventricular white matter on MRI. Two patients presented with widely gyri-like high signal intensity at the cortex on DWI, but routine MRI showed bilateral paraventricular long T(2) signal intensity in 1 patient and no abnormal findings in another. No abnormalities were shown by both routine MRI and DWI in the last patient. CONCLUSIONS: DWI is more sensitive than its conventional counterpart in the depiction of CJD. DWI is more sensitive to detect cortical abnormal signal intensity in CJD not detected by T(2)WI.

Differentiation of clinically benign and malignant breast lesions using diffusion-weighted imaging.

PURPOSE: To evaluate the value of diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions. MATERIALS AND METHODS: Fifty-two female subjects (mean age = 58 years, age range = 25-75 years) with histopathologically proven breast lesions underwent DWI of the breasts with a single-shot echo-planar imaging (EPI) sequence using large b values. The computed mean apparent diffusion coefficients (ADCs) of the breast lesions and cell density were then correlated. RESULTS: The ADCs varied substantially between benign breast lesions ((1.57 +/- 0.23) x 10(-3) mm(2)/second) and malignant breast lesions ((0.97 +/- 0.20) x 10(-3) mm(2)/second). In addition, the mean ADCs of the breast lesions correlated well with tumor cellularity (P < 0.01, r = -0.542). CONCLUSION: The ADC would be an effective parameter in distinguishing between malignant and benign breast lesions. Further, tumor cellularity has a significant influence on the ADCs obtained in both benign and malignant breast tumors.