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OBJECTIVE: Differentiating unicystic ameloblastomas from keratocystic odontogenic tumors (KCOT) is necessary for the planning of different treatment strategies; however, it is difficult based on conventional CT and MR sequences alone. The purpose of this study was to investigate the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficients (ADCs) in the differentiation of the two tumors. MATERIALS AND METHODS: We prospectively studied 40 patients with odontogenic cysts and tumors of the maxillomandibular region using conventional MR imaging and DWI. ADCs were measured using 2 b factors (500 and 1000). RESULTS: Unicystic ameloblastomas (n = 11) showed free diffusion on DWI and a mean ADC value of 2.309 ± 0.17 × 10-3 mm2/s. KCOT (n = 15) showed restricted diffusion on DWI with a mean ADC value of 0.923 ± 0.20 × 10-3 mm2/s. The ADC values of unicystic ameloblastomas were significantly higher than those of KCOT (p < 0.001, Mann-Whitney U-test). An ADC cut-off value of 2.0 × 10-3 mm2/s to differentiate KCOT and unicystic ameloblastomas resulted in a 100% sensitivity and 100% specificity. Dentigerous cysts (n = 3) showed restricted diffusion on DWI and similar ADC values (1.257 ± 0.05 × 10-3 mm2/s) to those of KCOT. CONCLUSION: Diffusion-weighted imaging and ADC determination can be used as an adjuvant tool to differentiate between unicystic ameloblastomas and KCOT, although the ADC values of dentigerous cysts overlap with those of KCOT.
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Humans , Ameloblastoma , Dentigerous Cyst , Diffusion , Magnetic Resonance Imaging , Odontogenic Cysts , Odontogenic Tumors , Prospective Studies , Sensitivity and SpecificityABSTRACT
Objective To investigate the correlation between DWI value of cervical cancer in stage Ib1-II A2 and its pelvic lymph node metastasis. Methods 103 patients with cervical cancer of stage Ib1 - IIa2 confimed by surgery and pathology in our hospital from January 2014 to July2016 were retro-spectively studied,78 cases of cervical squamous cell carcinoma group(lymph node metastasis of 22 cases,non- lymph node metastasis 56 cases);25 cases of Cervical adenocarcinoma group(9 cases with lymph node metastasis,16 cases of no lymph node metastasis). All patients with preoperative were performed MR routine scan and DWI examination. The ADC value(meanADC,minADC and maxADC)between the two groups and between the groups with and without metastasis were statistically analyzed. Results The value of ADC staging of cervical carcinoma had no correlation with clinical FIGO stage(Pmean = 0.847、Pmin = 0.393、Pmax = 0.219). The meanADC values、minADC value、maxADC value[(0.84 ± 0.09)× 10-3mm2/s、(0.78 ± 0.09)× 10-3mm2/s、(0.86 ± 0.07)× 10-3 mm2/s]of Squamous cell carcinomas was lower than that of adenocarcinoma[(0.98 ± 0.04)× 10-3mm2/s、(0.93 ± 0.09)×10-3mm2/s、(0.97 ± 0.23)× 10-3mm2/s]and the difference was statistically significant(P <0.05). The meanADC values and minADC value of cervical cancer within each group in lymph node metastasis group was lower than that of non- lymph node metastasis group,the difference was statistically significant(P <0.05). The maxADC value had no significant difference(P > 0.05). Conclusion The ADC value of cervical cancer has some correlation with lymph node metastasis,which can be helpful to predict the risk of lymph node metastasis.
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Objective To assess the value of magnetic resonance diffusion weighted imaging(DWI) and apparent diffusion coefficients(ADC) values of hepatic alveolar echinococcosis(HAE) in children.Methods 20 cases of children(≤14 years) with HAE were collected in this restrospective study.PNM staging was determined, the HAE peripheral area of DWI lesions with different P stages was observed, and the ADC value of the peripheral area was measured.The comparison of alveococcus lesions in different stages of DWI with continuous edge degree and ADC value difference was done to evaluate the growth activity.Results There were 5 cases of P1 lesions, 7 cases of P2 lesions, 2 cases of P3 lesions and 6 cases of P4 lesions.DWI features of peripheral area were as follows: High signal ring band between HAE lesion edge and adjacent normal hepatic parenchyma was observed.P1 lesions showed almost complete obviously high signal peripheral area, indicating the most active proliferation, P2 and P3 lesions of peripheral area were continuous and with high signal, and still had obvious growth activity.P4 lesions of peripheral area were not continuous, while the signal decreased, indicating the activity also decreased.The highest ADC value was detected in P1 lesions group of and the ADC value of P2 lesions group were lower than P1, and the ADC value of P4 lesions group were the lowest.P3 lesions samples were too small and thus no statistical analysis was done.Differences of ADC value between the three groups were statistically significant (P<0.05).Conclusion DWI image features could be used to assesse the growth activity of HAE in children with different stages to a certain extent.ADC values measurement provides important reference value for evaluating the growth activity at various stages of the lesions.
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Objective To explore the values of apparent diffusion coefficients (ADC) in staging the lesions of multiple sclerosis (MS) through analysing the differences of ADC in different types of lesions.Methods 137 lesions identified in 29 patients with MS,were characterized by their enhancement pattern on contrast-enhanced T1-weighted MR images and whether they were changing in appearance, size or signal.The lesions were classified into four groups:homogeneously enhancing lesions (HELs), ring-enhancing lesions (RELs), active nonenhancing lesions (ANELs), and inactive nonenhancing lesions (INELs).The mean ADC values for each type of lesions were calculated and compared.Results The ADC values for HELs, RELs, ANELs and INELs were (91.09±13.63)× 10 5 · m2 · s-1, (105.66±9.92) × 10-5 · m2 · s-1, (136.80±20.31) × 10-5 · m2 · s-1 and (127.46±13.65) ×10-5 · m2 · s-1.There were significant differences between the ADC values of any two groups in the four groups except the ADC values between ANELs and INELs.Conclusion ADC values are useful to differentiate each type of lesion,which can help stage the lesions of MS.
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Objective To explore the feasibility of diffusion-weighted imaging (DWI) in assessing the efficacy of chemoradiotherapy for cervical cancer.Methods Data of magnetic resonance imaging (MRI) and DWI were analyzed in 32 patients with uterine cervical cancer received conventional prior to chemoradiotherapy and after 1 and 3 months of therapy.13 cases of normal controls also had been examed by MRI and DWL DWI with b values of (0,300) s/mm2 and b values of (0,600) s/mm2 were performed in all patients.Pretreatment post-treatmentADC values were compared between the health group and patients group.Results When the b =300 s/mm2,normal cervical average ADC value was (1.72±0.31)×10-3 mm2/s,cervical cancer was (1.10±0.24)×10-3 mm2/s before treatment and was (1.61±0.23)×10-3 mm2/s after treatment.When the b =600 s/mm2,normal cervical average ADC value was (1.46±0.25)×10-3 mm2/s cervical cancer was (0.89±0.21)×10-3 mm2/s before treatment and was (1.54±0.18)×10-3 mm2/s after treatment.When b =300 s/mm2,ADC value was higher than when b =600 s/mm2.ADC values of cervical cancer was significantly lower than that of the normal cervix group,ADC values of cervical lesions after chemoradiotherapy was significantly higher than that before chemoradiotherapy (P ＜ 0.05).In the same group with different b values,ADC value was not significant (P ＞ 0.05).Conclusion Joint observation of DWI and ADC values could be more objective and accurate in the analysis of the disease and would help to evaluate the efficacy of chemoradiotherapy.
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Objective To study the effect of hyperbaric oxygen (HBO) therapy on perihematomal edema in acute spontaneous intracerebral hemorrhage. Methods Sixty-three consecutive hospitalized patients with supraten-torial intracerebral hemorrhage were allocated to an HBO group (n = 30) or a control group (n = 33) at random. Routine therapies were used with both groups. The treatment group received in addition twenty consecutive daily ses-sions of HBO therapy beginning 3～5 d after onset. MRI brain scans were performed on the 5～7th and 25th day. Absolute edema volumes and relative edema volumes were measured from T2-weighted images. Apparent diffusion co-efficients (ADCs) of the edematous regions were calculated on diffusion-weighted images (DWI). Results There were no statistical differences between the two groups in terms of age, sex, blood pressure, NIHSS, hematoma posi-tion or volume. At the 5th～7th d, both absolute and relative edema volumes in the HBO group were smaller than in the controls (P≤0.05). Brain edema was still prominent at the 25th d. Absolute edema volumes, relative edema volumes and ADC values were all smaller in the HBO group at the 25th day compared with the controls (P≤0.05). Conclusion HBO therapy soon after intracerebral hemorrhage can lessen the severity and range of brain edema. E-dema persists after the onset of the disease, and HBO can reduce such delayed brain edema. HBO may benefit func-tional recovery from intracerebral hemorrhage by reducing perihematomal edema.
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[Objective]To evaluate the value of diffusion weighted imaging(DWI)in breast disease.[Methods]7 cases suspected by molybdenum target and clinic were detected by MRI.we calculated ADC through two different b,also make time-signal plot.Then we compared the diagnostic conclusion to the normal MRI conclusion acquired with histopathological demonstration.[Results]3 cases were malignant,2 cases were benign and 2 cases were normal.The diagnostic coincidence rate of DWI and normal MRI was 100%.[Conclusion]DWI is a rapid and feasible method in detecting breast lesions.ADC is an effective parameter in discriminating malignant and benign breast lesions.