Submucosal Enhancing Stripe as a Contrast Material-enhanced MRI-based Imaging Feature for the Differentiation of Stage T0-T1 from Early T2 Rectal Cancers.

Background Accurate differentiation of stage T0-T1 rectal tumors from stage T2 rectal tumors facilitates the selection of appropriate surgical treatment. MRI is a recommended technique for local staging, but its ability to distinguish T1 from T2 tumors is poor. Purpose To explore the value of a submucosal enhancing stripe (SES), an uninterrupted enhancing band between the rectal tumor and the muscular layer on contrast material-enhanced T1-weighted images, as a potential imaging feature to differentiate T0-T1 from T2 rectal tumors. Materials and Methods This retrospective study included patients with pT0-T1 and pT2 rectal tumors who underwent pretreatment MRI and rectal tumor resection between January 2012 and November 2019. Two radiologists independently evaluated tumor characteristics (SES; status of muscularis propria [SMP]; and tumor shape, location, and size) at MRI. The associations of clinical and imaging characteristics with stage T0-T1 or T2 tumors were assessed, ß values were calculated, and predictive models were built. The diagnostic accuracies for the differentiation of T0-T1 tumors from T2 tumors with SES and SMP were compared. Results Data from 431 patients (mean age, 60 years ± 10 [standard deviation]; 261 men) were evaluated. SES (ß = 3.9; 95% CI: 3.1, 4.7; P < .001), SMP (ß = 1.3; 95% CI: 0.7, 1.9; P < .001), and carpetlike shape (ß = 1.6; 95% CI: 0.5, 2.8; P = .01) were independent factors distinguishing T0-T1 tumors from T2 tumors. The diagnostic accuracy was 87% (95% CI: 84, 90; 376 of 431) for SES and 67% (95% CI: 63, 72; 290 of 431) for SMP (P < .001). Conclusion Submucosal enhancing stripe (SES) at contrasted-enhanced MRI, status of muscularis propria (SMP) on T2-weighted images, and tumor shape can serve as independent imaging features to differentiate stage T0-T1 rectal tumors from stage T2 rectal tumors. Moreover, SES is a more accurate feature than is SMP. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Diagnostic value of single-source dual-energy spectral computed tomography for papillary thyroid microcarcinomas.

BACKGROUND: Ultrasound (US) and computed tomography (CT) are common diagnostic imaging methods for detecting and diagnosing papillary thyroid microcarcinoma (PTMC). However, single-source dual-energy spectral computed tomography (spectral CT) reduces beam hardening artefacts and optimizes contrast, which may add value in detecting PTMC. OBJECTIVE: To investigate values of applying single-source dual-energy spectral CT for diagnosing PTMCs, in comparison with high frequency ultrasound and conventional polychromatic images. METHODS: Thirty-one patients with suspected PTMC underwent contrast-enhanced dual-energy spectral CT. The images were analyzed by two experienced radiologists. Noise and contrast-noise-ratio (CNR) were compared between conventional CT and spectral CT. Ultrasonography was also performed by an experienced radiologist with a 7 to 12-MHz linear array transducer. Detection and diagnostic sensitivity were determined and compared. RESULTS: Forty-six pathologically-confirmed PTMC lesions were detected in 31 patients. Spectral CT had lower noise and higher CNR than conventional CT (P < 0.05). US detected more tumors (45/46 [97.8%] than conventional CT images (40/46 [87.0%]) or spectral CT images (44/46 [95.7%]). Among them, 30 (65.2%), 36 (78.3%), and 40 (87.0%) lesions were diagnosed correctly by conventional CT, spectral CT and US, respectively. Spectral CT had higher sensitivity than conventional CT (P = 0.031). However, there was no significant difference between spectral CT and US diagnostic sensitivities (P = 0.125). CONCLUSION: Single-source dual-energy spectral CT was superior to conventional polychromatic images and similar to high frequency ultrasound in detecting and diagnosing for PTMCs. CT had advantages in detecting level VI and VII lymph nodes. Spectral CT and US provided good results for PTMC, and aid preoperative diagnosis.

Improvement in the Detection of Cystic Metastatic Papillary Thyroid Carcinoma by Measurement of Thyroglobulin in Aspirated Fluid.

Cystic change in metastatic lymph nodes of papillary thyroid carcinoma (PTC) is a diagnostic challenge for fine needle aspiration (FNA) because of the scant cellularity. The aim of this study was to evaluate the measurement of thyroglobulin in fine needle aspirate (Tg-FNA) for detecting metastatic PTC in patients with cystic neck lesions and to validate the optimal cutoff value of Tg-FNA. A total of 75 FNA specimens of cystic lesions were identified, including 40 of metastatic PTC. Predetermined threshold levels of 0.04 (minimum detection level), 0.9, 10.0, and 77.0 ng/mL (maximum normal serum-Tg level) were used to evaluate the diagnostic accuracy of Tg-FNA for metastatic PTC detection. The areas under the receiver operating characteristic curve for diagnosing metastatic PTC of Tg-FNA values of 0.04, 0.9, 10.0, and 77.0 ng/mL were 0.5 (95% confidence interval [CI], 0.382-0.618), 0.645 (95% CI, 0.526-0.752), 0.945 (95% CI, 0.866-0.984), and 0.973 (95% CI, 0.907-0.996), respectively. With a cutoff value of 77.0 ng/mL, the combination of Tg-FNA and FNA cytology showed superior diagnostic power (97.5% sensitivity and 100% specificity) compared to FNA cytology alone (80% sensitivity and 100% specificity). We recommend a Tg-FNA cutoff of 77.0 ng/mL, the maximum normal serum-Tg level, for cystic neck lesions.

Small Bowel Stromal Tumors: Different Clinicopathologic and Computed Tomography Features in Various Anatomic Sites.

Gastrointestinal stromal tumors (GISTs) can present with different clinical and immunohistochemical characteristics according to different anatomic sites. The aim of this study was to compare clinicopathologic and computed tomography (CT) features of small bowel stromal tumors located in the duodenum, jejunum, and ileum. In total, 197 patients (109 male, 88 female) with small bowel GISTs were retrospectively reviewed. All tumors had definite anatomic sites in the small bowel tract with surgical confirmation. The clinicopathologic variables included age, sex, onset of symptoms, and tumor risk category. CT variables included tumor size, degree enhancement, enhancement pattern (region of necrosis), adjacent tissue involvement, lymphadenopathy, and distant metastasis. We assessed any possible differences according to different GIST site of origin. Based on tumor size and mitotic count, the risk categories in different anatomic sites did not differ significantly between duodenal and jejunal GISTs. However, high risk ileum GISTs accounted for 66.0% of ileal cases, which was higher than duodenum cases (36.8%, P = 0.002) and jejunum cases (43.9%, P = 0.004). The mean size of GISTs in the ileum was 9.77 cm, which was significantly larger than in the duodenum (7.41 cm, P = 0.043), and in the jejunum (8.14 cm, P = 0.027). On CT images, enhancement degree appeared to gradually increase from the duodenum to the ileum in the portal phase, and the enhancement pattern presented a tendency for heterogeneity. In Conclusions, the clinicopathologic and CT features of small bowel GISTs can differ according to different primary anatomic sites.

Feasibility Study of Using Gemstone Spectral Imaging (GSI) and Adaptive Statistical Iterative Reconstruction (ASIR) for Reducing Radiation and Iodine Contrast Dose in Abdominal CT Patients with High BMI Values.

PURPOSE: To prospectively investigate the effect of using Gemstone Spectral Imaging (GSI) and adaptive statistical iterative reconstruction (ASIR) for reducing radiation and iodine contrast dose in abdominal CT patients with high BMI values. MATERIALS AND METHODS: 26 patients (weight > 65kg and BMI ≥ 22) underwent abdominal CT using GSI mode with 300mgI/kg contrast material as study group (group A). Another 21 patients (weight ≤ 65kg and BMI ≥ 22) were scanned with a conventional 120 kVp tube voltage for noise index (NI) of 11 with 450mgI/kg contrast material as control group (group B). GSI images were reconstructed at 60keV with 50%ASIR and the conventional 120kVp images were reconstructed with FBP reconstruction. The CT values, standard deviation (SD), signal-noise-ratio (SNR), contrast-noise-ratio (CNR) of 26 landmarks were quantitatively measured and image quality qualitatively assessed using statistical analysis. RESULTS: As for the quantitative analysis, the difference of CNR between groups A and B was all significant except for the mesenteric vein. The SNR in group A was higher than B except the mesenteric artery and splenic artery. As for the qualitative analysis, all images had diagnostic quality and the agreement for image quality assessment between the reviewers was substantial (kappa = 0.684). CT dose index (CTDI) values for non-enhanced, arterial phase and portal phase in group A were decreased by 49.04%, 40.51% and 40.54% compared with group B (P = 0.000), respectively. The total dose and the injection rate for the contrast material were reduced by 14.40% and 14.95% in A compared with B. CONCLUSION: The use of GSI and ASIR provides similar enhancement in vessels and image quality with reduced radiation dose and contrast dose, compared with the use of conventional scan protocol.

Value of R2* obtained from T2*-weighted imaging in predicting the prognosis of advanced cervical squamous carcinoma treated with concurrent chemoradiotherapy.

BACKGROUND: To prospectively investigate the value of R2* in predicting the prognosis of advanced cervical squamous carcinoma treated with concurrent chemoradiotherapy. METHODS: Sixty-five patients with biopsy-proven cervical squamous carcinoma were enrolled in our study. All these subjects underwent multi-echo T2*-weighted MR imaging on a 3.0 Tesla MR scanner, and tumor R2* was calculated. The patients were divided into the responders and the nonresponders according to treatment effect. Tumor R2* values of these two groups were compared. The relationship between tumor R2* and prognosis after therapy was analyzed. RESULTS: The responder group had lower R2* value than the nonresponder group (P = 0.02). The area under the receiver operating characteristics curve for tumor R2* in discriminating responders from nonresponders was 0.769. A cutoff value of 23.87 Hz for tumor R2* resulted in a sensitivity of 78.3% and a specificity of 67.6%. The low R2* group (≤28.37 Hz) had longer median progression-free survival period and overall survival period (P = 0.01, 0.03). Multivariate analysis showed that tumor R2* was a significant prognostic factor for progression-free survival and overall survival (adjusted hazards ratio = 5.34, 4.78; P = 0.02, 0.01). CONCLUSION: R2* value obtained from T2*-weighted imaging, as an imaging biomarker, may be an important predictor for the prognosis of advanced cervical squamous carcinoma treated with concurrent chemoradiotherapy.

Value of whole-tumor dual-input perfusion CT in predicting the effect of multiarterial infusion chemotherapy on advanced non-small cell lung cancer.

OBJECTIVE: The purposes of this study were to prospectively evaluate tumor perfusion using whole-tumor dual-input perfusion CT in advanced non-small cell lung cancer treated with multiarterial infusion chemotherapy and to determine whether treatment effect can be predicted in light of perfusion parameters. SUBJECTS AND METHODS: Forty-two patients with advanced non-small cell lung cancer were enrolled in this study. Whole-tumor dual-input perfusion CT was performed for all these patients, who subsequently received multiarterial infusion chemotherapy. The patients were divided into responders and nonresponders according to response to treatment. The relation between baseline perfusion parameters and prognosis after therapy was analyzed. RESULTS: The responder group had higher bronchial flow than the nonresponder group (p = 0.02). The AUC for bronchial flow was 0.83; pulmonary flow, 0.71; and perfusion index, 0.66. The higher bronchial flow group (≥ 65.34 mL/min/100 mL) and lower pulmonary flow group (< 23.05 mL/min/100 mL) had longer median progression-free survival periods (p = 0.01, p = 0.03) and overall survival periods (p = 0.04, p = 0.04). Multivariate analysis showed that bronchial flow was a significant prognostic factor for progression-free survival and overall survival (p = 0.01, p = 0.02) and that pulmonary flow may be helpful for predicting progression-free survival (p = 0.04) and overall survival (p = 0.03). CONCLUSION: Whole-tumor dual-input perfusion CT can provide information on the dual blood supply of tumors, which is helpful for predicting the treatment effect of multiarterial infusion chemotherapy for advanced non-small cell lung cancer.

Time-intensity curve parameters in rectal cancer measured using endorectal ultrasonography with sterile coupling gels filling the rectum: correlations with tumor angiogenesis and clinicopathological features.

The primary aim of this study was to investigate the relationship between contrast-enhanced ultrasonography (CEUS) imaging parameters and clinicopathological features of rectal carcinoma and assess their potential as new radiological prognostic predictors. A total of 66 rectal carcinoma patients were analyzed with the time-intensity curve of CEUS. The parameter arrival time (AT), time to peak enhancement (TTP), wash-in time (WIT), enhanced intensity (EI), and ascending slope (AS) were measured. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumor staging, histological grading, and MVD. The mean values of AT, TTP, WIT, EI, and AS value of the rectal carcinoma were 10.84 ± 3.28 s, 20.61 ± 5.52 s, 9.78 ± 2.83 s, 28.68 ± 4.67 dB, and 3.20 ± 1.10, respectively. A positive linear correlation was found between the EI and MVD in rectal carcinoma (r = 0.295, P = 0.016), and there was a significant difference for EI among histological grading (r = -0.264, P = 0.007). EI decreased as T stage increased with a trend of association noted (P = 0.096). EI of contrast enhanced endorectal ultrasonography provides noninvasive biomarker of tumor angiogenesis in rectal cancer. CEUS data have the potential to predict patient prognosis.

Ultrasound findings of papillary thyroid microcarcinoma: a review of 113 consecutive cases with histopathologic correlation.

Papillary thyroid microcarcinoma (PTMC) is a malignant thyroid tumor of less than 1 cm in size. Ultrasound (US) is the preferred imaging modality for PTMC. This study retrospectively evaluated the US results from 113 consecutive cases of PTMC with 127 nodules and correlated the results with the histopathologic findings. The results showed none of the PTMC nodules had a cystic element. Half of the PTMC nodules had a well-defined boundary and the remaining half had an ill-defined boundary. A percent (6.3%) of the nodules had a halo sign. Microcalcification was present in approximately half of the PTMC nodules. The cancerous tissue with a papillary structure was hypoechogenic and the amount of fibrous stroma determined whether the nodule echogenicity was heterogeneous or homogeneous. Heterogeneous echogenicity was associated with a fibrous stroma proportion of >20%. Only PTMC nodules with predominantly follicular structures containing a large proportion of colloid demonstrated isoechogenicity. Well-defined boundaries on US were associated with well-defined histologic margins, with or without the presence of an intact fibrous pseudo-capsule. A halo sign with a well-defined boundary detected by US was associated with the presence of an intact fibrous pseudo-capsule. Half of the PTMC nodules with ill-defined boundaries exhibited infiltration into the surrounding thyroid tissue, while the remaining half of the PTMC nodules with ill-defined boundaries on US presented irregular nodule margins by histology, rather than nodule infiltration. Psammoma bodies detected at a frequency ≥5 per ×200 microscopic field of view were detectable on US as microcalcifications.

Improvement in T-staging of rectal carcinoma: using a novel endorectal ultrasonography technique with sterile coupling gel filling the rectum.

Our purpose was to study the accuracy of using endorectal ultrasonography (ERUS) with sterile coupling gels filling the rectum in the preoperative T-staging of rectal carcinoma. A total of 189 patients with confirmed rectal carcinoma were recruited. All underwent ERUS and surgery within the week following sonography. EURS was performed by introducing sterile coupling gel into the rectum. Two radiologists looked at the images at the same time and agreed upon staging. Rectal carcinoma was staged from Tis to T4. The accuracy of T-staging by ERUS was 89.95%. The sensitivity, specificity, PPV and NPV for ERUS at different stages were calculated. For early stage (Tis and T1), these values were 93.62%, 97.89%, 93.62% and 97.89%, respectively. ERUS filling with sterile coupling gel in the rectum overcomes the pressure effect from a water bath and the restriction caused by tumor stenosis, thus, greatly improving the accuracy of T-staging. The examination is real-time, safe and inexpensive.

The value of perfusion CT in predicting the short-term response to synchronous radiochemotherapy for cervical squamous cancer.

OBJECTIVE: To determine the value of the perfusion parameters in predicting short-term tumour response to synchronous radiochemotherapy for cervical squamous carcinoma. METHODS: Ninety-three patients with cervical squamous carcinoma later than stage IIB were included in this study. Perfusion CT was performed for all these patients who subsequently received the same synchronous radiochemotherapy. The patients were divided into responders and non-responders according to short-term response to treatment. Baseline perfusion parameters of the two groups were compared. The perfusion parameters that might affect treatment effect were analysed by using a multivariate multi-regression analysis. RESULTS: The responders group had higher baseline permeability-surface area product (PS) and blood volume (BV) values than the non-responders group (P < 0.05). There was no statistical difference in baseline mean transit time (MTT) and blood flow (BF) value between the two groups (P >0.05). At multivariate multi-regression analysis, BV, PS and tumour size were significant factors in the prediction of treatment effect. Small tumours usually had high PS and BV values, and thus had a good treatment response. CONCLUSION: Perfusion CT can provide some helpful information for the prediction of the short-term effect. Synchronous radiochemotherapy may be more effective in cervical squamous carcinoma with higher baseline PS and BV. KEY POINTS: • Perfusion CT can reflect tumour vascular physiology in cervical squamous carcinoma. • Perfusion CT helps predict the short-term effect before treatment • Synchronous radiochemotherapy may be more effective in patients with higher baseline BV and PS.

[Evaluation of the efficacy of bronchial arterial infusion chemotherapy for the treatment of central non-small cell lung cancer].

OBJECTIVE: To evaluate the long-term efficacy of bronchial arterial infusion (BAI) chemotherapy in the treatment of centeral non-small cell lung cancer. METHODS: Fifty-eight patients with central non-small-cell lung cancer, who were assessed as difficult operable or non-operable by imaging examination, received BAI of cisplatin, epirubicin and mitomycin alone or in combination. It includes 51 cases of squamous cell carcinoma, 6 cases of adenocarcinoma and 1 case of adenosquamous carcinoma. The cinical stage before BAI wasIIb in 3 cases, IIIa in 26 cases and IIIb in 29 cases. Long term follow-up was conducted and the results were statistically analyzed. RESULTS: The total effective rate of BAI was 43.1%. The mediam survival (MS) of all 58 patients was 29.1 months. 31 patients after BAI became operable and were resected, had a median survival of 65.2 months. 27 patients after BAI were not resected and had a MS of 15.9 months. There was a significant difference between the patients who had been resected and not. The MS of IIIa stage patients was 39.0 months, and IIIb stage 20.4 months. CONCLUSION: Bronchial arterial infusion chemotherapy is a better choice with a definite efficacy for treatment of center-based NSCLC patients, estimated as difficult operable but without distant metastasis.

[Impact of 2009 FIGO staging system on the diagnostic value of preoperative MRI staging of endometrial carcinoma].

OBJECTIVE: To analyze the changes of 2009 FIGO staging system compared with the 1988 FIGO staging system of endometrial carcinoma and evaluate the diagnostic value of MRI staging by the 2009 FIGO criteria. METHODS: A retrospective study was performed on 63 consecutive patients with pathologically confirmed endometrial carcinoma who were treated by surgery initially from January to December 2009. The diagnostic value of preoperative MRI by the 2009 FIGO staging system was compared with that using the 1988 FIGO system, respectively. RESULTS: According to the 2009 FIGO staging system of endometrial carcinoma, stage Ia was defined as no or less than half myometrial invasion, which included stage Ia (confined to endometrium) and stage Ib (invasion less than half of the myometrium) of the 1988 FIGO staging system. Stage Ib assessed by the 2009 FIGO system was the same as the stage Ic of 1988 FIGO system, indicating the lesions more than half myometrial invasion. Endocervical glandular involvement only (stage IIa of 1988 FIGO system) was classified as stage I. Positive cytology of ascites (stage IIIa of 1988 FIGO system) was excluded by the 2009 FIGO criteria. Using the 1988 FIGO system, the accuracy of MRI for the evaluation of endometrial carcinoma of stage Ia, Ib, Ic, whole stage I, IIa, IIb, whole stage II, IIIa, IIIb, IIIc, whole stage III and IVb were 95.2%, 79.4%, 81.0%, 84.1%, 96.8%, 90.5%, 90.5%, 92.1%, 98.4%, 92.1%, 82.5%, and 98.4%, respectively, while using the 2009 FIGO system, the accuracy of MRI of stage Ia, Ib, whole stage I, II, IIIa, IIIb, IIIc, whole stage III and IVb were 88.9%, 81.0%, 88.9%, 92.1%, 98.4%, 98.4%, 92.1%, 88.9% and 98.4%, respectively. CONCLUSIONS: The 2009 FIGO staging system is simplified on the basis of the 1988 FIGO system. It gives an improved accuracy of MRI in evaluating the stage I to III endometrial carcinoma.

[CT features of ovarian Brenner tumor and a report of 9 cases].

OBJECTIVE: In order to improve the preoperative diagnostic accuracy, the computed tomographic (CT) features of ovarian Brenner tumor were described and analyzed. METHODS: CT image and clinical data of nine patients with pathologically confirmed Brenner tumor were collected and analyzed retrospectively. There were 8 benign lesions and 1 borderline lesion. RESULTS: All lesions in the nine cases were unilateral, round, lobulated or irregular in shape and well defined, in a mean diameter of 7.8 cm. Among the nine cases, 5 were benign tumors with uniform structure, 3 were benign tumors accompanied with other pathological components, and 1 was borderline tumor. On the CT images, the 5 uniform benign lesions showed to be solid tumor of low density (lower than that of muscle) or with small cyst inside, two of the 5 lesions had calcification, and other 2 lesions showed slightly heterogeneous enhancement after enhanced scanning. The 3 benign Brenner tumors accompanied with other pathological structures were solid-cystic or cystic, with a clear demarcation of solid and cystic components. The density of solid parts was lower than that of muscle, and slight enhancement, and one of them had calcification. The one borderline tumor was a heterogeneous solid one and its density was higher than that of muscle, with a large proportion of low density and large calcification, and moderately enhanced after enhancing. None of the 9 cases had metastasis or effusion. CONCLUSION: Ovarian Brenner tumors are usually unilateral and often accompanied with other type of tumor components. When a tumor is of uniform component, the CT imaging often shows a homogeneous solid tumor with homogeneous or heterogeneous density. When a tumor is accompanied with other tumor components, it may be solid-cystic or cystic and has partial calcification. After enhancing, a benign Brenner tumor is slightly enhanced, while the borderline one is moderately/highly enhanced.

[Preliminary application of diffusion-weighted imaging with 3.0 T magnetic resonance scanner for nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the clinical value of diffusion-weighted imaging (DWI) with 3.0 T magnetic resonance scanner for nasopharyngeal carcinoma (NPC) and to explore the appropriate b value during this procedure. METHODS: Totally 50 patients with histopathologically confirmed NPC and 20 volunteers underwent DWI using single-shot echo-planar imaging technique were enrolled in this study. Four groups of b value (600, 800, 1000 and 1200) were applied. The apparent diffusion coefficients (ADC) between the primary tumor of NPC and the metastatic lymph nodes were compared in each group. ADC between the metastatic lymph nodes and benign nodes were also compared. RESULTS: Although the mean ADC were not significantly different between NPC and those of metastatic cervical lymph nodes in each group, the mean ADC of the metastatic lymph nodes were significantly lower than those of benign nodes (P<0.05). When b value was 800, both satisfying images and accurate measurements were acquired. CONCLUSION: DWI is helpful in the diagnosis of primary lesions and their lymph node metastases of NPC.

[Role of 125I seed implantation in treatment of unresectable pancreatic cancer].

OBJECTIVE: To study the role of (125)I seed implantation in the treatment of unresectable pancreatic cancer. METHODS: From April 2004 to march 2006, 66 untreated patients with locally advanced pancreatic cancer (LAPC) were randomized into two groups: Group A: (125)I seeds implantation (n = 31) and Group B: control (n = 34). The objective tumor response, clinical benefit response, toxicity, complications and survival of two groups were observed. RESULTS: In Group A, the overall response rate (PR + NC) was 80.6%. Clinical benefit response rate was 54.8%. No toxicity was observed. Gastrointestinal hemorrhage and pancreatic fistula occurred in 1 patient respectively in Group A. The survival rates of 6 and 12 months were 56.0% vs 31.4% and 16.8% vs 2.9% respectively in two groups (P < 0.05). The median survival time of two groups was 8.0 months vs 4.0 months (P < 0.05). CONCLUSION: (125)I seed implantation is a simple, safe and effective method in the treatment of locally advanced pancreatic cancer.

[Value of high-field MR diffusion-weighted MR imaging in the diagnosis of endometrial carcinoma].

OBJECTIVE: To investigate the usefulness of high-field MR diffusion-weighted imaging (DWI) in the diagnosis of endometrial carcinoma. METHODS: Thirty-five female patients with pathologically proven endometrial carcinoma, 10 patients with pathologically proven endometrial dysplasia and 41 normal volunteers were enrolled into this study. MR images were obtained at a 3.0 T MR scanner (GE, SIGNA EXCITE HD 3.0T) and an 8-element phased-array torsopa coil was used to receive MR signal. The conventional pulse sequences included axial SE T1WI, FSE T2WI and fat saturated FSE T2WI, sagittal FSE T2WI, and coronal fat saturated FSE T2WI. Axial DWI was performed in all patients using a SE-EPI sequence with a 1000 s/mm(2) b value. The apparent diffusion coefficients (ADC) of carcinoma, dysplasia and normal mucosa were measured among the patients. RESULTS: Compared with myometrium, all the endometrial carcinoma, dysplasia and normal endometrium had a markedly high signal intensity on DWI. The ADC of endometrial carcinoma, dysplasia and normal endometrium was (1.08 +/- 0.23) x 10(-3)mm(2)/s, (1.29 +/- 0.21) x 10(-3) mm(2)/s and (1.41 +/- 0.21) x 10(-3) mm(2)/s, respectively. There were statistically significant differences between the carcinoma and normal endometrium (t = -6.416, P = 0.000), and between the carcinoma and dysplasia (t = -2.590, P = 0.013). However, no significant difference in ADC was found between highly-differentiated and moderately-differentiated adenocarcinomas. CONCLUSION: High-field MR diffusion-weighted imaging (DWI) is highly sensitive in detecting endometrial lesions. It can be used to differentiate the endometrial carcinoma from either dysplasia or normal endometrium, but is difficult to differentiate highly-differentiated adenocarcinoma from moderately-differentiated one.

Post-radiation CT changes and recurrent nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is endemic in Southern Asia. Radiation therapy remains the mainstay of treatment strategies for NPC. Although approximately 19% - 56% of patients develop a recurrent disease 5 years after their primary treatment, recognition of post-radiation changes and early detection of relapse are important in improving the outcome of NPC. Our aim was to analyze the post-radiation changes and recurrent diseases related to NPC using computed tomography (CT) scans and to investigate their relationship. METHODS: CT scans of 510 pathologically proven NPC patients who have been followed up for more than 2 years after radiation were reviewed. The tumor's response to the radiation therapy and its relevance to recurrence were evaluated. RESULTS: For patients who were followed up for more than 2 years, their CT scans-obtained within 3 months, during the 4th to the 6th month, and beyond 7 months after radiation therapy, showed a normal nasopharyngeal cavity with a slight thickening in the wall in 93.5%, 95.0% and 84.8% of the patients respectively. The degree of tumor regression had no significant relevance to the risk of recurrence within the initial 3 months (P = 0.094). During this term, the relapse rates in the cases in which the nasopharyngeal walls were displayed as normal, slightly or moderately thickening, or with obvious residual masses on CT scans were 7.1%, 11.7%, 23.5% and 23.1% respectively. The degree of tumor regression beyond 3 months after radiation therapy had a considerable reverse relevance to the risk of recurrence (P = 0.000). The relapse rates were 13.2%, 14.1%, 10.2% and 2.1%, respectively, in the cases with a normal and a slightly thickening nasopharyngeal wall during the 4th to the 6th month, the 7th to the 12th month, the 13th to the 24th month, and beyond 25 months after radiation. In contrast, the percents in cases with moderate or more aggressive thickening walls in the corresponding periods were 62.5%, 88.9%, 100% and 100%. Within 6 months after radiation therapy, shown by CT scans, the metastatic lymph nodes disappeared, markedly decreased, slightly decreased, or enlarged in 37.4%, 51.8%, 4.7%, and 0.4%, respectively, of the patients. During 6 to 12 months after radiation therapy, the proportions were 78.5%, 19.2%, 0.6% and 1.7% correspondingly. Beyond 12 months, the proportions were 83.7%, 7.9%, 0%, and 8.4%. The regression degree of the malignant nodes after radiation therapy showed a remarkable reverse relevance to the risk of recurrence in lymph nodes (P = 0.000). In the cases with disappearing, markedly decreased, slightly decreased, or enlarged malignant nodes within six months after radiation, the relapse rates were 2.9%, 4.5%, 12.5% and 100%, respectively. CONCLUSIONS: If the nasopharyngeal walls are shown to remain moderately thick on a CT scan beyond 6 months after radiotherapy, the risk of relapse will increase. The baseline images taken within 3 months after radiotherapy and regular follow-up studies are the key to pick up the tumor recurrences in an earlier stage.