To prospectively evaluate diffusion-weighted (DW) magnetic resonance (MR) imaging with a split acquisition of fast spin-echo signals for diffusion imaging (SPLICE) sequence for tissue characterization of lung carcinomas by using apparent diffusion coefficients (ADCs). An institutional review board approved this study; informed consent was obtained from patients. Thirty patients (nine women, 21 men; mean age, 68.0 years) with lung carcinoma underwent DW MR imaging with the SPLICE sequence. ADC of each lung carcinoma was calculated from DW MR images obtained with low and high b values. ADCs of lung carcinomas were statistically compared among histologic types. Nine surgically excised lung carcinomas were evaluated for correlation between ADCs and tumor cellularities. Analysis of variance was used to determine changes in ADCs and histologic lung carcinoma types. Spearman rank correlation was calculated between ADCs and tumor cellularities. ADCs for lung carcinomas were 1.63 x 10(-3) mm(2)/sec +/- 0.5 (mean +/- standard deviation) for squamous cell carcinoma, 2.12 x 10(-3) mm(2)/sec +/- 0.6 for adenocarcinoma, 1.30 x 10(-3) mm(2)/sec +/- 0.4 for large-cell carcinoma, and 2.09 x 10(-3) mm(2)/sec +/- 0.3 for small-cell carcinoma. ADC of adenocarcinoma was significantly higher than that of squamous cell carcinoma and large-cell carcinoma (P < .05). ADCs were 1.59 x 10(-3) mm(2)/sec +/- 0.5 and 1.70 x 10(-3) mm(2)/sec +/- 0.4 for moderately and poorly differentiated squamous cell carcinoma, respectively. ADCs were 2.52 x 10(-3) mm(2)/sec +/- 0.4 and 1.44 x 10(-3) mm(2)/sec +/- 0.3 for well- and poorly differentiated adenocarcinoma, respectively. ADC of well-differentiated adenocarcinoma was significantly higher than that of moderately and poorly differentiated squamous cell carcinoma and poorly differentiated adenocarcinoma (P < .05). With the Spearman rank test, ADCs of lung carcinomas correlated well with tumor cellularities (Spearman coefficient, -0.75; P < .02). ADCs of lung carcinomas overlap, but ADCs of well-differentiated adenocarcinoma appear to be higher than those of other histologic lung carcinoma types.

ADC provides a measure of water molecule diffusion in tissue. The aim of this study was to evaluate whether the fractional change in ADC during therapy can be used as a valid predictive indicator of treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy. Forty patients underwent DWI at pretreatment and 3 weeks after the start of treatment. The pretreatment ADC, fractional change in ADC, tumor regression rate, and other clinical variables were compared with locoregional control and locoregional failure and were analyzed by using logistic regression analysis and receiver operating characteristic analysis. Furthermore, progression-free survival curves divided by the corresponding threshold value were compared by means of the log-rank test. The fractional change in ADCprimary, the fractional change in ADCnode, primary tumor volume, nodal volume, tumor regression ratenode, N stage, and tumor location revealed significant differences between locoregional failure and locoregional control (P < .05). In univariate analysis, the fractional change in ADCprimary, fractional change in ADCnode, tumor regression ratenode, N stage, and tumor location showed significant association with locoregional control (P < .05). In multivariate analysis, however, only the fractional change in ADCprimary was identified as a significant and independent predictor of locoregional control (P = .04). A threshold fractional change in ADCprimary of 0.24 revealed a sensitivity of 100%, specificity of 78.7%, and overall accuracy of 84.8% for the prediction of locoregional control. Progression-free survival of the 2 groups divided by the fractional change in ADCprimary at 0.24 showed a significant difference (P < .05). The results suggest that the fractional change in ADCprimary is a valid imaging biomarker for predicting treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy.

We present serial changes on diffusion-weighted MRI (DWI) in a patient with Creutzfeldt-Jakob disease (CJD). DWI revealed serial changes of abnormal hyperintense lesions that had become more extensive and conspicuous with progression of neurologic findings, more sensitively than conventional MRI. In the late stage, disappearance of abnormal hyperintense lesions on DWI was observed. DWI proved to be particularly useful for monitoring the progression of CJD.

It is not clear whether magnetic resonance imaging (MRI) is useful for the assessment of pleural diseases. The aim of this study is to determine whether diffusion-weighted magnetic resonance imaging (DWI) can differentiate malignant pleural mesothelioma (MPM) from pleural dissemination of lung cancer, empyema or pleural effusion. The DWI was calibrated with the b value of 0 and 800 s/mm². There were 11 MPMs (8 epithelioid and 3 biphasic), 10 pleural disseminations of lung cancer, 10 empyemas, and 12 pleural effusions. The apparent diffusion coefficient (ADC) of the pleural diseases was 1.22 ± 0.25 × 10⁻³ mm²/s in the MPMs, 1.31 ± 0.49 × 10⁻³ mm²/s in the pleural disseminations, 2.01 ± 0.45 × 10⁻³ mm²/s in the empyemas and 3.76 ± 0.62 × 10⁻³ mm²/s in the pleural effusions. The ADC of the MPMs and the pleural disseminations were significantly lower than the ADC of the empyemas and the pleural effusions. Concerning the diffusion pattern of DWI, all 11 MPMs showed strong continuous diffusion, 9 of 10 pleural disseminations showed strong scattered diffusion and 1 pleural dissemination showed strong continuous diffusion, all 10 empyemas showed weak continuous diffusion, and all 12 pleural effusions showed no decreased diffusion. DWI can evaluate pleural diseases morphologically and qualitatively, and thus differentiate between malignant and benign pleural diseases.

OBJECTIVE. The purpose of this study was to evaluate prospectively the depiction of hypervascular hepatocellular carcinoma on 64-MDCT scans obtained with contrast agents of varying iodine concentrations administered with and without saline flush.SUBJECTS AND METHODS. The study included 149 patients, among whom 36 patients with hypervascular hepatocellular carcinoma were identified. Patients were randomly assigned to one of three protocols: A, contrast material of 300 mg I/mL; B, 370 mg I/mL; C, 370 mg I/mL plus saline flush. In all protocols, the same iodine load per kilogram of body weight (516 mg/kg) was administered for the same injection duration (30 seconds). Enhancement values in the aorta, liver, and portal vein and tumor–liver contrast were measured at multiphase CT.RESULTS. Aortic enhancement was significantly different between protocols A and B (p = 0.04, p < 0.0001) and protocols B and C (p = 0.02, p < 0.001) in the first and second phases. Portal venous enhancement was significantly different ...

It is well known that significant variations in stomach size, shape, and respiratory motion lead to uncertainties in target localization during treatment for gastric lymphoma. In this study, the usefulness of 4D-CT for radiation planning of gastric MZBCL/MALT was evaluated. Treatment planning using 4DCT (plan A) and conventional planning with a uniform margin (plan B) were compared using dose volume histograms (DVH) of the planning target volume (PTV) and the organ at risk, as well as the dose coverage of the clinical target volume (CTV) assessed by weekly online cone beam CT (CBCT) during the treatment course. In addition, regarding the image quality of CBCT , the interobserver agreement for the delineated volume of the CTV on CBCT was analyzed. The mean PTV of plan A was significantly smaller than that of plan B (p = 0.008). The mean doses to the liver and heart in plan A were significantly lower than those in plan B (p = 0.02 and 0.03, respectively). The reductions of V₂₀ of each kidney in plan A compared with those in plan B were 4.8 ± 2.4% in the right kidney and 16.3 ± 10.4% in the left. There was no significant difference in the dose coverage of the CTV between the plans during the treatment course. The interobserver agreement for the volume of the CTV was moderate correlation. Treatment planning using 4DCT for gastric MZBCL/MALT was useful for effective and safe irradiation with minimizing exposure of the organ at risk.