T2 hypointense signal discovered incidentally at the posterior edge of the adenohypophysis on MRI: its prevalence and morphology and their relationship to age.

PURPOSE: T2 hypointense signal at the posterior edge of the adenohypophysis (T2HSPA) on magnetic resonance imaging (MRI) is incidentally encountered. We aimed to investigate the prevalence and morphology of T2HSPA and their relationship to age. METHODS: A total of 212 cases between 3 and 88 years old were examined. Sagittal T2-weighted image (T2WI) was evaluated for the presence of T2HSPA, which classified by its morphology into two types (belt-like or nodal). The Wilcoxon rank sum test and chi-square test were used to evaluate the differences between the groups. The T2HSPA was extracted by ImageJ software and measured as a cross-sectional area (CSA) quantitatively by threshold setting. We examined the relationship between CSA of T2HSPA and age, and Spearman's correlation coefficients were used for statistical analysis. RESULTS: Of the 212 cases, 80 (37.7%) were identified with T2HSPA. The groups with T2HSPA were significantly younger than the groups without it (p = .01). Groups with belt-like T2HSPA were significantly younger than the groups with nodal T2HSPA (p = .01). There was a weak negative correlation between CSA of T2HSPA and age (p = .02). CONCLUSION: T2HSPAs were incidentally detected in 37.7% of all cases, tended to be more common in younger cases, and their morphology was related to age. They seem to have little clinical significance as they tend to decrease in size with age.

The value of CT findings for prognostic prediction of spontaneous superior mesenteric artery dissection.

BACKGROUND: Spontaneous superior mesenteric artery (SMA) dissection is rare cause of acute abdomen. Time-dependent change of SMA dissection has not been established. PURPOSE: To determine Sakamoto classification (SC) type of acute and chronic SMA dissection (aSMAD and cSMAD) to predict the treatment methods and outcome. MATERIAL AND METHODS: From April 2003 to March 2017, unenhanced and contrast-enhanced CT were used to diagnose acute symptomatic or chronic asymptomatic SMA dissection in 25 consecutive patients without aortic dissection. Correlations between SCs and treatment methods and outcomes were investigated. RESULTS: All 13 patients with aSMAD initially received conservative treatment. Initial SCs in aSMAD were type I = 1, type III = 9, and type IV = 3. Three of nine initial type III and two of three initial type IV changed to type I at follow-up. One of nine type III changed to type II at follow-up. Ohers did not change. One with initial type III required vascular repair, so the final SC was not available. Three patients required bowel resection. In cSMAD of 12 patients, the initial/final SC were type I and IV in ten and two patients, respectively, without change during follow-up. cSMAD was significantly older than aSMAD. The initial length of dissection of aSMAD was longer than in the cSMAD group. In aSMAD, the final length of dissection was significantly shorter than in the initial computed tomography scan. CONCLUSION: Initial SC differed significantly between aSMAD and cSMAD. Initial SC types in aSMAD were type III and IV mainly, and changed during the observation period. In cSMAD, SC types were I and IV without change.

Whole brain analysis of postmortem density changes of grey and white matter on computed tomography by statistical parametric mapping.

OBJECTIVES: This study examined the usefulness of statistical parametric mapping (SPM) for investigating postmortem changes on brain computed tomography (CT). METHODS: This retrospective study included 128 patients (23 - 100 years old) without cerebral abnormalities who underwent unenhanced brain CT before and after death. The antemortem CT (AMCT) scans and postmortem CT (PMCT) scans were spatially normalized using our original brain CT template, and postmortem changes of CT values (in Hounsfield units; HU) were analysed by the SPM technique. RESULTS: Compared with AMCT scans, 58.6 % and 98.4 % of PMCT scans showed loss of the cerebral sulci and an unclear grey matter (GM)-white matter (WM) interface, respectively. SPM analysis revealed a significant decrease in cortical GM density within 70 min after death on PMCT scans, suggesting cytotoxic brain oedema. Furthermore, there was a significant increase in the density of the WM, lenticular nucleus and thalamus more than 120 min after death. CONCLUSIONS: The SPM technique demonstrated typical postmortem changes on brain CT scans, and revealed that the unclear GM-WM interface on early PMCT scans is caused by a rapid decrease in cortical GM density combined with a delayed increase in WM density. SPM may be useful for assessment of whole brain postmortem changes. KEY POINTS: • The original brain CT template achieved successful normalization of brain morphology. • Postmortem changes in the brain were independent of sex. • Cortical GM density decreased rapidly after death. • WM and deep GM densities increased following cortical GM density change. • SPM could be useful for assessment of whole brain postmortem changes.

Effect of the forward-projected model-based iterative reconstruction solution algorithm on image quality and radiation dose in pediatric cardiac computed tomography.

BACKGROUND: Some iterative reconstruction algorithms are useful for reducing the radiation dose in pediatric cardiac CT. A new iterative reconstruction algorithm (forward-projected model-based iterative reconstruction solution) has been developed, but its usefulness for radiation dose reduction in pediatric cardiac CT is unknown. OBJECTIVE: To investigate the effect of the new algorithm on CT image quality and on radiation dose in pediatric cardiac CT. MATERIALS AND METHODS: We obtained phantom data at six dose levels, as well as pediatric cardiac CT data, and reconstructed CT images using filtered back projection, adaptive iterative dose reduction 3-D (AIDR 3-D) and the new algorithm. We evaluated phantom image quality using physical assessment. Four radiologists performed visual evaluation of cardiac CT image quality. RESULTS: In the phantom study, the new algorithm effectively suppressed noise in the low-dose range and moderately generated modulation transfer function, yielding a higher signal-to-noise ratio compared with filtered back projection or AIDR 3-D. When clinical cardiac CT was performed, images obtained by the new method had less perceived image noise and better tissue contrast at similar resolution compared with AIDR 3-D images. CONCLUSION: The new algorithm reduced image noise at moderate resolution in low-dose CT scans and improved the perceived quality of cardiac CT images to some extent. This new algorithm might be superior to AIDR 3-D for radiation dose reduction in pediatric cardiac CT.

Delayed gadolinium-enhanced MRI of cartilage and T2 mapping for evaluation of reparative cartilage-like tissue after autologous chondrocyte implantation associated with Atelocollagen-based scaffold in the knee.

OBJECTIVE: To elucidate the quality of tissue-engineered cartilage after an autologous chondrocyte implantation (ACI) technique with Atelocollagen gel as a scaffold in the knee in the short- to midterm postoperatively, we assessed delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) and T2 mapping and clarified the relationship between T1 and T2 values and clinical results. MATERIALS AND METHODS: In this cross-sectional study, T1 and T2 mapping were performed on 11 knees of 8 patients (mean age at ACI, 37.2 years) with a 3.0-T MRI scanner. T1implant and T2implant values were compared with those of the control cartilage region (T1control and T2control). Lysholm scores were also assessed for clinical evaluation. The relationships between the T1 and T2 values and the clinical Lysholm score were also assessed. RESULTS: There were no significant differences in the T1 values between the T1implant (386.64 ± 101.78 ms) and T1control (375.82 ± 62.89 ms) at the final follow-up. The implants showed significantly longer T2 values compared to the control cartilage (53.83 ± 13.89 vs. 38.21 ± 4.43 ms). The postoperative Lysholm scores were significantly higher than the preoperative scores. A significant correlation was observed between T1implant and clinical outcomes, but not between T2implant and clinical outcomes. CONCLUSION: Third-generation ACI implants might have obtained an almost equivalent glycosaminoglycan concentration compared to the normal cartilage, but they had lower collagen density at least 3 years after transplantation. The T1implant value, but not the T2 value, might be a predictor of clinical outcome after ACI.

Evaluation of the Effect of Attenuation Correction by External CT in a Semiconductor SPECT.

The discovery of NM530c with a cadmium-zinc-telluride detector (CdZnTe-SPECT) is superior to the conventional Anger-type SPECT with a sodium-iodide detector (NaI-SPECT) in terms of sensitivity and spatial resolution. However, in the clinical example, even in CdZnTe-SPECT, a count decrease in myocardium due to the attenuation of the gamma ray is an issue. This study was conducted to evaluate the effect of computed tomography attenuation correction (CTAC) in CdZnTe-SPECT with the help of external CT. We evaluated the revision effect of uniformity, influence by the difference in attenuation distance, contrast ratio, an uptake rate using the heart phantom. As a result of the phantom studies, a good revision effect was obtained. In the clinical study, there was a statistical significant difference between the contrast ratio before and after CTAC in the inferior wall. In addition, the contrast ratio before and after CTAC in CdZnTe-SPECT image was equal to those of NaI-SPECT image. It was suggested that CTAC using external CT in CdZnTe-SPECT was clinically useful for inferior wall.

Evaluation of Resolution Recovery for Each Collimator in Brain Perfusion Image.

PURPOSE: This study aimed to verify the resolution recovery for each collimator in the brain perfusion image. METHOD: To verify the effect of the resolution recovery for each collimator, we evaluated via the three-dimensional brain phantom (phantom) and the normal brain perfusion single photon emission computed tomography (SPECT) data. These data were reconstructed using the three-dimensional ordered subset expectation maximization method (3D-OSEM) (Evolution for boneTM) that was performed with scatter correction, attenuation correction, and resolution recovery (RR). The performance of resolution recovery was evaluated in the two collimator systems (ELEGP and MEGP) reconstruction condition via the contrast value, mean counts, normalized mean square error (NMSE), and regional brain activity. RESULT: In the "with resolution recovery (+RR)", the NMSE indicated minimum value with SI (subset×iteration) = 100, cut-off frequency (Fc) = 0.50 cycles/cm. The contrast value in the "+RR" increased 20% for the cortical region and decreased 28% and 6% at ELEGP collimator and MEGP collimator for the central region, as compared to the "without resolution recovery (-RR)". In the phantom study, the error of the brain activity using MEGP collimator at the temporal lobe and sub-lobar decreased 15%, compared with ELEGP collimator in the + RR. In the clinical study, the error of the regional brain activity using MEGP collimator in the "+RR" increased from 3% to 8%, compared with "-RR". DISCUSSION: The accurate resolution recovery was obtained at SI = 100 and Fc = 0.50 cycles/cm. The contrast value and regional brain activity at the central region decreased due to incomplete resolution recovery by use of ELEGP collimator.

Comparison of utility of tumor size and apparent diffusion coefficient for differentiation of low- and high-grade clear-cell renal cell carcinoma.

BACKGROUND: There is a significant correlation between tumor size and tumor grade for clear-cell renal cell carcinoma (RCC) in pathology. Thus, apparent diffusion coefficient (ADC) of clear-cell RCC might be influenced by tumor size. PURPOSE: To compare the utility of tumor size and ADC for distinguishing low-grade from high-grade clear-cell RCC. MATERIAL AND METHODS: Forty-nine patients undergoing preoperative magnetic resonance imaging were retrospectively assessed. ADC values were calculated using b-value combinations of 0 and 800 s/mm(2) at 1.5 T. Two radiologists in consensus measured ADC values via small region of interest (ROI) (mean ROI area, 88.8 mm(2); range, 80-108 mm(2)) placement on an area of solid tumor on a single slice. Maximum tumor diameter was measured at the maximum tumor area. A single pathologist reviewed all pathological slides to determine the nuclear grade according to the Fuhrman classification. The utility of ADC, tumor size, and ADC/size ratio for distinguishing low-grade from high-grade tumors was assessed. Receiver-operating characteristic (ROC) analysis and regression analysis of the each index were performed. The correlation between ADC and tumor size was also investigated. RESULTS: The 49 clear-cell RCC included 34 low-grade and 15 high-grade tumors. The differences of ADC, tumor size, and ADC/size ratio between high-grade and low-grade tumors were statistically significant (P <0.05). The area under the ROC curve of ADC, tumor size, and ADC/size ratio were 0.802, 0.763, and 0.804 respectively. However, using regression analysis, only ADC (P <0.05) was statistically significant index as independent risk factors for high-grade clear-cell RCC. Moreover, weak significant correlation was observed between tumor size and ADC (R(2) = 0.3865, P <0.01). CONCLUSION: There was a weak significant correlation between tumor size and ADC value of clear-cell RCC. Using ROC and regression analysis, ADC was statistically significant index for distinguishing low-grade from high-grade clear-cell RCC more than tumor size and ADC/size ratio.

Short treatment time and excellent treatment outcome in accelerated hyperfractionated radiotherapy for T1 glottic cancer.

Accelerated hyperfractionated radiotherapy was performed as treatment for patients with T1 glottic cancer, and its utility was evaluated based on treatment outcomes and adverse effects. Fifty-eight men who had undergone radiotherapy were retrospectively reviewed. Tumor classification was Tis in 4 patients, T1a in 38, and T1b in 16. Histological examination revealed squamous cell carcinoma in 55 patients. Travel time from home to hospital was 0-1 hour for 24 patients, 1-2 hours for 9, and >2 hours for 25. Laser vaporization was performed prior to radiotherapy in 38 patients, and 19 patients received concurrent chemotherapy with an agent such as S-1. Patients were irradiated twice daily using an irradiation container. Most patients received a dose of 1.5 Gy/fraction up to a total of 60 Gy. The median overall treatment time was 30 days, with a median observation period of 59.6 months. A complete response was observed in all patients. The 5-year overall survival, disease-free survival, and local control rates were 97.2%, 93.2%, and 97.8%, respectively. Although grade 3 pharyngeal mucositis was observed in 2 patients, there were no other grade 3 or higher acute adverse events. As late toxicity, grade 2 laryngeal edema and grade 1 laryngeal hemorrhage were observed in 1 patient each, but no serious events such as laryngeal necrosis or laryngeal stenosis were observed. In conclusion, this treatment method brings excellent outcome and will substantially reduce the treatment duration among patients who need to stay at nearby hotels while undergoing treatment at hospitals in rural areas.

Usefulness of direct-conversion flat-panel detector system as a quality assurance tool for high-dose-rate 192Ir source.

The routine quality assurance (QA) procedure for a high-dose-rate (HDR) 192Ir radioactive source is an important task to provide appropriate brachytherapy. Traditionally, it has been difficult to obtain good quality images using the 192Ir source due to irradiation from the high-energy gamma rays. However, a direct-conversion flat-panel detector (d-FPD) has made it possible to confirm the localization and configuration of the 192Ir source. The purpose of the present study was to evaluate positional and temporal accuracy of the 192Ir source using a d-FPD system, and the usefulness of d-FPD as a QA tool. As a weekly verification of source positional accuracy test, we obtained 192Ir core imaging by single-shot radiography for three different positions (1300/1400/1500 mm) of a check ruler. To acquire images for measurement of the 192Ir source movement distance with varying interval steps (2.5/5.0/10.0 mm) and temporal accuracy, we used the high-speed image acquisition technique and digital subtraction. For accuracy of the 192Ir source dwell time, sequential images were obtained using various dwell times ranging from 0.5 to 30.0 sec, and the acquired number of image frames was assessed. Analysis of the data was performed using the measurement analysis function of the d-FPD system. Although there were slight weekly variations in source positional accuracy, the measured positional errors were less than 1.0 mm. For source temporal accuracy, the temporal errors were less than 1.0%, and the correlation between acquired frames and programmed time showed excellent linearity (R2 = 1). All 192Ir core images were acquired clearly without image halation, and the data were obtained quantitatively. All data were successfully stored in the picture archiving and communication system (PACS) for time-series analysis. The d-FPD is considered useful as the QA tool for the 192Ir source.

[Comparison of Quantitative Value of Dopamine Transporter Scintigraphy Calculated from Different Analytical Software].

In the dopamine transporter scintigraphy there are two quantitative analysis softwares, DaTView and DaTQUANT. The quantitative value of both software has to be treated independently because there is a difference between them in the point of how to set the region of interest on the striatum and the background, calculation formula of quantitation. And also DaTQUANT has a capability of performing anatomical standardization which DaTView does not have. The aim of this study was to evaluate the accuracy of registration on DaTQUANT using a phantom, and to evaluate the correlation between the quantitative values between DaTView and DaTQUANT using clinical data. As a result, the accuracy of registration was acceptable. Regardless of the degree of accumulation in the striatum, there was a high correlation to each analysis software (r>0.85).

Feasible and technical aspects of transcatheter arterial chemoembolization for non-resectable hepatocellular carcinoma using a 3.5-French catheter system.

PURPOSE: To evaluate the feasibility and technical aspects of transcatheter arterial chemoembolization (TACE) for non-resectable hepatocellular carcinoma (HCC) using a 3.5-French (Fr) catheter system. METHODS: This study included 328 consecutive cases of HCC among 232 patients who underwent TACE procedures using both a 3.5-Fr catheter system and a microcatheter fitted to a 3.5-Fr system between April 2009 and November 2011. We assessed the ability to reach the catheter into the proper hepatic artery (PHA), main hepatic branch, segmental artery, and subsegmental or sub-subsegmental artery. The feasibility was rated according to the following factors: (1) the number of arteries that could be used to reach the target artery/total number of procedures using the 3.5-Fr system, (2) the rate of successful completion of the procedures without changing over to the 4-Fr system and (3) the reasons for changing over the 4-Fr system. RESULTS: TACE of the PHA (27 sessions), RHA/LHA (103 sessions), segmental (31 sessions), or subsegmental/sub-subsegmental arteries (162 sessions) was performed. The rate of successfully reaching the target artery using the 3.5-Fr system was 93% (306/328 sessions). We were unable to reach the target artery in 22 sessions, including 11/8/3 procedures targeting the sub-subsegmental artery, subsegmental artery, and RHA/LHA, respectively. We changed over to the 4-Fr system in six sessions; therefore, the rate of successful completion of the procedures without changing over to the 4-Fr system was 98% (322/328 sessions). CONCLUSIONS: TACE of the target artery can be successfully performed using the 3.5-Fr system in most patients with HCC.

Continuous imaging of esophagogastric junction in patients with reflux esophagitis using 320-row area detector CT: a feasibility study.

BACKGROUND AND AIM: The function of the lower esophageal sphincter (LES) is evaluated using an esophageal manometric study. However, information regarding the surrounding organs is difficult to obtain with use of a sensor catheter. We investigated the utility of 320-row area detector computed tomography (CT) to evaluate morphological changes of the esophagogastric junction and surrounding organs. METHODS: The study subjects were 18 healthy volunteers and 29 patients with reflux esophagitis (RE). Immediately after swallowing a diluted contrast agent, continuous imaging of the esophagogastric junctional area was performed for 15 s. Using CT images, the presence or absence of esophageal hiatal hernia, His angle before and after swallowing, size of the diaphragmatic hiatus, morphologically identified-LES (MI-LES) length, intraluminal horizontal area of MI-LES during relaxation phase, MI-LES thickness, abdominal esophagus length, subcutaneous fat area, visceral fat area, and esophagogastric junction fat area were evaluated. RESULTS: Analysis of CT images showed more frequent occurrence of hiatal hernia, greater His angle, and a larger diaphragmatic hiatus in patients with severe RE, while the lengths of MI-LES and abdominal esophagus were shorter in those patients. Visceral and esophagogastric junction fat areas tended to be greater in patients with RE. In all subjects, the posterior wall of the MI-LES was thicker than the anterior wall. CONCLUSION: Continuous imaging with 320-row area detector CT is useful to evaluate morphological changes in the esophagogastric junction area in both normal individuals and patients with reflux esophagitis.

Liver regeneration after portal vein embolization: comparison between absolute ethanol and N-butyl-cyanoacrylate in an in vivo rat model.

PURPOSE: To compare the effects of absolute ethanol (ethanol) and N-butyl-cyanoacrylate (NBCA) on non-embolized liver lobe regeneration in a rat model. METHODS: Twenty-seven Sprague-Dawley rats underwent portal vein embolization (PVE) using ethanol:lipiodol, 1:1 (ethanol group, n = 11, 40.74%), NBCA:lipiodol, 1:1 (NBCA group, n = 11, 40.74%), or sham treatment (sham group, n = 5, 18.52%). The non-embolized and embolized lobe-to-whole liver weight ratios 14 days after PVE were compared among the groups (n = 5, 18.52%). The expressions of CD68 and Ki-67 and embolized-lobe necrotic area percentages one day after PVE were compared between the ethanol (n = 3, 11.11%) and NBCA (n = 3, 11.11%) groups. RESULTS: The non-embolized lobe-to-whole liver weight ratio after PVE was significantly higher in the NBCA group (n = 5, 33.33%) than in the ethanol group (n = 5, 33.33%) (84.28% ± 1.53% vs. 76.88% ± 4.12%, P = 0.029). The embolized lobe-to-whole liver weight ratio after PVE was significantly lower in the NBCA group than in the ethanol group (15.72% ± 1.53% vs. 23.12% ± 4.12%, P = 0.029). The proportions of CD68- and Ki-67-positive cells in the non-embolized lobe after PVE were significantly higher in the NBCA group (n = 30, 50%) than in the ethanol group (n = 30, 50%) [60 (48-79) vs. 55 (37-70), P = 0.003; 1 (0-2) vs. 1 (0-2), P = 0.004]. The embolized-lobe necrotic area percentage after PVE was significantly larger in the NBCA group (n = 30, 50%) than in the ethanol group (n = 30, 50%) [29.46 (12.56-83.90%) vs. 16.34 (3.22-32.0%), P < 0.001]. CONCLUSION: PVE with NBCA induced a larger necrotic area in the embolized lobe and promoted greater non-embolized liver lobe regeneration compared with PVE with ethanol.

Prediction of survival benefit using an automated bone scan index in patients with castration-resistant prostate cancer.

UNLABELLED: What's known on the subject? and What does the study add? A bone scan index (BSI) can quantify the extent of bone involvement and response to treatment, but it has not been widely accepted, because of its time-consuming nature. The study is the first to demonstrate that automated BSI calculated with a computer-assisted diagnosis system is effective in judging the chemotherapeutic response of bone metastatic lesions in patients with castration-resistant prostate cancer. OBJECTIVE: • To evaluate the value of an automated bone scan index (aBSI), calculated using a computer-assisted diagnosis system, to indicate chemotherapy response and to predict prognosis in patients with castration-resistant prostate cancer (CRPC) with bone metastasis. PATIENTS AND METHODS: • Forty-two consecutive CRPC patients underwent taxane-based chemotherapy between November 2004 and March 2011 at our institution. • The aBSIs were retrospectively calculated at the diagnosis of CRPC and 16 weeks after starting chemotherapy. • Cox proportional hazards regression models were applied to multivariate analyses with and without aBSI response in addition to the basic model. • Based on the difference in the concordance index (c-index) between each model, the prognostic relevance of adding the aBSI response was determined. RESULTS: • A decrease in aBSI was found in 28 patients (66.7%), whereas a response was shown by bone scan in only 23.8% of patients. • Patients with a reduction in aBSI had longer overall survival (OS) in comparison with the other patients (P= 0.0157). • Multivariate analysis without aBSI response showed that performance status (P= 0.0182) and PSA response (P= 0.0375) were significant prognosticators. • By adding the aBSI response to this basic model, the prognostic relevance of the model was improved with an increase in the c-index from 0.621 to 0.660. CONCLUSIONS: • The aBSI reflected the chemotherapy response in bone metastasis. • The index detected small changes of bone metastasis response as quantified values and was a strong prognostic indicator for patients with CRPC.

Design of hemispherical radio frequency (RF) capacitive-type electrode free of edge effects for treatment of intracavitary tumors.

A new hemispherical electrode to heat oral cavity cancer is proposed. The electrode does not produce a hot spot around its edge, a feature that usually arises when using radio frequency (RF) capacitive-type heating. The hemispherical electrode was designed by computer simulation using a 3-D finite element method. To assess its practicality and effectiveness, we built a prototype hemispherical electrode and evaluated its heating characteristics by phantom experiments. The heating effects on the phantom were measured by thermography. The concave phantom surface in contact with the hemispherical electrode showed a uniform increase in temperature, with no obvious edge effect. The proposed electrode allows non-invasive RF capacitive-type heating for intracavity tumors that was not previously considered possible, and should contribute to the multidisciplinary treatment of intracavity tumors.

Pseudohemothorax induced by residual contrast medium mimicking aortic dissection rupture.

Hemothorax is an urgent condition, and its accurate diagnosis and the identification of the cause are important. Herein, we report a case of a 74-year-old man with end-stage renal disease who was presented with high-concentration pleural effusion owing to residual contrast medium. The case required differentiation from hemothorax owing to an aortic dissection and its rupture. In patients with end-stage renal disease, noncontrast-enhanced computed tomography after contrast-enhanced computed tomography may result in high-concentration pleural effusion owing to the existence of residual contrast medium. This realization is important to determine whether high-concentration pleural effusion symptoms reflect an urgent hemothorax case possibly related to an imminent rupture of an aortic aneurysm or intrathoracic penetration of aortic dissection, and whether invasive procedures, such as thoracentesis, ought to be avoided.

Clinicoradiological Characteristics of Gastric Metastases: A Single Center Retrospective Study.

BACKGROUND:  With recent advances in treatment, gastric metastases are increasingly becoming the subject of diagnostic imaging. On the other hand, it is difficult to detect gastric metastasis on CT finding images. PURPOSE:  To characterize the CT findings of gastric metastasis and investigate its treatment method and natural history in patients. MATERIALS AND METHODS:  We retrospectively reviewed the CT findings of 15 patients diagnosed with gastric metastasis between April 2003 and December 2019 in our hospital. The location, size, and shape of the tumors on CT were evaluated. Moreover, their medical records, characteristics, complications, treatment options, and natural course were evaluated. RESULTS:  Of the 15 patients with gastric metastasis, 9 were male and 6 were female. The median age was 74 (55-87) years. Gastric metastasis was diagnosed simultaneously with primary cancer in five patients. In other patients, the median interval time from the date of primary cancer diagnosis to gastric metastasis diagnosis was 27 (10-259) months. CT findings revealed that the gastric metastasis had a median size of 18 (12-135) mm and was mainly located in the middle third of the stomach. In addition, most patients had a submucosal tumor (SMT) pattern, followed by diffuse wall thickness and polypoid patterns (11 [73.3%], 3 [20.0%], and 1 [6.7%], respectively). The median time to death after gastric metastasis diagnosis was 112 (17-883) days. CONCLUSION:  The SMT pattern in the middle third of the stomach is the characteristic CT finding of gastric metastasis.