Exploration of tumor size measurement methods in preoperative breast cancer assessment using whole-body silicon photomultiplier PET: feasibility and first results.

PURPOSE: Whole-body silicon photomultiplier positron emission tomography (WB SiPM PET) could be used to diagnose breast cancer spread before lumpectomy. We aimed to investigate the method of measuring the tumor size by WB SiPM PET as a basis for diagnosing breast cancer spread in the breast. MATERIALS AND METHODS: We retrospectively reviewed 35 breast cancer lesions in 32 patients who underwent WB SiPM PET/CT in the prone position as preoperative breast cancer examinations from September 2020 to March 2022. In all cases, a 20-mm spherical VOI was placed in the normal mammary gland to measure the mean standardised uptake value (SUVmean) and the standard deviation (SD) of 18F-fluorodeoxyglucose (FDG) uptake. We prepared four types of candidates (SUVmean + 2 SD, SUVmean + 3 SD, 1.5 SUVmean + 2 SD, 1.5 SUVmean + 3 SD) for thresholds for delineating tumor contours on PET images. On the semiautomatic viewer soft, the maximum tumor sizes were measured at each of the four thresholds and compared with the pathological tumor sizes, including the extensive intraductal component (EIC). RESULTS: The lesion detection sensitivity was 97% for WB SiPM PET. PET detected 34 lesions, excluding 4-mm ductal carcinomas in situ (DCIS). PET measurements at the '1.5 SUVmean + 2 SD' threshold demonstrated values closest to the pathological tumor sizes, including EIC. Moreover, '1.5 SUVmean + 2 SD' had the highest concordance (63%). CONCLUSIONS: The study demonstrated that among various PET thresholds, the '1.5 SUVmean + 2 SD' threshold exhibited the best performance. However, even with this threshold, the concordance rate was limited to only 63%.

Acute abdomen by red degeneration of a parasitic leiomyoma: A case report and literature review.

A 43-year-old woman, with a history of uterine fibroids and multiple myomectomy, presented with acute lower abdominal pain. Computed tomography revealed multiple tumors, including a high-density mass in the left lower abdomen indicative of a parasitic leiomyoma undergoing red degeneration. This uncommon condition is due to acute occlusion, often caused by peripheral venous thrombosis at the fibroid edge. The diagnosis was corroborated by distinctive findings on magnetic resonance imaging and computed tomography. Notably, high signal intensity on T1-weighted images (T1WI) suggested methemoglobin presence due to hemorrhagic infarction, whereas low signal intensity on T2-weighted images (T2WI) indicated deoxyhemoglobin. Symptom improvement followed treatment with analgesics. This case underscores the significance of considering parasitic myomas in the differential diagnosis of intraperitoneal tumors after myomectomy and proposes that vascular torsion from mechanical stress on the mobile mesentery may contribute to red degeneration in such tumors. In this report, we detail the imaging characteristics and clinical progression of red degeneration in a parasitic leiomyoma, emphasizing the importance of this diagnosis in patients with a history of uterine surgery.

Radiological Features of T1a Renal Cell Carcinoma on Axial Unenhanced Computed Tomography.

CT has become a commonly used diagnostic procedure in clinical practice, particularly in emergency healthcare delivery. Accordingly, the increase in CT usage has increased the likelihood of incidental detections (ID) of renal cell carcinomas (RCCs). This article discusses key points and limitations associated with the diagnosis and characterization of T1a RCC (≤4 cm in diameter) and shows how to improvise on the differentiation of T1a RCC with unenhanced CT (UE-CT). We retrospectively reviewed UE-CT findings of cases associated with the histopathologic diagnosis of T1a RCC and examined the discrimination capacity and radiological characteristics with regard to small RCCs (SRCCs). Detection and characterization of T1a RCC based on UE-CT are not easy in many cases due to limitations in CT findings, but there are notable radiological features to facilitate detection and differentiation. The growth pattern is important for the detection of SRCCs. Internal characteristic features (average attenuation, heterogeneity) are useful for the characterization of the RCC. In addition, CT image visualization techniques may help improve the detectability of RCCs on UE-CT. Radiological features are important in detecting SRCCs and facilitating further examination. In this study, we discuss some cases of T1a RCCs and evaluate the radiological characteristics of the tumors seen on UE-CT.

A case of breast cancer: Suppression of lactation-related FDG uptake 2 days after cabergoline administration.

We present a case of a 35-year-old woman with breast cancer in lactation 3 months after childbirth, in which a lactation inhibitor was useful for 18F-FDG PET/CT examination. Via ultrasonography and biopsy with histopathology, we diagnosed the lesion in the upper region of the left breast as invasive ductal carcinoma. She stopped breastfeeding and was administered cabergoline to suppress lactation. Two days after the administration, 18F-FDG PET/CT revealed segmental uptake (10 cm in diameter) and no lactation-related uptakes. Dynamic MRI also revealed a segmental enhancement of the same size as 18F-FDG PET/CT. The lactation inhibitor was useful to delineate the extent of the lesion during the 18F-FDG PET/CT examination.

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.

Inverted intercostal hernia of elastofibroma dorsi mimicking well-differentiated liposarcoma in the chest wall.

Elastofibroma dorsi is a well-known benign chest wall tumor. Herein, we present a case in which an elastofibroma protruded into the thoracic cavity, leading to inverted intercostal hernia. Imaging revealed a soft tissue mass containing fat, typical of elastofibroma dorsi; however, precise diagnosis was difficult owing to the location of this mass that protruded into the thoracic cavity. Liposarcoma had to be ruled out because it was a growing fat-containing mass. Considering that the tumor moved while the patient was undergoing computed tomography-guided biopsy in the prone position, a diagnosis of inverted intercostal hernia of elastofibroma dorsi was made. We report this case with a review of current literature.

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.

Osteoid osteoma of the rib with strong F-18 fluoro-deoxyglucose uptake mimicking osteoblastoma: a case report with literature review.

Osteoid osteoma is a benign osteoblastic bone lesion, characterized by nocturnal pain alleviated by salicylates or nonsteroidal anti-inflammatory drugs. This tumor distinctly affects the long bones, typically the femur or tibia and is rarely located in the ribs. Usually, this tumor is usually diagnosed by computed tomography or magnetic resonance imaging, but F-18 fluoro-deoxyglucose positron emission tomographic (FDG-PET)/computed tomography is usually negative and is not used for diagnosis. We recently encountered a case of an osteoid osteoma located in the rib of 44-year-old Asian male with strong FDG uptake as high as 12.0 at the maximum standardized uptake value at FDG-PET/computed tomography. His computed tomography and magnetic resonance imaging showed osteosclerosis, bone marrow edema, and edema of surrounding tissues not only in the bone with nidus but also in the adjacent bone, and pathological findings showed strong infiltration munched radiology. Strong FDG uptake mimicking osteoblastoma. Osteoid osteoma with strong FDG uptake suggested a strong inflammatory response.

Coil volume embolization ratio for preventing recanalization after portal vein embolization.

PURPOSE: The purpose of this study was to evaluate the optimum volume embolization ratio (VER) for the prevention of recanalization after portal vein embolization (PVE) and the influence of recanalization on future liver remnant (FLR) function using technetium-99m galactosyl human serum albumin single-photon emission computed tomography (99mTc-GSA SPECT/CT) fusion imaging. METHODS: We analyzed procedural data of 18 patients who underwent PVE from 2015 to 2018. A total of 29 portal branches were embolized (12 anterior branch, 11 posterior branch, 4 left branch, 2 right branch) with absolute ethanol and coils. Portal vein recanalization was evaluated three weeks after PVE by contrast-enhanced CT. We classified the treated portal branches as non-recanalized and recanalized. VER was compared between the groups. In addition, for each patient, we calculated and evaluated the ratio of FLR volume to total liver volume (volumetric %FLR), FLR count to total liver count on 99mTc-GSA SPECT/CT fusion imaging (functional %FLR), and functional-volumetric ratio (functional %FLR/ volumetric %FLR). RESULTS: Twenty-six portal branches showed no recanalization (non-recanalized group, n=26, 89.7%), while three portal branches showed recanalization (recanalized group, n=3, 10.3%). The median VER was 4.94% (3.12%-11.1%) in the non-recanalized group and 3.49% (2.76%-4.32%) in the recanalized group, which was significantly different between the groups (p = 0.045, Mann-Whitney U test). The median functional-volumetric ratio was 1.16 (1.03-1.50) in non-recanalized patients (n=15, 83.3%) and 1.01 (0.96-1.13) in recanalized patients (n=3, 16.7%), and it was significantly higher in the non-recanalized patients (p = 0.021, Mann-Whitney U test). CONCLUSION: The VER for preventing recanalization after PVE was approximately 5% (> 4.94%). 99mTc-GSA SPECT/CT fusion imaging revealed a decrease in FLR function due to recanalization after PVE.

Comparison between turbo spin-echo and echo planar diffusion-weighted imaging of the female pelvis with 3T MRI.

BACKGROUND: Echo-planar imaging (EPI)-diffusion-weighted imaging (DWI) may take unclear image affected by susceptibility, geometric distortions and chemical shift artifacts. PURPOSE: To compare the image quality and usefulness of EPI-DWI and turbo spin echo (TSE)-DWI in female patients who required imaging of the pelvis. MATERIAL AND METHODS: All 57 patients were examined with a 3.0-T MR scanner. Both TSE- and EPI-DWI were performed with b values of 0 and 1000 s/mm2. We compared geometric distortion, the contrast ratio (CR) of the myometrium to the muscle and the apparent diffusion coefficient (ADC) values for the myometrium and lesion. Two radiologists scored the TSE- and EPI-DWI of each patient for qualitative evaluation. RESULTS: The mean percent distortion was significantly smaller with TSE- than EPI-DWI (p = 0.00). The CR was significantly higher with TSE- than EPI-DWI (p = 0.003). There was a significant difference in the ADC value for the uterus and lesions between the EPI- and TSE-DWI (p < 0.05). Finally, the ADC values of cancer were significantly different from those for the uterus and benign with both the two sequences (p < 0.05). The scores for ghosting artifacts were higher with TSE- than EPI-DWI (p = 0.019). But there were no significant differences between TSE- and EPI-DWI with regard to image contrast and overall image quality. CONCLUSION: TSE-DWI on the female pelvis by 3T MRI produces less distortion and higher CR than EPI-DWI, but there is no difference in contrast and image quality.

CT-guided color marking of impalpable pulmonary nodules prior to video-assisted thoracoscopic surgery.

OBJECTIVES: To investigate the utility and complications of computed tomography (CT)-guided color marking of impalpable pulmonary nodules for video-assisted thoracoscopic surgical resection. METHODS: This retrospective single institutional study has obtained Institutional Review Board approval. A total of 174 patients with 207 undiagnosed peripheral lesions of the lung were enrolled who had undergone preoperative computed tomography-guided color marking using colored collagen followed by video-assisted thoracoscopic surgery (VATS) from December 2015 to September 2018. RESULTS: All nodules (mean 14.0 mm, range 3.0-30.0 mm) were successfully marked by computed tomography-guided color marking, and 96.0% cases (167/174) were localized by means of intraoperative fluoroscopy as clear spots. Minor pneumothorax with a median volume of 3.8 mL (range 0.2-119.0 mL) occurred in 12 patients (6.9%) who were completely asymptomatic and were not in serious condition. No patient required a chest tube. No major bleeding complication occurred, and no air emboli were seen. No intra- or post-operative mortality of VATS was observed. CONCLUSIONS: Preoperative CT-guided color marking of impalpable pulmonary nodules is a safe and effective procedure that allows for successful surgical resection.

Diagnosis of a small Leydig cell tumor by dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging.

Leydig cell tumors are usually small and resemble normal ovarian stroma, so they are often difficult to localize. Here, we present a rare case in 39-year-old woman which dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging findings showed some differences between a Leydig cell tumor and normal ovarian stroma. Combining these 2 MRI techniques may be useful for diagnosing a Leydig cell tumor.

Gossypiboma penetrating into the small intestine similar to Meckel's diverticulum: a report and literature review.

Foreign body granuloma due to retained surgical sponge (gossypiboma) with penetration into the small intestine is very rare. Cases of gossypiboma in the abdominal cavity have sometimes been reported, yet the correct incidence has not been determined, only estimated to occur in one of every 1,000 to 1,500 intra-abdominal operations. Acute abdomen may be observed in some cases, requiring treatment. We herein introduce the case of a 70-year-old woman with gossypiboma penetrating into the small intestine presented with anemia and hematochezia. She had a history of emergency laparotomy for ectopic pregnancy several decades ago. A dynamic contrast-enhanced computed tomography revealed a hypovascular mass containing air bubbles that continued to the small intestine approximately 50 mm in size in the right lower abdomen. In addition to describing the presentation and outcome of our patient, we review the image findings of gossypiboma.

Dynamic CT findings of a polypoid gastric metastasis of clear renal cell carcinoma: a case report with literature review.

Metastatic disease involving the stomach is very rare. The gastric metastases of renal cell carcinoma (RCC) have rarely been reported, occurring in 0.2% of all RCC cases. Sometimes gastric metastases cause gastrointestinal bleeding and require treatment. We present the case of an 85-year-old woman with gastric metastasis from RCC diagnosed by anemia and bleeding. A dynamic contrast-enhanced computed tomography revealed a pedunculated and hypervascular polypoid mass approximately 100 mm in size with a washout enhancement pattern in the stomach. In addition to describing the case of our patient, we have reviewed computed tomography findings of gastric metastases from clear RCC.

Pulmonary Actinomycosis Mimicking Pulmonary Cancer on Fluorine-18 Fluorodeoxyglucose PET-CT.

Pulmonary actinomycosis is a rare disease frequently misdiagnosed as primary lung cancer. Herein, we presented pulmonary actinomycosis mimicking pulmonary cancer on fluorine-18 fluorodeoxyglucose (F-18-FDG) PET-CT.

T1a renal cell carcinoma on unenhanced CT: analysis of detectability and imaging features.

BACKGROUND: Increasing use of unenhanced computed tomography (CT) has been associated with the increasing incidental detection of renal cell carcinoma (RCC) at an earlier stage. PURPOSE: To evaluate the characteristics in detecting and differentiating T1a RCCs on unenhanced CT. MATERIAL AND METHODS: We retrospectively reviewed 68 patients with 68 T1a RCCs and 39 benign regions. Two radiologists interpreted the images on unenhanced axial CT and performed a blinded and independent review of T1a RCCs. The readers evaluated the presence of RCC and differentiated the detected lesions. RESULTS: The consensus of two readers detected 53 (78%) RCCs. Of the 53 detected RCCs, 42 (62%) RCCs were correctly diagnosed and 11 (16%) masses were misdiagnosed as benign. Of the 39 benign regions, 29 (74%) cysts were diagnosed correctly, but 10 (26%) cysts were misdiagnosed as malignant. The following values of the radiologists were obtained by consensus: sensitivity = 61.8% (42/68); specificity = 74.4% (29/39); positive predictive value = 80.8% (42/52); negative predictive value = 55.0% (29/55); accuracy = 66.4% (71/107). The receiver operating characteristic curve of consensus was 0.754. Inter-observer correlation was κ = 0.849. There was a significant difference in tumor size (P = 0.019) and the contour type of tumor (P = 0.0207) between correctly diagnosed RCCs and not correctly diagnosed RCCs. CONCLUSION: Our findings showed that tumor size and contour type could affect the detection and differentiation of T1a RCC on unenhanced CT. To detect and differentiate T1a RCC on unenhanced CT is difficult. However, the findings from this study may help detection of RCCs on unenhanced CT.

Usefulness of digital breast tomosynthesis for non-calcified benign breast masses.

Digital breast tomosynthesis (DBT) is a new modality that assists in detection of breast cancer. However, benign masses are also detected more easily by DBT and may require further workup. This article reviews typical imaging features of non-calcified benign masses on DBT. We also discuss the management of these benign masses. Knowledge of the imaging features of benign masses on DBT is required to minimize unnecessary callbacks.

Concurrent Chemoradiotherapy with Docetaxel, Cisplatin, and 5-fluorouracil Improves Survival of Patients with Advanced Esophageal Cancer Compared with Conventional Concurrent Chemoradiotherapy with Cisplatin and 5-fluorouracil.

Purpose: To compare treatment outcomes and adverse events between concurrent chemoradiotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF-RT) and conventional concurrent chemoradiotherapy with cisplatin and 5-fluorouracil (CF-RT). Methods and Materials: We retrospectively investigated treatment outcomes and adverse events in 121 patients with advanced esophageal cancer who underwent concurrent chemoradiotherapy with CF-RT (n = 83) or DCF-RT (n = 38). In the CF-RT group, patients were administered cisplatin (70 mg/m2) and 5-fluorouracil (700 mg/m2) for 5 days; in the DCF-RT group, patients were administered docetaxel (50 mg/m2), cisplatin (50 mg/m2), and 5-fluorouracil (500 mg/m2) for 5 days. The radiotherapy dose was 1.8-2 Gy per session, up to a total of 50-60 Gy. Results: The complete response (CR) rate was 37.8% in the CF-RT group and 52.6% in the DCF-RT group. Overall survival (OS) rates at 2 and 3 years were 45.0% and 37.5%, respectively, in the CF-RT group and 62.9% and 56.7%, respectively, in the DCF-RT group, with a significant intergroup difference (p = 0.032). Progression-free survival rates at 2 and 3 years were 44.1% and 36.9%, respectively, in the CF-RT group and 45.0% and 45.0%, respectively, in the DCF-RT group (p = 0.10). Local control rates at 2 and 3 years were 59.1% and 54.6%, respectively, in the CF-RT group and 71.8% and 71.8%, respectively, in the DCF-RT group (p = 0.12). The incidence of Grade 3/4 leukopenia was 55.4% (n = 46) in the CF-RT group and 78.9% (n = 30) in the DCF-RT group, with a significant intergroup difference (p = 0.022). The incidence of Grade 3/4 neutropenia was 47.0% (n = 39) in the CF-RT group and 65.8% (n = 25) in the DCF-RT group, with a notable albeit not statistically significant difference between the groups (p = 0.054). There were no significant intergroup differences in anemia, thrombocytopenia, radiation-induced dermatitis, radiation esophagitis, or late adverse events. Conclusions: Rates of OS and CR were improved after treatment with DCF-RT compared with CF-RT. Although DCF-RT-treated patients had higher rates of leukopenia, treatment safety was ensured through proper management of myelotoxicity. DCF-RT is a promising treatment regimen for advanced esophageal cancer.

Future Liver Remnant Indocyanine Green Plasma Clearance Rate as a Predictor of Post-hepatectomy Liver Failure After Portal Vein Embolization.

PURPOSE: To evaluate the utility of future liver remnant plasma clearance rate of indocyanine green (ICGK-F) for predicting post-hepatectomy liver failure (PHLF) compared with percentage future liver remnant volume-to-total liver volume ratio (%FLR) after portal vein embolization (PVE). MATERIALS AND METHODS: PVE procedures in 20 patients (15 patients underwent PVE with absolute ethanol; 5 patients with gelatin particles) from 2010 to 2017 were analyzed. %FLR = future liver remnant volume (ml)/[total liver volume (ml) - tumor volume (ml)] × 100; ICGK-F = plasma clearance rate of indocyanine green (ICGK) × %FLR/100 were calculated before and after PVE. PHLF was categorized according to the criteria of the International Study Group of Liver Surgery. For predicting PHLF, we compared the ICGK-F and %FLR after PVE between the grade A PHLF group and the non-grade A PHLF (grades B and C) group. RESULTS: All PVE procedures were successful. While the ICGK-F of the grade A PHLF group (median 0.073, n = 16) was about twice that of the non-grade A PHLF group (median 0.043, n = 4), showing a significant difference (Mann-Whitney U test: P = 0.002), there was no significant difference in %FLR between the grade A PHLF group and the non-grade A PHLF group (Mann-Whitney U test: P = 0.335). CONCLUSION: ICGK-F was significantly higher in the grade A PHLF group than in the non-grade A PHLF group (grades B and C), and ICGK-F was more useful for predicting PHLF than %FLR.