Case of Isolated Absence of the Azygos Vein: Evaluation Using Photon-counting Detector CT.

The isolated absence of the azygos vein was incidentally found on computed tomography (CT) examination in a 60-year-old female. The exact anomaly can be evaluated on high-resolution images of 0.4-mm slice thickness with low keV using photon-counting detector CT. The azygos vein, including the azygos arch, was absent, and a mildly dilated hemiazygos vein flowed to the left brachiocephalic vein through the left superior intercostal vein. A hemiazygos vein connected the left renal vein at the level of the first lumbar vertebra. This patient was the second patient to undergo evaluation using volume rendering images. High-resolution maximum-intensity projection images were useful for assessing the anatomy. Radiation dose was decreased compared with that in conventional CT.

Evaluation of Incidental Findings on Abdominopelvic CT: Potential Benefit of Photon-counting Detector CT Over Conventional Single-energy CT.

PURPOSE: To assese of potential benefint of photon-counting detector CT (PCD-CT) over conventional single-energy CT (CSE-CT) on accurate diagnosis of incidental findings with high clinical significance (IFHCS). MATERIALS AND METHODS: This retrospective study included 365 patients who initially underwent abdominopelvic contrast-enhanced CT (AP-CECT) without non-enhancement (PCD-CT: 187 and CSE-CT: 178). We selected IFHCS and evaluated their diagnosability using CE-CT alone. IFHCSs that could not be diagnosed with only CE-CT were evaluated using additional PCD-CT postprocessing techniques, including virtual non-contrast image, low keV image, and iodine map. A PCD-CT scanner (NAEOTOM Alpha, Siemens Healthineer, Erlangen, Germany) was used. RESULTS: Thirty-nine IFHCSs (PCD-CT: 22 and CSE-CT: 17) were determined in this study. Seven IFHCSs in each group were able to diagnose with only CE-CT. Fifteen IFHCSs were able to diagnose using the additional PCD-CT postprocessing technique, which was useful for detecting and accurately diagnosing 68.2% (15/22) of lesions and 65% (13/20) of patients. All IFHCSs were accurately diagonosed with PCD-CT. CONCLUSION: PCD-CT was useful for characterizing IFHCSs that are indeterminate at CSE-CT. PCD-CT offered potential benefit of PCD-CT over conventional single-energy CT on evaluation of IFHCS on only abdominopelvic CT.

A case of incomplete duplication of the portal vein associated with multiple congenital anomalies.

Double portal veins are a duplication of the portal vein and normal portal vein with an accessory portal vein. We report a case of a 63-year-old asymptomatic female with double portal veins. There was fat accumulation observed in the area which was supplied by the first portal vein in normal position, and fatty sparing of the liver was observed in the area which was supplied by the second portal vein in the preduodenal position. The 2 portal veins were equal in size. Furthermore, the patient presented with multiple congenital anomalies, including double inferior vena cava, splenic lobulation, and accessory liver lobe. Therefore, double portal veins in our case were thought to be an incomplete duplication of the portal vein with multiple congenital anomalies.

Delayed Enhancement of Ascites after Iodine Contrast Administration Assessed with Dual-energy Computed Tomography: A Case Report.

We report a case of 71-year-old woman with lung cancer and high-attenuation ascites (HAA) due to iodine contrast material (ICM). The patient underwent two sequential CT scans at interval of 4 h between examinations by using ICM. The second scan was obtained by dual-energy CT (DE-CT), yielding the virtual non-contrast (VNC) image and iodine map, which were used to evaluate HAA. The VNC image revealed ascites with water density, and HAA was thought to contain iodine because the attenuation of ascites around the liver was similar to that of the spleen on the iodine map. The VNC image and iodine map using DE-CT were useful in differentiating HAA due to iodine (delayed enhancement of ascites) from hemorrhagic ascites in this patient.

Persistent left superior vena cava with absent right superior vena cava in adults: CT and clinical findings.

PURPOSE: Persistent left superior vena cava (PLSVC) with absent right superior vena cava (ARSVC) is rare. We evaluated CT and clinical findings of adults with ARSVC. MATERIALS AND METHODS: Our study included 11 adults with ARSVC (mean age, 63 ± 17 years). We evaluated CT findings of the azygos vein system and coronary sinus (CS) using thin slice data of > 64 MDCT. Arrhythmia and congenial heart disease were assessed. We compared the CS diameters between the ARSVC group and the control group of 120 adults with normal vena cava (mean age, 60 ± 4 years). RESULTS: Adults with ARSVC had no azygos vein arch and the hemiazygos vein continued to PLSVCs via the superior intercostal vein. Eight adults had arrhythmia including conduction disturbance and one arrhythmia was associated with atrial septal defect. All adults with ARSVC had dilated CS larger than 11 mm. The mean diameter of the CS in the ARSVC group was 18.4 mm, and that of the control group was 6.8 mm. CS diameter in the ARSVC group was larger than that in the control group (p < 0.001). CONCLUSION: Adults with ARSVC had dilated CS and no azygos vein arch. Four adults had conduction disturbance.

Cutaneous Metastases from Testicular Diffuse Large B-cell Malignant Lymphoma and Bowen Disease: 18F-FDG PET-CT Findings.

Here, we report the case of cutaneous metastases from testicular diffuse large B-cell malignant lymphoma (DLBCL) concurrent with Bowen disease evaluated with 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT). A 60-year-old male underwent orchiectomy to remove his left testicle because of DLBCL. Multiple skin lesions appeared 1 month postoperatively. Furthermore, an intractable erythematous plaque localized to the right lower leg was present from 2 years before the operation. 18F-FDG PET-CT images revealed multiple skin lesions with marked FDG uptakes in the face, neck, and thigh of this patient, as well as a lower leg lesion with minimal FDG uptake. Biopsy of both lesions revealed cutaneous metastases from DLBCL and Bowen disease (BD) of the lower leg lesion. 18F-FDG PET-CT images following chemotherapy and resection of BD demonstrated no FDG uptake.

A case of intrahepatic splenosis: usefulness of splenic scintigraphy.

We report a 39-year-old male with intrahepatic and peritoneal splenosis, focusing on scintigraphic findings. Dynamic computed tomography (CT) showed a 3 cm lesion in the posterior right lobe of the liver with strong early phase enhancement that was homogenous to the liver enhancement in the late phase. A few enhancing nodules were also found in the peritoneum. On gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced dynamic magnetic resonance imaging (MRI), the hepatic lesion had abnormal signal on diffusion-weighted imaging, high signal intensity on T2-weighted imaging, and early enhancement with accumulation decline in the hepatocyte phase. CT and MRI findings of the hepatic lesion were similar to normal spleen. To rule out hepatic neuroendocrine tumor and peritoneal metastases, somatostatin receptor scintigraphy was performed and showed tracer accumulation in the hepatic lesion, which we considered a false positive. Splenic scintigraphy using Tc-99 m-phytate showed accumulation in the hepatic lesion and peritoneal nodules. Given the patient's history of splenic injury and splenectomy 15 years prior and the current imaging findings, we highly suspected splenosis. After surgical treatment, the patient was pathologically diagnosed with intrahepatic and peritoneal splenosis. Splenosis should be suspected when a patient has a history of trauma or abdominal surgery. Since intrahepatic splenosis presents as a nonspecific hypervascular lesion on CT and MRI, splenic scintigraphy should be considered in these patients. In addition Tc-99 m-phytate scintigraphy is easy to use and cost-effective.

18F-FDG Uptake of Localized Malignant Peritoneal Mesothelioma.

We present 2 cases of malignant peritoneal mesothelioma (MPM) characterized by a localized solid mass without ascites and showing F-FDG uptake. A 79-year-old man with a history of asbestos exposure suffered from an epithelioid MPM originating from the hepatoduodenal ligament with FDG uptake (SUVmax 16.8). Another 80-year-old man with esophageal cancer showed desmoplastic MPM of the small bowel mesentery with FDG uptake (SUVmax 4.0). Desmoplastic MPM is more aggressive and yields poorer prognosis compared with the epithelioid type. However, the present desmoplastic MPM case showed mild FDG uptake because of rich fibrosis.

Multicenter investigation of the incidence of inferior vena cava filter fracture.

PURPOSE: Inferior vena cava filter fracture (FF) may cause life-threatening complications, including cardiac tamponade, although the actual prevalence remains unclear. Therefore, we investigated the incidence of FF. MATERIALS AND METHODS: Data on fracture incidence with filter brands, filter positions [suprarenal (SR) vs. infrarenal (IR)], and follow-up durations were collected from the databases of eight hospitals. RESULTS: Of 532 patients, Günther Tulip (GT), Trap/OptEase (TE/OE), ALN and VenaTech (VT) were implanted in 345, 147, 38 and 2 patients, respectively. Of these, filter retrieval was attempted in 110 (21.7%) patients and was successful in 106 (96.4%). Of the remaining 426 patients, FFs were observed in two (0.7%) of 270 GT filters and 19 (14.1%) of 135 TE/OE filters. Fragment embolization occurred in one patient with a GT filter (50.0%) and three with a TE/OE filter (15.8%) with a total follow-up interval of 718.0 ± 1019.4 days. FF occurred more frequently in TE/OE than in GT filters (p < 0.001). Kaplan-Meier estimates showed significantly higher fracture-free rates for GT than TE/OE (p < 0.001) and IR-TE/OE than SR-TE/OE (p < 0.05). CONCLUSIONS: TE/OE filters are not suitable for permanent implantation due to the relatively early and high fracture rates.

Right Aortic Arch with Mirror-image Branching in Adults: Evaluation Using CT.

OBJECTIVE: We evaluated radiological findings and clinical significance of right aortic arch with mirror-image branching (RAMI) in adults using data from computed tomography (CT) examinations. MATERIAL AND METHODS: We reviewed recorded reports and CT images obtained from university and branch hospitals for RAMI in adults. The RAMI incidence in adults found on CT was assessed. Associated congenital and acquired cardiovascular diseases were evaluated. RESULTS: A total of 27 cases (14 men, 13 women; mean age, 59.4 ± 18.3 years) of RAMI were found. Among 107,014 cases in three hospitals, the RAMI incidence in the first, second, and third Tokai University hospitals were 0.018%, 0.012%, and 0.012%, respectively. Eight cases had high aortic arches and four cases had aortic diverticulum (AD) in proximal descending aorta. Three cases had a history of tetralogy of Fallot. One case with an absent left pulmonary artery and three cases with an aberrant left brachiocephalic vein were found incidentally. Two cases were associated with AD aneurysm and vascular ring formation. One case had stenosis of the left subclavian artery due to injury. CONCLUSION: Cases of RAMI found in CT examinations in adults were extremely rare. Some cases were associated with congenital anomalies and/or acquired cardiovascular disease.

Aberrant Left Brachiocephalic Vein versus Persistent Left Superior Vena Cava without Bridging Vein in Adults: Evaluation on Computed Tomography.

Objective: Persistent left superior vena cava without bringing vein (PLSVC w/o BV) is a common thoracic venous anomaly, while aberrant left brachiocephalic vein (ALBCV) is an uncommon condition. We compared the incidences of the two venous anomalies and assessed congenital cardiovascular diseases (CCDs) in adults using computed tomography (CT). Materials and Methods: We reviewed the recorded reports or CT images of 49,494 adults for PLSVC w/o BV and ALBCV in two hospitals. We determined incidences of two venous anomalies and the rate of associated CCDs. Results: 76 PLSVCs w/o BV and 27 ALBCVs were found. The incidence of PLSVC w/o BV was 0.15% and the incidence of ALBCV was 0.055%. PLSVC w/o BV had higher incidence than ALBCV (p<0.001). Four PLSVCs w/o BV and one ALBCV were associated with congenital heart diseases. Two PLSVCs w/o BV and four ALBCVs were associated with congenital aortic arch anomaly (CAAA). ALBCV had higher incidence of associated CAAA than PLSVC w/o BV (P=0.02). Conclusion: The incidence of ALBCV was <50% that of PLSVC w/o BV. The two venous anomalies found on CT during adulthood were rarely associated with CCDs.

Congenital anomalies of the left brachiocephalic vein detected in adults on computed tomography.

PURPOSE: Anomalous left brachiocephalic vein (BCV) is a rare and less known systemic venous anomaly. We evaluated congenital anomalies of the left BCV in adults detected during computed tomography (CT) examinations. MATERIALS AND METHODS: This retrospective study included 81,425 patients without congenital heart disease who underwent chest CT. We reviewed the recorded reports and CT images for congenital anomalies of the left BCV including aberrant and supernumerary BCVs. The associated congenital aortic anomalies were assessed. RESULTS: Among 73,407 cases at a university hospital, 22 (16 males, 6 females; mean age, 59 years) with aberrant left BCVs were found using keyword research on recorded reports (0.03%). Among 8018 cases at the branch hospital, 5 (4 males, 1 female; mean age, 67 years) with aberrant left BCVs were found using CT image review (0.062%). There were no significant differences in incidences of aberrant left BCV between the two groups. Two cases had double left BCVs. Eleven cases showed high aortic arches. Two cases had the right aortic arch, one case had an incomplete double aortic arch, and one case was associated with coarctation. CONCLUSION: Aberrant left BCV on CT examination in adults was extremely rare. Some cases were associated with aortic arch anomalies.

The Apparent Diffusion Coefficient (ADC) as a Potential Marker of Inflammation Associated with Body Abscesses.

OBJECTIVE: To assess the feasibility of apparent diffusion coefficient analysis in evaluating the inflammatory severity of extracranial abscesses. METHODS: This retrospective study included 23 patients with solitary body abscesses (except those in the brain) who underwent 1.5-T diffusion-weighted magnetic resonance imaging (DWI) at b-values of 0 and 1000 s/mm2. Three types of the Apparent Diffusion Coefficient (ADC) measurements of abscesses were performed: the mean ADC value in region of interest (ROI), volume of interest (VOI), and histogram analysis of the ADC distribution in the VOI. Furthermore, two different areas were used: high-intensity area on b = 0 and b = 1000 s/mm2 images. Subsequently, correlations between ADC data and C-reactive protein (CRP) levels were assessed using Pearson's correlation coefficient (R) analyses. RESULTS: The strongest correlation was observed between the mean ADC value in VOI and CRP level (R = 0.78, P < 0.01), followed by ROI (R = 0.77, P < 0.01) by using the high-intensity area on the b = 0 s/mm2 images. CONCLUSION: The mean ADC value in the ROI encompassing the abscess at a b-value of 0 s/mm2 may be useful to assess the inflammatory activity of an abscess in daily practice.

Cholangiolocellular Carcinoma of the Liver Exhibiting High F-18 FDG Uptake.

Cholangiolocellular carcinoma (CoCC) is a rare primary liver cancer. It is considered to originate from hepatic progenitor or stem cells. We report a rare case of a 74-year-old male with CoCC of the liver and duodenal gastrointestinal stromal tumor (GIST). Both tumors manifested tracer uptakes on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT); however, the uptake in hepatic tumor was extremely higher than that in the duodenal tumor. This finding was helpful to exclude the metastasis of GIST.

Kommerell Diverticulum in Adults: Evaluation of Routine CT Examinations.

UNLABELLED: Objection: To evaluate of Kommerell diverticulum (KD) in adults during routine CT examinations. MATERIAL AND METHODS: Eighty-seven cases of left aortic arch with aberrant right subclavian artery (LAARS) and 28 cases of right aortic arch with aberrant left subclavian artery (RAALS) were found on routine CT examinations using 64-128 multidetector CT. We assessed the incidence of KD and measured the size of KD, and compared the results between both groups. We evaluated associated congenital and acquired cardiovascular diseases on both groups. RESULTS: The incidence of KD in each group was as follows: RAALS 100 % and LAARS 48.3 % and incidence of KD in RAALS group was significant higher than in LAARS group. The mean KD size was as follows: RAALS 32.8 mm and LAARS 17.8 mm and, the size of KD in RAALS group was larger than that in LAARS group. Two cases were associated with congenital heart disease. Several cases were associated with acquired aortic diseases including aortic aneurysm, dissection, severe atherosclerosis and aortitis. CONCLUSION: KD was common among adults with an ASA and some adults were associated with aortic diseases.

A Case Report of an Incidentally Diagnosed Blind-ending Bifid Ureter in a Patient with Ovarian Cancer.

A 58-year-old Japanese female was admitted to our hospital for treatment of ovarian cancer. She had no urinary tract symptoms at the time of presentation. Preoperative CT (Computed Tomography) was performed for surgical planning, and it revealed two left-sided ureters including a short ureter with a blind, cystic ending and a short ureter joined to the main ureter before entering into the bladder. On CT urography, these radiological findings were compatible with a blind-ending bifid ureter. Preoperatively, a double J stent was inserted into the normal left ureter, and then the blind-ending bifid ureter was resected before an ovarian cancer operation.

A Case of Colon Cancer Associated with Ulcerative Colitis: Evaluation Using CT Colonography.

A 29-year-old female with ulcerative colitis was found to have advanced sigmoid colon cancer on colonoscopy. Computed tomography (CT) was performed after colonoscopy for the evaluation of metastasis. CT colonography (CTC) could be understood adding carbon dioxide because of soon after colonoscopic examination. Images of CTC were evaluated by two- and three-dimensional images including virtual endoscopic, virtual colon dissection and air images, and then compared with conventional endoscopic images. Virtual endoscopic images of flat elevated cancer with shallow ulcer were similar to those findings by conventional endoscopy. This lesion could be depicted by computer-aided detection.

Duodenal Emphysema Complicated with Superior Mesenteric Artery Syndrome in a Patient with Cerebral Paralysis: A Case Report.

Superior mesenteric artery syndrome (SMAS) is characterized by an arteriomesenteric duodenal compression commonly resulting from significant weight loss. Vomiting is the most frequent symptom. SMAS can be complicated by massive gastric dilatation. Patients with cerebral palsy have various factors that can predispose them to SMAS. In this paper, we report a rare case of SMAS complicated by duodenal, peritoneal and retroperitoneal emphysema in a patient with cerebral paralysis, referring to the relevant literature. In this case, severe vomiting associated with epilepsy and weight loss may have contributed to the development of duodenal emphysema.

Evaluation of Renal Artery Anomalies Associated with Horseshoe Kidney Using CT Angiography.

PURPOSE: To evaluate the incidence of supernumerary renal arteries in horseshoe kidney (HSK) patients, focusing on number and diameters using computed tomographic angiography (CTA). MATERIAL AND METHODS: Thirty-nine patients with HSK and 103 patients with normal kidney (NK) underwent 64 or 128 multidetector CT. Based on 2-dimensional CT, including multiplanar reconstruction, maximum intensity projection, and volume-rendered images with a 0.5-mm reconstruction interval on CTA, we assessed the incidence of supernumerary renal arteries, and large ( > 3 mm in diameter) supernumerary renal arteries, and compared the results between the HSK and NK patients using a chi-square test. RESULT: The mean number of renal arteries was 3.87 in HSK patients and 2.41 in the NK patients. The incidence rates of supernumerary arteries and supernumerary arteries greater than 3 mm were 92.3 %, 69.2 % in HSK patients and 33%, 8.7% in NK patients. Supernumerary and large supernumerary renal arteries had significantly higher incidence rates in the HSK patients than in the NK patients on CTA (p = 0.003, < 0.001). CONCLUSION: Supernumerary and large supernumerary renal arteries were frequently found among the HSK patients on CTA.