Tamaki Ichikawa

Visualization of the azygos arch valves on multidetector-row computed tomography

To evaluate the frequency and appearance of the azygos arch valves on chest examinations using multidetector-row computed tomography (MDCT), we retrospectively reviewed findings from 194 contrast-enhanced MDCT examinations of the chest. Rate of injection of 300 mgI/ml contrast materials was low (2.0 ml/s) and high (3.0 ml/s). Scanning delay was 80 s on examination on low-rate injection of contrast material and 20 s on high-rate injection of contrast material. The presence of residual contrast material in the azygos arch valves and reflux of contrast material into the azygos arch were recorded. The Cochran-Armitage trend test was used to compare the frequency of residual contrast material in the azygos arch valves and reflux of contrast material into the azygos arch in both groups. Of 92 examinations of high-rate injection of contrast material, 63 (68.5%) demonstrated residual contrast material in the azygos arch valves and 71 (77.2%) demonstrated reflux of contrast material into the azygos arch. A significantly higher frequency of reflux of contrast material into the azygos arch and residual contrast material in the azygos arch valves was seen in the high-rate injection group than in the low-rate injection group (P < 0.05). Residual contrast material in the azygos arch valves was demonstrated more frequently when contrast material was administered in the right side of the arm than in the left side of the arm (P < 0.05). Reflux of contrast material into the azygos arch was common in the high-injection-rate group and residual contrast material in the azygos arch valves was far more frequently seen in the high-injection-rate group than in the low-injection-rate group on MDCT.

C-arm CT-guided Foam Sclerotherapy for the Treatment of Gastric Varices

The authors describe here the use of foam sclerotherapy under C-arm computed tomography (CT) guidance for the treatment of gastric varices via balloon-occluded retrograde transvenous obliteration in seven patients and percutaneous transhepatic obliteration in one patient. All gastric varices were occluded successfully after replacement of blood by foam, which was trapped in the gastric varices as shown by C-arm CT. It also helped reduce the amount of sclerosant, an issue that is associated with severe complications, such as hemolysis, allergy, acute respiratory distress syndrome, and others. Foam sclerotherapy under C-arm CT guidance is a promising tool in the therapeutic armamentarium against gastric varices.

Carbon Dioxide (CO2) vs Iodinated Contrast Digital Subtraction Angiography during Balloon-occluded Retrograde Transvenous Obliteration (BRTO) Using Foam Sclerosant for Gastric Varices

PURPOSE To compare the visualization of the target gastric varices (GV) on balloon-occluded retrograde transvenous venography (BRTV) using iodinated contrast material vs carbon dioxide (CO(2)) in preparation for subsequent balloon-occluded retrograde transvenous obliteration (BRTO) using foam sclerotherapy. MATERIALS AND METHODS In 16 consecutive patients with nonruptured GV, BRTV was performed first using iodinated contrast material and then with CO(2). BRTV was repeated whenever there were changes in the catheter or patient position or when coil embolization of collaterals was needed. Each visualization grade of GV (grade 1 = GV only; grade 2 = GV > collaterals; 3 = GV < collaterals; grades 4-5 = collaterals only) was determined by two observers in consensus. During foam BRTO, the GV visualization grade was recorded again and confirmed by C-arm computed tomography (CT). RESULTS In 38 pairs of BRTV, GV grades were significantly (P < .0001) lower (ie, favoring BRTO) on CO(2) BRTV (mean ± standard deviation, 1.8 ± 0.8) than on iodine BRTV (3.4 ± 0.8). GV grades on foam BRTO (1.4 ± 0.7) were similar to the grades obtained on the most recent CO(2) BRTV (1.3 ± 0.5) but were significantly smaller (P < .0001) than on iodinated BRTV (3.1 ± 0.9). GV were opacified by foam on initial C-arm CT in 14 patients (87.5%), and complete thrombosis of GV was obtained without any complication in all 16 patients (100%). CO(2) reached the GV even when iodinated contrast material could not (grade 4) in seven of our 16 patients (43.8%), leading to successful BRTO. CONCLUSIONS CO(2) BRTV visualized GV better than did iodine BRTV and changed the management of more than 40% of patients by enabling successful foam BRTO in patients in which conventional liquid BRTO could not be performed.

Anomalous inferior vena cava associated with horseshoe kidney on multidetector computed tomography

We evaluated the prevalence of anomalous inferior vena cava (IVC) associated with 205 patients with horseshoe kidney (HSK) and 1990 patients without HSK on multidetector computed tomography and compared prevalence between both groups. We identified anatomical variations of the IVC in 8 patients (3.9%) with HSK (1 preisthmic IVC with retrocaval ureter, 4 double IVCs, 2 left IVCs, and 1 IVC with azygos continuation) and in 12 patients (0.6%) without HSK (8 double IVCs, 3 left IVCs, and 1 IVC with azygos continuation). Anomalous IVC was significantly more frequent in patients with HSK than those without it.

A case of right renal artery originating from the thoracic aorta

The renal arteries normally originate from the abdominal aorta between the first and second lumbar vertebrae. The main renal artery arising from the thoracic aorta is an uncommon anomaly. Here we report a rare case of a right renal artery originating above the celiac axis. A 38-year-old male underwent computed tomographic angiography in preparation for being a renal donor, and two right renal arteries were observed. A main renal artery arose from the thoracic aorta at the 11th thoracic vertebral level, and an accessory renal artery originated from the abdominal aorta at the renal hilum.

A case of right double inferior vena cava with circumcaval ureter

Congenital inferior vena cava (IVC) anomalies are silent and detected incidentally on imaging. Double IVC is the most common IVC anomaly and is usually characterized by the presence of an IVC on each side of the abdominal aorta. In contrast, right double IVC, which is defined as two post-renal IVCs positioned to the right of the abdominal aorta, is seldom recognized. We report a rare case of a complete right double IVC with a circumcaval ureter that was incidentally detected by CT and describe the embryological and clinical implications.

Congenital pericardial defect: a case of right pericardial partial absence with normal partial pleura

Congenital pericardial defect (CPD) is a rare cardiovascular anomaly. A right-sided CPD is much rarer than left-sided defects. Usually both the pericardium and parietal pleura are absent. We report a rare case of a right partial CPD involving the right atrial appendage, suspected by computed tomography and cine magnetic resonance imaging, and confirmed by thoracoscopy, which also demonstrated a normal parietal pleura.

Detection of Early Esophageal Cancer and Cervical Lymph Node Metastases by 18F-FDG PET/CT in a Patient With Fanconi Anemia

Fanconi anemia is a rare autosomal recessive disease characterized by multiple congenital anomalies, pancytopenia, and cancer susceptibility, especially to leukemia and squamous cell carcinoma of the head and neck or esophagus. F-FDG PET/CT is a useful tool to assess tumor staging and follow-up of esophageal cancer. We report a rare case of cervical esophageal cancer and lymph node metastases detected on F-FDG PET/CT in a patient with Fanconi anemia after bone marrow transplantation.

Initial experience with computed tomographic colonography applied for noncolorectal cancerous conditions

PurposeThe aim of this study was to asses retrospectively the performance of computed tomography colonography (CTC) for noncolorectal cancerous conditions.Material and methodsA total of 44 patients with non-colorectal cancerous conditions underwent CTC. We researched the indications for CTC or present illness and evaluated the CTC imaging findings. We assessed whether diagnosis by CTC reduced conventional colonoscopic examinations.ResultsA total of 47 examinations were performed in 44 patients. The indications for CTC or a present illness were as follows: 15 patients with impossible or incomplete colonoscopy, 7 with diverticular disease, 6 with malignancy (noncolorectal cancer), 6 with Crohn’s disease, 4 suspected to have a submucosal tumor on colonoscopy, 2 with ischemic colitis, and 4 with various other diseases. Colonic findings were diagnosed on CTC in 36 examinations, and extracolonic findings were identified in 35 of 44 patients. In all, 17 patients had undergone colonoscopy previously, 9 (52.9%) of whom did not require further colonoscopy by CTC. Five patients underwent colonoscopy after CTC.ConclusionThe indications for CTC were varied for patients with noncolorectal cancerous conditions. CTC examinations could be performed safely. Unlike colonoscopy or CT without preparation, CTC revealed colonic and extracolonic findings and may reduce the indication of colonoscopy in patients with noncolorectal cancerous conditions.

Renal angiomyolipoma with inferior vena caval extension: MRI demonstration of a “thread-and-streaks” sign

The MR findings in a case of tumor extension into an inferior vena cava from a right renal angiomyolipoma are reported. The flow void demonstrated within the intracaval tumor thrombus on T1-weighted images was consistent with the so-called thread-and-streaks sign.