Natural History of Unruptured Visceral Artery Aneurysms Due to Segmental Arterial Mediolysis and Efficacy of Transcatheter Arterial Embolization: A Retrospective Multiinstitutional Study in Japan.

OBJECTIVE. The purpose of this study was to clarify the natural history of unruptured visceral artery aneurysms due to segmental arterial mediolysis and the efficacy of transcatheter arterial embolization. MATERIALS AND METHODS. Patients with a pathologic or clinical diagnosis of visceral artery aneurysms due to segmental arterial mediolysis between 2005 and 2015 were enrolled. For patients with clinical diagnoses, images were collected and assessed by central radiologic review. To clarify the natural history of unruptured aneurysms, the morphologic changes were assessed. The efficacy and safety of transcatheter arterial embolization for aneurysms due to segmental arterial mediolysis were evaluated. RESULTS. Forty-five patients with 123 aneurysms due to segmental arterial mediolysis were enrolled. Among the 123 aneurysms, 70 unruptured aneurysms were evaluated for natural history. Forty-five of the 70 (64%) aneurysms had no change in morphology. Among the other 25 aneurysms, nine (13% of the 70) were reduced in size, 13 (19%) disappeared, and three (4%) were newly found at follow-up. Aneurysms of the middle colic artery were ruptured in 10 of 11 (91%) cases. Transcatheter arterial embolization was performed on 45 aneurysms and was successful in all cases but caused slight arterial injury in three cases (6.7%). CONCLUSION. At initial diagnosis, unruptured aneurysms due to segmental arterial mediolysis are likely to be stable or to resolve, but the risk of rupture of aneurysms of the middle colic artery appears high. Transcatheter arterial embolization is a useful treatment, but careful manipulation is necessary.

Rare causes of hematuria associated with various vascular diseases involving the upper urinary tract.

Hematuria is a commonly encountered symptom of a wide spectrum of diseases, including calculi, tumors, and vascular abnormalities. In rare cases, hematuria is caused by life-threatening vascular diseases. When hematuria is encountered, physicians sometimes fail to include vascular diseases in the differential diagnosis because of their rare association with hematuria. Likewise, radiologists often fail to do so because of the low frequency of occurrence of these diseases. Multidetector computed tomography performed with the bolus injection technique should be the first-line diagnostic test when vascular disease is suspected. Radiologists should be familiar with the various imaging findings of hematuria caused by vascular disease. They should also be familiar with the management options (including endovascular techniques) for hematuria caused by vascular disease, since in some cases affected patients can be treated with interventional procedures.

Rate of liver volume increase: can it predict recipient prognosis after left lobe transplantation from living related donors?

PURPOSE: The purpose of this study was to determine whether liver volume increase can predict recipient outcome. MATERIALS AND METHODS: Size-matched left lobe transplantation was performed for 16 patients. Computed tomography was performed in Week 1 after transplantation. Rate of liver volume increase was compared between survivors and deceased subjects. RESULTS: Mean rate of liver volume increase was significantly higher for survivors than for fatalities. CONCLUSION: Rate of liver volume increase might be useful for predicting outcome of living donor liver transplantation.

Hypopituitarism and diabetes insipidus with localized hypertrophic pachymeningitis (Tolosa-Hunt syndrome) associated with Hashimoto thyroiditis.

We report a 69-year-old woman with intracranial pachymeningitis showing hypopituitarism, diabetes insipidus, and Tolosa-Hunt syndrome associated with Hashimoto thyroiditis confirmed by autopsy. A large tumorous lesion of the hypothalamo-pituitary gland was revealed on magnetic resonance imaging, after the patient complained of gait and visual field disturbance. These symptoms subsided after thyroid hormone supplementation. Hypopituitarism and diabetes insipidus were diagnosed after cessation of the treatment by the patient herself. Multiple cranial nerve palsies and orbito-frontalgia appeared. Methylprednisolone pulse therapy improved the symptoms, but they recurred when the dose of glucocorticoid was decreased. The patient died of brain thrombosis. Autopsy revealed typical findings of Hashimoto thyroiditis and intracranial pachymeningitis involving the cranial base and pituitary gland. The high titer of rheumatoid factor and Hashimoto thyroiditis in this patient suggest an immunological role in the pathogenesis of pachymeningitis.

Thin-slice CT findings of biliary stricture due to blunt abdominal trauma: reports of three cases.

Thin-slice CT findings were reviewed in three patients with biliary stricture due to blunt abdominal trauma. In all cases, the stricture was located at the suprapancreatic portion of the common bile duct. Central enhancement with a low attenuation rim at the bile duct between the stricture and the papilla of Vater was apparent in all cases. Ancillary findings such as focal renal laceration (1 case) and left rib fracture (1 case) were also seen. These CT findings may help in the diagnosis of biliary injury for patients with blunt abdominal trauma.

Apparent diffusion coefficient in pancreatic cancer: characterization and histopathological correlations.

PURPOSE: To clarify the components primarily responsible for diffusion abnormalities in pancreatic cancerous tissue. MATERIALS AND METHODS: Subjects comprised 10 patients with surgically confirmed pancreatic cancer. Diffusion-weighted (DW) echo-planar imaging (b value = 0, 500 s/mm(2)) was employed to calculate the apparent diffusion coefficient (ADC). ADC values of cancer and noncancerous tissue were calculated. Furthermore, ADC values of the cancer were compared with histopathological results. RESULTS: The mean (+/-standard deviation) ADC value was significantly lower for tumor (1.27 +/- 0.52 x 10(-3) mm(2)/s) than for noncancerous tissue (1.90 +/- 0.41 x 10(-3) mm(2)/s, P < 0.05). Histopathological examination showed similar proportions of fibrotic area, cellular component, necrosis, and mucin in each case. Regarding the density of fibrosis in cancer, three cases were classified in the loose fibrosis group and the remaining seven cases were classified in the dense fibrosis group. The mean ADC value was significantly higher in the loose fibrosis group (1.88 +/- 0.39 x 10(-3) mm(2)/s) than in the dense fibrosis group (1.01 +/- 0.29 x 10(-3) mm(2)/s, P < 0.05). In quantitative analysis, ADC correlated well with the proportion of collagenous fibers (r = -0.87, P < 0.05). CONCLUSION: Collagenous fibers may be responsible for diffusion abnormalities in pancreatic cancer.

Endovascular treatment for an iliac artery-ureteral fistula with a covered stent.

Iliac artery-ureteral fistula (IAUF) is a rare entity that has a potential risk of life-threatening hemorrhage. It is difficult to diagnose and treat appropriately. Conventional treatment for the disease consists of surgical ligation and vascular reconstruction or coil embolization. Surgical treatment is usually difficult for patients with several risk factors. In recent years, endovascular stent-graft treatment for iliac artery pseudoaneurysm has been reported. The present report describes two cases in which endovascular covered stent-graft treatment was successfully applied to treat IAUF, with good clinical outcomes.

Yamanouchi magnetic compression anastomosis for bilioenteric anastomotic stricture after living-donor liver transplantation.

Yamanouchi magnetic compression anastomosis (YMCA) is a novel interventional method that creates an anastomosis between the bile duct and small intestine. The method uses two magnets to compress the stricture transmurally, causing gradual ischemic necrosis of the stricture. This ischemic necrosis creates an anastomosis between the two magnets. The present report describes two cases in which YMCA was successfully applied to treat bilioenteric anastomotic stricture after living-donor liver transplantation. These two patients exhibited good long-term clinical courses.