単純CTの図１〜図８で，肝周囲に腹水があり（※），↑が脾臓でその周囲の，densityの高い△は血腫で脾臓損傷を強く示唆するが，単純CTだけでは確定診断は困難で，ましてや外傷例で最も重要な所見である活動性出血を意味するextravasation（造影剤の血管外漏出）は描出されない．造影CT図９〜図１８では肝臓と脾臓の実質が造影効果を受け，肝臓には損傷はなく，図１１〜図１７で無血管域の脾臓損傷（白矢印）が明瞭になる．肝周囲に腹水があり（※），脾臓周囲の▲はややdensityの高い部分を含み不均一だから血腫であろう．図１０〜図１４の△は連続しており，図１３と図１４でdensityが脾臓実質より高く大動脈と同等だから“contrast blush”（下記解説）であるが，このsingle phase造影CTではextravasation，extravasationを伴う仮性動脈瘤，extravasationを伴わない仮性動脈瘤，動静脈瘻の4病変の鑑別は不可能である．塞栓術（TAE：transcatheter arterial embolization）目的に血管造影（図Aと図B）を施行した．損傷部位（↑間）は認識できるがextravasationを認めないためTAEを行わず保存的に経過観察した．Hbが10.8から5.5g/dlに低下したため輸血6単位を要したが，その後は順調に経過した．外傷症例に対しては単純CTだけでは情報不足であり，実質臓器の損傷ならびに活動性出血（extravasation）の有無を評価するために造影CT検査（double phaseが望ましい）は必須である．

文献考察：contrast blush
１）J Trauma. 2001 Aug;51(2):272-7; discussion 277-8.
Implications of the "contrast blush" finding on computed tomographic scan of the spleen in trauma.
Omert LA, Salyer D, Dunham CM, Porter J, Silva A, Protetch J.

BACKGROUND: The "contrast blush" (CB) computed tomographic (CT) scan finding has often been used clinically as an indicator for therapeutic splenic intervention (SI) (splenectomy, splenorrhaphy, or angiographic embolization). We sought to examine the prognostic significance of this finding. METHODS: The records and CT scans of 324 trauma patients from two Level I trauma centers who had blunt splenic injury and a CT scan of the abdomen within 24 hours of admission were reviewed and screened for CB. RESULTS: CB was identified in 11% of patients, and its incidence was significantly related to the grade of injury: grade I/II, 3.2%; grade III, 11.8%; and grade IV/V, 26.3% (p
２）Elliott JA, Millward SF, Kribs SW.
Use of computed tomographic scanning and embolization to improve the nonoperative management of splenic trauma: critically appraised topic.
Can Assoc Radiol J. 2003 Jun;54(3):183-4. 　PMID: 12866247

contrast blushとは，実質臓器内外で，臓器実質よりdensityの高い造影剤が貯留している状態で，１：extravasation（造影剤の血管外漏出），２：extravasationを伴う仮性動脈瘤（pseudoaneurysm），３：extravasationを伴わないpseudoaneurysmと，４：動静脈瘻（arteriovenous fistula）の４つの病態が含まれる．１と２は即刻，塞栓術目的の血管造影の適応であり，３と４は夜中であれば明朝まで待てる病態だから，extravasationの有無の診断は極めて重要である．しかし，single phaseの造影CTではextravasationとpseudoaneurysmの鑑別は困難なこともまれではなく，時間が許せばdouble phase造影CT（early phaseは造影剤注入開始から30秒，delayed phaseは造影剤注入開始から2〜3分）を撮ることが望ましい．

文献考察：double phase造影CT．extravasationはdelayed phaseで拡散して大きくなる，pseudoaneurysmとarteriovenous fistulaは大きさに変化をみないので鑑別が可能である．
３）Radiology. 2007 Apr;243(1):88-95. 2007 Feb 9.
Blunt splenic trauma: delayed-phase CT for differentiation of active hemorrhage from contained vascular injury in patients.
Anderson SW, Varghese JC, Lucey BC, Burke PA, Hirsch EF, Soto JA.

PURPOSE: To retrospectively evaluate delayed-phase computed tomography (CT) in the differentiation of active splenic hemorrhage requiring emergent treatment from contained vascular injuries (pseudoaneurysms or arteriovenous fistulas) that can be treated electively or managed conservatively. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant retrospective study; the informed consent requirement was waived. Forty-seven patients with blunt splenic injury diagnosed at CT after blunt abdominal trauma were evaluated. Abdominal and pelvic dual-phase CT was performed; images were obtained 60-70 seconds and 5 minutes after contrast material injection. Scans were reviewed in consensus by two radiologists. Splenic injuries were graded with the American Association for the Surgery of Trauma Splenic Injury Scale. Patients with intrasplenic hyperattenuating foci on portal venous phase images were classified as having active splenic hemorrhage (group 1) or a contained vascular injury (group 2) on the basis of delayed-phase imaging findings. Findings suggestive of active hemorrhage included areas that remained hyperattenuating or increased in size on delayed-phase images. The clinical outcome of these patients was determined by reviewing their medical records. Relationships between several factors were tested with the Fisher exact test, including (a) the presence or absence of hyperattenuating foci and management and (b) the presence of contained vascular injury or active extravasation and management. RESULTS: Portal venous phase CT revealed a focal high-attenuation parenchymal contrast material collection in 19 patients: nine patients were classified as group 1 and 10 were classified as group 2. All patients in group 1 underwent emergent splenectomy, and all patients in group 2 were initially treated without surgery. Significant differences in management were noted on the basis of whether hyperattenuating foci were seen on portal venous phase images (P