Language：English   Publishing type：Research paper (scientific journal)  

Background and Objectives: In the field of orthopedic surgery, novel techniques of three-dimensional shape modeling using two-dimensional tomographic images are used for bone-shape measurements, preoperative planning in joint-replacement surgery, and postoperative evaluation. ZedView® (three-dimensional measurement instrument and preoperative-planning software) had previously been developed. Our group is also using ZedView® for preoperative planning and postoperative evaluation for more accurate implant placement and osteotomy. This study aimed to evaluate the measurement error in this software in comparison to a three-dimensional measuring instrument (3DMI) using human bones. Materials and Methods: The study was conducted using three bones from cadavers: the pelvic bone, femur, and tibia. Three markers were attached to each bone. Study 1: The bones with markers were fixed on the 3DMI. For each bone, the coordinates of the center point of the markers were measured, and the distances and angles between these three points were calculated and defined as "true values." Study 2: The posterior surface of the femur was placed face down on the 3DMI, and the distances from the table to the center of each marker were measured and defined as "true values." In each study, the same bone was imaged using computed tomography, measured with this software, and the measurement error from the corresponding "true values" was calculated. Results: Study 1: The mean diameter of the same marker using the 3DMI was 23.951 ± 0.055 mm. Comparisons between measurements using the 3DMI and this software revealed that the mean error in length was <0.3 mm, and the error in angle was <0.25°. Study 2: In the bones adjusted to the retrocondylar plane with the 3DMI and this software, the average error in the distance from the planes to each marker was 0.43 (0.32-0.58) mm. Conclusion: This surgical planning software could measure the distance and angle between the centers of the markers with high accuracy; therefore, this is very useful for pre- and postoperative evaluation.

DOI： 10.3390/medicina59061030

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

A Japanese man in his 30s died suddenly. Postmortem computed tomography and autopsy revealed a pulmonary embolism from an organizing thrombus in the inferior vena cava as the cause of death. Genomic analysis of congenital thrombophilia-related genes (i.e., SERPINC1, PROC, PROS1, F2, F5, PLG, and MTHFR) revealed a heterozygous variant of PROS1 (p.A139V), which has been reported in patients with congenital protein S deficiency. After a genetic conference that included forensic pathologists, molecular scientists, genetic researchers, genetic clinicians, and clinical physicians, the results of the genetic analysis were explained to the family. Biochemical analyses of protein S (PS) activity and total PS antigen levels were performed with samples from the deceased's family and genetic analysis was not performed until clinical symptoms appear. Herein we demonstrate the importance of genetic background in cases of a sudden death due to pulmonary embolism.

DOI： 10.1016/j.legalmed.2022.102029

PubMed

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Acute subdural hematoma (SDH) occurs following severe head trauma with brain contusion or rupture of bridging veins. Conversely, SDH caused by rupture of a cortical artery without trauma or with minor trauma is also possible. Although over 180 cases of the latter SDH have been reported, they were predominantly diagnosed only during surgery, and therefore, no adequate histological evaluation has been performed. Therefore, essential etiology of this SDH type has remained unclear. In addition, the scarcity of autopsy cases may be attributed to arterial rupture being missed if the microscopic findings are too minimal to detect during autopsy. Here, we describe two autopsy cases of SDH of cortical artery origin. Extravasation on postmortem computed tomography angiography and arterial leakage on macroscopic observation during autopsy facilitated detection of the ruptured artery and allowed detailed histological evaluation of the ruptured artery and adjacent dura mater. The etiology of arterial rupture is briefly described on the basis of histopathological findings in this study and the available literature.

DOI： 10.1016/j.legalmed.2021.101941

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Introduction: A major challenge in anthropology is the estimation of human stature based on human bones since the stature of cadavers is slightly different from that of living humans. This study aimed to investigate the feasibility of estimating living stature in Japanese subjects based on sacral and coccygeal lengths as measured on three-dimensional (3D) models of the femur and pelvis reconstructed from cross-sectional computed tomography (CT) images. Subjects and methods: For this cross-sectional study, 106 healthy Japanese subjects (54 men and 52 women) were recruited. We measured the distances from the anterosuperior iliac spine (ASIS) to the most posterior point of the ischial spine (IS) (ASIS-IS), and from the ASIS to the most inferior point of the ischial tuberosity (IT) (ASIS-IT) on 3D bone models reconstructed from multi-slice CT images. Correlations of living stature with ASIS-IS and/or ASIS-IT on the left and right sides of the pelvis were evaluated. Multiple regression equations were derived and used as formulas for living stature estimation. Results: In men, living stature had strong correlations with ASIS-IS + ASIS-IT on both the left and right sides; Pearson's correlation coefficients were 0.717 and 0.706, respectively. In contrast, in women, living stature showed stronger correlations with all of the studied parameters; Pearson's correlation coefficients were highest for ASIS-IS + ASIS-IT on both the left and right sides (r = 0.753 and 0.744, respectively) compared with those in men. Formulas based on ASIS-IS + ASIS-IT provided the best estimation in both men and women, while ASIS-IS alone demonstrated a better estimation than ASIS-IT on both the left and right sides. Conclusions: This study revealed that ASIS-IS and ASIS-IT measured from CT images were reliable predictors of living stature in the Japanese population. Our estimation formulas were derived from measurements of living stature that were not affected by the physiological changes observed in cadavers. To the best of our knowledge, this is the first study to derive estimation formulas based on living stature. Our method may be useful in the identification of disaster victims, wherein long bones are usually not found intact but pelvic bones are. Furthermore, the findings could be relevant to the field of anthropology for estimating living stature.

DOI： 10.1127/homo/2021/1239

PubMed

researchmap

Language：Japanese   Publisher：(株)メディカルアイ  

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

We investigated the feasibility of estimating living stature in Japanese subjects using femoral length and pelvic dimensions measured on three-dimensional (3D) pelvic models reconstructed from cross-sectional computed tomography (CT) images. For this cross-sectional study, we recruited 106 healthy Japanese subjects. Maximum and bicondylar femoral length, as well as pelvic width, depth, and height, were measured on 3D bone models reconstructed from multi-slice CT images. The correlation of stature with each parameter was evaluated, and multiple regression equations were derived as formulae for living stature estimation. Prediction accuracy was evaluated as the mean absolute difference (MAD) between the measured and estimated statures. Maximum and bicondylar femoral lengths were similar and showed strong correlations with stature (> 0.8 in both males and females). Among the pelvic dimensions, height (craniocaudal length) showed the strongest correlation with stature in both males (r = 0.649) and females (r = 0.684). Formulae using femoral length plus pelvic height provided the best estimation of living stature in both males and females (MAD, 25-26 mm). Among the studied pelvic dimensions, height provided the best estimation of living stature when used alone (MAD, 34-36 mm) in both males and females. The intraclass correlation coefficients were high (> 0.9) for both intraobserver and interobserver reliability. Femoral length and pelvic height measured on CT images are reliable predictors of living stature in the Japanese population. Such tools are particularly useful in disaster victim identification, when the long bones are often not intact but the pelvic bones are.

DOI： 10.1127/homo/2020/1116

PubMed

researchmap

Language：Japanese   Publisher：法医学談話会  

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Yearly, several reports of unknown boats and corpses brought by the Tsushima Current are found ashore Japanese coast. Niigata prefecture had the highest number of the drifting ashore corpses in Japan with 45.7% (16/35) in 2017. Corpses from North Korea, confirmed by documents and photos were autopsied and in 3/16 was possible to recover worms full of eggs, morphologically identified as ascarids. Further molecular analysis of ITS1, 5.8S rDNA and ITS2 sequences confirmed all specimens were Ascaris lumbricoides. The contamination level by Ascaris lumbricoides eggs in the coast, the health impact and consequences of the epidemiological bridging produced by this forced migration in public health should be investigated. Moreover, control of helminthiases might be a necessary task in North Korea.

DOI： 10.1016/j.parint.2019.01.002

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

This report describes the autopsy case of a 4-year-old boy who died from hepatic hemorrhage and rupture caused by peliosis hepatis with X-linked myotubular myopathy. Peliosis hepatis is characterized by multiple blood-filled cavities of various sizes in the liver, which occurs in chronic wasting disease or with the use of specific drugs. X-linked myotubular myopathy is one of the most serious types of congenital myopathies, in which an affected male infant typically presents with severe hypotonia and respiratory distress immediately after birth. Although each disorder is rare, 12 cases of pediatric peliosis hepatis associated with X-linked myotubular myopathy have been reported, including our case. Peliosis hepatis should be considered as a cause of hepatic hemorrhage despite its low incidence, and it requires adequate gross and histological investigation for correct diagnosis.

DOI： 10.1016/j.legalmed.2019.04.005

PubMed

researchmap

Language：Japanese   Publisher：産業開発機構(株)  

researchmap

Other Link： https://search.jamas.or.jp/default/link?pub_year=2018&ichushi_jid=J00116&link_issn=&doc_id=20180727080009&doc_link_id=%2Fan7eizoc%2F2018%2F005008%2F014%2F0085-0089%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fan7eizoc%2F2018%2F005008%2F014%2F0085-0089%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Language：Japanese   Publisher：法医学談話会  

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

A foreign body impacted in the esophagus is not a rare incident among adults or children. In adults, a dental prosthesis is prone to become impacted in the esophagus. The diagnostic difficulty of this often causes a delay in its removal, which can lead to serious complications, including death. This report describes the autopsy case of a man who died of prolonged asphyxiation induced by the delayed removal of an impacted denture, which was misdiagnosed on his first visit notwithstanding that a part of the denture could be seen on X-rays. Cases in which an impacted denture led to death have rarely been reported in contrast to numerous papers about recovered cases.

DOI： 10.1016/j.legalmed.2016.10.006

PubMed

researchmap

Language：Japanese   Publisher：新潟県医師会  

法医学における個人識別は、死体や生体が誰であるかという身元確認を行うことで、戸籍上の人物との「異同識別」を行うことになる。まず、身分証明書、所持品、指輪、着衣などから「候補者探し」をし、次いで指紋・掌紋・足底紋、血液型・DNA型、手術痕や傷痕、歯科所見、顔・身長・体重などから「異同識別」を行う。日航ジャンボ機墜落事故、中華航空機の名古屋空港墜落事故、阪神淡路大震災、9.11多発同時テロ事件、中越地震と中越沖地震、東日本大震災における個人識別について概説した。また、前頭洞の形態による個人識別についても述べた。

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

PURPOSE: The purpose of this study is to evaluate the postmortem deformation of the aorta on postmortem computed tomography (CT) by comparison with the antemortem CT in the same patient. MATERIALS AND METHODS: A total of 58 non-traumatic patients without hemorrhagic events who underwent torso CT before and shortly after death were enrolled. Antemortem chest and abdominal CT were obtained in 44 cases and in 57 cases, respectively. The lengths of the major and minor axes of the ascending and descending thoracic aorta and the abdominal aorta were measured on both antemortem and postmortem CT in the same patient. To evaluate the shape of the aorta, the major axis-minor axis ratio (Ma-MiR) was calculated. Mean values of the diameters of the aorta and Ma-MiRs on postmortem CT were compared with those on antemortem CT using the Wilcoxon signed-rank test. We also evaluated the major and minor axes and Ma-MiRs on both antemortem and postmortem CT in two age groups: 65 years and under (n=13) and over 65 years (n=45). RESULTS: At each level tested, the aorta significantly shrank after death (p<0.001) (ascending thoracic aorta, descending thoracic aorta, and abdominal aorta: 38.5 mm × 33.5 mm, 28.0 mm × 25.9 mm, and 24.4 mm × 21.8 mm on antemortem CT, 30.0 mm × 26.2 mm, 24.4 mm × 20.7 mm, and 21.5 mm × 14.5 mm on postmortem CT, respectively). The postmortem Ma-MiRs significantly increased at the descending thoracic aorta and the abdominal aorta (p<0.001). The diameters of the aorta are longer in older cases at all levels on both antemortem and postmortem CT. The reduction rates were larger in younger cases than older cases at all levels. CONCLUSIONS: After death, the aorta shrunk at all levels, and became oval in shape in descending thoracic and abdominal aorta. The contraction was greater in younger cases than older cases. Investigators who interpret postmortem imaging should be aware of the postmortem deformation of the aorta.

DOI： 10.1016/j.forsciint.2012.04.037

PubMed

researchmap

Language：Japanese   Publisher：(一社)日本交通科学学会  

Abbreviated Injury Scale(AIS)を用いて交通事故死の死後CTにおける損傷身体部位と重症度を評価した。交通外傷で搬送された後、死亡または死亡が確認され、死後CTが行われた51例を対象とした。受傷者の内訳は、歩行者20例、自転車あるいはバイク運転手12例、自動車運転手あるいは同乗者19例であった。死後CTでは、骨折、多量の出血、気胸、体腔内ガスが明瞭に認めた。診察では外傷所見が明らかでなく、死後CTで損傷部位が明瞭となった例もあった。ISSは、歩行者で13から75、自転車あるいはバイク運転手で13から75、四輪車搭乗者で25から75であった。死後CTで認められた損傷は、頭頸部、胸部に多く認めた。複数身体部位の損傷は44例で認め、40例では複数身体部位にAIS3(重症)以上の損傷を認めた。

researchmap

Language：Japanese   Publisher：法医学談話会  

researchmap

Language：Japanese   Publisher：法医学談話会  

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVES: To investigate the diagnostic performance of postmortem multidetector computed tomography (PMMDCT) for the detection of fatal findings related to causes of non-traumatic death in the emergency department (ED). METHODS: 494 consecutive cases of clinically diagnosed non-traumatic death in ED involving PMMDCT were enrolled. The fatal findings were detected on PMMDCT and classified as definite or possible findings. These findings were confirmed by autopsy in 20 cases. RESULTS: The fatal findings were detected in 188 subjects (38.1%) including 122 with definite (24.7%) and 66 with possible finding (13.4%). Definite findings included 21 cases of intracranial vascular lesions, 84 with intra-thoracic haemorrhage, 13 with retroperitoneal haemorrhage and one with oesophagogastric haemorrhage. In three patients who had initially been diagnosed with non-traumatic death, PMMDCT revealed fatal traumatic findings. Two definite findings (two haemopericardiums) and seven possible findings (two intestinal obstructions, one each of multiple liver tumours central pulmonary artery dilatation, pulmonary congestion, peritoneal haematoma, and brain oedema) were confirmed by autopsy. The causes of death were not determined in cases with possible findings without autopsy. CONCLUSIONS: PMMDCT is a feasible tool for detecting morphological fatal findings in non-traumatic death in ED. It is important to know the ability and limitation of PMMDCT.

DOI： 10.1007/s00330-011-2248-6

PubMed

researchmap

Language：Japanese   Publisher：新潟県医師会  

2008年5月から2年4ヵ月間に超音波画像診断装置を用いて死因診断(死後エコー)を行った92例(検死41例、解剖51例)の死後エコーの状況と結果を報告した。外傷初期診療の超音波検査法FASTの6点に傍胸骨肋骨間操作を加えた計7点でecho free spaceの有無を判定し、死因との関連を推定した結果、92例中24例に1ヶ所以上のecho free spaceを認め、外傷死の約65%と非外傷死の約0.3%で死因との直接的関連を認めた。また、検死例におけるエコーガイド下穿刺では正確な部位からの採取が可能で、特に心腔や大血管を穿刺することで動静脈血の選択的採取が可能となり、死因推定の一助となった。死後エコーは検査そのものの制約や精度などに関して欠点を有するものの、非侵襲的に内部の形態的情報が得られるほかにも機動性という独自の利点があり、その有用性が示唆された。

researchmap

Language：Japanese   Publisher：日本法医病理学会  

researchmap

Language：Japanese   Publisher：(一社)日本交通科学学会  

衝突時にシート座面が下方へ変形する原因を明らかにするために、ダミーを乗せた実車を用いた衝突実験を実施し、シートベルトが乗員腹部に与える影響等について検討した。衝突開始から0.017秒後ころにダミー臀部が前進を開始し、これとほぼ同じころにハンドルのエアバッグが展開を開始した。作動開始から約0.006秒の間にシートベルトが約17cm引き込まれた。さらにダミー上体は前傾姿勢になりながら臀部もシート座面上を前進し続けて行き、これにともなってシート座面の前部が下方に沈み込んでいく。その後、膝部がダッシュボードに衝突したのち、衝突開始から0.083秒後ころにダミー磐部の前進および沈み込み量が最大となった。また、このころ、頭部および胸部がエアバッグを押しつぶしてハンドルに衝突した。

researchmap

Language：Japanese   Publisher：岩手県立病院医学会  

61歳男.肝門部胆管癌術後3ヵ月に腹痛・嘔吐が出現した.腹部CTでfree airはみられず,部分的な小腸の著明な拡張と壁肥厚を認めた.腸閉塞を示唆する所見であり,筋性防御が増強したため,汎発性腹膜炎疑いで緊急手術となった.肉眼的には穿孔のみの所見で,穿孔部の空腸を穿孔部から口側・肛門側それぞれ5cm離し部分切除,ドレナージを行った.病理所見からMALTリンパ腫と考えられた.リンパ腫細胞は小腸壁の静脈壁に強く浸潤しており,これにより循環障害をきたしたと考えられ,全層性の腫瘍細胞の浸潤と共に穿孔の原因となったと考えられた.化学療法を望まなかったため,クラリスロマイシン・アモキシリン・ランソプラゾールを2週間経口投与した.外来でHPの除菌の成功を確認し経過観察中であるが,10ヵ月以上寛解を続けている.検索した限りでは小腸MALTリンパ腫と胆管癌の合併はみられなかった

researchmap

Language：Japanese   Publisher：岩手県立病院医学会  

65歳男.慢性骨髄性白血病でインターフェロン療法を開始したが,皮疹出現のためイマチニブ400mg/日に変更した.1ヵ月後300mg/日に減量し,Ph染色体は陰性化した.イマチニブ開始16ヵ月後に左側腹部の疼痛が出現し,境界不明瞭な軽度発赤を伴う12×10cmの皮下硬結を触知した.腹部CTで左腹壁に皮下脂肪組織,腹直筋,腹横筋を含む板状の濃度上昇域を認め,炎症反応は軽度であったが,感染性脂肪織炎を否定できず,イミペネム投与を開始した.第9病日の同部位生検では,多形核白血球を含むリンパ球主体の細胞が脂肪組織隔壁の血管周囲に軽度に浸潤しているのみであった.抗生剤をパンスポリン,ミノマイシンに変更したが,硬結に変化はなく,第28日に再度生検を行った.泡沫細胞とリンパ球が脂肪小葉を含めた脂肪組織へ浸潤し,明らかな脂肪織炎の像であったが,多形核白血球は少数であった.ミノマイシンを第36病日まで継続したところ,疼痛は消失し,硬結も縮小傾向となって第39病日に退院した

researchmap

Language：Japanese   Publisher：岩手県立病院医学会  

74歳男.右季肋部痛が認められた.上部消化管内視鏡で,十二指腸副乳頭より3cm肛門側に1/2周の不整な潰瘍性病変を認め,生検でT細胞性悪性リンパ腫と診断された.下痢,低栄養はなかったが,腫瘍はCD20-,D79a-,CD2-,CD3+,CD5-,CD7+,CD4-,CD8-,CD56-,TIA1+の表現型を示しWHO分類の腸症型T細胞リンパ腫に相当すると考えられた.年齢を考慮してCHOP療法を6コース施行した.脱毛及び心窩部不快感が認められたが,重篤な副作用はみられなかった.潰瘍底は消失し壁集中を伴う瘢痕となっていた.同部位よりの生検では再生粘膜のみであった.現在外来で再発なく経過している

researchmap

Other Link： https://search.jamas.or.jp/default/link?pub_year=2003&ichushi_jid=J00099&link_issn=&doc_id=20040113360007&doc_link_id=%2Fec8iwpho%2F2003%2F004302%2F007%2F0161-0165%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fec8iwpho%2F2003%2F004302%2F007%2F0161-0165%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：日本法医病理学会  

researchmap

Language：Japanese   Publisher：日本法医病理学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：法医学談話会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：法医学談話会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Language：Japanese   Publisher：(NPO)日本法医学会  

researchmap

Event date： 2018.12

Language：Japanese  

researchmap

Event date： 2018.6

Language：Japanese  

researchmap

Event date： 2017.7

Language：Japanese  

researchmap

Event date： 2017.5

Language：Japanese  

researchmap

Event date： 2016.12

Language：Japanese  

researchmap

Event date： 2016.11

Language：Japanese  

researchmap

Event date： 2016.5

Language：Japanese  

researchmap

Event date： 2016.5

Language：Japanese  

researchmap

Event date： 2016.5

Language：Japanese  

researchmap

Event date： 2015.12

Language：Japanese  

researchmap

Event date： 2014.12

Language：Japanese  

researchmap

Event date： 2014.12

Language：Japanese  

researchmap

Event date： 2014.11

Language：Japanese  

researchmap

Event date： 2014.5

Language：Japanese  

researchmap

Event date： 2013.12

Language：Japanese  

researchmap

Event date： 2013.5

Language：Japanese  

researchmap

Event date： 2013.5

Language：Japanese  

researchmap

Event date： 2013.5

Language：Japanese  

researchmap

Event date： 2013.4

Language：Japanese  

researchmap

Other Link： https://search.jamas.or.jp/default/link?pub_year=2013&ichushi_jid=J00990&link_issn=&doc_id=20130918110005&doc_link_id=%2Fdg3nigta%2F2013%2Fs12704%2F002%2F0210-0210%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fdg3nigta%2F2013%2Fs12704%2F002%2F0210-0210%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2012.12

Language：Japanese  

researchmap

Event date： 2012.5

Language：Japanese  

researchmap

Event date： 2012.5

Language：Japanese  

researchmap

Event date： 2012.5

Language：Japanese  

researchmap

Event date： 2011.12

Language：Japanese  

researchmap

Event date： 2011.10

Language：Japanese  

researchmap

Event date： 2011.5

Language：Japanese  

researchmap

Event date： 2011.5

Language：Japanese  

researchmap

Event date： 2010.12

Language：Japanese  

researchmap

Event date： 2010.5

Language：Japanese  

researchmap

Event date： 2010.5

Language：Japanese  

researchmap

Event date： 2010.5

Language：Japanese  

researchmap

Event date： 2009.11

Language：Japanese  

researchmap

Event date： 2009.4

Language：Japanese  

researchmap

Event date： 2009.4

Language：Japanese  

researchmap