Ultrasonographic evaluation of geniohyoid muscle mass in perioperative patients

Surgical invasion and postoperative disuse are known to promote systemic skeletal muscle atrophy; however, similar effects on the mass of the muscles of deglutition have yet to be confirmed. Our method of using ultrasonography to measure the area of the geniohyoid muscle (GM), to evaluate the mass of the muscles of deglutition, has been shown to have high reliability. In the present study, we measured the GM area before and after surgery in patients to investigate changes in their muscle mass. Parameters including GM area, quadriceps femoris muscle (QF) thickness, hand grip strength (HGS), and arm muscle circumference were measured preoperatively and at 7 and 14 days postoperatively in patients who underwent thoracotomy and laparotomy. Patient height, weight, and serum albumin (Alb) level were also obtained from medical charts. Comparison of each evaluation parameter between measurement time points demonstrated significant decreases in GM area, QF thickness, HGS, and Alb between preoperatively and both postoperative day (POD) 7 and POD 14. The patients were divided into good (n = 19) and poor (n = 12) postoperative oral intake groups for comparison of GM area. The percentage decrease in GM area was significantly greater in patients with poor oral intake. To our knowledge, this is the first study to demonstrate that muscle atrophy due to surgical invasion or disuse may occur in the muscles of deglutition, as in the limb muscles. The findings showed that muscle atrophy occurs in the early postoperative period and persists even at 2 weeks postoperatively. Furthermore, insufficient oral intake may promote disuse muscle atrophy

当院におけるPoint-of-Care Ultrasonography（POCUS）の現状 : ICU におけるベッドサイド腹部超音波症例での検討

　近年point-of-care 超音波（以下POCUS）の有用性が注目されている．しかし，その定義，対象臓器や疾患，必要とされる手技などは明らかとなっていない．当施設でICU（intensive-careunit）入院患者に対しベッドサイドで腹部超音波検査（abdominal ultrasound: AUS）を施行した症例をPOCUS 症例とし，当院のPOCUS の現状をretrospective に検討した．POCUS 施行例245例で，検査依頼領域は肝胆膵領域が最多で次に消化管領域が続いた．検査依頼領域に何らかの所見が認められた症例は47.8％であった．POCUS の正診率については94.5％であった．診断困難例は全例が消化管疾患でその中でも消化管出血とくに出血性直腸潰瘍が多く，いずれも内視鏡検査で診断されていた．POCUS で緊急対応が必要と指摘した症例は28例あり，その28.6％は検査依頼領域以外の部位に病変を認めた．28例の内訳では消化管領域（60.7％）と循環器領域（17.9％）であった．POCUS では検査依頼領域以外の領域に所見を認める事もあり，腹部全体の検索が重要である．また消化管領域はPOCUS による診断が困難なこともあり，AUS 所見で症状が説明できない場合には、内視鏡検査なども検討すべきである．以上のことから，緊急疾患は消化管領域と循環器領域に多く，特に消化管領域については慎重な検索が重要と考えられた．また，AUS を用いて適切なPOCUS を行うためには，急性腹症を含めた腹部疾患の横断的かつ総合的な病態判断が必要である．　The usefulness of point-of-care ultrasonography (POCUS) has been attracting attention in recent years, but its definition, target organs and diseases, procedures required, etc., have not been clarified. We considered cases in which abdominal ultrasound (AUS) had been performed at the bedside of patients admitted to the intensive-care unit (ICU) in our institution to be POCUS cases and assessed its current status retrospectively. There were 245 POCUS cases, and the location of abdominal area from which the greatest number of requests for the examination had been received was the hepato-biliary-pancreatology area, which was followed by the gastrointestinal area. Some sort of finding in the area from which the examination had been requested was detected in 47.8% of the cases. The diagnostic accuracy rate of POCUS was 94.5%. All difficult diagnosis cases were gastrointestinal diseases, many of which were gastrointestinal bleeding cases, especially bleeding hemorrhagic rectal ulcers, and all were diagnosed by endoscopy. There were 28 cases in which emergency management was indicated based on the POCUS findings, and in 28.6% of them the findings were detected at other area that had requested the examination. The breakdown of the emergency 28 cases showed that they included cases in the gastrointestinal area (60.7%) and cardiovascular area (17.9%). Since some of the findings detected by POCUS were in other area than the field that requested the examination, it is important to search the entire abdomen. Also, sometimes diagnosis by POCUS in the gastrointestinal area is difficult, and when the symptoms cannot be explained by the AUS findings, other examinations, such as endoscopy, should be examined. Based on the above, it appeared that diseases that require emergency management are most common in the gastrointestinal and cardiovascular area, and that very careful searches are important, especially in the gastrointestinal area. The most important, in order to perform appropriate POCUS with AUS, it is necessary to judge cross-sectional and comprehensive pathophysiological conditions of abdominal disease include acute abdomen

A dialysis patient with multiple intestinal diverticula in whom partial penetration was recognized.

　小腸憩室は比較的稀な疾患で，多くが無症状で経過するが，穿孔した場合は腸間膜内に穿通し膿瘍形成をきたす．高齢者に多く，その診断および治療の遅れから重篤な経過をたどることも少なくない．その診断にはコンピュータ断層撮影（CT）が有用とされているが，穿孔部位や憩室の特定は困難とされ，術前に指摘できるものは決して多くない．透析患者では高リン血症に対し陰イオン交換樹脂剤などが一般的に使用されるが，消化管穿孔の注意が記載されている．今回我々は，透析患者の腸管穿孔の原因検索に体外式超音波（US）が有用であった１例を経験したので，文献的考察を含めて報告する．症例は70歳台男性，18年前から血液透析を行っている．10日前に発熱で近医を受診し，保存的に経過を見ていたが炎症反応の上昇を認め当院紹介受診した．身体所見は心窩部付近に軽度の圧痛を認めたが腹膜刺激兆候は明らかでなかった．単純 CT で消化管外の free air が疑われ，精査目的に US が行われた．US では空腸に多発している憩室と，憩室周囲の膿瘍形成およびその内部の free air と思われる点状高エコーが認められ，小腸憩室穿通と診断した．同日小腸切除術が行われ，病理組織学的検索の結果，US と同様の所見であった．また穿通した憩室にセベラマー結節が認められ，憩室穿通に関与した可能性が示唆された．US は透析患者における憩室穿通の診断に有用である．　Jejunal diverticula (JD) are considered to be rare and are asymptomatic in most cases. However, they are potentially associated with serious complications, such as diverticulitis and perforation/penetration, especially in the elderly. In the event of perforation/ penetration, JD usually penetrates the mesentery, resulting in the formation of an abscess in the mesentery, which is difficult to diagnose, because there are no specific signs. Anion exchange resin agents, such as sevelamer hydrochloride (SH), are often used for hyperphosphatemia in dialysis patients, but the package insert cautions against the development of the adverse effect of gastrointestinal perforation. Herein, we report a case in which abdominal ultrasonography (US) was useful for the diagnosis of jejunal diverticular penetration in a hemodialysis patient. The patient was a male in his 70s who had been on hemodialysis for 18 years and was receiving SH 2.25g/day. He presented to a neighborhood hospital with a 10-days’history of fever. The fever did not improve with conservative therapy, and the patient was referred to our hospital. Physical examination revealed mild epigastric tenderness, but there were no signs of peritoneal irritation. Computed tomography (CT) was performed, and the presence of free air was suspected. Abdominal US performed subsequently showed multiple jejunal diverticula and abscess formation around the diverticulum. Furthermore, free air was recognized in the abscess, which was finally diagnosed as a mesenteric abscess complicating JD penetration. On the same day, jejunal resection was performed and histopathological examination of the surgical specimen revealed findings consistent with the US findings. Histopathology revealed sevelamer crystals in the penetrated diverticulum. US is useful for the diagnosis of penetration of JD in dialysis patients

含糖酸化鉄注射液の長期投与でFGF23関連低リン血症性骨軟化症を来たしたクローン病の１例

症例は50歳代，男性．クローン病で２年前に右半結腸切除術，小腸部分切除を施行．術後に他院にてアダリムマブを導入され，クローン病は臨床的寛解の状態であった．４か月前より下肢を中心とした疼痛が出現した．アダリムマブによる薬剤起因性ループスあるいは腸炎性関節炎を疑い，２か月前よりアダリムマブ投与を中止し，プレドニゾロンの内服を開始するも改善を認めなかった．血液検査にて，低リン血症と高アルカリフォスファターゼ血症を認め，精査治療目的で当院に紹介入院となった．骨塩定量検査にて骨密度の低下を，骨シンチグラフィーで疼痛を認める骨への多発取り込みを認め，骨軟化症と診断した．血清のfibroblast growth factor 23（FGF23）が175pg/ml と高値であり，入院前まで定期的に使用されていた含糖酸化鉄注射液による，FGF23関連低リン血症性骨軟化症と診断した．含糖酸化鉄注射液投与を中止し，リン製剤とビタミンD 製剤の投与を開始したところ，徐々に低リン血症と高アルカリフォスファターゼ血症の改善を認めた．その後の経過は良好で，FGF23値は徐々に低下を示し，下肢を中心とした疼痛は軽快し，退院した．長期的に含糖酸化鉄注射液を投与する場合は，FGF23関連低リン血症の早期発見のため，血中リン濃度を定期的に測定する必要がある．The case is a man in his 50s. He underwent operations of right half colon resection and small intestine segmental resection due to Crohn’s disease two years ago. After surgery, Adalimumab was introduced in other hospital, and he was a state of the clinical remission in Crohn’s disease. The sharp pain mainly on lower limbs develops from four months ago. We doubted drug origin-related lupus with Adalimumab or enteritis-related joint pain. Therefore, we stopped Adalimumab injection and started internal use of the prednisolone, however the symptoms did not improve and had continued for two months.Laboratory test showed hypophosphatemia and hyperphosphatasemia and then he was transported to our hospital. Bone mineral quantity showed bone salt decrease and bone scan showed increased uptakes in multiple bones. Fibroblast growth factor23 (FGF23) of the serum was high (175pg/ml), and we diagnosed him FGF23-mediated hypophosphatemic osteomalasia induced by prolonged administration of saccharated ferric acid.Saccharated ferric acid has regularly been used until hospitalization. After stopping the ferric acid injection, and taking phosphorus and vitamin D, hypophosphatemia and hyperphosphatasemia was gradually improved. FGF23 level gradually reduced, and the sharp pain mainly on lower limbs was relieved, and it became a discharge. Regular measurement of serum phosphorus concentration is necessary for early detection of the FGF23-related hypophosphatemia in patients with long term use of saccharated ferric acid

上腸間膜動脈限局性の高安動脈炎の一例

腹痛を呈した上腸間膜動脈（superior mesenteric artery: SMA）に限局した高安動脈炎の一例を経験したので，文献的考察を加えて報告する．症例は17歳，男性．心窩部痛・右背部痛を認め，近医を受診し，その際施行した体外式腹部超音波検査（ultrasound: US）でSMA の壁肥厚が疑われ，当院総合診療科を紹介受診した．身体診察では上腹部正中に軽度圧痛を認め，血液生化学検査では血沈（60min）35mm, CRP 3.92mg/dL と軽度上昇を認めた．US では，腹痛を訴える部位に一致してSMA 起始部にびまん性の壁肥厚を認め，血管炎が疑われた．胸部造影・上腹骨盤部単純造影CT 検査（computed tomography: CT）ではSMA 周囲に造影効果を認める軟部影を認め，18F-FDGPET（18F-fluorodeoxyglucose positron emission tomography: PET）/CT 検査ではSMA 起始部付近に腫大と軽度のFDG 集積を認め，動脈炎による集積で矛盾しない所見であった．以上のことから，SMA に限局した高安動脈炎と診断した．ステロイド治療を開始し腹痛は速やかに消褪すると共に，US 所見にも改善がみられた．We report the case of a 17-year-old male who visited a hospital complaining of epigastric and right back pain. Thickening of the wall of the superior mesenteric artery （SMA) was suspected by ultrasound （US), and he was referred to our hospital. Physical examination revealed median upper abdominal tenderness. Laboratory tests showed an erythrocyte sedimentation rate （60 min) of 35 mm and C-reactive protein of 3.92mg/dL. US examination in our hospital showed diffuse wall thickening at the origin of the SMA. Because the location of the pain and the affected area identified by US were the same, we suspected angiitis. An enhanced area around the SMA was revealed by computed tomography. 18F-fluorodeoxyglucose positron emission tomography/computed tomography showed swelling at the origin of the SMA and mild accumulation of fluorodeoxyglucose. He was diagnosed with Takayasu arteritis involving the SMA. Steroid therapy was started, and his abdominal pain and US findings improved

Diagnostic yield of transabdominal ultrasonography of pancreatic solid pseudopapillary neoplasm: a case report

　症例は10歳代，女性．主訴は左上腹部痛．部活中に腹部を強打し，左上腹部痛が出現した．食物残渣様嘔吐も認め，当院に救急搬送された．当院搬送時，左上腹部に疼痛及び圧痛を認めたが，反跳痛はなかった．当院搬送時の血液検査は白血球8,950 /μl，アミラーゼ204 U/l と高値を示していた．体外式腹部超音波検査では膵体部に76.1×68.1 mm 大の境界明瞭な被膜を伴う類円形腫瘤を認めた．周囲臓器への浸潤所見は認めず，腫瘍内部は不整で一部無エコー領域を伴い，ペルフルブタン（ソナゾイド ®）による造影超音波検査では腫瘍内部の血流は乏しい所見であった．超音波内視鏡検査所見も体外式腹部超音波検査と同様であった．以上より，腫瘍内出血を伴った solidpseudopapillary neoplasm（SPN）が最も考えられた．第10病日に膵体尾部切除術を施行し，術後経過は良好である．腹部打撲を契機に偶然発見され，体外式腹部超音波検査が質的診断に有用であった膵 SPN を経験したので文献的考察を加えて報告する．　We report a teenage girl with a solid pseudopapillary neoplasm (SPN) of the pancreas. The patient was transported to our hospital by ambulance and presented with left-sided abdominal pain after sustaining abdominal trauma during sports activities. Her white blood cell count (8950 cells/μl) and serum amylase level were increased (204 U/l) on admission. Transabdominal ultrasonography showed a well-encapsulated, complex pancreatic body mass measuring 76.1 × 68.1 mm with solid and cystic components. Contrastenhanced ultrasonography using Perflubutane (Sonazoid®) revealed poor contrast inside the tumor. Abdominal computed tomography and magnetic resonance imaging revealed similar findings. Partial pancreatectomy was performed 10 days after admission. The gross appearance of the resected specimen revealed mixed cystic and solid components with thick walls, and microscopy revealed the characteristic pseudopapillary pattern of SPN. The patient’s postoperative course proceeded well without recurrence as of this report. The imaging features of transabdominal ultrasonography and contrast-enhanced ultrasonography are useful to diagnose SPN. We discussed this patient’s detailed information and reviewed the related literature in this report

体外式腹部超音波が診断に有用であった十二指腸巨大Brunner 腺過形成の一例

Brunner 腺過形成は十二指腸腫瘍性病変で，大きさが40mm を超えるものは10% 未満と稀である．医学中央雑誌で「腹部超音波」「Brunner 腺過形成」のキーワードで検索すると，関連した報告はない．体外式超音波検査（US）が診断に有用であったBrunner 腺過形成の一例を報告する．症例は50歳代，女性．食欲不振，心窩部痛とタール便を主訴に近医受診．貧血を認め，出血源検索目的に行った上部消化管内視鏡検査（EGD）で胃内に約 45 mm の腫瘤性病変を認め精査目的に当院紹介となった．血液生化学検査ではHb 9.1 g/dl，MCV 89.1 fl，MCH 30.0 pg と正球性正色素性貧血を認め，BUN/CRE 比は43.1と上昇していた．当院でのEGD では十二指腸球部に内腔をほぼ閉塞する45×40 mm の腫瘤性病変を認めた．腫瘤表面の異型性は目立たないが，oozing bleeding を伴ったびらん形成を認めた．粘膜下腫瘍を疑い生検も行われたが確定診断には至らなかった．単純造影CT では十二指腸球部に 45 mm 程度の腫瘤性病変を認め，辺縁は遷延性に造影された．内部は低吸収域が認められ，嚢胞変性や壊死が疑われた．周囲臓器への浸潤や転移を示唆する所見は認めず，粘膜下腫瘍が疑われたが癌は否定できなかった．US では十二指腸球部後壁の第２層から第３層に存在する約55 mm の粘膜下腫瘍が認められた．固有筋層は正常で，内部は大半が多房性嚢胞からなり，嚢胞間に充実成分がみられた．血流は比較的豊富であるが血管径や形状に明らかな不整は認めなかった．以上より十二指腸Brunner 腺過形成が疑われた．外科的切除の方針となり，開腹で十二指腸粘膜下層剥離術を行った．術材の組織診断はBrunner 腺過形成で超音波診断と矛盾しない所見であった．十二指腸粘膜下腫瘍の鑑別には超音波内視鏡が有用であるが，大きな病変では全体の描出が困難などの欠点もある．一方でUS は内視鏡侵襲なく，比較的大きな病変も描出可能で，特に本症例の様に前庭部付近は良好な観察が期待できるため，上部消化管の精査に応用できる．Brunner’s gland hyperplasia is a duodenal neoplastic lesion, and its lesions measuring >40 mm in diameter are rare, accounting for <10% of cases. A search of the Ichushi (Japana Centra Revuo Medicina) database using the keywords “abdominal ultrasound” and “Brunner’s gland hyperplasia” yielded no relevant articles. Here we report a case of Brunner’s gland hyperplasia in which transabdominal ultrasonography (US) was useful for diagnosis. A female in her 50s presented to a local hospital complaining of anorexia, epigastric pain and tarry stool. She had anemia and esophagogastroduodenoscopy (EGD), which was performed to identify the source of bleeding, revealed a mass lesion measuring approximately 45 mm in diameter in the stomach. She was referred to our hospital for further examination. Blood biochemistry showed a hemoglobin (Hb) level of 9.1 g/dL, mean corpuscular volume (MCV) of 89.1 fL and mean corpuscular hemoglobin (MCH) of 30.0 pg, indicating normocytic normochromic anemia. The blood urea nitrogen (BUN)/creatinine (CRE) ratio was as high as 43.1. In our hospital, EGD revealed a 45×40 mm mass lesion almost obstructing the lumen in the duodenal bulb. Atypia of the mass surface was not prominent, but erosion with oozing bleeding was observed. A submucosal tumor was suspected, and biopsy was performed but did not lead to a definitive diagnosis. Plain contrast-enhanced computed tomography (CT) revealed a mass lesion with prolonged peripheral enhancement measuring approximately 45 mm in diameter in the duodenal bulb. There was a low-density area inside the mass, raising the suspicion of cystic degeneration and necrosis. There were no findings suggesting infiltration or metastasis to the surrounding organs, raising the suspicion of a submucosal tumor, but cancer could not be ruled out. US revealed a submucosal tumor measuring approximately 55 mm in diameter in the second to third layer of the posterior wall of the duodenal bulb. The muscularis propria was normal and mostly composed of multilocular cysts with solid components in the space between the cysts. Blood flow was relatively abundant, but there were no obvious irregularities in the diameter or shape of blood vessels. The above findings raised the suspicion of duodenal Brunner’s gland hyperplasia. It was decided to perform surgical resection, and she underwent open duodenal submucosal dissection. Histology of the surgical specimen revealed Brunner’s gland hyperplasia, cons istent with the ultrasonographic findings. Endoscopic ultrasonography is useful in the differential diagnosis of duodenal submucosal tumors, but also has disadvantages such that it is difficult to visualize the entire lesion, when the lesion is large. On the other hand, US can be applied to the detailed examination of the upper gastrointestinal tract, because there are no invasive endoscopic procedures and US can visualize relatively large lesions and, in particular, can be expected to satisfactory observe around the vestibule, like in the present case

内視鏡的ドレナージが有効であった胃壁膿瘍を合併した胃迷入膵の１例

　症例は30歳代女性．３日前から心窩部痛が出現し，徐々に増悪してきたため当院を受診した．血液検査でWBC 15,120/μl，CRP 2.95mg/dl と炎症反応上昇を認め，腹部超音波検査で胃幽門前庭部前壁に約3.5cm の粘膜下腫瘍様隆起を認めた．腫瘍内部はechogenic particles の混在する液体の貯留を認めた．腹部造影CT 検査では，胃前庭部から胃体部前壁にリング状の造影効果を伴う著明な壁肥厚を認めた．以上より胃壁膿瘍と診断した．胃前庭部前壁の弾性硬のやや発赤した粘膜下腫瘍様隆起に対して，超音波内視鏡下穿刺術（EUS-FNA）を行った．粘稠な白色液体の流出を認め，膿瘍を示唆する所見であった．絶食・点滴・抗生剤投与による保存的加療を施行後，速やかに腹部症状は消失し，EUS-FNA 施行後５日目に退院した．４か月後，病変は上部内視鏡検査で頂部に陥凹を有する腫瘍に形態変化を認め，さらに縮小傾向であった．また，腹部超音波検査では粘膜下層内に約５mm 大の嚢胞性領域とそれに接する約４mm 大の境界不明瞭な低エコー域，不整な固有筋層の肥厚を認め，胃迷入膵の所見であった．以上より，胃壁膿瘍を合併した胃迷入膵と診断した．現在，再発なく当科で経過観察中である．胃壁膿瘍を合併した胃迷入膵の報告は非常に稀であり，貴重な症例と考えられた．　Here, we report a case of gastric wall abscess in aberrant pancreas. A 30-yearold woman visited our hospital for epigastric pain. Routine hematological examination showed increased white blood cell count and biochemical tests revealed elevated C reactive protein levels. Abdominal ultrasound revealed a submucosal tumor that appeared as a hypoechoic heterogenous mass in the stomach. Abdominal computed tomography revealed a thickened gastric wall with a low-density area. This mass was diagnosed as a gastric wall abscess, which was treated with endoscopic ultrasound-guided fine needle aspiration and conservative therapy with antibiotics. The patient’s pain resolved after the treatment. Four months after the episode, follow-up examinations showed that the submucosal tumor had changed to a small submucosal mass with depression. This lesion was diagnosed as an aberrant pancreas. Thus, the final diagnosis was a gastric wall abscess in the aberrant pancreas. This patient was followed up for one year following this episode with no incidence of recurrence

当院における便潜血陽性者に対する大腸CT(CTコロノグラフィー)検査の有用性:大腸がん検診への導入と課題

大腸がん検診におけるスクリーニング検査としての大腸CT(CT colonography: CTC)検査の有用性を検討するために,当院における便潜血陽性者に対するCTCと大腸内視鏡検査の精度比較を行った.2009年7月から2014年1月までに川崎医科大学附属病院で施行されたCTC検査673件中,スクリーニング目的で行われた411件の中で便潜血陽性者に対して行われた183名を対象とした.全例CTC検査と同日に全大腸内視鏡検査も行った.対象とする病変は内視鏡観察あるいは病理組織学的に腺腫,がんと診断されたものとした.CTCの前処置は,経口腸管洗浄剤に水溶性造影剤による標識(タギング)を付けて行った.CT装置は16列Multi-slice CT(MSCT),腸管拡張は自動炭酸ガス注入器を使用した.CTC読影は,まず仮想内視鏡(3D)で行い,後に多断面再構成像(Multi-planar reconstruction: MPR 像(2D))を行う3D primary 法で行った.183名(男性98名,女性85名,年齢40～86歳,平均年齢62.1歳±0.8歳)のうち,病変を認めなかったのは87名(47.5%)であり,病変を認めたのは96名(53%)であった.総病変数は191個であり,うち6mm以上の病変は77個(40%)で,そのうち10mm以上のものは46個(24%)であった.大腸癌は25例(全病変中13%)で,うち腺腫内癌16例(全病変中8%)であった.側方発育型腫瘍は8例(4%)(大きさ平均17mm)であった.病変のうち,内視鏡的切除が行われたものは34病変であり,手術が行われたものは22病変であった.病変形態別による描出率は隆起型病変80%で,平坦型病変65%であった.病変サイズ別の精度は10mm以上の病変(n=46)で感度96%,陽性適中率98%であり,6mm以上の病変(n=77)で感度83%,陽性適中率79%であった.CTCは便潜血陽性者において良好な精度を示し,大腸がんスクリーニング法としての可能性がある.The purpose of this study was to estimate the sensitivity and specificity of CT colonography (CTC) for colorectal cancer screeing following positive fecal occult blood test (FOBT) in Japan. To compare detection rates of colorectal cancer and adenoma between CTC and optical total colonoscopy (TCS). This study included 183 patients with positive result of FOBT in Japanese colorectal cancer screening program. The patients had both CTC and TCS on the same day. 96 patients (53%) had colorectal lesions, on the other hand 87 patients had no lesions. The total number of lesions was 191, including 77 lesions 6 mm in maximum diameter and larger, including 46 lesions 10 mm and larger