These sizes and other reference materials were gathered from a host of articles, books, lectures, and occasionally the internet in the spring of 2007 by Travis Browning and Amy DeFatta. Though they have been listed here in good faith, this list is neither complete nor infallible. Also, remember that measurements are often just part of a diagnosis criterion. We hope this helps with call and other occasions, but be aware that nothing is certain and all things are subject to change. We also hope that others will continue to add to this file over the coming years so all may benefit. CARDIAC Right atrial size right atrial bulge >5.5cm from midline on PA CXR Left atrial size 40mm in diastole (on echocardiogram), on CXR 1.8cm at a level cephalad to intersection of LV and IVC

Interatrial septum normally 4.5cm aneurysmal Ascending aorta and aortic arch normal 3.0-3.5 cm Abdominal aortic aneurysm >3cm diameter (1.5 times greater than normal vessel diameter), 5cm

is indication for repair Iliac artery diameter normal 8-10mm, >3cm aneurysm is indication for repair Pulmonary arteries normal diameters on CT (Requisites) Main pulmonary artery 28.6mm, left

main pulmonary artery 28mm, proximal right main pulmonary artery 24.3mm Right interlobar artery on lat CXR 13mm in men, 12.5mm in women (intermediate bronchus as

medial border) Pulmonary artery to bronchus size ratio normal 1.3-1.4:1 after takeoff of upper-lobe bronchi, in

periphery on CT ratio approaches 1:1 Main pulmonary artery diameter correlates to pulmonary artery pressure, >29mm is PAH Normal pulmonary artery pressure Psys 20mmHg, Pdias 10mmHg, Pmean 14mmHg, capillary

wedge pressure 5mmHg Pulmonary artery hypertension Psys >30mmHg or Pmean >25mmHg Portal hypertension >5-10mmHg Main portal vein on US normal 20 degrees, less than this is a set up for SMA syndrome Ankle/Brachial Index (ABI) in peripheral arterial disease >0.9 nl, 0.5-0.9 mild-moderate disease,

50-69% Stenosis Primary: ICA PSV 125-230cm/sec; Plaque Estimate = 50% Secondary: ICA/CCA PSV Ratio 2.0-4.0, ICA EDV 40-100 cm/sec

70% Stenosis Primary: ICA PSV >230cm/sec; Plaque Estimate = 50% Secondary: ICA/CCA PSV Ratio >4, ICA EDV >100 cm/sec

Near Occlusion Primary: ICA PSV high, low, or undetectable; Plaque Estimate = visible Secondary: ICA/CCA PSV Ratio variable, ICA EDV variable

Total Occlusion Primary: ICA PSV undetectable; Plaque Estimate = visible to no lumen seen Secondary: Not applicable

AIRWAY/LUNG Trachea and bronchus (Woodring et al, JTI 1991; 6:1-10)

o Male tracheomegally >25mm transverse and >27mm sagittal o Female tracheomegally >21mm transverse and >23mm sagittal o Male bronchomegally >21mm right mainstem bronchus, >18mm left o Female bronchomegally >20mm right mainstem bronchus, >18mm left

Posterior tracheal stripe on lateral CXR 7mm, >7mm is soft sign for esophageal CA Saber-sheath trachea reduced coronal diameter of trachea (3 small segmental lesions, no perfusion to an entire lung, solitary lobar mismatch, moderate pleural effusion (

for internal mammary LN if see, then abnormal for azygoesophageal access LN 1.5cm for retrocrural LN 0.6cm for porta hepatis LN 0.8cm for portacaval space LN 1.2cm for mesenteric LN 0.5cm for retroperitoneal LN 1cm for perirectal LN 0.3-0.5cm for upper paraaortic region LN 0.9cm for lower paraaortic region LN 1.1cm for pelvic LN 1.0 cm for inguinal LN 1.5cm Pediatrics:

LIVER/SPLEEN Hepatomegally >17cm in length (right lobe length), possibly less if left lobe prominent Splenomegally >12cm in length Splenic index normal 120 to 480 cm3 (L*W*D) Fatty liver changes ( normal liver 50-70HU) >10HU less than spleen noncontrast

o >25HU less than spleen during portal-venous phase of contrast (less specific and need additional findings to suggest)

Fatty liver on MR >10% signal dropout on out-of-phase sequence Liver transplant US evaluation hepatic artery acceleration time

Pediatrics: Hypertrophic pyloric stenosis single wall thickness >3mm, length >14mm (think , 3.14)

DUODENUM Papilla along medial surface of 2nd duodenum, normal up to 1cm, >1.5cm enlarged Giant ulcer benign ulcer 2cm diameter Pediatrics:

SMALL BOWEL Small bowel wall >3mm is considered abnormally thick Small bowel diameter 12mm for fluid filled appendix is abnormal (>8mm if additional signs can also suggest appendicitis)

Pediatrics:

COLON Colon wall - >3mm is abnormal Colon diameter 2.5 times width of L1 vertebral body Air-enema for intusssception max pressure 120mmHg, hydrostatic method uses Rule of 3s

with 3 attempts, 3 minutes each, 3ft barium column above the table Hirschsprungs disease Rectum/sigmoid ratio >0.9 (rectum is normally wider than sigmoid)

RECTUM Presacral space measured at S4-S5, >1.5 or 2cm is too wide Rectal valves of Houston normal width 5mm, width >7mm is usually abnormal, may be absent

in normal people Anorectal angle normal 70 to 130 degrees, approaches 180 degrees with defecation, maintained

by puborectalis muscle In defecography, movement of pelvic floor in excess of 3cm indicates abnormal descent

anorectal junction descending 3-4cm below ischial tuberosities is sign of weak perineum Pediatrics: Hirschsprungs disease Rectum/sigmoid ratio >0.9 (rectum is normally wider than sigmoid)

ADRENAL Size 2-4cm length, 2-2.5cm width, 1cm thick (overall shape more important than any particular

measurement) Adrenal adenoma measurements - 50% washout of enhancement,

30cc volume on US ((L*W*D)/2) Ave prostate sono measurements 20-40mm CC, 21-34mm AP, 39-53mm TR Ave nl prostate volume is 12.9cc to 37.1cc Pediatrics:

TESTIS/EPYDIDYMIS Normal adult size 5 x 3 x 3cm (normal volume 15-20cc by equation (L*W*D)/2) Varicocele >2mm diameter veins Epididymal head diameter 0.45-1.5cm any significant asymmetry is abnormal Epididymal body/tail thickness 12mm thick or >50% thickness of myometrium Arcuate uterus cleft or impression on single endometrial cavity 1.5cm Ovarian cystic mass vascular characteristics worrisome for malignancy internal flow, pulsatility

index (PI) 3mm, concerning for malignancy Ovarian veins in pelvic congestion syndrome tortuous and dilated with diameter >4mm and flow

Pediatrics: Uterine length pre-pubertal 4-6cm Endometrial stripe thickness premenstrual normally not seen, if present then very thin line

OB SONO First trimester is 0-14wks, 2nd trimester is 14-28wks, third trimester is 28wks-term Quad test performed between 16-18wks (upto 15-20wks): MS-AFP, B-hCG, estriol, inhibin AFI >25cm is polyhydramnios, single deepest pocket (mild >8cm, mod >12cm, severe >16cm) AFI 3mm abnormal Nuchal fold outer skull to outer skin, >5mm is abnormal (measured 15-20 weeks gestation) Spine seen in entirety through L5 by 16 weeks, S1-S5 then ossify sequentially every 2-3wks Fetal renal pelvis hydronephrosis 4mm @16-20 weeks, 7mm after 34 weeks gestation Fetal heart rate nl 120-160 bpm, bradycardia 400 bpm Twin discordance (largest weight-smallest weight)/(largest weight), >25% worrisome for twin-

twin transfusion First trimester demise fetal pole 10mm (>25mm transabdominally) and no heart motion by m-

mode or color Doppler Anembryonic pregnancy mean gestational sac diameter 20mm and no fetal pole seen Intrauterine pregnancy mean gestational sac diameter 2mm is deep notch sign associated with ACL injury Scaphoid-lunate joint 4mm indicates fasciitis Boehlers angle angle between lines from anterosuperior angle of calcaneus to superior most

point of calcaneus and superior calcaneal tuberosity to most superior part of calcaneus, normal is 30-35 degrees,

o STANDARD mean BMD of 25 yo female o NORMAL BMD from mean to 1 SD below mean (mean to -1 SD) o OSTEOPENIA T-score 1 to 2.5 SD below mean (-1 to -2.5 SD) o OSTEOPOROSIS T-score >2.5 below mean (>-2.5 SD)

Pediatrics: Slipped capital femoral epiphysis - 1cm is abnormal Pediatrics: Thickened filum terminale >2mm at L5 Cerebellar tonsils 5mm below foramen magnum, >5mm is Chiari I Pineal gland calcification before 6 years old is abnormal

Helpful Illustrations

1. Peroneus tertius M. 2. Calcaneal (Achilles) tendon 3. Inferior extensor retinaculum 4. Superior peroneal retinaculum 5. Tendons m. extensor digitorum longus 6. Inferior extensor retinaculum 7. Extensor digitorum brevis m. 8. Tendon m. peroneus tertius 9. Tendon m. peroneus longus 10. Tendon m. peroneus brevis 11. Tuberosity, fifth metatarsal bone

Trauma Scales

Grading Systems and Workup Flowcharts

These sizes and other reference materials were gathered fromCARDIACMAJOR VESSELS

Aortic root diameter normal 20 to 40mm, >4.5cm aneurysmalCAROTID ARTERY USMEDIASTINUMLYMPH NODESLIVER/SPLEENBILIARY SYSTEM/GALLBLADDER

ESOPHAGUSPediatrics:

STOMACHDUODENUMSMALL BOWELILEOCECAL VALVE/APPENDIXCOLONRECTUMADRENALKIDNEYBLADDER/URETHRA/PROSTATETESTIS/EPYDIDYMISUTERUS/OVARIESOB SONOMSK