Peter Callen, MD

Professor Emeritus
Prof In Residence


Dr. Peter W. Callen, MD, is a Professor of Radiology, Obstetrics, Gynecology, and Reproduction Sciences at the University of California, San Francisco. He obtained his medical degree from the University of California, San Francisco in 1973, and completed his residency in Diagnostic Radiology from UCSF in 1977, followed by a fellowship at the University of California, San Francisco.

Dr. Callen’s general research has been focused on discovering the sonographic signs that allow the sonographer to detect abnormalities and avoid false positive diagnosis of abnormalities in the obstetric, pediatric and adult patient. A specific area of interest has been in fetal dysmorphology and the detection of abnormalities involving the fetal, neural axis, thorax, skeletal system, genitourinary tract, gastrointestinal, and abnormalities of the placenta and umbilical cord.

Dr. Callen has published more than 200 peer-reviewed articles, and 65 book chapters. He is well known for his textbook, Ultrasonography in Obstetric and Gynecology, now in its fifth edition and considered the most extensively used book on obstetrical ultrasound worldwide.


Obstetrical, gynecology, pediatric urology

Professional Interests:
Obstetrical ultrasound, fetal dysmorphology, internet based learning, application of PACS systems to diagnostic ultrasound, perception of normal and abnormal findings at the time of ultrasound examination

Education and Training:
• Medical School: University of California, San Francisco School of Medicine
• Internship: University of California, San Francisco - Medicine
• Residency: University of California, San Francisco - Diagnostic Radiology
• Fellowship: University of California, San Francisco
• National Board of Medical Examiners
• California Medical License
• American Board of Radiology


M.D., 1973 - Medicine, University of California, San Francisco
Residency, - School of Medicine, University of California, San Francisco

Honors and Awards

Outstanding Alumni Award, University of California, San Francisco, 2010
Fellow, American Institute of Ultrasound in Medicine, 1986
Commendation for Excellence in Teaching, University of California, San Francisco Department of Obstetrics and Gynecology, 1982


Shoo BA, Kangelaris G, Callen PW, Kashani-Sabet M, Leong SP. Detection of occult melanoma by preoperative positron emission tomography-computed tomography and intraoperative ultrasonography. J Cutan Med Surg. 2010 May-Jun; 14(3):130-5.
Filly MR, Callen PW, Yegul NT, Filly RA. The yolk stalk sign: evidence of death in small embryos without heartbeats. J Ultrasound Med. 2010 Feb; 29(2):237-41.
Qayyum A, Chen DM, Breiman RS, Westphalen AC, Yeh BM, Jones KD, Lu Y, Coakley FV, Callen PW. Evaluation of diffuse liver steatosis by ultrasound, computed tomography, and magnetic resonance imaging: which modality is best? Clin Imaging. 2009 Mar-Apr; 33(2):110-5.
Kassab A, El-Bialy G, Hashesh H, Callen P. Magnetic resonance imaging and hysteroscopy to diagnose colo-uterine fistula: a rare complication of diverticulitis. J Obstet Gynaecol Res. 2008 Feb; 34(1):117-20.
Callen PW, Callen AL, Glenn OA, Toi A. Columns of the fornix, not to be mistaken for the cavum septi pellucidi on prenatal sonography. J Ultrasound Med. 2008 Jan; 27(1):25-31.
Glenn OA, Bianco K, Barkovich AJ, Callen PW, Parer JT. Fetal cerebellar hemorrhage in parvovirus-associated non-immune hydrops fetalis. J Matern Fetal Neonatal Med. 2007 Oct; 20(10):769-72.
Yang SH, Nobuhara KK, Keller RL, Ball RH, Goldstein RB, Feldstein VA, Callen PW, Filly RA, Farmer DL, Harrison MR, Lee H. Reliability of the lung-to-head ratio as a predictor of outcome in fetuses with isolated left congenital diaphragmatic hernia at gestation outside 24-26 weeks. Am J Obstet Gynecol. 2007 Jul; 197(1):30.e1-7.
Aziz S, Callen PW, Vincenti F, Hirose R. Rapidly developing nephrocalcinosis in a patient with end-stage liver disease who received a domino liver transplant from a patient with known congenital oxalosis. J Ultrasound Med. 2005 Oct; 24(10):1449-52.
Wu YW, Hamrick SE, Miller SP, Haward MF, Lai MC, Callen PW, Barkovich AJ, Ferriero DM. Intraventricular hemorrhage in term neonates caused by sinovenous thrombosis. Ann Neurol. 2003 Jul; 54(1):123-6.
Kinoshita LL, Callen PW, Filly RA, Hill LM. Sonographic detection of gallbladder duplication: two cases discovered in utero. J Ultrasound Med. 2002 Dec; 21(12):1417-21.
Filly RA, Reddy SG, Nalbandian AB, Lu Y, Callen PW. Sonographic evaluation of liver nodularity: Inspection of deep versus superficial surfaces of the liver. J Clin Ultrasound. 2002 Sep; 30(7):399-407.
Paek BW, Callen PW, Kitterman J, Feldstein VA, Farrell J, Harrison MR, Albanese CT. Successful fetal intervention for congenital high airway obstruction syndrome. Fetal Diagn Ther. 2002 Sep-Oct; 17(5):272-6.