Bio

Clinical Focus


  • Body Imaging
  • Diagnostic Radiology
  • virtual colonoscopy
  • Gastrointestinal Diseases

Academic Appointments


Administrative Appointments


  • Associate Director, Stanford Diagnostic Radiology Residency Program (2009 - Present)

Professional Education


  • Board Certification: Diagnostic Radiology, American Board of Radiology (2008)
  • Fellowship:Stanford University Medical Center (2009) CA
  • Residency:Stanford University Medical Center - Radiology (2008) CA
  • Fellowship:Univ of California San Francisco (2003) CA
  • Residency:University of California San Francisco (2002) CA
  • Medical Education:University of Texas Medical School at Houston (1999) TX

Publications

All Publications


  • Predictors of appendicitis on computed tomography among cases with borderline appendix size. Emergency radiology Thompson, A. C., Olcott, E. W., Poullos, P. D., Jeffrey, R. B., Thompson, M. O., Rosenberg, J., Shin, L. K. 2015; 22 (4): 385-394

    Abstract

    Confident diagnosis of appendicitis when the appendix is borderline (6 to 7 mm) in size can be challenging. This retrospective study assessed computed tomography (CT) findings that are most predictive of appendicitis when the appendix is borderline in diameter. Three radiologists conducted separate, blind retrospective reviews of 105 contrast-enhanced CTs with borderline appendices. Presence or absence of appendicitis was confirmed by chart review of clinical or surgical outcomes. Logistic regression was used to determine the odds ratio (OR) and the receiver operating characteristic for CT features predictive of appendicitis. Absence of intraluminal air (OR?=?5.11, p?

    View details for DOI 10.1007/s10140-015-1297-6

    View details for PubMedID 25687166

  • Ischemic colitis due to a mesenteric arteriovenous malformation in a patient with a connective tissue disorder. Journal of radiology case reports Poullos, P. D., Thompson, A. C., Holz, G., Edelman, L. A., Jeffrey, R. B. 2014; 8 (12): 9-21

    Abstract

    Ischemic colitis is a rare, life-threatening, consequence of mesenteric arteriovenous malformations. Ischemia ensues from a steal phenomenon through shunting, and may be compounded by the resulting portal hypertension. Computed tomographic angiography is the most common first-line test because it is quick, non-invasive, and allows for accurate anatomic characterization. Also, high-resolution three-dimensional images can be created for treatment planning. Magnetic resonance angiography is similarly sensitive for vascular mapping. Conventional angiography remains the gold standard for diagnosis and also allows for therapeutic endovascular embolization. Our patient underwent testing using all three of these modalities. We present the first reported case of this entity in a patient with a vascular connective tissue disorder.

    View details for DOI 10.3941/jrcr.v8i12.1843

    View details for PubMedID 25926912

  • Pancreatic neuroendocrine tumours: hypoenhancement on arterial phase computed tomography predicts biological aggressiveness HPB Worhunsky, D. J., Krampitz, G. W., Poullos, P. D., Visser, B. C., Kunz, P. L., Fisher, G. A., Norton, J. A., Poultsides, G. A. 2014; 16 (4): 304-311

    Abstract

    Contrary to pancreatic adenocarcinoma, pancreatic neuroendocrine tumours (PNET) are commonly hyperenhancing on arterial phase computed tomography (APCT). However, a subset of these tumours can be hypoenhancing. The prognostic significance of the CT appearance of these tumors remains unclear.From 2001 to 2012, 146 patients with well-differentiated PNET underwent surgical resection. The degree of tumour enhancement on APCT was recorded and correlated with clinicopathological variables and overall survival.APCT images were available for re-review in 118 patients (81%). The majority had hyperenhancing tumours (n = 80, 68%), 12 (10%) were isoenhancing (including cases where no mass was visualized) and 26 (22%) were hypoenhancing. Hypoenhancing PNET were larger, more commonly intermediate grade, and had higher rates of lymph node and synchronous liver metastases. Hypoenhancing PNET were also associated with significantly worse overall survival after a resection as opposed to isoenhancing and hyperenhancing tumours (5-year, 54% versus 89% versus 93%). On multivariate analysis of factors available pre-operatively, only hypoenhancement (HR 2.32, P = 0.02) was independently associated with survival.Hypoenhancement on APCT was noted in 22% of well-differentiated PNET and was an independent predictor of poor outcome. This information can inform pre-operative decisions in the multidisciplinary treatment of these neoplasms.

    View details for DOI 10.1111/hpb.12139

    View details for Web of Science ID 000332989700002

  • Current techniques in the performance, interpretation, and reporting of CT colonography. Gastrointestinal endoscopy clinics of North America Poullos, P. D., Beaulieu, C. F. 2010; 20 (2): 169-192

    Abstract

    The technical objective of computed tomographic colonography (CTC) is to acquire high-quality computed tomography images of the cleansed, well-distended colon for polyp detection. In this article the authors provide an overview of the technical components of CTC, from preparation of the patient to acquisition of the imaging data and basic methods of interpretation. In each section, the best evidence for current practices and recommendations is reviewed. Each of the technical components must be optimized to achieve high sensitivity in polyp detection.

    View details for DOI 10.1016/j.giec.2010.02.007

    View details for PubMedID 20451809

  • MR colonography and MR enterography. Gastrointestinal endoscopy clinics of North America Shin, L. K., Poullos, P., Jeffrey, R. B. 2010; 20 (2): 323-346

    Abstract

    The bowel is a common site for pathologic processes, including malignancies and inflammatory disease. Colorectal cancer accounts for 10% of all new cancers and 9% of cancer deaths. A significant decrease in the incidence of colorectal cancer and cancer death rates has been attributed to screening measures, earlier detection, and improved therapies. Virtual colonoscopy (VC), also known as computed tomography colonography, is an effective method for detecting polyps. However, in light of increasing concerns about ionizing radiation exposure from medical imaging and potential increased risk of future radiation-induced malignancies, magnetic resonance imaging (MRI) is seen as an increasingly attractive alternative. Improvements in MRI technology now permit three-dimensional volumetric imaging of the entire colon in a single breath hold at high spatial resolution, making VC with MRI possible.

    View details for DOI 10.1016/j.giec.2010.02.010

    View details for PubMedID 20451820

  • Gastrointestinal Amyloidosis: Approach to Treatment. Current treatment options in gastroenterology Poullos, P. D., Stollman, N. 2003; 6 (1): 17-25

    Abstract

    The main treatment goals in amyloidosis are twofold: 1) to diagnose the underlying disease state accurately to guide effective primary therapy (if available) and 2) to ameliorate symptoms. The correct diagnosis is essential because disease-modifying therapies vary widely according to the underlying primary pathology. Primary treatment options remain limited. The best evidence is for high-dose chemotherapy, followed by autologous stem cell transplantation in patients with primary systemic amyloidosis. High-flux hemodialysis (HD) may prevent HD-related amyloidosis. Liver transplantation may be an option for patients with familial amyloidotic polyneuropathy. Several novel specific therapies are under investigation, including small molecule drugs and vaccines. Their efficacy and safety in humans remain to be demonstrated. In the absence of specific cures, symptom-directed therapy assumes a paramount role and can improve quality of life by mitigating diarrhea or pain, for example.

    View details for PubMedID 12521568

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