Perry J Pickhardt

University of Wisconsin–Madison, Madison, Wisconsin, United States

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Publications (82)221.87 Total impact

  • Perry J Pickhardt
    Digestive Diseases and Sciences 12/2014; DOI:10.1007/s10620-014-3454-2 · 2.26 Impact Factor
  • Margriet C de Haan, Perry J Pickhardt, Jaap Stoker
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    ABSTRACT: Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. The introduction of CRC screening programmes using stool tests and flexible sigmoidoscopy, have been shown to reduce CRC-related mortality substantially. In several European countries, population-based CRC screening programmes are ongoing or being rolled out. Stool tests like faecal occult blood testing are non-invasive and simple to perform, but are primarily designed to detect early invasive cancer. More invasive tests like colonoscopy and CT colonography (CTC) aim at accurately detecting both CRC and cancer precursors, thus providing for cancer prevention. This review focuses on the accuracy, acceptance and safety of CTC as a CRC screening technique and on the current position of CTC in organised population screening. Based on the detection characteristics and acceptability of CTC screening, it might be a viable screening test. The potential disadvantage of radiation exposure is probably overemphasised, especially with newer technology. At this time-point, it is not entirely clear whether the detection of extracolonic findings at CTC is of net benefit and is cost effective, but with responsible handling, this may be the case. Future efforts will seek to further improve the technique, refine appropriate diagnostic algorithms and study cost-effectiveness. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Gut 12/2014; 64(2). DOI:10.1136/gutjnl-2014-308696 · 13.32 Impact Factor
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    ABSTRACT: Purpose To retrospectively identify morphologic findings at computed tomographic (CT) colonography that are the most reliable in the differentiation of masslike chronic diverticular disease from sigmoid carcinoma in a large patient cohort. Materials and Methods This study was approved by the institutional review boards. The need for signed consent was waived for this retrospective study. The cohort consisted of 212 patients (mean age, 68 years; 113 women, 99 men) with focal masslike findings in the sigmoid colon at CT colonography, representing chronic diverticular disease (n = 97) or sigmoid carcinoma (n = 115). CT colonography studies were scored according to presence or absence of potential discriminators by a panel of four readers in consensus. Sensitivity, specificity, positive predictive value ( PPV positive predictive value ), negative predictive value ( NPV negative predictive value ), and accuracy were calculated, and multivariate analysis was performed. Results Absence of diverticula in the affected segment showed high NPV negative predictive value and PPV positive predictive value (0.95 and 0.93, respectively). Also, shoulder phenomenon showed a high NPV negative predictive value (0.92) and PPV positive predictive value (0.75). Segment length of 10 cm or less ( NPV negative predictive value , 0.85; PPV positive predictive value , 0.61) and destroyed mucosal folds ( NPV negative predictive value , 1.00; PPV positive predictive value , 0.62) had a high NPV negative predictive value but a low PPV positive predictive value . Although segments affected by carcinoma often showed straightened and eccentric growth patterns, no thick fascia sign, and more and larger local-regional lymph nodes (all P < .05), NPV negative predictive value was insufficient for discrimination ( NPV negative predictive value ≤ 0.66). Combination of absence of diverticula and presence of shouldering showed a high diagnostic certainty (93%). Conclusion Carcinoma is best differentiated from masslike diverticular disease by the absence of diverticula in the affected segment and the presence of shoulder phenomenon. © RSNA, 2014.
    Radiology 11/2014; DOI:10.1148/radiol.14132829 · 6.21 Impact Factor
  • Perry J Pickhardt
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    ABSTRACT: The aim of this review is to provide an update on important recent advances in radiologic colorectal imaging, with emphasis on detection, staging, and surveillance of colorectal neoplasia.
    Current Opinion in Gastroenterology 11/2014; DOI:10.1097/MOG.0000000000000141 · 3.66 Impact Factor
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    Dataset: STM Cover
  • P Bannas, J Bakke, A Munoz Del Rio, P J Pickhardt
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    ABSTRACT: To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with the current front-line laxative magnesium citrate (MgC) versus the former front-line laxative sodium phosphate (NaP) at CT colonography (CTC).
    Clinical Radiology 09/2014; DOI:10.1016/j.crad.2014.08.001 · 1.66 Impact Factor
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  • Journal of Clinical Densitometry 07/2014; 17(3):408. DOI:10.1016/j.jocd.2014.04.036 · 1.60 Impact Factor
  • Journal of Clinical Densitometry 07/2014; 17(3):408–409. DOI:10.1016/j.jocd.2014.04.037 · 1.60 Impact Factor
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    ABSTRACT: To objectively compare residual colonic fluid volume and attenuation of oral sulfate solution (OSS) with four different established cathartic regimens using an automated volumetric software tool at CT colonography (CTC). This HIPAA-compliant study had institutional review board approval. Volumetric analysis of residual contrast-tagged colonic fluid was performed on CTC studies in 263 adults (mean age 60.1 years; 137M/126F) using an automated volumetric software tool. Twenty-three patients receiving 177 mL OSS (SUPREP; single-bottle purgation) were compared with 60 patients each receiving 45 mL sodium phosphate (NaP), 90 mL NaP (2x NaP), 592 mL (two bottles) magnesium citrate (MgC), and 4,000 mL polyethylene glycol (PEG). All patients received oral contrast cleansing after catharsis. Data were analyzed with unpaired t test with Welch correction and F test. The mean volume of residual colonic fluid was less with OSS (125 +/- A 60 mL) than for established cathartic agents: 2x NaP (206 +/- A 125 mL, P < 0.0001), MgC (184 +/- A 125 mL, P < 0.01), PEG (166 +/- A 114 mL, P < 0.05), and NaP (165 +/- A 135 mL, P = 0.067). Variance of volumes was also significantly lower for OSS (range 28-251 mL) than for established agents (range 4-853 mL) (all P < 0.01). Mean fluid attenuation was higher with OSS (956 +/- A 168 HU) than for established agents (all P < 0.05): 2x NaP (455 +/- A 191 HU), MgC (691 +/- A 154 HU), NaP (779 +/- A 127 HU), and PEG (843 +/- A 193 HU). Automated volumetry allows rapid objective assessment of bowel preparation quality at CTC. Purgation with the novel oral sulfate solution (SUPREP) consistently resulted in less residual colonic fluid and higher fluid attenuation compared with established cathartic regimens.
    Abdominal Imaging 06/2014; 40(1). DOI:10.1007/s00261-014-0186-x · 1.91 Impact Factor
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    ABSTRACT: Many solid tumors contain an overabundance of phospholipid ethers relative to normal cells. Capitalizing on this difference, we created cancer-targeted alkylphosphocholine (APC) analogs through structure-activity analyses. Depending on the iodine isotope used, radioiodinated APC analog CLR1404 was used as either a positron emission tomography (PET) imaging ((124)I) or molecular radiotherapeutic ((131)I) agent. CLR1404 analogs displayed prolonged tumor-selective retention in 55 in vivo rodent and human cancer and cancer stem cell models. (131)I-CLR1404 also displayed efficacy (tumor growth suppression and survival extension) in a wide range of human tumor xenograft models. Human PET/CT (computed tomography) and SPECT (single-photon emission computed tomography)/CT imaging in advanced-cancer patients with (124)I-CLR1404 or (131)I-CLR1404, respectively, demonstrated selective uptake and prolonged retention in both primary and metastatic malignant tumors. Combined application of these chemically identical APC-based radioisosteres will enable personalized dual modality cancer therapy of using molecular (124)I-CLR1404 tumor imaging for planning (131)I-CLR1404 therapy.
    Science translational medicine 06/2014; 6(240):240ra75. DOI:10.1126/scitranslmed.3007646 · 14.41 Impact Factor
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    ABSTRACT: For patients undergoing screening computed tomography colonography (CTC), an opportunity exists for bone mineral density (BMD) screening without additional radiation exposure using quantitative computed tomography (QCT). This study investigated the use of dual-energy X-ray absorptiometry (DXA)-equivalent QCT Computed Tomography X-Ray Absorptiometry (CTXA) analysis at the hip obtained using CTC examinations using a retrospective asynchronous calibration of patient scans. A cohort of 33 women, age 61.3 (10.6) yr (mean [standard deviation]), had routine CTC using various GE LightSpeed CT scanner models followed after 0-9 mo by a DXA hip BMD examination using a GE Lunar Prodigy machine. Areal bone mineral density (aBMD) and T-scores of the proximal femur were measured from either prone or supine CTC examinations using Mindways QCT Pro software following standard workflow except that the CT scanners were asynchronously calibrated by phantoms scanned retrospectively of the CTC examination without the subject present. CTXA and DXA aBMD were highly correlated (R(2) = 0.907) with a linear relationship of DXA_BMD = 1.297*CTXA_BMD + 0.048. The standard error of estimate (SEE) on the linear fit was 0.053 g/cm(2). CTXA and DXA T-scores showed a linear relationship of DXA_T-score = 1.034*CTXA_T-score + 0.3 and an SEE of 0.379 T-scores. CTXA and DXA aBMD and T-score measurements showed good correlation despite asynchronous scan acquisition and retrospective QCT calibration. The SEE of 0.053 g/cm(2) is on par with the literature comparing Hologic and Lunar DXA devices. The observed relationship between CTXA and Lunar DXA aBMD matches predictions from published cross-calibrations relating CTXA to DXA aBMD measurement. Thus, opportunistic use of CTXA T-scores obtained at the time of CTC could enhance osteoporosis screening.
    Journal of Clinical Densitometry 05/2014; DOI:10.1016/j.jocd.2014.03.002 · 1.60 Impact Factor
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    Perry J Pickhardt
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    ABSTRACT: Existing and emerging colorectal screening tests can be assessed in terms of the key categories of diagnostic performance, procedural risks, patient acceptability, and cost-effectiveness. To push a new screening test to acceptance, it need not outperform existing strategies in all of these criteria. Rather, a relative advantage in one criterion combined with acceptable performance in the others may be considered adequate. For computed tomographic colonography (CTC), a strong case can be made that this test meets or exceeds optical colonoscopy, the current screening standard, in all of these categories. Published data, including our own experience with CTC screening, will be reviewed to support this claim. Reasons why CTC has not yet achieved its full potential as a valuable screening test for colorectal cancer prevention will also be considered.
    Expert review of gastroenterology & hepatology 02/2014; DOI:10.1586/17474124.2014.887436
  • Article: Response.
    Perry J Pickhardt, George Carberry
    Radiology 02/2014; 270(2):632. · 6.21 Impact Factor
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    ABSTRACT: For patients undergoing screening computed tomography colonography (CTC), an opportunity exists for bone mineral density (BMD) screening without additional radiation exposure using quantitative computed tomography (QCT). This study investigated the use of dual-energy X-ray absorptiometry (DXA)–equivalent QCT Computed Tomography X-Ray Absorptiometry (CTXA) analysis at the hip obtained using CTC examinations using a retrospective asynchronous calibration of patient scans. A cohort of 33 women, age 61.3 (10.6) yr (mean [standard deviation]), had routine CTC using various GE LightSpeed CT scanner models followed after 0–9 mo by a DXA hip BMD examination using a GE Lunar Prodigy machine. Areal bone mineral density (aBMD) and T-scores of the proximal femur were measured from either prone or supine CTC examinations using Mindways QCT Pro software following standard workflow except that the CT scanners were asynchronously calibrated by phantoms scanned retrospectively of the CTC examination without the subject present. CTXA and DXA aBMD were highly correlated (R2 = 0.907) with a linear relationship of DXA_BMD = 1.297*CTXA_BMD + 0.048. The standard error of estimate (SEE) on the linear fit was 0.053 g/cm2. CTXA and DXA T-scores showed a linear relationship of DXA_T-score = 1.034*CTXA_T-score + 0.3 and an SEE of 0.379 T-scores. CTXA and DXA aBMD and T-score measurements showed good correlation despite asynchronous scan acquisition and retrospective QCT calibration. The SEE of 0.053 g/cm2 is on par with the literature comparing Hologic and Lunar DXA devices. The observed relationship between CTXA and Lunar DXA aBMD matches predictions from published cross-calibrations relating CTXA to DXA aBMD measurement. Thus, opportunistic use of CTXA T-scores obtained at the time of CTC could enhance osteoporosis screening.
    Journal of Clinical Densitometry 01/2014; · 1.60 Impact Factor
  • Nicola Flor, Francesco Sardanelli, Perry J Pickhardt
    Scandinavian Journal of Gastroenterology 11/2013; DOI:10.3109/00365521.2013.857714 · 2.33 Impact Factor
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    ABSTRACT: OBJECTIVE: We propose a diverticular disease severity score (DDSS) based on CT colonography (CTC) findings. METHODS: Seventy-nine patients (62 ± 14.5 years) underwent CTC after recovering from an episode of acute diverticulitis. Two independent readers classified each case using a four-point scale (DDSS), based on maximum sigmoid colon wall thickness (MSCWT) and minimum lumen diameter at CTC: 1 = MSCWT <3 mm, lumen diameter ≥15 mm; 2 = MSCWT 3-8 mm, lumen diameter ≥5 mm; 3 = MSCWT ≥8 mm, lumen diameter ≥5 mm; 4 = MSCWT ≥8 mm, lumen diameter <5 mm. Intra- and interobserver reproducibility was evaluated. Of 79 patients, 32 (40 %) underwent surgery after CTC; MSCWT was directly measured on the pathological specimen. RESULTS: Intra- and interobserver reproducibility of DDSS were almost perfect (k = 0.90-0.84). DDSS significantly correlated with the probability of surgery (P = 0.001). After surgery, histopathology revealed acute/chronic diverticular inflammation only in 29 cases, and superimposed sigmoid cancer (n = 2) or Crohn's disease (n = 1) in 3 patients with a DDSS of 4. MSCWT at histopathology correlated with DDSS (P = 0.008). CONCLUSION: DDSS is highly reproducible and correlates with pathological MSCWT. Nearly 1 in 3 patients with a DDSS of 4 had significant superimposed histopathology. CTC with DDSS can provide colorectal surgeons with valuable information. KEY POINTS: • A diverticular disease severity score (DDSS) based on CT colonography is proposed. • This DDSS is based on sigmoid colon wall thickness and lumen diameter. • High scores may be associated with relevant coexisting lesions. • A CTC-based DDSS may influence therapeutic decision-making.
    European Radiology 05/2013; DOI:10.1007/s00330-013-2882-2 · 4.34 Impact Factor
  • Article: Preface.
    Perry J Pickhardt
    Radiologic Clinics of North America 01/2013; 51(1):xi. DOI:10.1016/j.rcl.2012.10.002 · 1.83 Impact Factor
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    ABSTRACT: The effect of CT colonography (CTC) screening on colonoscopy is unknown. The objective of this study is to determine the effect of a CTC screening program on the number of screening, therapeutic and total colonoscopies performed. We compared the quarterly mean numbers of colonoscopic examinations performed for 50-79 year olds undergoing colorectal cancer screening in 2003, before initiation of a CTC program, to 2011, seven years after the CTC program began at our academic tertiary care facility. The CTC program began in 2004 with a peak number of 387 CTC examinations performed in the 3rd quarter of 2005 and 275 examinations in the final quarter of 2011. Screening colonoscopies increased from 555 mean/quarter in 2003 to 1460 in 2011 (P < 0.001). The mean/quarter number of total colonoscopies performed increased from 1104 in 2003 to 2382 in 2011 (P < 0.001). The number of overall colon cancer screening examinations (Colonoscopy + CTC) increased from 555/quarter in 2003 to 1736 in 2011 (P < 0.001). Since the initiation of CTC screening at our institution, the overall number of total colorectal cancer screening examinations (CTC + colonoscopy) has greatly increased. The initiation of a CTC screening program did not lead to a reduction in the number of colonoscopic examinations performed. Conversely, a significant increase in the number of screening and total colonoscopies completed was observed.
    Journal of gastrointestinal and liver diseases: JGLD 12/2012; 21(4):391-5. · 1.85 Impact Factor
  • Hongbin Zhu, Matthew Barish, Perry Pickhardt, J Liang
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    ABSTRACT: Human colon has complex structures mostly because of the haustral folds. The folds are thin flat protrusions on the colon wall, which complicate the shape analysis for computer-aided detection (CAD) of colonic polyps. Fold segmentation may help reduce the structural complexity, and the folds can serve as anatomic reference for computed tomographic colonography (CTC). Therefore, in this study, based on a model of the haustral fold boundaries, we developed a level-set approach to automatically segment the fold surfaces. To evaluate the developed fold segmentation algorithm, we first established the ground truth of haustral fold boundaries by experts drawing on 15 patient CTC datasets without severe under/over colon distention from two medical centers. The segmentation algorithm successfully detected 92.7% of the folds in the ground truth. In addition to the sensitivity measure, we further developed a merit of segmented area ratio (SAR), i.e., the ratio between the area of the intersection and union of the expert-drawn folds and the area of the automatically-segmented folds, to measure the segmentation accuracy. The segmentation algorithm reached an average value of SAR=86.2%, showing a good match with the ground truth on the fold surfaces. We believe the automatically-segmented fold surfaces have the potential to benefit many post-procedures in CTC, e.g., CAD, taenia coli extraction, supine-prone registration, etc.
    IEEE transactions on bio-medical engineering 10/2012; 60(2). DOI:10.1109/TBME.2012.2226242 · 2.15 Impact Factor

Publication Stats

345 Citations
221.87 Total Impact Points

Institutions

  • 2004–2014
    • University of Wisconsin–Madison
      • Department of Radiology
      Madison, Wisconsin, United States
  • 2013
    • University of Milan
      • Department of Health Science - DISS
      Milano, Lombardy, Italy