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Dive into the research topics where Nicholas Papanicolaou is active.

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Featured researches published by Nicholas Papanicolaou.


Emergency Radiology | 2006

Incidence of visualization of the normal appendix on different MRI sequences

Paul Nikolaidis; Nancy A. Hammond; Jamie Marko; Frank H. Miller; Nicholas Papanicolaou; Vahid Yaghmai

The purpose of this paper is to assess the incidence of visualization of the normal appendix on magnetic resonance imaging (MRI) examinations of the pelvis in a large adult population and to compare the yield of commonly used sequences. Pelvic MRI scans of 111 randomly selected patients were retrospectively reviewed by two fellowship-trained body imagers. Thirty-six cases, where the entire cecum and terminal ileum were not included in the field of view, were excluded. A normal appendix was definitively visualized in 55 of 71 patients on T1 spin echo (SE) sequences (78%). The appendix was seen on 25 of 42 (60%) half-Fourier single-shot turbo spin echo T2. Visualization rates were 42% on pre-gadolinium T1 FS GRE, 54% on post-gadolinium T1 fat-suppressed gradient echo, and 17% of short tau inversion recovery sequences. MRI is an effective modality for visualization of the normal appendix. This may have important implications in patients with abdominal or pelvic pain, as visualization of a normal appendix should exclude the possibility of acute appendicitis from the differential diagnosis.


Ultrasound Quarterly | 2012

ACR Appropriateness Criteria ® acute onset of scrotal pain--without trauma, without antecedent mass.

Erick M. Remer; David D. Casalino; Ronald S. Arellano; Jay T. Bishoff; Courtney A. Coursey; Manjiri Dighe; Gary M. Israel; Elizabeth Lazarus; John R. Leyendecker; Massoud Majd; Paul Nikolaidis; Nicholas Papanicolaou; Srinivasa R. Prasad; Parvati Ramchandani; Sheila Sheth; Raghunandan Vikram; Boaz Karmazyn

Men or boys, who present with acute scrotal pain without prior trauma or a known mass, most commonly suffer from torsion of the spermatic cord; epididymitis or epididymoorchitis; or torsion of the testicular appendages. Less common causes of pain include a strangulated hernia, segmental testicular infarction, or a previously undiagnosed testicular tumor. Ultrasound is the study of choice to distinguish these disorders; it has supplanted Tc-99 m scrotal scintigraphy for the diagnosis of spermatic cord torsion. MRI should be used in a problem solving role if the ultrasound examination is inconclusive. The ACR Appropriateness Criteria ® are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.


Journal of The American College of Radiology | 2011

ACR Appropriateness Criteria® Posttreatment Follow-up of Prostate Cancer

David D. Casalino; Erick M. Remer; Ronald S. Arellano; Jay T. Bishoff; Courtney A. Coursey; Manjiri Dighe; Douglas F. Eggli; Gary M. Israel; Elizabeth Lazarus; John R. Leyendecker; Paul Nikolaidis; Nicholas Papanicolaou; Srinivasa R. Prasad; Parvati Ramchandani; Sheila Sheth; Raghunandan Vikram

Although prostate cancer can be effectively treated, recurrent or residual disease after therapy is not uncommon and is usually detected by a rise in prostate-specific antigen. Patients with biochemical prostate-specific antigen relapse should undergo a prompt search for the presence of local recurrence or distant metastatic disease, each requiring different forms of therapy. Various imaging modalities and image-guided procedures may be used in the evaluation of these patients. Literature on the indications and usefulness of these radiologic studies and procedures in specific clinical settings is reviewed. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.


The American Journal of Medicine | 2014

ACR appropriateness criteria® on renal failure

Erick M. Remer; Nicholas Papanicolaou; David D. Casalino; Jay T. Bishoff; M. Donald Blaufox; Courtney A. Coursey; Manjiri Dighe; Steven C. Eberhardt; Stanley Goldfarb; Howard J. Harvin; Marta E. Heilbrun; John R. Leyendecker; Paul Nikolaidis; Aytekin Oto; Glenn M. Preminger; Steven S. Raman; Sheila Sheth; Raghunandan Vikram; Robert M. Weinfeld

Imaging plays a role in the management of patients with acute kidney injury or chronic kidney disease. However, clinical circumstances strongly impact the appropriateness of imaging use. In patients with newly detected renal dysfunction, ultrasonography can assess for reversible causes, assess renal size and echogenicity, and thus, establish the chronicity of disease. Urinary obstruction can be detected, but imaging is most useful in high-risk groups or in patients in whom there is a strong clinical suspicion for obstruction. Computed tomography, computed tomography or magnetic resonance arteriography, and percutaneous ultrasound-guided renal biopsy are valuable in other clinical situations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.


Abdominal Imaging | 2013

Perspectives on radiation dose in abdominal imaging.

Tessa S. Cook; Susan Hilton; Nicholas Papanicolaou

Reported instances of patients’ overexposure to imaging-related radiation have spurred the radiology and medical physics communities to identify and develop methods for decreasing the amount of radiation used to achieve diagnostic-quality images. These initiatives include examining and optimizing conventional CT scanning parameters, introducing innovative scan protocols, and incorporating novel dose reduction technologies. The greatest challenge to effective dose reduction in the abdomen and pelvis remains patient size. Here, we review the state of the art in abdominopelvic CT in both adult and pediatric patients and describe some of our own efforts in dose reduction for these types of examinations.


European Journal of Radiology | 2010

Asymmetric spermatic cord vessel enhancement and enlargement on contrast-enhanced MDCT as indicators of ipsilateral scrotal pathology

Paras Lakhani; Nicholas Papanicolaou; Parvati Ramchandani; Drew A. Torigian

PURPOSE To determine the association of asymmetric spermatic cord vessel enhancement and enlargement on contrast-enhanced CT with ipsilateral scrotal pathology. METHODS This case series included 30 men with contrast-enhanced CT: 10 cases had asymmetric enhancement and enlargement of spermatic cord vessels with confirmed ipsilateral scrotal pathology determined by additional imaging and/or clinical records; 20 negative reference cases had no such findings with normal corresponding scrotal ultrasound. Maximum spermatic vessel diameters and attenuation values were determined bilaterally. Two blinded radiologists independently assessed all exams for interobserver agreement. RESULTS For cases, maximum spermatic cord vessel diameters were greater ipsilaterally (5.9+/-1.7 mm) than contralaterally (4.0+/-1.1mm), p<0.001. Maximum HU values were greater ipsilaterally (139.5+/-29.5) than contralaterally (70.6+/-17.5), p<0.0003. Maximum spermatic vessel diameters and attenuation values were significantly greater for positive than negative reference cases (p<3.9 x 10(-8) and p<4.9 x 10(-7) respectively). There was substantial interobserver agreement for asymmetric spermatic vessel enlargement (kappa=0.79) and enhancement (kappa=0.73). In 3 cases, the CT findings lead to a scrotal ultrasound that confirmed the diagnosis and altered patient management. CONCLUSION MDCT findings of asymmetric spermatic vessel enlargement and enhancement are indicators of ipsilateral scrotal pathology. The detection of such findings may have implications for patient care and should prompt further evaluation of the scrotum in the proper clinical setting.


Breast Journal | 2012

Low-dose cyclophosphamide associated with hemorrhagic cystitis in a breast cancer patient

Ariela Marshall; Cindy McGrath; Drew A. Torigian; Nicholas Papanicolaou; Priti Lal; Carol Kaplan Tweed

Abstract:  Hemorrhagic cystitis is a known complication of high‐dose cyclophosphamide treatment, generally occurring at doses greater than 100 g. There are few reports of hemorrhagic cystitis occurring with low‐dose cyclophosphamide therapy, and this complication has not been described in breast cancer patients. We present a case of a patient with stage IIB breast cancer who developed clinical, radiographic, and pathologic evidence of hemorrhagic cystitis after a single 600 mg/m2 dose of cyclophosphamide. Three subsequent cycles of cyclophosphamide with the addition of IV hydration and MESNA were given without complication, and the patient’s urologic symptoms resolved. Repeat cystoscopy demonstrated pathologic resolution of the cystitis. We review the literature regarding proposed mechanisms of hemorrhagic cystitis, and discuss the applicability of these hypotheses in our patient.


Journal of The American College of Radiology | 2010

ACR Appropriateness Criteria® on Obstructive Voiding Symptoms Secondary to Prostate Disease

Manjiri Dighe; Isaac R. Francis; David D. Casalino; Ronald S. Arellano; Deborah A. Baumgarten; Nancy S. Curry; Gary M. Israel; John R. Leyendecker; Nicholas Papanicolaou; Srinivasa R. Prasad; Parvati Ramchandani; Erick M. Remer; Sheila Sheth

Obstructive voiding symptoms are most commonly due to prostatic hyperplasia, but other causes include bladder neck contractures, prostatic carcinomas, neurogenic bladder, and urethral stricture. Symptoms include hesitancy, dribbling, decreased force of stream, and postvoid fullness. Imaging is useful in evaluating the presence and degree of hydronephrosis, estimation of renal function, evaluation of the bladder and prostate, and detection of incidental upper tract malignancies or stones. Various modalities have been used for evaluation of the cause of obstruction. Literature on the indications and usefulness of these radiologic studies for obstructive voiding symptoms in different clinical settings is reviewed.


Abdominal Radiology | 2018

Voiding cystourethrography after prostatectomy: spectrum of appearances

Matthew A. Morgan; Nicholas Papanicolaou

PurposeThis article reviews current prostatectomy techniques and then techniques for fluoroscopic voiding cystourethrography (VCUG) evaluation of the prostate and bladder after prostatectomy. Both normal post-prostatectomy appearances and complications will be reviewed.ConclusionVCUG is a useful evaluation for both common and uncommon post-prostatectomy complications and appropriate interpretation of the VCUG complications is important to aid the urologist’s clinical decision making.


American Journal of Roentgenology | 2004

The Nonvisualized Appendix: Incidence of Acute Appendicitis When Secondary Inflammatory Changes Are Absent

Paul Nikolaidis; Caroline M. Hwang; Frank H. Miller; Nicholas Papanicolaou

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Manjiri Dighe

University of Washington

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Sheila Sheth

Johns Hopkins University

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Jay T. Bishoff

American Urological Association

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