Air Quality Monitoring and the Safety of Farmworkers in Wildfire Mandatory Evacuation Zones.

The increasing frequency and severity of wildfires due to climate change pose health risks to migrant farm workers laboring in wildfire-prone regions. This study focuses on Sonoma County, California, investigating the effectiveness of air monitoring and safety protections for farmworkers. The analysis employs AirNow and PurpleAir PM2.5 data acquired during the 2020 wildfire season, comparing spatial variability in air pollution. Results show significant differences between the single Sonoma County AirNow station data and the PurpleAir data in the regions directly impacted by wildfire smoke. Three distinct wildfire pollution episodes with elevated PM2.5 levels are identified to examine the regional variations. This study also examines the system used to exempt farmworkers from wildfire mandatory evacuation orders, finding incomplete information, ad hoc decision-making, and scant enforcement. In response, we make policy recommendations that include stricter requirements for employers, real-time air quality monitoring, post-exposure health screenings, and hazard pay. Our findings underscore the need for significant consideration of localized air quality readings and the importance of equitable disaster policies for protecting the health of farmworkers (particularly those who are undocumented migrants) in the face of escalating wildfire risks.

Elevation of Peripheral Blood CD34+ and Platelet Levels After Exercise With Cooling and Compression.

PURPOSE: To analyze the cellular response and chemokine profiles following exercise using cooling and blood flow restriction on the Vasper system. METHODS: Healthy male patients between the ages of 20 and 39 years were recruited. Testing was performed on the Vasper system, a NuStep cross-trainer with concomitant 4-limb venous compression with proximal arm cuffs at 40 mm Hg and proximal leg cuffs at 65 mm Hg. A cooling vest and cooling mat (8.3°C) were used. A 7-minute warm-up followed by alternating 30- and 60-second sprints with 1.5 and 2 minutes of active recovery, respectively, between each sprint. Peripheral blood was drawn before exercise, immediately following exercise (T20), 10 minutes after the first post-exercise blood draw (T30), and then every 30 minutes (T60, T90, T120, T150, T180). A blood draw occurred at 24 hours' postexercise. Complete blood count, monoclonal flow cytometry for CD34+, and enzyme-linked immunosorbent assay were used to analyze the samples. RESULTS: Sixteen healthy male patients (29.5 ± 4.5years, 1.78 ± 0.05m, 83.7 ± 11.4 kg) were enrolled. There was an immediate, temporary increase in white blood cell counts, marked by an increase in lymphocyte differential (38.3 ± 6.5 to 44.3 ± 9.0%, P = .001), decrease in neutrophil differential (47.8 ± 6.6 to 42.0 ± 9.1%, P < .001), and platelets (239.5 ± 57.2 to 268.6 ± 86.3 K⋅µL-1, P = .01). Monocytes significantly decreased from PRE to T90 (9.8 ± 1.1 to 8.9 ± 1.1K/µL, P < .001) and T120 (8.9 ± 1.1 K/µL, P < .0001). There was a significant increase in CD34+ cells (3.9 ± 2.0 to 5.3 ± 2.8 cells⋅µL-1, P < .001). No detectable differences in measured cytokine levels of interleukin (IL)-10, IL-6, granulocyte-macrophage colony-stimulating factor , IL-1ra, tumor necrosis factor-α, or IL-2 were observed. CONCLUSIONS: A significant elevation of peripheral blood CD34+ and platelet levels immediately following the exercise session was observed; however, there was no effect on peripheral circulation of IL-10, IL-6, IL-1ra, tumor necrosis factor-α, or IL-2. CLINICAL RELEVANCE: Exercise can be considered as a way to manipulate point-of-care blood products like platelet-rich plasma and may increase product yield.

Outcomes After Ulnar Collateral Ligament Revision Reconstruction in Baseball Players.

BACKGROUND: There is a lack of evidence regarding the success of ulnar collateral ligament (UCL) revision reconstruction. Understanding outcomes after UCL revision reconstruction is important in clinical decision making for overhead athletes. PURPOSE: To evaluate return to play and patient-reported outcomes after UCL revision reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All patients who underwent UCL revision reconstruction, attributed to retear of the ligament or pain, between June 2004 and July 2016 at 2 surgical centers were identified. Charts were reviewed for age, sex, date of primary and revision reconstruction, sport played, level of play, graft type, and complications. Patients were contacted by telephone to determine time to return to play, current level of participation, Conway score, Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow Score, and satisfaction. RESULTS: Of the 65 consecutive baseball players who underwent revision UCL reconstruction, 40 (62%) were contacted at a minimum 22 months after surgery. Of these, 38 (95%) were pitchers and 2 (5%) were position players. Time to return to throwing was 6.2 ± 2.3 months (mean ± SD), and the KJOC score was 74.2 ± 20.7. Based on the Conway score, 50% (20/40) had an excellent result, indicating a return to the previous competition level for at least 1 year, and 30% (12/40) had a good result, indicating a return to a lower level for at least 1 year. For those who were able to return to competition, it took 12.7 ± 3.6 months. In pitchers, 47% (18/38) returned to their previous competition levels for at least 1 year, with a KJOC score of 73.7 ± 21.1. Pitchers were able to return to throwing at 6.3 ± 2.3 months and competition at 12.8 ± 3.7 months. CONCLUSION: Only half of baseball players undergoing UCL revision reconstruction were able to return to their previous levels of competition. Outcomes for revision reconstructions are not as promising as primary procedures. Baseball players should be cautioned that they may not return to their previous levels of play after a revision reconstruction.

Denosumab-Associated Peri-Implant Atypical Femur Fracture: A Case Report.

Bisphosphonate use has been associated with atypical pathologic fracture and slowed bone turnover. We present a case of a bisphosphonate-associated peri-implant atypical femur fracture following use of a recon nail for treatment of a prior bisphosphonate-associated atypical femur fracture.

Emerging Orthobiologic Techniques and the Future.

The future of orthopedic surgery appears to be intimately associated with the development of orthobiologics to facilitate healing and the treatment of multiple disease processes. The orthopedic community should understand developmental processes to ensure that products are adequately studied and the effects are fully known before widespread implementation in the clinical setting. Technologies that embrace this paradigm will impact the field the most.

Presentation of soft tissue anatomy of mirror hand: an anatomical case report with implications for surgical planning.

PURPOSE: Mirror hand or ulnar dimelia is a rare and poorly studied congenital anomaly of the upper extremity. Understanding of its anatomy is limited by the rarity of the deformity and the variability in presentation. We present the case of an 80-year-old female donor with an incidental finding of mirror hand. METHODS: Medical history indicated no record of any surgical procedures or interventions to the right upper extremity suggesting that the donor had lived an independent life without the need for prosthetic aids. Unfortunately, no record of a hand examination or any visit to a hand specialist was identified within the medical record. Following imaging and disarticulation of the arm at the glenohumeral joint, an anatomical dissection was performed on the right upper extremity. RESULTS: Findings were recorded and compared to three earlier reports in the limited literature with a strong focus on understanding the anatomy of this deformity important for surgical planning. The anatomy is highlighted with a brief description of the embryology associated with mirror hand deformity. The case presents a classic example of ulnar dimelia. Arterial patterns compared favorably with those described in the literature. In addition an aberrant branch of the median nerve and a deep branch supplying the extensor compartment were noted. CONCLUSION: Based on the observations of this study (and the previous reports) we would recommend a study of vascular tree of the hand either through conventional arteriography or CT angiography prior to pollicization. The surgeon should also be prepared to perform a microsurgical arterial anastomosis if pollicization is not possible in case of an incomplete arch similar to one we described.

Comparison of MITF and Melan-A Immunohistochemistry During Mohs Surgery for Lentigo Maligna-Type Melanoma In Situ and Lentigo Maligna Melanoma.

BACKGROUND: Mohs micrographic surgery (MMS) with frozen section immunohistochemistry is a treatment option for malignant melanoma in situ (MMIS) and lentigo maligna melanoma (LMM). Melan-A is a cytoplasmic melanocyte immunostain useful on frozen sections but may lack specificity. Microphthalmia transcription factor (MITF) is a more specific nuclear melanocyte immunostain less frequently used in MMS. OBJECTIVE: To quantify melanocyte density in chronic sun-damaged skin (CSDS), negative margin, and tumor from patients undergoing MMS for MMIS and LMM using MITF and melan-A. METHODS: Sixteen patients with MMIS or LMM had frozen sections from CSDS, negative margin, and 12 tumor samples, stained with MITF and melan-A. Melanocyte counts were performed. RESULTS: Chronic sun-damaged skin mean melanocyte count (MMC) for MITF and melan-A was 9.8 and 13.7, respectively, (p < .001). Negative margin MMC for MITF and melan-A was 8.84 and 14.06, respectively, (p < .001). Tumor MMC for MITF and melan-A was 63.5 and 62.4, respectively. CONCLUSION: Although both MITF and melan-A facilitate the identification of tumor during MMS for MMIS and LMM, the apparent melanocyte density on tumor-free CSDS appears higher with melan-A than MITF. Microphthalmia transcription factor provides a crisp outline of melanocyte nuclei and is a useful alternative stain to melan-A for MMS of melanoma.

A conceptual framework for navigating the superficial territories of the face: Relevant anatomic points for the dermatologic surgeon.

Recent publications in the dermatologic surgery literature have sparked a re-emergence of interest in anatomy relevant for the Mohs surgeon necessitating a re-visit of under-appreciated concepts, regarding the topography of the face and its visceral contents from a surgically relevant perspective. This paper presents a pre-operative review and a conceptual framework for intra-operative planning for Mohs micrographic surgery and reconstruction. The key concepts presented are based on a series of (1) reviews regarding clinically significant points aimed at improving outcomes for reconstructive surgery, (2) anatomical dissections of fresh frozen cadavers, and (3) surgical experience of the authors. Basic anatomical concepts have been assimilated, surgically evaluated and re-directed toward the dermatologic surgeon in the hope that improved anatomic competence will reduce surgical hesitance.

Carbon dioxide laser treatment for Hailey-Hailey disease: a retrospective chart review with patient-reported outcomes.

BACKGROUND: Hailey-Hailey disease (HHD) is an autosomal dominant genodermatosis that leads to skin breakdown and blister formation, usually in intertriginous areas. Laser ablation is a known surgical treatment for HHD. OBJECTIVES: We report outcomes in a series of patients with HHD treated with carbon dioxide (CO2 ) laser ablation. METHODS: A retrospective chart review of data for 13 patients who underwent CO2 laser ablation for HHD was conducted. Questionnaires assessing effectiveness, pain, healing time, recurrence, new disease, complications, additional ablation, improvement in quality of life (QoL), and overall satisfaction were completed by all patients. RESULTS: All patients had been recalcitrant to previous treatments prior to CO2 laser ablation. Anatomic sites treated and anesthesia techniques for the procedure varied. The mean ± standard deviation (SD) score for the effectiveness of CO2 laser ablation for HHD was 9.3 ± 0.9 (maximum: 10). All patients reported improved QoL. No patient had recurring disease within the treatment field. Five patients underwent additional CO2 laser treatments at new sites. One patient reported postoperative infection. No other complications were identified. The mean ± SD score for overall satisfaction with CO2 laser ablation was 8.9 ± 1.1. CONCLUSIONS: Treatment with CO2 laser ablation is very effective and can lead to prolonged or permanent remission in most HHD patients. Patients are highly satisfied with the results and report a substantial improvement in QoL.

Pediatric Lichen Planopilaris: Clinicopathologic Study of Four New Cases and a Review of the Literature.

Lichen planopilaris (LPP) is a rare form of cicatricial alopecia that has occasionally been reported in children. Because of the limited number of patients reported, little information is available about demographic characteristics, clinical presentation, or treatment options for these patients. A retrospective chart review of LPP cases in patients under 18 years of age from 1976 to 2013 was performed to further define clinicopathologic features of pediatric LPP. Four pediatric LPP patients ages 13 to 16 years were identified (three male, one female). One patient had scalp pruritus and one had other cutaneous findings of lichen planus (LP). Perifollicular scale and scarring were the most common physical examination findings, although changes mimicking those of alopecia areata were observed. Three patients were treated with topical or intralesional steroids. One patient was treated with minocycline. Histopathologic findings included perifollicular interface and perifollicular fibrosis in all cases. There was focal interfollicular interface in two cases and mild dermal mucin in one case. LPP is exceedingly rare in children. It may be misdiagnosed as alopecia areata in children because of the lack of symptoms and other features of LP. There should be a high index of suspicion for LPP in children with alopecia that is unresponsive to standard treatment or who have findings that are atypical for more common childhood alopecias.

Outcomes of basal cell carcinomas directly invading the parotid gland.

BACKGROUND: Parotid involvement by basal cell carcinoma (BCC) is rare, and therefore management is controversial. OBJECTIVE: To review the treatment and outcomes of patients with BCC involving the parotid by direct infiltration. METHODS AND MATERIALS: The authors performed a retrospective chart review of BCC cases involving the parotid. RESULTS: From 1994 to 2007, there were 19 cases of BCC involving the parotid gland by direct extension. Nine were primary tumors, and 10 recurrent (nonprimary). Eight tumors were treated with Mohs micrographic surgery (MMS), and 11 with wide local excision (WLE). One patient died of unrelated causes 5 months after treatment, and 2 did not follow up. The remaining 16 cases had an average follow-up of 55.2 months (range, 18-112 months). No primary BCC recurred after treatment. Six of 10 nonprimary BCC (60%) recurred, 2 of 10 metastasized, and 1 of 10 died of metastatic BCC. Two recurrences occurred after MMS, and 4 occurred after WLE with or without parotidectomy. CONCLUSION: Mohs micrographic surgery or WLE with intra-operative margin control seems to be an acceptable first-line treatment for primary BCC involving the parotid. Recurrent BCC involving the parotid gland through direct infiltration has high rates of future recurrence, and adjuvant treatment may be required.

Comparison of full-thickness skin grafts versus second-intention healing for Mohs defects of the helix.

BACKGROUND: Two repair options for Mohs defects of the helix include full-thickness skin grafting and second-intention healing. Limited long-term data exist comparing these 2 repair options. OBJECTIVE: To compare outcomes of full-thickness skin grafts (FTSG) versus second-intention wound healing for Mohs defects on the helix. METHODS: In this study, 29 second-intention and 18 FTSG repairs were evaluated using a visual analog scale (VAS). Patient questionnaires and retrospective chart analysis were used to assess secondary outcomes. RESULTS: The average second-intention VAS score was 82.1 (standard deviation [SD] = 7.6), and the average FTSG VAS score was 75.2 (SD = 16.7) (difference of 6.9, 95% confidence interval: -1.3 to 15.1, p = .061). A subsequent noninferiority test indicated that cosmetic outcome of second-intention healing was at least as good as that of FTSG in the authors' study (p < .001). Retrospective chart analysis revealed no significant difference in complications. Patient-reported outcomes were not significantly different. CONCLUSION: Mohs surgical defects of the helix left to heal by second-intention have comparable long-term cosmetic outcomes to those repaired by FTSG. There was no significant difference in complications, and patients were highly satisfied with both repair options.

Cutaneous depth of the supraorbital nerve: a cadaveric anatomic study with clinical applications to dermatology.

BACKGROUND: Common dermatologic procedures performed on the forehead may injure the supraorbital nerve (SON) leading to adverse outcomes. OBJECTIVE: To describe SON anatomic course and cutaneous depth. MATERIALS AND METHODS: Sixteen cadaver specimens were dissected. RESULTS: The supraorbital nerve originated 2.63 ± 0.27 (range, 2.1-3.5) cm from the midline and 0.25 ± 0.16 (range, 0-0.5) cm above the orbital rim. Supraorbital nerve emerged as 1 root dividing into superficial (SON-S) and deep (SON-D) branches. The supraorbital nerve deep branch remained deep to the aponeurosis of the corrugator supercilii and frontalis muscles and coursed laterally toward the scalp. Supraorbital nerve superficial branch emerged nearly perpendicular to the orbital rim and traveled under the corrugator supercilii with an average depth of 0.75 ± 0.16 (range, 0.5-1.1) cm. Supraorbital nerve superficial branches entered the subfrontalis plane at a mean distance of 1.29 ± 0.20 (range, 1.0-1.8) cm above the orbital rim with an average depth of 0.45 ± 0.13 (range, 0.3-0.8) cm. These branches entered the subcutaneous plane by piercing through the frontalis muscle at a mean distance of 2.60 ± 0.32 (range, 1.9-3.2) cm above the orbital rim with an average depth of 0.30 ± 0.10 (range, 0.2-0.6) cm. CONCLUSION: The supraorbital nerve depth and course are relevant when performing procedures on the forehead. A thorough understanding of the anatomy and depth of SON-S is critical to help minimize nerve damage and optimize patient counseling.

Anatomy teaching assistants: facilitating teaching skills for medical students through apprenticeship and mentoring.

BACKGROUND: Significant increase in the literature regarding "residents as teachers" highlights the importance of providing opportunities and implementing guidelines for continuing medical education and professional growth. While most medical students are enthusiastic about their future role as resident-educators, both students and residents feel uncomfortable teaching their peers due to the lack of necessary skills. However, whilst limited and perhaps only available to select individuals, opportunities for developing good teaching practice do exist and may be identified in courses that offer basic sciences. The Department of Anatomy, College of Medicine, Mayo Clinic offers a teaching assistant (TA) elective experience to third- and fourth-year medical students through integrated apprenticeship and mentoring during the human structure didactic block. AIM: This article, aims to describe a curriculum for a TA elective within the framework of a basic science course through mentoring and apprenticeship. RESULTS: Opportunities for medical students to become TAs, process of TAs' recruitment, mentoring and facilitation of teaching and education research skills, a method for providing feedback and debriefing are described. CONCLUSION: Developing teaching practice based on apprenticeship and mentoring lends to more accountability to both TA's and course faculty by incorporating universal competencies to facilitate the TA experience.

Quantification of gadolinium in fresh skin and serum samples from patients with nephrogenic systemic fibrosis.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a rare, potentially fatal fibrosing disorder associated with renal insufficiency and gadolinium (Gd)-based contrast exposure. The cause remains unknown. To date, all efforts to investigate skin Gd concentrations in patients with NSF have been performed on paraffin-embedded samples, and Gd deposition has not been correlated with disease activity by a statistically significant analysis. OBJECTIVE: We sought to: (1) quantify Gd concentration in fresh tissue skin biopsy specimens; (2) quantify and compare synchronous Gd concentration of affected skin and unaffected skin in patients with NSF (n = 13) with a control group (n = 13); and (3) quantify serum Gd. METHODS: We used inductively coupled plasma mass spectrometry. RESULTS: In patients with NSF, the mean ratio of paired Gd concentrations of affected skin to unaffected skin was 23.1, ranging from 1.2 to 88.9. Mean serum Gd concentrations in patients with NSF were 4.8 ng/mL, which is more than 10 times the level in control patients. A statistically significant correlation existed between serum and affected skin Gd concentrations (r(2) = .74, P < .0001). LIMITATIONS: Because of the feasibility of this study, the main limitation was the small sample size (n = 13 affected and 13 control). CONCLUSIONS: Determination of Gd concentrations in fresh skin samples and serum using inductively coupled plasma mass spectrometry demonstrates significant differences in the amounts of Gd in involved versus nonlesional skin of patients with NSF. This supports the role of differential free Gd deposition from Gd-based contrast in the pathogenesis of NSF.

Discovery of 2-substituted benzoxazole carboxamides as 5-HT3 receptor antagonists.

A new class of 2-substituted benzoxazole carboxamides are presented as potent functional 5-HT(3) receptor antagonists. The chemical series possesses nanomolar in vitro activity against human 5-HT(3)A receptors. A chemistry optimization program was conducted and identified 2-aminobenzoxazoles as orally active 5-HT(3) receptor antagonists with good metabolic stability. These novel analogues possess drug-like characteristics and have potential utility for the treatment of diseases attributable to improper 5-HT(3) receptor function, especially diarrhea predominant irritable bowel syndrome (IBS-D).

Morbidity and mortality among older individuals with undiagnosed celiac disease.

BACKGROUND & AIMS: Outcomes of undiagnosed celiac disease (CD) are unclear. We evaluated the morbidity and mortality of undiagnosed CD in a population-based sample of individuals 50 years of age and older. METHODS: Stored sera from a population-based sample of 16,886 Olmsted County, Minnesota, residents 50 years of age and older were tested for CD based on analysis of tissue transglutaminase and endomysial antibodies. A nested case-control study compared serologically defined subjects with CD with age- and sex-matched, seronegative controls. Medical records were reviewed for comorbid conditions. RESULTS: We identified 129 (0.8%) subjects with undiagnosed CD in a cohort of 16,847 older adults. A total of 127 undiagnosed cases (49% men; median age, 63.0 y) and 254 matched controls were included in a systematic evaluation for more than 100 potentially coexisting conditions. Subjects with undiagnosed CD had increased rates of osteoporosis and hypothyroidism, as well as lower body mass index and levels of cholesterol and ferritin. Overall survival was not associated with CD status. During a median follow-up period of 10.3 years after serum samples were collected, 20 cases but no controls were diagnosed with CD (15.2% Kaplan-Meier estimate at 10 years). CONCLUSIONS: With the exception of reduced bone health, older adults with undiagnosed CD had limited comorbidity and no increase in mortality compared with controls. Some subjects were diagnosed with CD within a decade of serum collection, indicating that although most cases of undiagnosed CD are clinically silent, some result in symptoms. Undiagnosed CD can confer benefits and liabilities to older individuals.

Pictorial review of colonic polyp and mass distortion and recognition with the CT virtual dissection technique.

Virtual dissection is a three-dimensional (3D) display technique for CT colonography that could potentially reduce interpretation times. With virtual dissection, the 3D model of the colon is "sliced" open along a centerline trace, rendering a 360° view of the endoluminal mucosa as a rectangular image. However, one must be familiar with several pitfalls and limitations to avoid errors in interpretation. One of the main limitations is the anatomic distortion that results. Polyp shape and colonic folds can be distorted and colonic or polyp mobility can lead to mischaracterization of polyps. Distorted folds, which frequently occur at flexures, can mimic polyps. Annular constricting masses can lead to skip areas, where the abnormality is not displayed. Various entities including diverticula and stool can mimic polyps at virtual dissection. Finally, technical errors such as an inadequate centerline trace can render a polyp occult. The purpose of this review is to demonstrate the spectrum of appearances of polyps at virtual dissection, with an emphasis on more difficult to detect polyps. In addition, 10 interactive virtual dissection quiz cases are presented along with corresponding two-dimensional and 3D endoluminal fly-through views.

Anatomic assessment of the bifurcation of the left main coronary artery using multidetector computed tomography.

PURPOSE: Multiple techniques for stenting left main coronary artery (LMCA) bifurcation lesions exist, and an accurate understanding of normal LMCA anatomy is essential for proper diagnosis and therapeutic intervention for these lesions. The purpose of this paper is to identify various anatomic LMCA characteristics at the point of bifurcation and draw relevant clinical lessons from these characteristics. METHODS: Two independent observers analyzed 105 cardiac dual-source computed tomography images recording LMCA length, angle of bifurcation, and cross-sectional area of the LMCA, left circumflex artery (LCX), and anterior interventricular artery (AIVA) at the point of LMCA bifurcation. Frequency of left dominance, right dominance, and codominance, as well as LMCA trifurcation was also noted. RESULTS: Average LMCA length was 9.9 ± 4.15 (range 2-21 mm). Average angle of bifurcation between LCX and AIVA was found to be 69.3° ± 33.3° (range 14°-200°). The most frequent division of the LMCA is a bifurcation into the terminal LCX and AIVA. In 20/105 cases (19.0%) a trifurcation pattern was identified. Average cross-sectional areas at point of LMCA bifurcation were as follows for LMCA, LCX, and AIVA respectively: 12.4 ± 4.4 mm(2) (range 2.3-25.9 mm(2)), 7.4 ± 3.5 mm(2) (range 1.2-23 mm(2)), 8.5 ± 3.5 mm(2) (range 1.3-25.9 mm(2)). Frequency of heart dominance was as follows for right dominant, left dominant, and codominant 85.7, 9.5, and 4.8%, respectively. CONCLUSION: Accurate knowledge of the in vivo anatomy of the area of bifurcation of the LMCA is essential for avoiding the misdiagnoses of diseases and for proper stent placement during percutaneous intervention in the area of bifurcation.

Descriptive anatomy of the dominant septal perforators using Dual Source Coronary CT Angiography.

Although clinical outcomes for septal ablation in treating left ventricular outflow tract obstructions are generally favorable, a variety of complications have been reported including a high incidence of right bundle branch block. These complications may be attributed to anatomic variability of the dominant septal perforator. We used Dual Source CT Coronary Angiography (DS-CTA) to determine the location of the termination point of the dominant septal perforator as well as the distance of the termination point from the mitral annulus in patients undergoing DS-CTA. One-hundred-fourteen DS-CTA scans were retrospectively reviewed by two observers by consensus. The left ventricle was divided into anterior wall, anterioseptum, and inferioseptum. For each segment, the myocardium was divided into three layers (1) right ventricular side, (2) mid portion, and (3) left ventricular side. The zone of termination of the dominant septal perforator was identified as well as the distance of the termination point from the mitral annulus. The dominant septal perforator terminated in the right ventricular side of the anterioseptum in 86 of the 118 visualized terminations (73%) and in the left ventricular anterior wall in 6 visualized terminations (5%). On average, the dominant septal perforator terminated 26.3 +/- 8.6 mm from the mitral annulus. In the majority of cases, the dominant septal perforator terminates in the right ventricular side of anterioseptum. In addition, there is great variability in the distribution of the termination point of the dominant septal perforator from the mitral annulus.