PI-RADS 3 lesions: Does the association of the lesion volume with the prostate-specific antigen density matter in the diagnosis of clinically significant prostate cancer?

IntroductionCurrently, a new subclassification of the Pi-RADS 3 lesions and subgroups is being used: 3a (indolent or low-risk lesions with volume <0.5 ml) and 3b (significant or high-risk lesions with volume ≥0.5 ml). The prostate-specific antigen density (PSAd) has been identified as a diagnostic tool that helps to predict clinically significant prostate cancer (csCaP). The aim of this study is to evaluate the association of the volume of the Pi-RADS 3 lesions and the PSAd in the diagnosis of csCaP.Material and MethodsWe conducted a retrospective study that included prostate biopsies performed using a transperineal approach and guided by ultrasound between 2015 and 2020. csCaP was defined as Gleason score ≥3 + 4. The population was divided into groups according to the Pi-RADS 3 subclassification and the PSAd value. We calculated sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of 3b lesions for the detection of high-grade prostate cancer, alone and combined with PSAD groups.ResultsIn total, 99 patients with Pi-RADS 3 lesions were included. Forty-three patients were in group 3a and 56, in 3b. Mean PSA was 7.28 ± 2.6 ng/ml. Pi-RADS 3a lesion did not present csCaP but 17.8% of Pi-RADS 3b lesion did. In group 3b with PSAd > 0.15, 62.5% presented csCaP. In those Pi-RADS 3b with PSAd ≤ 0.15, all biopsies were insignificant prostate cancer (isCaP) and 40 biopsies could have been avoided. Considering 3b as positive for csCaP detection, sensitivity was 100%, specificity 48.3%, NPV 17.8%, and PPV 100%. When adding PSAd to group 3b, sensitivity was 100%, specificity was 86.9%, NPV was 62.5%, PPV was 100%. In total, only the subgroup 3b with PSAd > 0.15 presented csCaP and 83.8% biopsies could be avoided.ConclusionsIn this series, the association of the volume of PIRADS 3 lesion and the PSAd improves specificity and PPV contributing to improve the management of csCaP.     

Detection of clinical unilateral T3a prostate cancer – by digital rectal examination or transrectal ultrasonography?

OBJECTIVE: To assess, in a retrospective study, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of digital rectal examination (DRE), transrectal ultrasonography (TRUS) and the combination of both in unilateral clinical T3a (cT3a) prostate cancer. PATIENTS AND METHODS: The long-term outcome of surgical treatment for locally advanced prostate cancer is very good and surpasses that for radiotherapy outcomes, so it is anticipated that surgical management for cT3a disease will become more important, but staging methods for cT3a disease are not well studied. Between 1990 and 2004, 2240 patients had a radical prostatectomy at our institution; 267 were diagnosed as having clinical cT3a prostate cancer either by DRE or TRUS. The final histopathology was compared with the findings of DRE and TRUS. The sensitivity, specificity, PPV and NPV for DRE, TRUS and the combination of both were calculated. RESULTS: The sensitivity, specificity, PPV and NPV by DRE only was 90.9%, 15.8%, 47.2% and 67.7%, by TRUS only was 80.2%, 25.3%, 47.1% and 60.7%, and by both DRE and TRUS was 71.1%, 41.1%, 50.0% and 63.2%. Although the sensitivity was lower in the combined group, it had the highest specificity (41.1%) and PPV (50.0%). The combination of DRE and TRUS can detect T3a prostate cancer more accurately than either method alone. CONCLUSION: Until data on staging methods like magnetic resonance imaging become available, the combination of DRE and TRUS is advisable in selecting cT3a patients for primary radical prostatectomy.     

A Prospective Analysis of Positron Emission Tomography and Conventional Imaging for Detection of Stage IV Metastatic Melanoma in Patients Undergoing Metastasectomy

Background: Positron emission tomography with 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG-PET) is available for evaluation of patients with melanoma. This study evaluates the potential of FDG-PET to improve on conventional imaging (CI) in patients with stage IV melanoma undergoing metastasectomy.Methods: This was a prospective study comparing radiological evaluation of patients who underwent metastasectomy for palliation or cure. Patients underwent preoperative evaluation by physical examination, CI by computed tomography and/or magnetic resonance imaging, and FDG-PET. Independent observers performed three separate analyses of CI alone, FDG-PET alone, or FDG-PET read with knowledge of CI (FDG-PET + CI). Abnormalities were reported as benign or malignant and assessed by pathologic analysis or by clinical outcome determined by disease progression detected on serial evaluations.Results: Ninety-four lesions were noted in 18 patients who underwent preoperative assessment, metastasectomy, and long-term follow up (median, 24 months). Lesion-by-lesion analysis for CI demonstrated a sensitivity of 76%, a specificity of 87%, a positive predictive value (PPV) of 86%, and a negative predictive value (NPV) of 76%. FDG-PET demonstrated a sensitivity of 79%, a specificity of 87%, a PPV of 86%, and an NPV of 80%. For FDG-PET + CI, the sensitivity was 88%, specificity was 91%, and PPV and NPV were 91% and 88%, respectively.Conclusions: Combined use of FDG-PET and CI may be an accurate strategy to identify sites of disease in patients with stage IV melanoma being considered for metastasectomy. Interpreted independently, FDG-PET and CI seemed to be equivalent modalities. FDG-PET + CI had both the highest sensitivity on lesion-by-lesion analysis and the best accuracy on patient-by-patient analysis.     

18F-FDG PET/CT在胆道系统恶性肿瘤中的应用

目的探讨~(18)F-FDG PET/CT诊断胆道系统恶性肿瘤的价值。方法回顾性分析34例临床疑似胆道恶性肿瘤患者的PET/CT影像资料,均获得术后病理结果,其中12例经手术切除淋巴结或淋巴结穿刺活检对18枚淋巴结获得病理诊断;与病理结果对照,计算PET/CT对胆道恶性病变原发灶、淋巴结转移的灵敏度、特异度、阳性预测值、阴性预测值及准确率。结果 34例中,31例为恶性病变,3例为良性病变。PET/CT诊断胆道恶性肿瘤原发灶的灵敏度100%(31/31),特异度66.67%(2/3),阳性预测值96.88%(31/32),阴性预测值100%(2/2),准确率97.06%(33/34)。胆道恶性病变原发灶最大标准摄取值(SUV_(max))为8.42±4.27;3例胆道良性疾病SUV_(max)分别为12.90、2.00及1.90。共18枚淋巴结获得病理结果,包括转移性淋巴结13枚,良性增生5枚。PET/CT诊断淋巴结转移的灵敏度76.92%(10/13),特异度60.00%(3/5),阳性预测值83.33%(10/12),阴性预测值50.00%(3/6),准确率72.22%(13/18)。结论 PET/CT对胆道系统恶性肿瘤的诊断具有重要价值。     

Ultrasound criteria for severe in-stent restenosis following carotid artery stenting

PURPOSE: In-stent restenosis (ISR) is a known complication following carotid artery stenting (CAS). However, ultrasound criteria determining ISR are not well established. We evaluated alternative ultrasound velocity criteria for >70% ISR in our institution. METHODS: Clinical records of 256 patients undergoing 282 consecutive CAS procedures over a 42-month period were reviewed. Follow-up ultrasounds were available for analysis in 237 patients. Selective angiograms and repeat interventions were performed for >70% ISR. Ultrasound criteria including peak systolic velocity (PSV), end diastolic velocity (EDV), and internal carotid to common carotid artery ratios (ICA/CCA) were examined. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for PSV (200, 250, 300, 350, and 400 cm/s), EDV (70, 80, 90, 100 cm/s), and CCA/ICA (3, 3.5, 4, 4.5, 5). RESULTS: Twenty-two carotid angiograms were performed and 18 lesions had confirmations of >70% ISR in 11 patients including prior CEA in five patients and neck irradiation in two patients. Receiver operator characteristics (ROC) was analyzed for PSV, EDV, and CCA/ICA ratio. For 70% or greater angiographic ISR, PSV > 300 cm/s correlated to a 94% sensitivity, 50% specificity, 90% positive predictive value (PPV), and 67% negative predictive value (NPV); EDV > 90 cm/s correlated to an 89% sensitivity, 100% specificity, 100% PPV, and 67% NPV; and ICA/CCA > 4 had a 94.4% sensitivity, 75% specificity, 94% PPV, and 75% NPV. A significant color flow disturbance was detected in one patient who did not meet the aforementioned ultrasound velocity criteria. Further statistical analysis showed that an EDV of 90 cm/s provided the best discriminant value. CONCLUSION: Our study demonstrated that PSV > 300 cm/s, EDV > 90 cm/s, and ICA/CCA > 4 correlated well with >70% ISR. Although still rudimentary, these velocity criteria combined with color flow patterns can reliably predict severe ISR in our vascular laboratory. However, due to the relatively infrequent cases of severe ISR following CAS, a multicentered study is warranted to establish standard post-CAS ultrasound surveillance criteria for severe ISR.     

Re-evaluation of the role of impedance plethysmography in the diagnosis of deep vein thrombosis in surgical patients

The clinical diagnosis of deep-vein thrombosis (DVT) is nonspecific and nonsensitive. As a result invasive and non-invasive laboratory tests are needed. In order to detect the diagnostic value of impedance plethysmography (IPG), a widely used non-invasive laboratory test, a prospective clinical trial was performed to compare IPG with color Doppler-ultrasonography (CDUS) and venography. Seventy-six (41 female, 35 male) high-risk abdominal surgery patients were included in the study. IPG and CDUS were performed preoperatively. During the postoperative period IPG, CDUS and venography were carried out. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of IPG were all determined. The preoperative IPG was positive in 32 patients, being (+) in 29 patients postoperatively. On the other hand, two of the 29 postoperative IPG (+) patients had DVT diagnosed postoperatively by CDUS and venography. One of 47 IPG (-) patients had DVT diagnosed postoperatively. According to these findings, the sensitivity of IPG was 67%, specificity 63%, and PPV, NPV and accuracy were 7%, 98% and 63%, respectively. Our study showed that IPG was not a reliable non-invasive laboratory method in the diagnosis and screening of DVT of the lower extremity.     

The Predictive Value of Ductography and Magnetic Resonance Imaging in the Management of Nipple Discharge

Background Standard evaluation (physical examination, mammography, sonography) often fails to identify an underlying lesion in patients with suspicious nipple discharge. The aim of this study was to determine the predictive value of ductography (DG) and magnetic resonance imaging (MRI) in this setting. Methods Using ICD-9 codes, we retrospectively identified 376 patients who presented with suspicious nipple discharge (ND) (1995–2005); 306 patients (68%) had negative standard evaluation. Results Among 306 patients, 186 (61%) underwent further evaluation with DG (n = 163) and/or MRI (n = 52), 35 (11%) underwent major duct excision alone (MDE), and 85 (28%) were followed clinically. Ultimately, 182/306 (59%) patients underwent surgery and/or biopsy. Overall incidence of malignant or high-risk pathology was 15% (46/306). DG was completed in 139/163 (85%) studies and detected 12 cancers and seven high-risk lesions (HRL), but failed to identify four cancers and 2 HRL (PPV 19%, NPV 63%). MRI detected seven cancers and three HRL, but failed to identify one cancer and one HRL (PPV 56%, NPV 87%). MDE alone (n = 35) detected five cancers and three HRL. Of all patients not having surgery, (142/306, 41%), one (0.01%) presented with an invasive cancer at 102 months (median follow-up, 6.3 months; range, 0–124 months). Conclusions An underlying malignancy was identified in 30/306 (10%) patients with ND and negative standard evaluation. Ductography is a poor predictor of underlying pathology and cannot exclude malignancy. MRI’s higher predictive values may allow for improved patient selection and treatment planning; however, MRI should not replace MDE as the gold standard to exclude malignancy in patients with ND and negative standard evaluation.     

11C-choline positron emission tomography/computerized tomography for preoperative lymph-node staging in intermediate-risk and high-risk prostate cancer: comparison with clinical staging nomograms

BACKGROUND: Conventional imaging (CI) techniques are inadequate for lymph node (LN) staging in prostate cancer (PCa). OBJECTIVES: To assess the accuracy of (11)C-Choline positron emission tomography/computerized tomography (PET/CT) for LN staging in intermediate-risk and high-risk PCa and to compare it with two currently used nomograms. DESIGN, SETTING, AND PARTICIPANTS: From January 2007 to September 2007, 57 PCa patients at intermediate risk (n=27) or high risk (n=30) were enrolled at two academic centres. All patients underwent preoperative PET/CT and radical prostatectomy with extended pelvic LN dissection (PLND). Risk of LN metastasis (LNM) was assessed using available nomograms. MEASUREMENTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and number of correctly recognized cases for LNM detection at PET/CT were assessed. The accuracy of PET/CT for LNM detection was compared with the accuracy of nomograms for LNM prediction by using receiver operating characteristic (ROC) analysis. RESULTS AND LIMITATIONS: Fifteen patients (26%) had LNMs, and a total of 41 LNMs were identified. On a patient analysis, sensitivity, specificity, PPV, NPV, and number of correctly recognized cases at PET/CT were 60.0%, 97.6%, 90.0%, 87.2%, and 87.7% while, on node analysis, these numbers were 41.4%, 99.8%, 94.4%, 97.2%, and 97.1%. The mean diameter (in mm) of the metastatic deposit of true-positive LNs was significantly higher than that of false-negative LNs (9.2 vs 4.2; p=0.001). PET/CT showed higher specificity and accuracy than the nomograms; however, in pairwise comparison, the areas under the curve (AUCs) were not statistically different (all p values >0.05). CONCLUSIONS: In patients with intermediate-risk and high-risk PCa, (11)C-Choline PET/CT has quite a low sensitivity for LNM detection but performed better than clinical nomograms, with equal sensitivity and better specificity.     

Is a palpable short saphenous vein a useful clinical sign in varicose vein assessment?

The short saphenous vein (SSV) may be palpable in the popliteal fossa in patients with varicose veins. A prospective study has been carried out to determine the significance of this sign in the presence of primary varicose veins. The SSV was assessed by palpation of the popliteal fossa with the knee slightly flexed. Hand-held Doppler insonation (HHD) was also used in the out-patient clinic. All patients had SSV assessment by duplex scanning. One hundred and sixty legs were examined. In 68 the SSV was palpable; 39 (57%) of these had SSV reflux on duplex examination. When the SSV was not palpable (92 legs), only 1% (1 leg) refluxed on duplex scanning. SSV palpability had a 98% sensitivity, 75% specificity, 57% positive predictive value (PPV), and 99% negative predictive value (NPV). In comparison, HHD had 80% sensitivity, 87% specificity, 67% PPV and 93% NPV. The combined tests had 78% sensitivity, 73% specificity, 76% PPV and 100% NPV. Palpation of the SSV is a valuable part of clinical examination. If the SSV is not palpable, it is unlikely to reflux.     

超声引导针吸活检术评价乳腺癌腋窝淋巴结转移

目的 研究超声引导针吸活检在术前判断乳腺癌腋窝淋巴结转移中的应用,评价该方法的可行性和诊断的准确率. 方法对40例腋窝触诊阴性的高度可疑乳腺癌患者的40个腋窝淋巴结进行超声引导针吸活检,将结果与前哨淋巴结活检或腋窝淋巴结清扫的组织学病理结果进行对照.分析超声引导针吸活检判断乳腺癌腋窝淋巴结转移的敏感性、特异性、阳性预测值、阴性预测值和诊断准确率.结果 40例患者全部经病理证实为浸润性乳腺癌.超声引导针吸活检判断腋窝淋巴结转移的敏感性、特异性、阳性预测值、阴性预测值和诊断准确率分别为52.2%、100%、100%、60.7%、72.5%.有12例(30%)术前细针穿刺活检阳性的患者避免了前哨活检,直接接受了腋窝清扫.结论 应用超声引导针吸活检在术前判断乳腺癌的腋窝淋巴结转移情况创伤小、特异性高,可以避免部分患者接受前哨淋巴结活检术.

Abstract：

Objective To study the utilization of preoperative ultrasound-guided fine-needle aspiration(USFNA) for axillary lymphnode(ALN) metastasis in breast cancer and to evaluate the feasibility and accuracy of the technique. Methods Forty ALNs in 40 armpit negative palpation highly suspective breast cancer patients underwent USFNA. The cytopathological results were compared with the histopathological results of sentinel lymphnode(SLN) biopsy or axillary lymphnode dissection(ALND). The sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) and diagnostic accuracy of USFNA for the ALN metastasis were analysed. Results All the 40 patients were confirmed with breast cancer by pathology. Sensitivity of USFNA was 52. 2%, specificity was 100%, PPV was 100%,NPV was 60. 7% and diagnostic accuracy was 72. 5%. 12(30% ) patients with positive cytology proceeded to ALND, avoiding SLN biopsy. Conclusions USFNA is a minimally invasive, highly specified technique for prediction of breast cancer ALN metastasis before operation.     

Use of limited color-flow duplex for a carotid screening project.

BACKGROUND: Although the efficacy of carotid endarterectomy for asymptomatic carotid stenosis has been established, no cost-effective approach for identification of these patients has yet been devised. The purpose of this study was to develop a limited carotid duplex screening examination to be utilized for the detection of asymptomatic carotid stenoses. METHODS: Carotid screening examinations employed rapid identification of the carotid bifurcation using color-flow duplex imaging and an immediate Doppler-derived velocity of the segment of the internal carotid artery with the most turbulent flow. Complete examinations were then finished using well-established protocols in our accredited vascular laboratory. A total of 512 patients were referred for complete studies based upon standard indications. Criteria for at least a 50% internal carotid artery stenosis on the complete examination was defined as a peak systolic velocity (PSV) of at least 125 cm/sec. Receiver operator characteristic (ROC) curves were then constructed to identify the optimal screening velocity criteria as compared with the final results on the complete examination. RESULTS: Five screening examinations were technically limited yielding a total of 507 patients with 1,014 carotid arteries available for analysis. Comparison of screening examinations versus complete examinations for a PSV of 125 cm/sec yielded sensitivity 86%, specificity 98%, positive predictive value (PPV) 95%, and a negative predictive value (NPV) 93%. ROC analysis identified a "cut point" of 115 cm/sec on the screening examinations to achieve sensitivity 91%, specificity 95%, PPV 89%, and NPV 96%. Time to perform screening examinations averaged 3.2 minutes per patient. Three patients had common carotid lesions not identified on the limited internal carotid screening examinations. CONCLUSIONS: Screening carotid examinations are a rapid, reliable, and relatively inexpensive method for detection of patients with asymptomatic internal carotid artery stenosis. Limited screening examinations should be developed in each vascular laboratory and utilized in high-risk patients.     

Physical exam and occult post-traumatic vascular lesions: implications for the evaluation and management of arterial injuries in modern warfare in the endovascular era

Based on complexity of extremity wounds sustained in recent combat, arteriography had been used routinely in evaluations for delayed or occult arterial injuries. This report aims to quantitatively analyze the sensitivity and specificity of physical exam (PE) in predicting the presence of these injuries. United States service members sustaining extremity trauma in the Global War on Terrorism were evacuated to our medical center and evaluated by a senior vascular surgeon. Those with an abnormal PE, at risk based on wounding patterns, or previously treated for vascular injury underwent arteriography. Data from each patient were prospectively entered into a Vascular Injury registry. Comprehensive information about the injuries, interventions, arteriogram results, and any periprocedural complications were analyzed. Twenty-five endovascular or open surgical interventions were performed in forty-six of 99 patients that had lesions on arteriography. Seventy-three patients had a normal PE, of which 36 had lesions that prompted 6 subsequent interventions. Twenty-two of 26 patients with an abnormal PE had lesions that prompted 19 interventions. For PE, sensitivity was 38%, specificity was 90%, and positive predictive value (PPV) and negative predictive value (NPV) were 85% and 51%, respectively. In proximity injuries, PPV improved to 100%, but was only 15% sensitive with a NPV of 60%. In conclusion normal PE did not reliably predict post-traumatic arterial lesions in these military extremity injuries. These lesions are amenable to endovascular therapies, and should be considered in cases of complex trauma involving high amounts of energy, penetrating mechanisms, or wounding patterns in proximity to named vessels.     

Use of a predictive equation for diagnosis of acute gangrenous cholecystitis

BACKGROUND: Factors previously identified by multivariate logistic regression that were predictive for gangrenous cholecystitis (GC) were used to develop a predictive equation. Our objective was to evaluate the sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of this equation for detecting GC in patients with acute cholecystitis (AC). METHODS: Medical records of patients who presented to a tertiary care hospital with AC were reviewed. Twenty-one patient and clinical variables were recorded. We prospectively tested the results of the following equation against pathologic diagnosis: P=e((0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT.2.0518.ALP+2.7078.PCF))/(1+e([-0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT-2.0518.ALP+2.7078.PCF])), where P = predicted value; DM = diabetes mellitus; WBC = white blood cell count; ALT = alanine aminotransferase; AST = aspartate aminotransferase; and PCF = pericholecystic fluid. RESULTS: Ninety-eight patients presented with AC and 18% had GC (18 of 98). Using a cutoff of P = 0.724, our equation had a specificity of 93%, sensitivity of 83%, PPV of 71%, and NPV of 96%, P <0.001 for the detection of GC. CONCLUSIONS: Our study demonstrates the equation may be useful in detecting the subset of AC patients who have GC.     

直肠癌直肠系膜浸润程度的术前螺旋CT与术后病理对照研究

目的 结合大组织切片技术,评价螺旋CT预测直肠癌直肠系膜浸润程度和环周切缘状态的价值.方法 对2007年3月至12月经纤维结肠镜及病理证实的直肠癌患者57例术前行64层螺旋CT增强扫描,预测直肠系膜浸润程度和环周切缘状态.全直肠系膜切除术后,利用大组织切片技术观察直肠系膜浸润程度和环周切缘状态,并与CT预测结果比较.计算螺旋CT预测直肠系膜浸润程度和环周切缘状态的准确率、敏感度、特异度、阳性预测值和阴性预测值.结果 肿瘤按直肠系膜浸润深度分级为Ⅰ度、Ⅱ度、Ⅲ度;螺旋CT预测系膜浸润程度总准确率为93.0%(53/57),其中Ⅰ度、Ⅱ度、Ⅲ度预测准确率分别为94.7%、94.7%、96.5%,与术后病理结果之间有较好的一致性(K=0.89,P<0.01).螺旋CT预测直肠癌环周切缘状态准确率93.0%(53/57),敏感度80.0%(12/15),特异度97.6%(41/42),阳性预测值92.3%(12/13),阴性预测值93.2%(41/44),与术后病理结果之间有较好的一致性(κ=0.76,P<0.05).结论 螺旋CT可准确预测直肠癌直肠系膜浸润程度和环周切缘状态.可作为术前影像学评估的常规手段.     

Evaluation of breast lesions with contrast-enhanced ultrasound using the microvascular imaging technique: initial observations

The objective of this study was to evaluate the usefulness of contrast-enhanced ultrasound using the microvascular imaging technique in the diagnosis of breast lesions. In 104 patients with 104 breast lesions scheduled for surgery, conventional and contrast-enhanced ultrasound using the microvascular imaging technique were performed after administration of SonoVue. The enhancement patterns of breast lesions were classified as no enhancement, peripheral enhancement, homogeneous enhancement, regional enhancement, or heterogeneous enhancement based on the morphologic features of enhancement. The diagnostic value of contrast-enhanced ultrasound using the microvascular imaging technique was analyzed with the observers blinded to the clinical data and pathology (which served as the gold standard). None of the enhancement patterns was suggestive of benignity, with a sensitivity of 18.3%, specificity of 97.7%, positive predictive value (PPV) of 91.7%, negative predictive value (NPV) of 46.2%, and accuracy of 51.5%. The peripheral enhancement pattern was suggestive of malignancy, with a sensitivity of 39.5%, specificity of 98.3%, PPV of 94.4%, NPV of 69.4%, and accuracy of 73.8%. Homogeneous, regional, and heterogeneous enhancement patterns did not show meaningful diagnostic information. Contrast-enhanced ultrasound using the microvascular imaging technique provides diagnostic information on breast lesions.     

Ultrasonography in the evaluation of renal scarring using DMSA scan as the gold standard

Dimercaptosuccinic acid (DMSA) renal scan is presently the technique of choice for assessing renal scars. Recent advances suggest that ultrasonography could replace DMSA scan for this purpose. This paper describes the experience of a tertiary pediatric referral hospital performing ultrasonography and DMSA scans in the assessment of renal scarring. Investigations were conducted 3–6 months after patients presented with urinary tract infection (UTI). Results were extracted from the radiology information system and recorded for analysis. All children with a UTI who had undergone DMSA and ultrasound examination on the same day between January 1995 and December 1999 were included; 930 kidneys were compared. DMSA scan was utilized as the reference method. When used to detect focal renal scarring, ultrasonography had a sensitivity of 5.2%, specificity of 98.3%, a positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 75.8%. When used to detect diffuse renal scarring, ultrasonography had a sensitivity of 47.2%, specificity of 91.8%, PPV of 60.8% and NPV of 86.6%. Our results demonstrate that although ultrasonography has a good specificity for the detection of renal scarring compared with DMSA, it has low sensitivity, PPV and NPV. Ultrasonography cannot be substituted for DMSA scan in the evaluation of focal renal scarring.     

Clinical uses of diagnostic peritoneal lavage in stab wounds of the anterior abdomen: a prospective study.

OBJECTIVE: To evaluate patients with stab wounds of the anterior abdomen with diagnostic peritoneal lavage (DPL), by using initial aspiration of gross blood from the lavage catheter of more than 10 ml or red blood cell (RBC) count in the lavage fluid of more than 10,000/mm3 as criteria for exploratory laparotomy. DESIGN: Prospective study. SETTING: University hospital, Thailand. PATIENTS: 40 patients who had stab wounds of the anterior abdomen penetrating through the peritoneum but had no obvious indications for immediate exploratory laparotomy. INTERVENTIONS: Diagnostic peritoneal lavage (DPL), exploratory laparotomy. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of positive DPL as an indication for exploratory laparotomy. RESULTS: In 27 patients (68%) the DPL was positive and in 13 (33%) it was negative. In 18 patients (67%) the initial aspiration of gross blood was more than 10 ml and in 9 (33%) the RBC count in lavage fluid was more than 10,000/mm3. These 27 patients had exploratory laparotomies, 2 of which were negative. All 13 patients who had negative DPL were observed and discharged home uneventfully. The sensitivity of DPL for positive laparotomy was 100%, the specificity was 87%, the PPV was 93%, the NPV was 100% and the accuracy was 95%. When operative findings of bleeding from the stab wound into the peritoneal cavity were considered as a "negative" laparotomy (n = 7) the sensitivity, the specificity, the PPV, the NPV and the accuracy became 100%, 59%, 67%, 100%, and 78%, respectively. CONCLUSION: The use of DPL in patients with stab wounds of the anterior abdomen, using initial aspiration of gross blood from the lavage catheter of more than 10 ml or RBC count in the lavage fluid of more than 10,000/mm3 as positive criteria for exploratory laparotomy, is safe and practical.     

Cost-effective screening for urinary tract infections in urogynaecological patients

This study aims to test the cost-effectiveness of reagent-strip urine nitrite compared with microbiological laboratory testing for screening of urinary tract infections (UTI). The study is a retrospective review of 708 female patients who underwent cystometry during a 1-year period. Urine dipstick nitrite was used as a screening test for UTI while urine cultures were taken as an outcome. Symptoms of UTI were noted. Of 708 patients screened, 70 (9.9%) had a significant UTI. Only 32 (4.5%)of 708 patients were nitrite positive. Urine dipstick nitrite has sensitivity of 40%, specificity of 99%, positive predictive value (PPV) of 88 % and negative predictive value (NPV) of 94%. If the screening test included symptoms for UTI together with urine nitrite, the results are: sensitivity 89%, specificity 31%, PPV 12% and NPV 96%. A combination of screening with urine nitrite and UTI symptoms can increase sensitivity to 89%. A total of 29% of specimens (screen negative=nitrite negative/asymptomatic) can then be excluded from UFEME/culture testing, thus resulting in cost savings.