肿块型胰腺炎的CT诊断

目的探讨肿块型胰腺炎的CT征象特征.方法回顾性分析经病理证实的25例肿块型胰腺炎的CT资料,采用PQ5000V螺旋CT,平扫及增强,层厚及层距均为10 mm.结果 25例中23例肿块位于胰头部,2例位于胰体部.16例肿块密度均匀,增强一致.5例可见钙化;胰管扩张15例,14例轻度,10例不规则扩张,6例穿过肿块;12例合并胆总管炎,5例胆总管内可见结石;肝外胆管扩张18例,15例轻度,12例下端逐渐变细;肾前筋膜增厚10例;胰前脂肪层模糊6例.结论肿块型胰腺炎具有较可靠的CT征象,CT能对大多数的肿块型胰腺炎作出较准确诊断.     

胰腺癌的不典型64排螺旋CT影像表现

目的 分析胰腺癌的64排螺旋CT的不典型表现,以提高对该肿瘤的CT征象的认识水平.方法 回顾性分析经手术病理证实的缺乏典型CT征象的12例胰腺导管腺癌的64排螺旋CT资料.结果 12例均为胰腺导管腺癌.其中,中分化导管腺癌7例,中高分化导管腺癌1例;黏液腺癌1例;腺鳞癌3例.8例导管腺癌病灶中位于胰头及(或)钩突部7例,胰颈部1例,表现为等、低密度或囊实性肿块,增强后无明显强化;5例肿瘤呈明显外生性或有外生倾向;5例肿瘤远端胰管无扩张,2例出现胆总管和肝内胆管扩张,仅1例出现肿瘤远端胰腺萎缩.1例黏液腺癌CT平扫示胰头部5 cm囊性病灶,增强后仅囊性病灶下方少许实性部分轻度强化,体尾部胰管中度扩张(7 mmn),胆总管及邻近血管未受侵犯.3例腺鳞癌病灶中位于胰头2例,胰体部1例,肿块最大径3.0～4.5 cm,CT增强扫描胰腺实质期示3例病灶内均见液化坏死区,病灶远端胰管均轻度扩张(4～5 mm),胆总管和肝内胆管均未见扩张.结论 胰腺癌可出现不典型的CT影像表现,要注意与易混淆疾病进行鉴别诊断.     

胰胆管扩张的MRCP表现对胰腺癌和慢性胰腺炎的诊断意义

目的 研究胰胆管扩张对胰腺癌和慢性胰腺炎的诊断价值。方法 回顾性分析45例胰腺癌和41例慢性胰腺炎的MRCP资料。结果 胰腺癌组的MRCP主要特征包括：(1)胰管扩张多呈管腔光滑，明显扩张，并多在胰头肿块处截断(26例，占74．3％)；(2)扩张的胆总管多呈突然截断(26例，占89．7％)；(3)双管征(28例，占62．2％)。慢性胰腺炎组的MRCP主要特征：(1)胰管扩张多呈粗细不均的不规则型，并贯通病变(18例，占60．0％)，部分可见胰管结石(6例，占14．6％)；(2)扩张的胆总管由上至下逐渐变细(18例，占90．0％)。结论 胰胆管MRCP表现的形态特征对胰腺癌和慢性胰腺炎的诊断有鉴别意义。     

肿块型慢性胰腺炎11例的临床及影像学特征

目的 分析肿块型慢性胰腺炎的临床和影像学特点,并与胰腺肿瘤相鉴别.方法 回顾性分析11例肿块型慢性胰腺炎的临床、影像学、实验室和病理特征.结果 肿块型慢性胰腺炎多见于老年人、男性患者,临床主要表现为梗阻性黄疸和腹部不适.血清CA19-9水平可轻度升高,通常＜100U/ml,较胰腺癌低.B超对肿块型CP诊断的准确率仅18.2%,只能作为初筛手段;CT的诊断准确率为45.5%,表现为主胰管及其分支呈球样扩张,可见胰腺假性囊肿和钙化;MRCP和EUS均可见胆总管、胰管不规则扩张,表现与胰腺癌相似;ERCP可清楚显示胰胆管的病变部位、梗阻性质、胰胆管的狭窄及扩张情况等,与CT检查结合,对鉴别肿块型CP与胰头癌有重要意义.根据组织病理检查,少部分肿块型慢性胰腺炎属于自身免疫性胰腺炎.结论肿块型慢性胰腺炎临床和影像学特征与胰腺癌相似,需结合病史、临床表现、实验室及影像学检查、组织病理综合判断.     

慢性胰腺炎ERCP X线表现分析

目的探讨慢性胰腺炎ERCPX线征象的诊断价值.方法通过分析我院25例资料完整的慢性胰腺炎ERCP的X线表现,男16例,女19例,年龄20岁～60岁,平均38.5岁.5例经手术病理证实.17例做B超检查,诊断慢性胰腺炎7例,正确率为41.1%.结果本组重度胰腺炎6例(24%),中度胰腺炎19例(76%),轻度0例.主胰管X线表现僵直硬化17例(68%);粗细不均10例(40%);多处狭窄8例(32%);广泛扩张6例(25%);囊肿2例(8%);结石2例(8%);胰管闭塞1例(4%);正常1例(4%).25例中15例有胆系异常表现.其中胆总管结石8例,大多数伴有胆总管扩张或胆管炎.结论慢性胰腺炎ERCP的X线主要征象为主胰管的僵直硬化、粗细不均、扭曲、广泛扩张、多处狭窄.其中最有价值的是范围广泛的粗细不均和多处狭窄.如果为一处狭窄,伴有主胰管扩张时,需与胰腺癌鉴别.胰实质的假性囊肿形成与胰腺结石对慢性胰腺炎均有确诊价值.     

急性胰腺炎胰外并发症的CT表现

目的 探讨急性胰腺炎（AP）胰外并发症的CT征象对判断AP严重程度的价值。方法 收集89例AP患者的临床资料和CT片，分析AP时胰腺外组织或器官并发症的发生率及CT征象。结果 89例AP中30例（33．7％）CT扫描仅见胰周组织坏死，59例（66．3％）显示胰外并发症，其中6例（6．7％）出现腹腔血管并发症，包括5例腹腔积血和1例胰周动脉瘤；1例（1．1％）并发肝脓肿；52例（58．4％）显示腹水，其中合并胸水29例（32．6％），心包积液2例（2．2％），肺底局限性片状炎症渗出7例（7．9％）；15例（16．9％）并发肺水肿，其中11例（12．4％）进展为成人呼吸窘迫综合征（ARDS）后死亡。结论 AP时腹部血管破裂或栓塞、胸腹水及肺部ARDS是严重的并发症，这些并发症的CT征象是判断AP严重程度的重要指标。     

假瘤型胰腺炎5例

例1,男,44岁,进行性黄疸2月,无腹痛、消瘦。体检:剑突下1cm处可触及一条状肿物约5cm×4cm大小,质硬,活动度差。B型超声加CT扫描:胰头部占位性病变,见4.5cm×4cm低回声之实性肿物,边界模糊不清。胆囊大,胆总管扩张,胰管扩张。逆行胰胆管造影示仅一长1.5cm胆总管显影,远端的胆总管呈尖锥状,壁不规则,胰头部胰管显著狭窄。拟诊“胰头癌”剖腹探查:胰头部变硬,增大似鹅蛋,与周围组织粘连。胆囊增大,胆总管扩张。肿块活检:慢性胰腺炎。     

胰腺囊腺瘤与囊腺癌39例的CT影像学特征

目的 探讨胰腺囊腺瘤与囊腺癌的CT影像学特征.方法 回顾性分析经过病理证实的21例浆液性囊腺瘤、12例黏液性囊腺瘤、6例黏液性囊腺癌的CT影像学资料,分析肿瘤部位、单(多)囊、最大囊直径、囊壁特征、囊内分隔、肿瘤边界、肿瘤与胰管关系等影像学征象.结果 21例浆液性囊腺瘤中17例位于胰头颈部,5例位于胰体尾部,其中1例为多发;均为多囊,平均最大囊直径为1.8 cm;4例囊壁或分隔有钙化,7例分隔可见软组织成分;10例胰管轻度增宽.12例黏液性囊腺瘤中6例位于胰头颈部,6例位于胰体尾部;4例为多囊,平均最大囊直径为4.5 cm;1例分隔可见钙化,6例囊壁可见软组织成分;2例胰管扩张,3例胰管轻度增宽.6例黏液性囊腺癌中5例位于胰体尾部,1例位于胰头颈部;4例为多囊,平均最大囊直径为5.1 cm;1例分隔可见钙化,5例囊壁可见软组织成分;1例胰管扩张,1例胰管轻度增宽.所有病灶与胰管均不相通,增强后病灶软组织成分及分隔均有不同程度强化.结论 胰腺囊腺瘤与囊腺癌的CT表现具有一定的特征性,但对于少数不典型表现病例,诊断仍存在困难.     

胰胆管扩张的MRCP表现对胰腺癌和慢性胰腺炎的诊断意义

目的研究胰胆管扩张对胰腺癌和慢性胰腺炎的诊断价值.方法回顾性分析45例胰腺癌和41例慢性胰腺炎的MRCP资料.结果胰腺癌组的MRCP主要特征包括:(1)胰管扩张多呈管腔光滑,明显扩张,并多在胰头肿块处截断(26例,占74.3%);(2)扩张的胆总管多呈突然截断(26例,占89.7%);(3)双管征(28例,占62.2%).慢性胰腺炎组的MRCP主要特征:(1)胰管扩张多呈粗细不均的不规则型,并贯通病变(18例,占60.0%),部分可见胰管结石(6例,占14.6%);(2)扩张的胆总管由上至下逐渐变细(18例,占90.0%).结论胰胆管MRCP表现的形态特征对胰腺癌和慢性胰腺炎的诊断有鉴别意义.     

巨大先天性胰腺囊肿一例

患者男 ,2 0岁。发现上腹部肿块 1年伴持续性上腹痛半个月。体检 :右上腹触及一肿块。实验室检查 :血、尿淀粉酶升高。ＣＴ检查 :胰头区见最大径为 6 .5ｃｍ多房囊性病灶 ,囊壁光整 ,轻度增厚 ,边界尚清楚 ,囊内分隔增厚 ,增强后囊壁及分隔有较明显强化 ,胆囊轻度增大 ,胆总管上段及肝内胆管轻度扩张。诊断 :胰头囊腺瘤或假性囊肿 ;先天性胆总管囊肿。逆行胰胆管造影 (ＥＲＣＰ) :胰头部巨大肿块压迫胆总管并使之呈弧形向外侧移位 ,胆总管上段及肝内胆管轻度扩张 ,胰头颈部胰管受压移位 ,胆囊轻度增大。诊断 :胰头部良性占位性病变。手术所…     

Management of complicated acute pancreatitis: Impact of computed tomography

The usefulness of computed tomography (CT) in guiding the management of 43 patients who had a complicated clinical course of acute pancreatitis was retrospectively studied. The CT scans were performed when patients had persistent fever, leucocytosis, hyperamylasaemia, palpable abdominal masses or when there was organ failure. The CT scans showed normal findings in six patients, features of pancreatic abscess in three patients, pseudocysts in three patients and inflammatory masses (a mixture of sterile inflammation and necrosis) in 31 patients. Patients with pancreatic abscesses underwent emergency laparotomy, drainage and debridement; patients with pseudocysts had delayed drainage unless complication occurred; patients with normal CT scan or findings of inflammatory masses were managed conservatively. For patients undergoing conservative management, repeated CT scanning and percutaneous aspiration of the inflammatory mass was performed when pancreatic sepsis was strongly suspected. By this approach, basing on careful clinical and CT scan surveillance, five patients with pancreatic sepsis (pancreatic abscess and localized abscess collection in pseudocyst) underwent emergency surgery and four survived, while 25 patients with inflammatory masses were successfully managed conservatively and some who may have been operated on clinical grounds were spared unnecessary early debridement surgery.     

Lymphoplasmacytic sclerosing pancreatitis forming a localized mass: a variant form of autoimmune pancreatitis

Background To elucidate the correlation of autoimmune pancreatitis (AIP) and mass-forming pancreatitis, in which a localized mass is formed in the pancreas. Methods Nine cases of mass-forming pancreatitis were divided into two groups, one consisting of cases that met the histological diagnostic criteria for AIP by the Japan Pancreas Society (JPS) and the other consisting of cases which did not. Histological findings, immunohistological findings, and pancreatograms were compared between these groups. Results Six cases met the histological criteria of JPS (group A) and the other three did not (group B). In the mass-forming portion in group A, the wall of the pancreatic duct showed marked thickening. However, the epithelium was well preserved, and dilatation of the branch ducts or protein plugs were rarely observed. All cases showed marked obliterative phlebitis. The IgG4 labeling index (LI) was 25% or more in all but one case. In the portion other than the mass, the lobular structure was well preserved and the IgG4 LI was less than 10%. The pancreatogram showed localized stenosis or obstruction at the site of the mass associated with a normal-appearing main pancreatic duct in the remaining portion. In group B, histological findings typical of chronic pancreatitis with dilated branch ducts and protein plugs were observed. Obliterative phlebitis was not confirmed. The IgG4 LI in the mass-forming portion was low (2.3%–11.1%). Conclusions There exists a subgroup of AIP showing localized mass formation and stenosis or obstruction of the main pancreatic duct with prominent obliterative phlebitis associated with a normal ductal segment.     

Juxtapapillary duodenal diverticula and abnormalities by endoscopic retrograde cholangio-pancreatography (ERCP).

In a consecutive series of 174 patients the biliary and pancreatic ducts were demonstrated by endoscopic retrograde cholangio-pancreatography (ERCP). In 84 patients with normal duct systems, juxtapapillary diverticula were found in 5 patients (6%). In 90 cases with ductal abnormalities due to biliary concrements, dilated common bile duct and pancreatitis, diverticula were found in 35 patients (39%). In patients with abnormalities in both duct systems, diverticula were found in 52%, and in patients with changes in one duct system diverticula were found in 33%. The difference in occurrence of diverticula in patients with normal duct systems and pathological duct systems was statistically significant (p less than 0.02). The findings indicate a correlation between juxtapapillary diverticula and pathological changes due to biliary concrements, dilated common bile duct without concrements and pancreatitis.     

A search for acute necrotic pancreatitis in early stages of alcoholic chronic pancreatitis

OBJECTIVES: Various investigators believe that alcoholic chronic pancreatitis is the result of recurrent episodes of acute necrotic pancreatitis. The aim of this work is to study pancreatic histology in early stages of the disease to search for evidence of these acute episodes. STUDY: Of about 650 patients with alcoholic pancreatitis seen during the 30-year period from 1972 to 2002, 45 underwent surgery for this disease, all within 2 years of clinical onset. Of these 45, tissue samples adequate for study were obtained from 42, and this was the study material. Tissue samples were prepared for histologic examination by standard procedures. RESULTS: Areas of pancreatic necrosis were seen in tissue samples of only three (7%) of the 42 patients, and in all three cases chronic lesions were also present. No evidence of localized scarring that could be attributed to prior episodes of focal necrotic pancreatitis was found. A typical feature was the patchy distribution of the lesions in largely normal pancreatic tissue. The main lesions observed were perilobular and intralobular fibrosis, dilation of acini and ducts, and protein plugs in dilated ducts surrounded by periductal fibrosis. CONCLUSIONS: This study shows that, in the early stages of alcoholic chronic pancreatitis, signs of acute necrotic pancreatitis are very infrequent and, when present, they are associated with chronic lesions. These findings suggest that alcoholic pancreatitis begins as a chronic disease.     

肿块型慢性胰腺炎39例临床分析

目的 探讨肿块型慢性胰腺炎的临床特征.方法 回顾分析2005年1月至2007年12月间39例经手术病理证实的肿块型慢性胰腺炎患者临床表现、影像学及病理学资料,并与经手术病理检查证实的17例胰腺癌患者进行比较.结果 39例肿块型慢性胰腺炎和17例胰腺癌患者中黄疸分别有14例和1例.差异有统计学意义(χ2=0.111,P=0.045),血清癌胚抗原升高分别为0例和3例,糖链抗原(CA)19-9升高分别为12例和11例,差异均有统计学意义(P值均＜0.05);CT显示胰腺萎缩、胰腺周围及血管侵犯分别有0、5例和3、8例,差异均有统计学意义(P值均＜0.05).31例肿块型慢性胰腺炎和14例胰腺癌患者行磁共振胰胆管造影检查,胰管扩张、胰管中断、胆管扩张分别有14、2、15例和11、6、2例.差异均有统计学意义(P值均＜0.05).18例肿块型慢性胰腺炎和14例胰腺癌患者行超声内镜引导下细针穿刺检查,前者未找到肿瘤细胞,后者中10例发现恶性肿瘤细胞.结论 肿块型慢性胰腺炎诊断困难,结合临床特点、肿瘤血清标志物检查、影像学检查对诊断有一定帮助,尤其活组织病理检查有较高的诊断价值.     

Imaging diagnosis of 12 patients with hepatic tuberculosis

AIM: To assess CT, MR manifestations and their diagnostic value in hepatic tuberculosis. METHODS: CT findings in 12 cases and MR findings in 4 cases of hepatic tuberculosis proved by surgery or biopsywere retrospectively analyzed. RESULTS: (1) CT findings: One case of serohepatic type of hepatic tuberculosis had multiple-nodular lesions in the subcapsule of liver. Parenchymal type was found in 10 cases, including multiple, miliary, micronodular and low-density lesions with miliary calcifications in 2 cases; singular, low-density mass with multiple flecked calcifications in 3 cases; multiple cystic lesions in i case; multiple micronodular and low-density lesions fusing into multiloculated cystic mass or “cluser“ sign in 3 cases; and singular, macronodular and low-density lesion with multiple miliary calcifications in 1 case. One case of tuberculous cholangitis showed marked dilated intrahepatic ducts with multiple flecked calcifications in the porta hepatis. (2) MR findings in 4 cases were hypointense on both Tl-weighted imagings and T2-weighted imagings in one case, hypointense on Tl-weighted imagings and hyperintense on T2-weighted imagings in 3 cases. Enhanced MR in 3 cases was slightly shown peripheral enhancementor with multilocular enhancement. CONCLUSION: Various types of hepatic tuberculosis have different imaging findings, and typical CT and MR findingscan suggest the diagnosis.     

A distinctive myoepithelial hamartoma of the pancreas histologically confirmed in the mother of a previously reported patient

We encountered a 62-year-old female patient with a distinctive pancreatic myoepithelial hamartoma characterized by dilated loops formed by pancreatic branch ducts. The patient, who experienced recurrent acute pancreatitis caused by pancreatic juice stasis, underwent subtotal stomach-preserving pancreatoduodenectomy, achieving remission of pancreatitis. Computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) demonstrated a honeycomb appearance of the pancreatic head, consisting largely of loop-forming dilated pancreatic branch ducts. Radiography of resected specimens demonstrated a tortuous main pancreatic duct that narrowed in the head, but communicated with the pancreatic branch ducts forming intricate loops within the lesion. Histologic examination showed dilated pancreatic ducts embedded in thick layers of smooth muscle, leading to a diagnosis of myoepithelial hamartoma. Her son shared a similar clinical course, radiologic findings, and histopathologic findings with his mother. MRCP demonstrated a honeycomb appearance of the pancreatic head in her daughter, who complained of persistent diarrhea. To our knowledge, this is the first English-language reports of such a myoepithelial hamartoma of the pancreas showing familial occurrence.     

Autoimmune pancreatitis associated with retroperitoneal fibrosis

CONTEXT: Autoimmune pancreatitis is sometimes associated with other autoimmune diseases. We have presented two cases of autoimmune pancreatitis with retroperitoneal fibrosis and compared our findings with those found in the literature. CASE 1: A 71-year-old male developed anorexia and weight loss. Abdominal ultrasonography (US) and computed tomography (CT) showed diffuse swelling of the pancreas and the peritoneal soft tissue surrounding the aorta, associated with right hydronephrosis. Endoscopic retrograde pancreatography showed narrowing of the main pancreatic duct. He was diagnosed as having autoimmune pancreatitis associated with retroperitoneal fibrosis and underwent steroid therapy. After 3 weeks, a follow-up CT showed a marked reduction in the size of both the pancreas and retroperitoneal mass. CASE 2: A 62-year-old male was admitted to another hospital complaining of obstructive jaundice. Abdominal CT and US showed swelling of the pancreas. Endoscopic retrograde cholangiopancreatography demonstrated stenosis of the lower bile duct and narrowing of the main pancreatic duct. With the diagnosis of pancreatic head carcinoma, a choledochojejunostomy and a gastrojejunostomy were performed. Histological examination of the biopsy of the pancreatic mass revealed marked fibrosis with lymphoplasmacytic infiltration. One year later, a retroperitoneal mass was detected on follow-up CT. He was treated with prednisolone for two years. Recurrence of retroperitoneal mass with left hydronephrosis occurred 18 months later. There was no sign of recurrence of the autoimmune pancreatitis. He was again treated with prednisolone, and the retroperitoneal mass was gradually reduced. CONCLUSIONS: A total of 7 cases including the present cases have been reported. All were middle-aged males. Steroid therapy was effective for both the pancreatic and the retroperitoneal masses.     

Diagnostic Accuracy of Cardiac Computed Tomography and 18-F Fluorodeoxyglucose Positron Emission Tomography in Cardiac Masses

ObjectivesThis study sought to assess the diagnostic accuracy of cardiac computed tomography (CT) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) with positron emission tomography/computed tomography (PET/CT) in defining the nature of cardiac masses.BackgroundThe diagnostic accuracy of cardiac CT and ¹⁸F-FDG PET/CT in identifying the nature of cardiac masses has been analyzed to date only in small samples.MethodsOf 223 patients with echocardiographically diagnosed cardiac masses, a cohort of 60 cases who underwent cardiac CT and ¹⁸F-FDG PET/CT was selected. All masses had histological confirmation, except for a minority of thrombotic formations. For each mass, 8 morphological CT signs, standardized uptake value (SUV_max, SUV_mean), metabolic tumor volume, and total lesion glycolysis in ¹⁸F-FDG PET were used as diagnostic markers.ResultsIrregular tumor margins, pericardial effusion, invasion, solid nature, mass diameter, CT contrast uptake, and pre-contrast characteristics were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of 3 or 4 CT signs did not accurately discriminate the masses’ nature. The mean SUV_max, SUV_mean, metabolic tumor volume, and total lesion glycolysis values were significantly higher in malignant than in benign masses. The diagnostic accuracy of SUV, metabolic tumor volume, and total lesion glycolysis ¹⁸F-FDG PET/CT parameters was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, the presence of at least 1 abnormal ¹⁸F-FDG PET/CT parameter significantly increased the identification of malignancies.ConclusionsCardiac CT is a powerful tool to diagnose cardiac masses as the number of abnormal signs was found to correlate with the lesions’ nature. Similarly, ¹⁸F-FDG PET/CT accurately identified malignant masses and contributed with additional valuable information in diagnostic uncertainties after cardiac CT. These imaging tools should be performed in specific clinical settings such as involvement of great vessels or for disease-staging purposes.     

EUS-assisted rendezvous stenting of the pancreatic duct for chronic calcifying pancreatitis with multiple pseudocysts.

Introduction: The best choice of endoscopic drainage of pancreatic pseudocysts complicating chronic pancreatitis is currently unknown, with EUS-guided transmural drainage competing with ERCP transpapillary techniques. However, recent studies currently recommend the use of both techniques in complex cases. Case Presentation: We present the case of a 60-year-old male patient with chronic calcifying pancreatitis, with severe ductal obstruction and multiple communicating pancreatic pseudocysts. The patient presented in the emergency department with weight loss, jaundice, steatorrhea and diabetes. Initial imaging evaluation (by transabdominal US, EUS and MRCP) depicted a dilated common bile duct, intrahepatic bile ducts and dilated main pancreatic duct (up to 1 cm) with multiple stones, as well as three pseudocysts at the level of the pancreatic head and one pseudocyst at the level of the pancreatic tail. ERCP with direct cannulation and transpapillary drainage of the bile duct or pancreatic duct was unsuccessful. Consequently, a EUS-assisted rendezvous stenting of the pancreatic duct was done, with the transpapillary placement of a 5-cm stent. Biliary cannulation was also possible with the placement of a double pigtail 9-cm stent in the common bile duct. Subsequent evolution was rapidly favorable with the disappearance of the pancreatic pseudocysts on the control CT after 24 h. Conclusion: Our case clearly showed the benefit of combined draining procedures even in cases of chronic pancreatitis with multiple pseudocysts where surgical drainage was previously deemed necessary.